/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <algorithm>
#include "msgCore.h"
#include "prmem.h"
#include "nsArrayUtils.h"
#include "nsIMsgCustomColumnHandler.h"
#include "nsMsgDBView.h"
#include "nsISupports.h"
#include "nsIMsgFolder.h"
#include "nsIDBFolderInfo.h"
#include "nsIMsgDatabase.h"
#include "nsIMsgFolder.h"
#include "MailNewsTypes2.h"
#include "nsIMsgImapMailFolder.h"
#include "nsImapCore.h"
#include "nsMsgFolderFlags.h"
#include "nsIMsgLocalMailFolder.h"
#include "nsIPrefService.h"
#include "nsIPrefBranch.h"
#include "nsIPrefLocalizedString.h"
#include "nsIMsgSearchSession.h"
#include "nsIMsgCopyService.h"
#include "nsISpamSettings.h"
#include "nsIMsgAccountManager.h"
#include "nsTreeColumns.h"
#include "nsTextFormatter.h"
#include "nsIMimeConverter.h"
#include "nsMsgMessageFlags.h"
#include "nsIPrompt.h"
#include "nsIWindowWatcher.h"
#include "nsIMsgFolderNotificationService.h"
#include "nsServiceManagerUtils.h"
#include "nsComponentManagerUtils.h"
#include "nsMemory.h"
#include "nsIAbManager.h"
#include "nsIAbDirectory.h"
#include "nsIAbCard.h"
#include "mozilla/Components.h"
#include "mozilla/Attributes.h"
#include "mozilla/dom/DataTransfer.h"
#include "mozilla/mailnews/MimeHeaderParser.h"
#include "nsTArray.h"
#include "mozilla/intl/OSPreferences.h"
#include "mozilla/intl/LocaleService.h"
#include "mozilla/intl/AppDateTimeFormat.h"

using namespace mozilla::mailnews;

nsString nsMsgDBView::kHighestPriorityString;
nsString nsMsgDBView::kHighPriorityString;
nsString nsMsgDBView::kLowestPriorityString;
nsString nsMsgDBView::kLowPriorityString;
nsString nsMsgDBView::kNormalPriorityString;

nsString nsMsgDBView::kReadString;
nsString nsMsgDBView::kRepliedString;
nsString nsMsgDBView::kForwardedString;
nsString nsMsgDBView::kRedirectedString;
nsString nsMsgDBView::kNewString;

nsString nsMsgDBView::kTodayString;
nsString nsMsgDBView::kYesterdayString;
nsString nsMsgDBView::kLastWeekString;
nsString nsMsgDBView::kTwoWeeksAgoString;
nsString nsMsgDBView::kOldMailString;
nsString nsMsgDBView::kFutureDateString;

bool nsMsgDBView::m_dateFormatsInitialized = false;
nsDateFormatSelectorComm nsMsgDBView::m_dateFormatDefault = kDateFormatShort;
nsDateFormatSelectorComm nsMsgDBView::m_dateFormatThisWeek = kDateFormatShort;
nsDateFormatSelectorComm nsMsgDBView::m_dateFormatToday = kDateFormatNone;

nsString nsMsgDBView::m_connectorPattern;
nsCOMPtr<nsIStringBundle> nsMsgDBView::mMessengerStringBundle;

static const uint32_t kMaxNumSortColumns = 2;

static void GetCachedName(const nsCString& unparsedString,
                          int32_t displayVersion, nsACString& cachedName);

static void UpdateCachedName(nsIMsgDBHdr* aHdr, const char* header_field,
                             const nsAString& newName);

// viewSortInfo is context data passed into the sort comparison functions -
// FnSortIdUint32 for comparing numeric fields, FnSortIdKey for everything
// else. If a comparison function finds two elements with equal primary
// ordering, it'll call SecondaryCompare() to break the deadlock.
// SecondaryCompare() uses the same comparison functions again, but using the
// secondary key and potentially with different criteria (eg secondary sort
// order might be different to primary). The viewSortInfo::isSecondarySort
// flag lets the comparison function know not to call SecondaryCompare()
// again (and again and again)...
class viewSortInfo {
 public:
  nsMsgDBView* view;
  nsIMsgDatabase* db;  // Which db to use for collation compares.
  bool isSecondarySort;
  bool ascendingSort;
};

NS_IMPL_ISUPPORTS(nsMsgDBViewService, nsIMsgDBViewService)
NS_IMETHODIMP nsMsgDBViewService::InitializeDBViewStrings() {
  nsMsgDBView::InitializeLiterals();
  nsMsgDBView::m_connectorPattern.Truncate();
  nsMsgDBView::mMessengerStringBundle = nullptr;
  // Initialize date display format.
  if (!nsMsgDBView::m_dateFormatsInitialized) {
    nsMsgDBView::InitDisplayFormats();
  }
  return NS_OK;
}

NS_IMPL_ADDREF(nsMsgDBView)
NS_IMPL_RELEASE(nsMsgDBView)

NS_INTERFACE_MAP_BEGIN(nsMsgDBView)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIMsgDBView)
  NS_INTERFACE_MAP_ENTRY(nsIMsgDBView)
  NS_INTERFACE_MAP_ENTRY(nsIDBChangeListener)
  NS_INTERFACE_MAP_ENTRY(nsITreeView)
  NS_INTERFACE_MAP_ENTRY(nsIJunkMailClassificationListener)
NS_INTERFACE_MAP_END

nsMsgDBView::nsMsgDBView() {
  // Member initializers and constructor code.
  m_sortValid = false;
  m_checkedCustomColumns = false;
  m_sortOrder = nsMsgViewSortOrder::none;
  m_sortType = nsMsgViewSortType::byNone;
  m_viewFlags = nsMsgViewFlagsType::kNone;
  m_secondarySort = nsMsgViewSortType::byId;
  m_secondarySortOrder = nsMsgViewSortOrder::ascending;
  m_cachedMsgKey = nsMsgKey_None;
  m_currentlyDisplayedMsgKey = nsMsgKey_None;
  m_currentlyDisplayedViewIndex = nsMsgViewIndex_None;
  mNumSelectedRows = 0;
  mSuppressMsgDisplay = false;
  mSuppressCommandUpdating = false;
  mSuppressChangeNotification = false;
  mSummarizeFailed = false;
  mSelectionSummarized = false;

  mIsNews = false;
  mIsRss = false;
  mIsXFVirtual = false;
  mDeleteModel = nsMsgImapDeleteModels::MoveToTrash;
  m_deletingRows = false;
  mNumMessagesRemainingInBatch = 0;
  mShowSizeInLines = false;
  mSortThreadsByRoot = false;

  // mCommandsNeedDisablingBecauseOfSelection - A boolean that tell us if we
  // needed to disable commands because of what's selected. If we're offline
  // w/o a downloaded msg selected, or a dummy message was selected.
  mCommandsNeedDisablingBecauseOfSelection = false;
  mRemovingRow = false;
  m_saveRestoreSelectionDepth = 0;
  mRecentlyDeletedArrayIndex = 0;
}

void nsMsgDBView::InitializeLiterals() {
  // Priority strings.
  GetString(u"priorityHighest", kHighestPriorityString);
  GetString(u"priorityHigh", kHighPriorityString);
  GetString(u"priorityLowest", kLowestPriorityString);
  GetString(u"priorityLow", kLowPriorityString);
  GetString(u"priorityNormal", kNormalPriorityString);

  GetString(u"read", kReadString);
  GetString(u"replied", kRepliedString);
  GetString(u"forwarded", kForwardedString);
  GetString(u"redirected", kRedirectedString);
  GetString(u"new", kNewString);

  GetString(u"today", kTodayString);
  GetString(u"yesterday", kYesterdayString);
  GetString(u"last7Days", kLastWeekString);
  GetString(u"last14Days", kTwoWeeksAgoString);
  GetString(u"older", kOldMailString);
  GetString(u"futureDate", kFutureDateString);
}

nsMsgDBView::~nsMsgDBView() {
  if (m_db) m_db->RemoveListener(this);
}

// Helper function used to fetch strings from the messenger string bundle
void nsMsgDBView::GetString(const char16_t* aStringName, nsAString& aValue) {
  nsresult res = NS_ERROR_UNEXPECTED;

  if (!nsMsgDBView::mMessengerStringBundle) {
    static const char propertyURL[] = MESSENGER_STRING_URL;
    nsCOMPtr<nsIStringBundleService> sBundleService =
        mozilla::components::StringBundle::Service();

    if (sBundleService)
      res = sBundleService->CreateBundle(
          propertyURL, getter_AddRefs(nsMsgDBView::mMessengerStringBundle));
  }

  if (nsMsgDBView::mMessengerStringBundle)
    res = mMessengerStringBundle->GetStringFromName(
        NS_ConvertUTF16toUTF8(aStringName).get(), aValue);

  if (NS_FAILED(res)) {
    aValue = aStringName;
  }
}

// Helper function used to fetch localized strings from the prefs
nsresult nsMsgDBView::GetPrefLocalizedString(const char* aPrefName,
                                             nsString& aResult) {
  nsresult rv = NS_OK;
  nsCOMPtr<nsIPrefBranch> prefBranch;
  nsCOMPtr<nsIPrefLocalizedString> pls;
  nsString ucsval;

  prefBranch = do_GetService(NS_PREFSERVICE_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = prefBranch->GetComplexValue(
      aPrefName, NS_GET_IID(nsIPrefLocalizedString), getter_AddRefs(pls));
  NS_ENSURE_SUCCESS(rv, rv);
  pls->ToString(getter_Copies(ucsval));
  aResult = ucsval.get();
  return rv;
}

nsresult nsMsgDBView::AppendKeywordProperties(const nsACString& keywords,
                                              nsAString& properties,
                                              bool* tagAdded) {
  *tagAdded = false;
  // Get the top most keyword's CSS selector and append that as a property.
  nsresult rv;
  if (!mTagService) {
    mTagService = do_GetService("@mozilla.org/messenger/tagservice;1", &rv);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  nsCString topKey;
  rv = mTagService->GetTopKey(keywords, topKey);
  NS_ENSURE_SUCCESS(rv, rv);
  if (topKey.IsEmpty()) return NS_OK;

  nsString selector;
  rv = mTagService->GetSelectorForKey(topKey, selector);
  if (NS_SUCCEEDED(rv)) {
    *tagAdded = true;
    properties.Append(' ');
    properties.Append(selector);
  }
  return rv;
}

///////////////////////////////////////////////////////////////////////////
// nsITreeView Implementation Methods (and helper methods)
///////////////////////////////////////////////////////////////////////////

static nsresult GetDisplayNameInAddressBook(const nsACString& emailAddress,
                                            nsAString& displayName) {
  nsresult rv;
  nsCOMPtr<nsIAbManager> abManager(
      do_GetService("@mozilla.org/abmanager;1", &rv));
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIAbCard> cardForAddress;
  rv = abManager->CardForEmailAddress(emailAddress,
                                      getter_AddRefs(cardForAddress));
  NS_ENSURE_SUCCESS(rv, rv);

  if (cardForAddress) {
    bool preferDisplayName = true;
    rv = cardForAddress->GetPropertyAsBool("PreferDisplayName", true,
                                           &preferDisplayName);

    if (NS_FAILED(rv) || preferDisplayName)
      rv = cardForAddress->GetDisplayName(displayName);
  }

  return rv;
}

/*
 * The unparsedString has following format:
 * "version|displayname"
 */
static void GetCachedName(const nsCString& unparsedString,
                          int32_t displayVersion, nsACString& cachedName) {
  nsresult err;

  // Get version #.
  int32_t cachedVersion = unparsedString.ToInteger(&err);
  if (cachedVersion != displayVersion) return;

  // Get cached name.
  int32_t pos = unparsedString.FindChar('|');
  if (pos != kNotFound) cachedName = Substring(unparsedString, pos + 1);
}

static void UpdateCachedName(nsIMsgDBHdr* aHdr, const char* header_field,
                             const nsAString& newName) {
  nsCString newCachedName;
  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
  int32_t currentDisplayNameVersion = 0;

  prefs->GetIntPref("mail.displayname.version", &currentDisplayNameVersion);

  // Save version number.
  newCachedName.AppendInt(currentDisplayNameVersion);
  newCachedName.Append('|');

  // Save name.
  newCachedName.Append(NS_ConvertUTF16toUTF8(newName));

  aHdr->SetStringProperty(header_field, newCachedName);
}

nsresult nsMsgDBView::FetchAuthor(nsIMsgDBHdr* aHdr, nsAString& aSenderString) {
  nsCString unparsedAuthor;
  bool showCondensedAddresses = false;
  int32_t currentDisplayNameVersion = 0;
  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));

  prefs->GetIntPref("mail.displayname.version", &currentDisplayNameVersion);
  prefs->GetBoolPref("mail.showCondensedAddresses", &showCondensedAddresses);

  aHdr->GetStringProperty("sender_name", unparsedAuthor);

  // If the author is already computed, use it.
  if (!unparsedAuthor.IsEmpty()) {
    nsCString cachedDisplayName;
    GetCachedName(unparsedAuthor, currentDisplayNameVersion, cachedDisplayName);
    if (!cachedDisplayName.IsEmpty()) {
      CopyUTF8toUTF16(cachedDisplayName, aSenderString);
      return NS_OK;
    }
  }

  nsCString author;
  (void)aHdr->GetAuthor(getter_Copies(author));

  nsCString headerCharset;
  aHdr->GetEffectiveCharset(headerCharset);

  nsString name;
  nsCString emailAddress;
  nsCOMArray<msgIAddressObject> addresses =
      EncodedHeader(author, headerCharset.get());
  bool multipleAuthors = addresses.Length() > 1;

  ExtractFirstAddress(addresses, name, emailAddress);

  if (showCondensedAddresses)
    GetDisplayNameInAddressBook(emailAddress, aSenderString);

  if (aSenderString.IsEmpty()) {
    // We can't use the display name in the card; use the name contained in
    // the header or email address.
    if (name.IsEmpty()) {
      CopyUTF8toUTF16(emailAddress, aSenderString);
    } else {
      int32_t atPos;
      if ((atPos = name.FindChar('@')) == kNotFound ||
          name.FindChar('.', atPos) == kNotFound) {
        aSenderString = name;
      } else {
        // Found @ followed by a dot, so this looks like a spoofing case.
        aSenderString = name;
        aSenderString.AppendLiteral(" <");
        AppendUTF8toUTF16(emailAddress, aSenderString);
        aSenderString.Append('>');
      }
    }
  }

  if (multipleAuthors) {
    aSenderString.AppendLiteral(" ");
    nsAutoString val;
    GetString(u"andOthers", val);
    aSenderString.Append(val);
  }

  UpdateCachedName(aHdr, "sender_name", aSenderString);

  return NS_OK;
}

nsresult nsMsgDBView::FetchAccount(nsIMsgDBHdr* aHdr, nsAString& aAccount) {
  nsCString accountKey;
  nsresult rv = aHdr->GetAccountKey(getter_Copies(accountKey));

  // Cache the account manager?
  nsCOMPtr<nsIMsgAccountManager> accountManager(
      do_GetService("@mozilla.org/messenger/account-manager;1", &rv));

  NS_ENSURE_SUCCESS(rv, rv);
  nsCOMPtr<nsIMsgAccount> account;
  nsCOMPtr<nsIMsgIncomingServer> server;
  if (!accountKey.IsEmpty())
    rv = accountManager->GetAccount(accountKey, getter_AddRefs(account));

  if (account) {
    account->GetIncomingServer(getter_AddRefs(server));
  } else {
    nsCOMPtr<nsIMsgFolder> folder;
    aHdr->GetFolder(getter_AddRefs(folder));
    if (folder) folder->GetServer(getter_AddRefs(server));
  }

  if (server)
    server->GetPrettyName(aAccount);
  else
    CopyASCIItoUTF16(accountKey, aAccount);

  return NS_OK;
}

nsresult nsMsgDBView::FetchRecipients(nsIMsgDBHdr* aHdr,
                                      nsAString& aRecipientsString) {
  nsCString recipients;
  int32_t currentDisplayNameVersion = 0;
  bool showCondensedAddresses = false;
  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));

  prefs->GetIntPref("mail.displayname.version", &currentDisplayNameVersion);
  prefs->GetBoolPref("mail.showCondensedAddresses", &showCondensedAddresses);

  aHdr->GetStringProperty("recipient_names", recipients);

  if (!recipients.IsEmpty()) {
    nsCString cachedRecipients;
    GetCachedName(recipients, currentDisplayNameVersion, cachedRecipients);

    // Recipients have already been cached, check if the addressbook
    // was changed after cache.
    if (!cachedRecipients.IsEmpty()) {
      CopyUTF8toUTF16(cachedRecipients, aRecipientsString);
      return NS_OK;
    }
  }

  nsCString unparsedRecipients;
  nsresult rv = aHdr->GetRecipients(getter_Copies(unparsedRecipients));

  nsCString headerCharset;
  aHdr->GetEffectiveCharset(headerCharset);

  nsTArray<nsString> names;
  nsTArray<nsCString> emails;
  ExtractAllAddresses(EncodedHeader(unparsedRecipients, headerCharset.get()),
                      names, UTF16ArrayAdapter<>(emails));

  uint32_t numAddresses = names.Length();

  nsCOMPtr<nsIAbManager> abManager(
      do_GetService("@mozilla.org/abmanager;1", &rv));

  NS_ENSURE_SUCCESS(rv, NS_OK);

  // Go through each email address in the recipients and compute its
  // display name.
  for (uint32_t i = 0; i < numAddresses; i++) {
    nsString recipient;
    nsCString& curAddress = emails[i];
    nsString& curName = names[i];

    if (showCondensedAddresses)
      GetDisplayNameInAddressBook(curAddress, recipient);

    if (recipient.IsEmpty()) {
      // We can't use the display name in the card; use the name contained in
      // the header or email address.
      if (curName.IsEmpty()) {
        CopyUTF8toUTF16(curAddress, recipient);
      } else {
        int32_t atPos;
        if ((atPos = curName.FindChar('@')) == kNotFound ||
            curName.FindChar('.', atPos) == kNotFound) {
          recipient = curName;
        } else {
          // Found @ followed by a dot, so this looks like a spoofing case.
          recipient = curName;
          recipient.AppendLiteral(" <");
          AppendUTF8toUTF16(curAddress, recipient);
          recipient.Append('>');
        }
      }
    }

    // Add ', ' between each recipient.
    if (i != 0) aRecipientsString.AppendLiteral(u", ");

    aRecipientsString.Append(recipient);
  }

  if (numAddresses == 0 && unparsedRecipients.FindChar(':') != kNotFound) {
    // No addresses and a colon, so an empty group like
    // "undisclosed-recipients: ;".
    // Add group name so at least something displays.
    nsString group;
    CopyUTF8toUTF16(unparsedRecipients, group);
    aRecipientsString.Assign(group);
  }

  UpdateCachedName(aHdr, "recipient_names", aRecipientsString);

  return NS_OK;
}

nsresult nsMsgDBView::FetchSubject(nsIMsgDBHdr* aMsgHdr, uint32_t aFlags,
                                   nsAString& aValue) {
  if (aFlags & nsMsgMessageFlags::HasRe) {
    nsString subject;
    aMsgHdr->GetMime2DecodedSubject(subject);
    aValue.AssignLiteral("Re: ");
    aValue.Append(subject);
  } else {
    aMsgHdr->GetMime2DecodedSubject(aValue);
  }

  return NS_OK;
}

// In case we want to play around with the date string, I've broken it out into
// a separate routine.  Set rcvDate to true to get the Received: date instead
// of the Date: date.
nsresult nsMsgDBView::FetchDate(nsIMsgDBHdr* aHdr, nsAString& aDateString,
                                bool rcvDate) {
  PRTime dateOfMsg;
  PRTime dateOfMsgLocal;
  uint32_t rcvDateSecs;
  nsresult rv;

  // Silently return Date: instead if Received: is unavailable.
  if (rcvDate) {
    rv = aHdr->GetUint32Property("dateReceived", &rcvDateSecs);
    if (rcvDateSecs != 0) Seconds2PRTime(rcvDateSecs, &dateOfMsg);
  }

  if (!rcvDate || rcvDateSecs == 0) rv = aHdr->GetDate(&dateOfMsg);
  NS_ENSURE_SUCCESS(rv, rv);

  PRTime currentTime = PR_Now();
  PRExplodedTime explodedCurrentTime;
  PR_ExplodeTime(currentTime, PR_LocalTimeParameters, &explodedCurrentTime);
  PRExplodedTime explodedMsgTime;
  PR_ExplodeTime(dateOfMsg, PR_LocalTimeParameters, &explodedMsgTime);

  // If the message is from today, don't show the date, only the time (3:15 pm).
  // If the message is from the last week, show the day of the week
  // (Mon 3:15 pm). In all other cases, show the full date (03/19/01 3:15 pm).

  nsDateFormatSelectorComm dateFormat = m_dateFormatDefault;
  if (explodedCurrentTime.tm_year == explodedMsgTime.tm_year &&
      explodedCurrentTime.tm_month == explodedMsgTime.tm_month &&
      explodedCurrentTime.tm_mday == explodedMsgTime.tm_mday) {
    // Same day.
    dateFormat = m_dateFormatToday;
  } else if (currentTime > dateOfMsg) {
    // The following chunk of code allows us to show a day instead of a number
    // if the message was received within the last 7 days. i.e. Mon 5:10pm
    // (depending on the mail.ui.display.dateformat.thisweek pref).
    // The concrete format used is dependent on a preference setting
    // (see InitDisplayFormats).
    // Convert the times from GMT to local time
    int64_t GMTLocalTimeShift =
        PR_USEC_PER_SEC * int64_t(explodedCurrentTime.tm_params.tp_gmt_offset +
                                  explodedCurrentTime.tm_params.tp_dst_offset);
    currentTime += GMTLocalTimeShift;
    dateOfMsgLocal = dateOfMsg + GMTLocalTimeShift;

    // Find the most recent midnight.
    int64_t todaysMicroSeconds = currentTime % PR_USEC_PER_DAY;
    int64_t mostRecentMidnight = currentTime - todaysMicroSeconds;

    // Most recent midnight minus 6 days.
    int64_t mostRecentWeek = mostRecentMidnight - (PR_USEC_PER_DAY * 6);

    // Was the message sent during the last week?
    if (dateOfMsgLocal >= mostRecentWeek) dateFormat = m_dateFormatThisWeek;
  }

  mozilla::intl::DateTimeFormat::StyleBag style;
  style.time = mozilla::Some(mozilla::intl::DateTimeFormat::Style::Short);
  switch (dateFormat) {
    case kDateFormatNone:
      rv = mozilla::intl::AppDateTimeFormat::Format(style, dateOfMsg,
                                                    aDateString);
      NS_ENSURE_SUCCESS(rv, rv);
      break;
    case kDateFormatLong:
      style.date = mozilla::Some(mozilla::intl::DateTimeFormat::Style::Long);
      rv = mozilla::intl::AppDateTimeFormat::Format(style, dateOfMsg,
                                                    aDateString);
      NS_ENSURE_SUCCESS(rv, rv);
      break;
    case kDateFormatShort:
      style.date = mozilla::Some(mozilla::intl::DateTimeFormat::Style::Short);
      rv = mozilla::intl::AppDateTimeFormat::Format(style, dateOfMsg,
                                                    aDateString);
      NS_ENSURE_SUCCESS(rv, rv);
      break;
    case kDateFormatWeekday: {
      // We want weekday + time.
      nsAutoString timeString;
      nsAutoString weekdayString;
      rv = mozilla::intl::AppDateTimeFormat::Format(style, dateOfMsg,
                                                    timeString);
      NS_ENSURE_SUCCESS(rv, rv);

      mozilla::intl::DateTimeFormat::ComponentsBag components{};
      components.weekday =
          mozilla::Some(mozilla::intl::DateTimeFormat::Text::Short);
      rv = mozilla::intl::AppDateTimeFormat::Format(
          components, &explodedMsgTime, weekdayString);
      NS_ENSURE_SUCCESS(rv, rv);

      if (nsMsgDBView::m_connectorPattern.IsEmpty()) {
        nsAutoCString locale;
        AutoTArray<nsCString, 10> regionalPrefsLocales;
        mozilla::intl::LocaleService::GetInstance()->GetRegionalPrefsLocales(
            regionalPrefsLocales);
        locale.Assign(regionalPrefsLocales[0]);
        nsAutoCString str;
        mozilla::intl::OSPreferences::GetInstance()
            ->GetDateTimeConnectorPattern(locale, str);
        nsMsgDBView::m_connectorPattern = NS_ConvertUTF8toUTF16(str);
      }

      nsAutoString pattern(nsMsgDBView::m_connectorPattern);
      int32_t ind = pattern.Find(u"{1}"_ns);
      if (ind != kNotFound) {
        pattern.Replace(ind, 3, weekdayString);
      }
      ind = pattern.Find(u"{0}"_ns);
      if (ind != kNotFound) {
        pattern.Replace(ind, 3, timeString);
      }
      aDateString = pattern;
      break;
    }

    default:
      break;
  }

  return rv;
}

nsresult nsMsgDBView::FetchStatus(uint32_t aFlags, nsAString& aStatusString) {
  if (aFlags & nsMsgMessageFlags::Replied)
    aStatusString = kRepliedString;
  else if (aFlags & nsMsgMessageFlags::Forwarded)
    aStatusString = kForwardedString;
  else if (aFlags & nsMsgMessageFlags::Redirected)
    aStatusString = kRedirectedString;
  else if (aFlags & nsMsgMessageFlags::New)
    aStatusString = kNewString;
  else if (aFlags & nsMsgMessageFlags::Read)
    aStatusString = kReadString;

  return NS_OK;
}

nsresult nsMsgDBView::FetchSize(nsIMsgDBHdr* aHdr, nsAString& aSizeString) {
  nsresult rv;
  nsAutoString formattedSizeString;
  uint32_t msgSize = 0;

  // For news, show the line count, not the size if the user wants so.
  if (mShowSizeInLines) {
    aHdr->GetLineCount(&msgSize);
    formattedSizeString.AppendInt(msgSize);
  } else {
    uint32_t flags = 0;

    aHdr->GetFlags(&flags);
    if (flags & nsMsgMessageFlags::Partial)
      aHdr->GetUint32Property("onlineSize", &msgSize);

    if (msgSize == 0) aHdr->GetMessageSize(&msgSize);

    rv = FormatFileSize(msgSize, true, formattedSizeString);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  aSizeString = formattedSizeString;
  // The formattingString Length includes the null terminator byte!
  if (!formattedSizeString.Last())
    aSizeString.SetLength(formattedSizeString.Length() - 1);

  return NS_OK;
}

nsresult nsMsgDBView::FetchPriority(nsIMsgDBHdr* aHdr,
                                    nsAString& aPriorityString) {
  nsMsgPriorityValue priority = nsMsgPriority::notSet;
  aHdr->GetPriority(&priority);

  switch (priority) {
    case nsMsgPriority::highest:
      aPriorityString = kHighestPriorityString;
      break;
    case nsMsgPriority::high:
      aPriorityString = kHighPriorityString;
      break;
    case nsMsgPriority::low:
      aPriorityString = kLowPriorityString;
      break;
    case nsMsgPriority::lowest:
      aPriorityString = kLowestPriorityString;
      break;
    case nsMsgPriority::normal:
      aPriorityString = kNormalPriorityString;
      break;
    default:
      break;
  }

  return NS_OK;
}

nsresult nsMsgDBView::FetchKeywords(nsIMsgDBHdr* aHdr,
                                    nsACString& keywordString) {
  NS_ENSURE_ARG_POINTER(aHdr);
  nsresult rv = NS_OK;
  if (!mTagService) {
    mTagService = do_GetService("@mozilla.org/messenger/tagservice;1", &rv);
    NS_ENSURE_SUCCESS(rv, rv);
  }
  nsCString keywords;
  aHdr->GetStringProperty("keywords", keywords);
  keywordString = keywords;
  return NS_OK;
}

// If the row is a collapsed thread, we optionally roll-up the keywords in all
// the messages in the thread, otherwise, return just the keywords for the row.
nsresult nsMsgDBView::FetchRowKeywords(nsMsgViewIndex aRow, nsIMsgDBHdr* aHdr,
                                       nsACString& keywordString) {
  nsresult rv = FetchKeywords(aHdr, keywordString);
  NS_ENSURE_SUCCESS(rv, rv);

  bool cascadeKeywordsUp = true;
  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
  prefs->GetBoolPref("mailnews.display_reply_tag_colors_for_collapsed_threads",
                     &cascadeKeywordsUp);

  if ((m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) &&
      cascadeKeywordsUp) {
    if ((m_flags[aRow] & MSG_VIEW_FLAG_ISTHREAD) &&
        (m_flags[aRow] & nsMsgMessageFlags::Elided)) {
      nsCOMPtr<nsIMsgThread> thread;
      rv = GetThreadContainingIndex(aRow, getter_AddRefs(thread));
      if (NS_SUCCEEDED(rv) && thread) {
        uint32_t numChildren;
        thread->GetNumChildren(&numChildren);
        nsCOMPtr<nsIMsgDBHdr> msgHdr;
        nsCString moreKeywords;
        for (uint32_t index = 0; index < numChildren; index++) {
          thread->GetChildHdrAt(index, getter_AddRefs(msgHdr));
          rv = FetchKeywords(msgHdr, moreKeywords);
          NS_ENSURE_SUCCESS(rv, rv);

          if (!keywordString.IsEmpty() && !moreKeywords.IsEmpty())
            keywordString.Append(' ');

          keywordString.Append(moreKeywords);
        }
      }
    }
  }

  return rv;
}

nsresult nsMsgDBView::FetchTags(nsIMsgDBHdr* aHdr, nsAString& aTagString) {
  NS_ENSURE_ARG_POINTER(aHdr);
  nsresult rv = NS_OK;
  if (!mTagService) {
    mTagService = do_GetService("@mozilla.org/messenger/tagservice;1", &rv);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  nsString tags;
  nsCString keywords;
  aHdr->GetStringProperty("keywords", keywords);

  nsTArray<nsCString> keywordsArray;
  ParseString(keywords, ' ', keywordsArray);
  nsAutoString tag;

  for (uint32_t i = 0; i < keywordsArray.Length(); i++) {
    rv = mTagService->GetTagForKey(keywordsArray[i], tag);
    if (NS_SUCCEEDED(rv) && !tag.IsEmpty()) {
      if (!tags.IsEmpty()) tags.Append((char16_t)' ');

      tags.Append(tag);
    }
  }

  aTagString = tags;
  return NS_OK;
}

/**
 * Lowercase the email and remove a possible plus addressing part.
 * E.g. John+test@example.com -> john@example.com.
 */
static void ToLowerCaseDropPlusAddessing(nsCString& aEmail) {
  ToLowerCase(aEmail);
  int32_t indPlus;
  if ((indPlus = aEmail.FindChar('+')) == kNotFound) return;
  int32_t indAt;
  indAt = aEmail.FindChar('@', indPlus);
  if (indAt == kNotFound) return;
  aEmail.ReplaceLiteral(indPlus, indAt - indPlus, "");
}

bool nsMsgDBView::IsOutgoingMsg(nsIMsgDBHdr* aHdr) {
  nsString author;
  aHdr->GetMime2DecodedAuthor(author);

  nsCString emailAddress;
  nsString name;
  ExtractFirstAddress(DecodedHeader(author), name, emailAddress);
  ToLowerCaseDropPlusAddessing(emailAddress);
  return mEmails.Contains(emailAddress);
}

// If you call SaveAndClearSelection make sure to call RestoreSelection(),
// otherwise m_saveRestoreSelectionDepth will be incorrect and will lead to
// selection msg problems.
nsresult nsMsgDBView::SaveAndClearSelection(nsMsgKey* aCurrentMsgKey,
                                            nsTArray<nsMsgKey>& aMsgKeyArray) {
  // Always return a value in the first parameter.
  if (aCurrentMsgKey) *aCurrentMsgKey = nsMsgKey_None;

  // We don't do anything on nested Save / Restore calls.
  m_saveRestoreSelectionDepth++;
  if (m_saveRestoreSelectionDepth != 1) return NS_OK;

  if (!mTreeSelection) return NS_OK;

  // First, freeze selection.
  mTreeSelection->SetSelectEventsSuppressed(true);

  // Second, save the current index.
  if (aCurrentMsgKey) {
    int32_t currentIndex;
    if (NS_SUCCEEDED(mTreeSelection->GetCurrentIndex(&currentIndex)) &&
        currentIndex >= 0 && uint32_t(currentIndex) < GetSize())
      *aCurrentMsgKey = m_keys[currentIndex];
    else
      *aCurrentMsgKey = nsMsgKey_None;
  }

  // Third, get an array of view indices for the selection.
  nsMsgViewIndexArray selection;
  GetIndicesForSelection(selection);
  int32_t numIndices = selection.Length();
  aMsgKeyArray.SetLength(numIndices);

  // Now store the msg key for each selected item.
  nsMsgKey msgKey;
  for (int32_t index = 0; index < numIndices; index++) {
    msgKey = m_keys[selection[index]];
    aMsgKeyArray[index] = msgKey;
  }

  // Clear the selection, we'll manually restore it later.
  if (mTreeSelection) mTreeSelection->ClearSelection();

  return NS_OK;
}

nsresult nsMsgDBView::RestoreSelection(nsMsgKey aCurrentMsgKey,
                                       nsTArray<nsMsgKey>& aMsgKeyArray) {
  // We don't do anything on nested Save / Restore calls.
  m_saveRestoreSelectionDepth--;
  if (m_saveRestoreSelectionDepth) return NS_OK;

  // Don't assert.
  if (!mTreeSelection) return NS_OK;

  // Turn our message keys into corresponding view indices.
  int32_t arraySize = aMsgKeyArray.Length();
  nsMsgViewIndex currentViewPosition = nsMsgViewIndex_None;
  nsMsgViewIndex newViewPosition = nsMsgViewIndex_None;

  // If we are threaded, we need to do a little more work
  // we need to find (and expand) all the threads that contain messages
  // that we had selected before.
  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) {
    for (int32_t index = 0; index < arraySize; index++)
      FindKey(aMsgKeyArray[index], true /* expand */);
  }

  for (int32_t index = 0; index < arraySize; index++) {
    newViewPosition = FindKey(aMsgKeyArray[index], false);
    // Add the index back to the selection.
    if (newViewPosition != nsMsgViewIndex_None)
      mTreeSelection->ToggleSelect(newViewPosition);
  }

  // Make sure the currentView was preserved.
  if (aCurrentMsgKey != nsMsgKey_None)
    currentViewPosition = FindKey(aCurrentMsgKey, true);

  if (mJSTree) mJSTree->SetCurrentIndex(currentViewPosition);

  // Make sure the current message is once again visible in the thread pane
  // so we don't have to go search for it in the thread pane
  if (currentViewPosition != nsMsgViewIndex_None) {
    if (mJSTree) {
      mJSTree->EnsureRowIsVisible(currentViewPosition);
    } else if (mTree) {
      mTree->EnsureRowIsVisible(currentViewPosition);
    }
  }

  // Unfreeze selection.
  mTreeSelection->SetSelectEventsSuppressed(false);
  return NS_OK;
}

nsresult nsMsgDBView::GenerateURIForMsgKey(nsMsgKey aMsgKey,
                                           nsIMsgFolder* folder,
                                           nsACString& aURI) {
  NS_ENSURE_ARG(folder);
  return folder->GenerateMessageURI(aMsgKey, aURI);
}

nsresult nsMsgDBView::GetMessageEnumerator(nsIMsgEnumerator** enumerator) {
  return m_db->EnumerateMessages(enumerator);
}

NS_IMETHODIMP
nsMsgDBView::IsEditable(int32_t row, nsTreeColumn* col, bool* _retval) {
  NS_ENSURE_ARG_POINTER(col);
  NS_ENSURE_ARG_POINTER(_retval);
  // Attempt to retrieve a custom column handler. If it exists call it and
  // return.
  const nsAString& colID = col->GetId();
  nsIMsgCustomColumnHandler* colHandler = GetColumnHandler(colID);

  if (colHandler) {
    colHandler->IsEditable(row, col, _retval);
    return NS_OK;
  }

  *_retval = false;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SetCellValue(int32_t row, nsTreeColumn* col,
                          const nsAString& value) {
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SetCellText(int32_t row, nsTreeColumn* col,
                         const nsAString& value) {
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetRowCount(int32_t* aRowCount) {
  *aRowCount = GetSize();
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetSelection(nsITreeSelection** aSelection) {
  NS_IF_ADDREF(*aSelection = mTreeSelection);
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SetSelection(nsITreeSelection* aSelection) {
  mTreeSelection = aSelection;
  return NS_OK;
}

nsresult nsMsgDBView::UpdateDisplayMessage(nsMsgViewIndex viewPosition) {
  nsCOMPtr<nsIMsgDBViewCommandUpdater> commandUpdater(
      do_QueryReferent(mCommandUpdater));
  if (!commandUpdater) return NS_OK;

  if (!IsValidIndex(viewPosition)) return NS_MSG_INVALID_DBVIEW_INDEX;

  // Get the subject and the folder for the message and inform the front
  // end that we changed the message we are currently displaying.
  nsresult rv;
  nsCOMPtr<nsIMsgDBHdr> msgHdr;
  rv = GetMsgHdrForViewIndex(viewPosition, getter_AddRefs(msgHdr));
  NS_ENSURE_SUCCESS(rv, rv);

  nsString subject;
  if (viewPosition >= (nsMsgViewIndex)m_flags.Length())
    return NS_MSG_INVALID_DBVIEW_INDEX;
  FetchSubject(msgHdr, m_flags[viewPosition], subject);

  nsCString keywords;
  rv = msgHdr->GetStringProperty("keywords", keywords);
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIMsgFolder> folder = m_viewFolder ? m_viewFolder : m_folder;

  commandUpdater->DisplayMessageChanged(folder, subject, keywords);

  if (folder) {
    if (viewPosition >= (nsMsgViewIndex)m_keys.Length())
      return NS_MSG_INVALID_DBVIEW_INDEX;
    rv = folder->SetLastMessageLoaded(m_keys[viewPosition]);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SelectionChangedXPCOM() {
  // If the currentSelection changed then we have a message to display -
  // not if we are in the middle of deleting rows.
  if (m_deletingRows) return NS_OK;

  nsMsgViewIndexArray selection;
  GetIndicesForSelection(selection);

  bool commandsNeedDisablingBecauseOfSelection = false;

  if (!selection.IsEmpty()) {
    if (WeAreOffline())
      commandsNeedDisablingBecauseOfSelection = !OfflineMsgSelected(selection);

    if (!NonDummyMsgSelected(selection))
      commandsNeedDisablingBecauseOfSelection = true;
  }

  bool selectionSummarized = false;
  mSummarizeFailed = false;
  // Let the front-end adjust the message pane appropriately with either
  // the message body, or a summary of the selection.
  nsCOMPtr<nsIMsgDBViewCommandUpdater> commandUpdater(
      do_QueryReferent(mCommandUpdater));
  if (commandUpdater) {
    commandUpdater->SummarizeSelection(&selectionSummarized);
    // Check if the selection was not summarized, but we expected it to be,
    // and if so, remember it so GetHeadersFromSelection won't include
    // the messages in collapsed threads.
    if (!selectionSummarized &&
        (selection.Length() > 1 ||
         (selection.Length() == 1 &&
          m_flags[selection[0]] & nsMsgMessageFlags::Elided &&
          OperateOnMsgsInCollapsedThreads()))) {
      mSummarizeFailed = true;
    }
  }

  bool summaryStateChanged = selectionSummarized != mSelectionSummarized;
  mSelectionSummarized = selectionSummarized;

  if (!mTreeSelection || selection.Length() != 1 || selectionSummarized) {
    // If we have zero or multiple items selected, we shouldn't be displaying
    // any message.
    m_currentlyDisplayedMsgKey = nsMsgKey_None;
    m_currentlyDisplayedMsgUri.Truncate();
    m_currentlyDisplayedViewIndex = nsMsgViewIndex_None;
  }

  // Determine if we need to push command update notifications out to the UI.
  // We need to push a command update notification iff, one of the following
  // conditions are met
  // (1) the selection went from 0 to 1
  // (2) it went from 1 to 0
  // (3) it went from 1 to many
  // (4) it went from many to 1 or 0
  // (5) a different msg was selected - perhaps it was offline or not,
  //     matters only when we are offline
  // (6) we did a forward/back, or went from having no history to having
  //     history - not sure how to tell this.
  // (7) whether the selection was summarized or not changed.

  // I think we're going to need to keep track of whether forward/back were
  // enabled/should be enabled, and when this changes, force a command update.

  if (!summaryStateChanged &&
      (selection.Length() == mNumSelectedRows ||
       (selection.Length() > 1 && mNumSelectedRows > 1)) &&
      commandsNeedDisablingBecauseOfSelection ==
          mCommandsNeedDisablingBecauseOfSelection) {
    // Don't update commands if we're suppressing them, or if we're removing
    // rows, unless it was the last row.
  } else if (!mSuppressCommandUpdating && commandUpdater &&
             (!mRemovingRow || GetSize() == 0)) {
    commandUpdater->UpdateCommandStatus();
  }

  mCommandsNeedDisablingBecauseOfSelection =
      commandsNeedDisablingBecauseOfSelection;
  mNumSelectedRows = selection.Length();
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetRowProperties(int32_t index, nsAString& properties) {
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  // This is where we tell the tree to apply styles to a particular row.
  nsCOMPtr<nsIMsgDBHdr> msgHdr;
  nsresult rv = NS_OK;

  rv = GetMsgHdrForViewIndex(index, getter_AddRefs(msgHdr));

  if (NS_FAILED(rv) || !msgHdr) {
    ClearHdrCache();
    return NS_MSG_INVALID_DBVIEW_INDEX;
  }

  if (IsOutgoingMsg(msgHdr)) properties.AppendLiteral(" outgoing");

  nsCString keywordProperty;
  FetchRowKeywords(index, msgHdr, keywordProperty);
  bool tagAdded = false;
  if (!keywordProperty.IsEmpty()) {
    AppendKeywordProperties(keywordProperty, properties, &tagAdded);
  }
  if (tagAdded) {
    properties.AppendLiteral(" tagged");
  } else {
    properties.AppendLiteral(" untagged");
  }

  uint32_t flags;
  msgHdr->GetFlags(&flags);

  if (!(flags & nsMsgMessageFlags::Read))
    properties.AppendLiteral(" unread");
  else
    properties.AppendLiteral(" read");

  if (flags & nsMsgMessageFlags::Replied) properties.AppendLiteral(" replied");

  if (flags & nsMsgMessageFlags::Forwarded)
    properties.AppendLiteral(" forwarded");

  if (flags & nsMsgMessageFlags::Redirected)
    properties.AppendLiteral(" redirected");

  if (flags & nsMsgMessageFlags::New) properties.AppendLiteral(" new");

  if (m_flags[index] & nsMsgMessageFlags::Marked)
    properties.AppendLiteral(" flagged");

  // Give the custom column handlers a chance to style the row.
  for (int i = 0; i < m_customColumnHandlers.Count(); i++) {
    nsString extra;
    m_customColumnHandlers[i]->GetRowProperties(index, extra);
    if (!extra.IsEmpty()) {
      properties.Append(' ');
      properties.Append(extra);
    }
  }

  // For threaded display add the ignoreSubthread property to the
  // subthread top row (this row). For non-threaded add it to all rows.
  if (!(m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) &&
      (flags & nsMsgMessageFlags::Ignored)) {
    properties.AppendLiteral(" ignoreSubthread");
  } else {
    bool ignored;
    msgHdr->GetIsKilled(&ignored);
    if (ignored) properties.AppendLiteral(" ignoreSubthread");
  }

  nsCOMPtr<nsIMsgLocalMailFolder> localFolder = do_QueryInterface(m_folder);

  if ((flags & nsMsgMessageFlags::Offline) ||
      (localFolder && !(flags & nsMsgMessageFlags::Partial)))
    properties.AppendLiteral(" offline");

  if (flags & nsMsgMessageFlags::Attachment)
    properties.AppendLiteral(" attach");

  if ((mDeleteModel == nsMsgImapDeleteModels::IMAPDelete) &&
      (flags & nsMsgMessageFlags::IMAPDeleted))
    properties.AppendLiteral(" imapdeleted");

  nsCString imageSize;
  msgHdr->GetStringProperty("imageSize", imageSize);
  if (!imageSize.IsEmpty()) properties.AppendLiteral(" hasimage");

  nsCString junkScoreStr;
  msgHdr->GetStringProperty("junkscore", junkScoreStr);
  if (!junkScoreStr.IsEmpty()) {
    if (junkScoreStr.ToInteger(&rv) == nsIJunkMailPlugin::IS_SPAM_SCORE)
      properties.AppendLiteral(" junk");
    else
      properties.AppendLiteral(" notjunk");

    NS_ASSERTION(NS_SUCCEEDED(rv), "Converting junkScore to integer failed.");
  }

  nsCOMPtr<nsIMsgThread> thread;
  rv = GetThreadContainingIndex(index, getter_AddRefs(thread));
  if (NS_SUCCEEDED(rv) && thread) {
    uint32_t numUnreadChildren;
    thread->GetNumUnreadChildren(&numUnreadChildren);
    if (numUnreadChildren > 0) properties.AppendLiteral(" hasUnread");

    // For threaded display add the ignore/watch properties to the
    // thread top row. For non-threaded add it to all rows.
    if (!(m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) ||
        ((m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) &&
         (m_flags[index] & MSG_VIEW_FLAG_ISTHREAD))) {
      thread->GetFlags(&flags);
      if (flags & nsMsgMessageFlags::Watched)
        properties.AppendLiteral(" watch");
      if (flags & nsMsgMessageFlags::Ignored)
        properties.AppendLiteral(" ignore");
    }
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetColumnProperties(nsTreeColumn* col, nsAString& properties) {
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetCellProperties(int32_t aRow, nsTreeColumn* col,
                               nsAString& properties) {
  if (!IsValidIndex(aRow)) return NS_MSG_INVALID_DBVIEW_INDEX;

  // This is where we tell the tree to apply styles to a particular row
  // i.e. if the row is an unread message...

  nsCOMPtr<nsIMsgDBHdr> msgHdr;
  nsresult rv = NS_OK;

  rv = GetMsgHdrForViewIndex(aRow, getter_AddRefs(msgHdr));

  if (NS_FAILED(rv) || !msgHdr) {
    ClearHdrCache();
    return NS_MSG_INVALID_DBVIEW_INDEX;
  }

  const nsAString& colID = col->GetId();
  nsIMsgCustomColumnHandler* colHandler = GetColumnHandler(colID);
  if (colHandler != nullptr) {
    colHandler->GetCellProperties(aRow, col, properties);
  } else if (colID[0] == 'c') {
    // Correspondent.
    if (IsOutgoingMsg(msgHdr))
      properties.AssignLiteral("outgoing");
    else
      properties.AssignLiteral("incoming");
  }

  if (!properties.IsEmpty()) properties.Append(' ');

  properties.Append(mMessageType);

  uint32_t flags;
  msgHdr->GetFlags(&flags);

  if (!(flags & nsMsgMessageFlags::Read))
    properties.AppendLiteral(" unread");
  else
    properties.AppendLiteral(" read");

  if (flags & nsMsgMessageFlags::Replied) properties.AppendLiteral(" replied");

  if (flags & nsMsgMessageFlags::Forwarded)
    properties.AppendLiteral(" forwarded");

  if (flags & nsMsgMessageFlags::Redirected)
    properties.AppendLiteral(" redirected");

  if (flags & nsMsgMessageFlags::New) properties.AppendLiteral(" new");

  if (m_flags[aRow] & nsMsgMessageFlags::Marked)
    properties.AppendLiteral(" flagged");

  // For threaded display add the ignoreSubthread property to the
  // subthread top row (this row). For non-threaded add it to all rows.
  if (!(m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) &&
      (flags & nsMsgMessageFlags::Ignored)) {
    properties.AppendLiteral(" ignoreSubthread");
  } else {
    bool ignored;
    msgHdr->GetIsKilled(&ignored);
    if (ignored) properties.AppendLiteral(" ignoreSubthread");
  }

  nsCOMPtr<nsIMsgLocalMailFolder> localFolder = do_QueryInterface(m_folder);

  if ((flags & nsMsgMessageFlags::Offline) ||
      (localFolder && !(flags & nsMsgMessageFlags::Partial)))
    properties.AppendLiteral(" offline");

  if (flags & nsMsgMessageFlags::Attachment)
    properties.AppendLiteral(" attach");

  if ((mDeleteModel == nsMsgImapDeleteModels::IMAPDelete) &&
      (flags & nsMsgMessageFlags::IMAPDeleted))
    properties.AppendLiteral(" imapdeleted");

  nsCString imageSize;
  msgHdr->GetStringProperty("imageSize", imageSize);
  if (!imageSize.IsEmpty()) properties.AppendLiteral(" hasimage");

  nsCString junkScoreStr;
  msgHdr->GetStringProperty("junkscore", junkScoreStr);
  if (!junkScoreStr.IsEmpty()) {
    if (junkScoreStr.ToInteger(&rv) == nsIJunkMailPlugin::IS_SPAM_SCORE)
      properties.AppendLiteral(" junk");
    else
      properties.AppendLiteral(" notjunk");

    NS_ASSERTION(NS_SUCCEEDED(rv), "Converting junkScore to integer failed.");
  }

  nsCString keywords;
  FetchRowKeywords(aRow, msgHdr, keywords);
  bool tagAdded = false;
  if (!keywords.IsEmpty()) {
    AppendKeywordProperties(keywords, properties, &tagAdded);
  }
  if (tagAdded) {
    properties.AppendLiteral(" tagged");
  } else {
    properties.AppendLiteral(" untagged");
  }

  // This is a double fetch of the keywords property since we also fetch
  // it for the tags - do we want to do this?
  // I'm not sure anyone uses the kw- property, though it could be nice
  // for people wanting to extend the thread pane.
  nsCString keywordProperty;
  msgHdr->GetStringProperty("keywords", keywordProperty);
  if (!keywordProperty.IsEmpty()) {
    NS_ConvertUTF8toUTF16 keywords(keywordProperty);
    int32_t spaceIndex = 0;
    do {
      spaceIndex = keywords.FindChar(' ');
      int32_t endOfKeyword =
          (spaceIndex == -1) ? keywords.Length() : spaceIndex;
      properties.AppendLiteral(" kw-");
      properties.Append(StringHead(keywords, endOfKeyword));
      if (spaceIndex > 0) keywords.Cut(0, endOfKeyword + 1);
    } while (spaceIndex > 0);
  }

#ifdef SUPPORT_PRIORITY_COLORS
  // Add special styles for priority.
  nsMsgPriorityValue priority;
  msgHdr->GetPriority(&priority);
  switch (priority) {
    case nsMsgPriority::highest:
      properties.append(" priority-highest");
      break;
    case nsMsgPriority::high:
      properties.append(" priority-high");
      break;
    case nsMsgPriority::low:
      properties.append(" priority-low");
      break;
    case nsMsgPriority::lowest:
      properties.append(" priority-lowest");
      break;
    default:
      break;
  }
#endif

  nsCOMPtr<nsIMsgThread> thread;
  rv = GetThreadContainingIndex(aRow, getter_AddRefs(thread));
  if (NS_SUCCEEDED(rv) && thread) {
    uint32_t numUnreadChildren;
    thread->GetNumUnreadChildren(&numUnreadChildren);
    if (numUnreadChildren > 0) properties.AppendLiteral(" hasUnread");

    // For threaded display add the ignore/watch properties to the
    // thread top row. For non-threaded add it to all rows.
    if (!(m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) ||
        ((m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) &&
         (m_flags[aRow] & MSG_VIEW_FLAG_ISTHREAD))) {
      thread->GetFlags(&flags);
      if (flags & nsMsgMessageFlags::Watched)
        properties.AppendLiteral(" watch");
      if (flags & nsMsgMessageFlags::Ignored)
        properties.AppendLiteral(" ignore");
    }
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::IsContainer(int32_t index, bool* _retval) {
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) {
    uint32_t flags = m_flags[index];
    *_retval = !!(flags & MSG_VIEW_FLAG_HASCHILDREN);
  } else {
    *_retval = false;
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::IsContainerOpen(int32_t index, bool* _retval) {
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) {
    uint32_t flags = m_flags[index];
    *_retval = (flags & MSG_VIEW_FLAG_HASCHILDREN) &&
               !(flags & nsMsgMessageFlags::Elided);
  } else {
    *_retval = false;
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::IsContainerEmpty(int32_t index, bool* _retval) {
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) {
    uint32_t flags = m_flags[index];
    *_retval = !(flags & MSG_VIEW_FLAG_HASCHILDREN);
  } else {
    *_retval = false;
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::IsSeparator(int32_t index, bool* _retval) {
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  *_retval = false;

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetParentIndex(int32_t rowIndex, int32_t* _retval) {
  *_retval = -1;

  int32_t rowIndexLevel;
  nsresult rv = GetLevel(rowIndex, &rowIndexLevel);
  NS_ENSURE_SUCCESS(rv, rv);

  int32_t i;
  for (i = rowIndex; i >= 0; i--) {
    int32_t l;
    GetLevel(i, &l);
    if (l < rowIndexLevel) {
      *_retval = i;
      break;
    }
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::HasNextSibling(int32_t rowIndex, int32_t afterIndex,
                            bool* _retval) {
  *_retval = false;

  int32_t rowIndexLevel;
  GetLevel(rowIndex, &rowIndexLevel);

  int32_t i;
  int32_t count;
  GetRowCount(&count);
  for (i = afterIndex + 1; i < count; i++) {
    int32_t l;
    GetLevel(i, &l);
    if (l < rowIndexLevel) break;

    if (l == rowIndexLevel) {
      *_retval = true;
      break;
    }
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetLevel(int32_t index, int32_t* _retval) {
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
    *_retval = m_levels[index];
  else
    *_retval = 0;

  return NS_OK;
}

// Search view will override this since headers can span db's.
nsresult nsMsgDBView::GetMsgHdrForViewIndex(nsMsgViewIndex index,
                                            nsIMsgDBHdr** msgHdr) {
  nsresult rv = NS_OK;
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  nsMsgKey key = m_keys[index];
  if (key == nsMsgKey_None || !m_db) return NS_MSG_INVALID_DBVIEW_INDEX;

  if (key == m_cachedMsgKey) {
    NS_IF_ADDREF(*msgHdr = m_cachedHdr);
  } else {
    rv = m_db->GetMsgHdrForKey(key, msgHdr);
    if (NS_SUCCEEDED(rv)) {
      m_cachedHdr = *msgHdr;
      m_cachedMsgKey = key;
    }
  }

  return rv;
}

void nsMsgDBView::InsertMsgHdrAt(nsMsgViewIndex index, nsIMsgDBHdr* hdr,
                                 nsMsgKey msgKey, uint32_t flags,
                                 uint32_t level) {
  if ((int32_t)index < 0 || index > m_keys.Length()) {
    // Something's gone wrong in a caller, but we have no clue why.
    // Return without adding the header to the view.
    NS_ERROR("Index for message header insertion out of array range!");
    return;
  }

  m_keys.InsertElementAt(index, msgKey);
  m_flags.InsertElementAt(index, flags);
  m_levels.InsertElementAt(index, level);
}

void nsMsgDBView::SetMsgHdrAt(nsIMsgDBHdr* hdr, nsMsgViewIndex index,
                              nsMsgKey msgKey, uint32_t flags, uint32_t level) {
  m_keys[index] = msgKey;
  m_flags[index] = flags;
  m_levels[index] = level;
}

nsresult nsMsgDBView::GetFolderForViewIndex(nsMsgViewIndex index,
                                            nsIMsgFolder** aFolder) {
  NS_IF_ADDREF(*aFolder = m_folder);
  return NS_OK;
}

nsresult nsMsgDBView::GetDBForViewIndex(nsMsgViewIndex index,
                                        nsIMsgDatabase** db) {
  NS_IF_ADDREF(*db = m_db);
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetImageSrc(int32_t aRow, nsTreeColumn* aCol, nsAString& aValue) {
  NS_ENSURE_ARG_POINTER(aCol);
  // Attempt to retrieve a custom column handler. If it exists call it and
  // return.
  const nsAString& colID = aCol->GetId();
  nsIMsgCustomColumnHandler* colHandler = GetColumnHandler(colID);

  if (colHandler) {
    colHandler->GetImageSrc(aRow, aCol, aValue);
    return NS_OK;
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetCellValue(int32_t aRow, nsTreeColumn* aCol, nsAString& aValue) {
  if (!IsValidIndex(aRow)) return NS_MSG_INVALID_DBVIEW_INDEX;

  nsCOMPtr<nsIMsgDBHdr> msgHdr;
  nsresult rv = GetMsgHdrForViewIndex(aRow, getter_AddRefs(msgHdr));

  if (NS_FAILED(rv) || !msgHdr) {
    ClearHdrCache();
    return NS_MSG_INVALID_DBVIEW_INDEX;
  }

  const nsAString& colID = aCol->GetId();

  aValue.Truncate();
  if (colID.IsEmpty()) return NS_OK;

  uint32_t flags;
  msgHdr->GetFlags(&flags);

  // Provide a string "value" for cells that do not normally have text.
  // Use empty string for the normal states "Read", "Not Starred",
  // "No Attachment" and "Not Junk".
  switch (colID.First()) {
    case 'a':
      if (colID.EqualsLiteral("attachmentCol") &&
          flags & nsMsgMessageFlags::Attachment) {
        GetString(u"messageHasAttachment", aValue);
      }
      break;
    case 'f':
      if (colID.EqualsLiteral("flaggedCol") &&
          flags & nsMsgMessageFlags::Marked) {
        GetString(u"messageHasFlag", aValue);
      }
      break;
    case 'j':
      if (colID.EqualsLiteral("junkStatusCol") && JunkControlsEnabled(aRow)) {
        nsCString junkScoreStr;
        msgHdr->GetStringProperty("junkscore", junkScoreStr);
        // Only need to assign a real value for junk, it's empty already
        // as it should be for non-junk.
        if (!junkScoreStr.IsEmpty() &&
            (junkScoreStr.ToInteger(&rv) == nsIJunkMailPlugin::IS_SPAM_SCORE))
          aValue.AssignLiteral("messageJunk");

        NS_ASSERTION(NS_SUCCEEDED(rv),
                     "Converting junkScore to integer failed.");
      }
      break;
    case 't':
      if (colID.EqualsLiteral("threadCol") &&
          (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)) {
        // thread column
        bool isContainer, isContainerEmpty, isContainerOpen;
        IsContainer(aRow, &isContainer);
        if (isContainer) {
          IsContainerEmpty(aRow, &isContainerEmpty);
          if (!isContainerEmpty) {
            IsContainerOpen(aRow, &isContainerOpen);
            GetString(
                isContainerOpen ? u"messageExpanded" : u"messageCollapsed",
                aValue);
          }
        }
      }
      break;
    case 'u':
      if (colID.EqualsLiteral("unreadButtonColHeader") &&
          !(flags & nsMsgMessageFlags::Read)) {
        GetString(u"messageUnread", aValue);
      }
      break;
    default:
      aValue.Assign(colID);
      break;
  }

  return rv;
}

void nsMsgDBView::RememberDeletedMsgHdr(nsIMsgDBHdr* msgHdr) {
  nsCString messageId;
  msgHdr->GetMessageId(getter_Copies(messageId));
  if (mRecentlyDeletedArrayIndex >= mRecentlyDeletedMsgIds.Length())
    mRecentlyDeletedMsgIds.AppendElement(messageId);
  else
    mRecentlyDeletedMsgIds[mRecentlyDeletedArrayIndex] = messageId;

  // Only remember last 20 deleted msgs.
  mRecentlyDeletedArrayIndex = (mRecentlyDeletedArrayIndex + 1) % 20;
}

bool nsMsgDBView::WasHdrRecentlyDeleted(nsIMsgDBHdr* msgHdr) {
  nsCString messageId;
  msgHdr->GetMessageId(getter_Copies(messageId));
  return mRecentlyDeletedMsgIds.Contains(messageId);
}

/**
 * CUSTOM COLUMNS.
 */

// Add a custom column handler.
NS_IMETHODIMP
nsMsgDBView::AddColumnHandler(const nsAString& column,
                              nsIMsgCustomColumnHandler* handler) {
  bool custColInSort = false;
  size_t index = m_customColumnHandlerIDs.IndexOf(column);

  nsAutoString strColID(column);

  // Does not exist.
  if (index == m_customColumnHandlerIDs.NoIndex) {
    m_customColumnHandlerIDs.AppendElement(strColID);
    m_customColumnHandlers.AppendObject(handler);
  } else {
    // Insert new handler into the appropriate place in the COMPtr array;
    // no need to replace the column ID (it's the same).
    m_customColumnHandlers.ReplaceObjectAt(handler, index);
  }

  // Check if the column name matches any of the columns in
  // m_sortColumns, and if so, set m_sortColumns[i].mColHandler
  for (uint32_t i = 0; i < m_sortColumns.Length(); i++) {
    MsgViewSortColumnInfo& sortInfo = m_sortColumns[i];
    if (sortInfo.mSortType == nsMsgViewSortType::byCustom &&
        sortInfo.mCustomColumnName.Equals(column)) {
      custColInSort = true;
      sortInfo.mColHandler = handler;
    }
  }

  if (m_viewFlags & nsMsgViewFlagsType::kGroupBySort)
    // Grouped view has its own ways.
    return NS_OK;

  // This cust col is in sort columns, and all are now registered, so sort.
  if (custColInSort && !CustomColumnsInSortAndNotRegistered())
    Sort(m_sortType, m_sortOrder);

  return NS_OK;
}

// Remove a custom column handler.
NS_IMETHODIMP
nsMsgDBView::RemoveColumnHandler(const nsAString& aColID) {
  // Here we should check if the column name matches any of the columns in
  // m_sortColumns, and if so, clear m_sortColumns[i].mColHandler.
  size_t index = m_customColumnHandlerIDs.IndexOf(aColID);

  if (index != m_customColumnHandlerIDs.NoIndex) {
    m_customColumnHandlerIDs.RemoveElementAt(index);
    m_customColumnHandlers.RemoveObjectAt(index);
    // Check if the column name matches any of the columns in
    // m_sortColumns, and if so, clear m_sortColumns[i].mColHandler.
    for (uint32_t i = 0; i < m_sortColumns.Length(); i++) {
      MsgViewSortColumnInfo& sortInfo = m_sortColumns[i];
      if (sortInfo.mSortType == nsMsgViewSortType::byCustom &&
          sortInfo.mCustomColumnName.Equals(aColID))
        sortInfo.mColHandler = nullptr;
    }

    return NS_OK;
  }

  // Can't remove a column that isn't currently custom handled.
  return NS_ERROR_FAILURE;
}

// TODO: NS_ENSURE_SUCCESS
nsIMsgCustomColumnHandler* nsMsgDBView::GetCurColumnHandler() {
  return GetColumnHandler(m_curCustomColumn);
}

NS_IMETHODIMP
nsMsgDBView::SetCurCustomColumn(const nsAString& aColID) {
  m_curCustomColumn = aColID;
  if (m_viewFolder) {
    nsCOMPtr<nsIMsgDatabase> db;
    nsCOMPtr<nsIDBFolderInfo> folderInfo;
    nsresult rv = m_viewFolder->GetDBFolderInfoAndDB(getter_AddRefs(folderInfo),
                                                     getter_AddRefs(db));
    NS_ENSURE_SUCCESS(rv, rv);
    folderInfo->SetProperty("customSortCol", aColID);
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetCurCustomColumn(nsAString& result) {
  result = m_curCustomColumn;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetSecondaryCustomColumn(nsAString& result) {
  result = m_secondaryCustomColumn;
  return NS_OK;
}

nsIMsgCustomColumnHandler* nsMsgDBView::GetColumnHandler(
    const nsAString& colID) {
  size_t index = m_customColumnHandlerIDs.IndexOf(colID);
  return (index != m_customColumnHandlerIDs.NoIndex)
             ? m_customColumnHandlers[index]
             : nullptr;
}

NS_IMETHODIMP
nsMsgDBView::GetColumnHandler(const nsAString& aColID,
                              nsIMsgCustomColumnHandler** aHandler) {
  NS_ENSURE_ARG_POINTER(aHandler);
  nsAutoString column(aColID);
  NS_IF_ADDREF(*aHandler = GetColumnHandler(column));
  return (*aHandler) ? NS_OK : NS_ERROR_FAILURE;
}

// Check if any active sort columns are custom. If none are custom, return false
// and go on as always. If any are custom, and all are not registered yet,
// return true (so that the caller can postpone sort). When the custom column
// observer is notified with MsgCreateDBView and registers the handler,
// AddColumnHandler will sort once all required handlers are set.
bool nsMsgDBView::CustomColumnsInSortAndNotRegistered() {
  // The initial sort on view open has been started, subsequent user initiated
  // sort callers can ignore verifying cust col registration.
  m_checkedCustomColumns = true;

  // DecodeColumnSort must have already created m_sortColumns, otherwise we
  // can't know, but go on anyway.
  if (!m_sortColumns.Length()) return false;

  bool custColNotRegistered = false;
  for (uint32_t i = 0; i < m_sortColumns.Length() && !custColNotRegistered;
       i++) {
    if (m_sortColumns[i].mSortType == nsMsgViewSortType::byCustom &&
        m_sortColumns[i].mColHandler == nullptr)
      custColNotRegistered = true;
  }

  return custColNotRegistered;
}
// END CUSTOM COLUMNS.

NS_IMETHODIMP
nsMsgDBView::GetCellText(int32_t aRow, nsTreeColumn* aCol, nsAString& aValue) {
  const nsAString& colID = aCol->GetId();

  if (!IsValidIndex(aRow)) return NS_MSG_INVALID_DBVIEW_INDEX;

  aValue.Truncate();

  // Attempt to retrieve a custom column handler. If it exists call it and
  // return.
  nsIMsgCustomColumnHandler* colHandler = GetColumnHandler(colID);

  if (colHandler) {
    colHandler->GetCellText(aRow, aCol, aValue);
    return NS_OK;
  }

  return CellTextForColumn(aRow, colID, aValue);
}

NS_IMETHODIMP
nsMsgDBView::CellTextForColumn(int32_t aRow, const nsAString& aColumnName,
                               nsAString& aValue) {
  if (aColumnName.IsEmpty()) {
    aValue.Truncate();
    return NS_OK;
  }

  nsCOMPtr<nsIMsgDBHdr> msgHdr;
  nsresult rv = GetMsgHdrForViewIndex(aRow, getter_AddRefs(msgHdr));

  if (NS_FAILED(rv) || !msgHdr) {
    ClearHdrCache();
    return NS_MSG_INVALID_DBVIEW_INDEX;
  }

  nsCOMPtr<nsIMsgThread> thread;

  switch (aColumnName.First()) {
    case 's':
      if (aColumnName.EqualsLiteral("subjectCol"))
        rv = FetchSubject(msgHdr, m_flags[aRow], aValue);
      else if (aColumnName.EqualsLiteral("senderCol"))
        rv = FetchAuthor(msgHdr, aValue);
      else if (aColumnName.EqualsLiteral("sizeCol"))
        rv = FetchSize(msgHdr, aValue);
      else if (aColumnName.EqualsLiteral("statusCol")) {
        uint32_t flags;
        msgHdr->GetFlags(&flags);
        rv = FetchStatus(flags, aValue);
      }
      break;
    case 'r':
      if (aColumnName.EqualsLiteral("recipientCol"))
        rv = FetchRecipients(msgHdr, aValue);
      else if (aColumnName.EqualsLiteral("receivedCol"))
        rv = FetchDate(msgHdr, aValue, true);
      break;
    case 'd':
      if (aColumnName.EqualsLiteral("dateCol")) rv = FetchDate(msgHdr, aValue);
      break;
    case 'c':
      if (aColumnName.EqualsLiteral("correspondentCol")) {
        if (IsOutgoingMsg(msgHdr))
          rv = FetchRecipients(msgHdr, aValue);
        else
          rv = FetchAuthor(msgHdr, aValue);
      }
      break;
    case 'p':
      if (aColumnName.EqualsLiteral("priorityCol"))
        rv = FetchPriority(msgHdr, aValue);
      break;
    case 'a':
      if (aColumnName.EqualsLiteral("accountCol"))
        rv = FetchAccount(msgHdr, aValue);
      break;
    case 't':
      // total msgs in thread column
      if (aColumnName.EqualsLiteral("totalCol") &&
          m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) {
        if (m_flags[aRow] & MSG_VIEW_FLAG_ISTHREAD) {
          rv = GetThreadContainingIndex(aRow, getter_AddRefs(thread));
          if (NS_SUCCEEDED(rv) && thread) {
            nsAutoString formattedCountString;
            uint32_t numChildren;
            thread->GetNumChildren(&numChildren);
            formattedCountString.AppendInt(numChildren);
            aValue.Assign(formattedCountString);
          }
        }
      } else if (aColumnName.EqualsLiteral("tagsCol")) {
        rv = FetchTags(msgHdr, aValue);
      }
      break;
    case 'u':
      // unread msgs in thread col
      if (aColumnName.EqualsLiteral("unreadCol") &&
          m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) {
        if (m_flags[aRow] & MSG_VIEW_FLAG_ISTHREAD) {
          rv = GetThreadContainingIndex(aRow, getter_AddRefs(thread));
          if (NS_SUCCEEDED(rv) && thread) {
            nsAutoString formattedCountString;
            uint32_t numUnreadChildren;
            thread->GetNumUnreadChildren(&numUnreadChildren);
            if (numUnreadChildren > 0) {
              formattedCountString.AppendInt(numUnreadChildren);
              aValue.Assign(formattedCountString);
            }
          }
        }
      }
      break;
    case 'j': {
      if (aColumnName.EqualsLiteral("junkStatusCol")) {
        nsCString junkScoreStr;
        msgHdr->GetStringProperty("junkscore", junkScoreStr);
        CopyASCIItoUTF16(junkScoreStr, aValue);
      }
      break;
    }
    case 'i': {
      if (aColumnName.EqualsLiteral("idCol")) {
        nsAutoString keyString;
        nsMsgKey key;
        msgHdr->GetMessageKey(&key);
        keyString.AppendInt((int64_t)key);
        aValue.Assign(keyString);
      }
      break;
    }
    case 'l': {
      if (aColumnName.EqualsLiteral("locationCol")) {
        nsCOMPtr<nsIMsgFolder> folder;
        nsresult rv = GetFolderForViewIndex(aRow, getter_AddRefs(folder));
        NS_ENSURE_SUCCESS(rv, rv);
        folder->GetPrettyName(aValue);
      }
      break;
    }
    default:
      break;
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::CellDataForColumns(int32_t aRow,
                                const nsTArray<nsString>& aColumnNames,
                                nsAString& aProperties, int32_t* aThreadLevel,
                                nsTArray<nsString>& _retval) {
  nsresult rv;
  _retval.Clear();

  uint32_t count = aColumnNames.Length();
  _retval.SetCapacity(count);
  for (nsString column : aColumnNames) {
    nsString text;
    rv = CellTextForColumn(aRow, column, text);
    if (NS_FAILED(rv)) {
      _retval.Clear();
      return rv;
    }
    _retval.AppendElement(text);
  }

  rv = GetRowProperties(aRow, aProperties);
  if (NS_FAILED(rv)) {
    _retval.Clear();
    return rv;
  }

  rv = GetLevel(aRow, aThreadLevel);
  if (NS_FAILED(rv)) {
    _retval.Clear();
    aProperties.Truncate();
  }

  return rv;
}

NS_IMETHODIMP
nsMsgDBView::SetTree(mozilla::dom::XULTreeElement* tree) {
  mTree = tree;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SetJSTree(nsIMsgJSTree* tree) {
  mJSTree = tree;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::ToggleOpenState(int32_t index) {
  uint32_t numChanged;
  nsresult rv = ToggleExpansion(index, &numChanged);
  NS_ENSURE_SUCCESS(rv, rv);
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::CycleHeader(nsTreeColumn* aCol) {
  // Let HandleColumnClick() in threadPane.js handle it
  // since it will set / clear the sort indicators.
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::CycleCell(int32_t row, nsTreeColumn* col) {
  if (!IsValidIndex(row)) {
    return NS_MSG_INVALID_DBVIEW_INDEX;
  }

  const nsAString& colID = col->GetId();

  // Attempt to retrieve a custom column handler. If it exists call it and
  // return.
  nsIMsgCustomColumnHandler* colHandler = GetColumnHandler(colID);

  if (colHandler) {
    colHandler->CycleCell(row, col);
    return NS_OK;
  }

  // The cyclers below don't work for the grouped header dummy row, currently.
  // A future implementation should consider both collapsed and expanded state.
  if (m_viewFlags & nsMsgViewFlagsType::kGroupBySort &&
      m_flags[row] & MSG_VIEW_FLAG_DUMMY)
    return NS_OK;

  if (colID.IsEmpty()) return NS_OK;

  switch (colID.First()) {
    case 'u':
      if (colID.EqualsLiteral("unreadButtonColHeader")) {
        ApplyCommandToIndices(nsMsgViewCommandType::toggleMessageRead,
                              {(nsMsgViewIndex)row});
      }
      break;
    case 't':
      if (colID.EqualsLiteral("threadCol")) {
        ExpandAndSelectThreadByIndex(row, false);
      } else if (colID.EqualsLiteral("tagsCol")) {
        // XXX Do we want to keep this behaviour but switch it to tags?
        // We could enumerate over the tags and go to the next one - it looks
        // to me like this wasn't working before tags landed, so maybe not
        // worth bothering with.
      }
      break;
    case 'f':
      if (colID.EqualsLiteral("flaggedCol")) {
        // toggle the flagged status of the element at row.
        if (m_flags[row] & nsMsgMessageFlags::Marked) {
          ApplyCommandToIndices(nsMsgViewCommandType::unflagMessages,
                                {(nsMsgViewIndex)row});
        } else {
          ApplyCommandToIndices(nsMsgViewCommandType::flagMessages,
                                {(nsMsgViewIndex)row});
        }
      }
      break;
    case 'j': {
      if (!colID.EqualsLiteral("junkStatusCol") || !JunkControlsEnabled(row)) {
        return NS_OK;
      }

      nsCOMPtr<nsIMsgDBHdr> msgHdr;
      nsresult rv = GetMsgHdrForViewIndex(row, getter_AddRefs(msgHdr));
      if (NS_SUCCEEDED(rv) && msgHdr) {
        nsCString junkScoreStr;
        rv = msgHdr->GetStringProperty("junkscore", junkScoreStr);
        if (junkScoreStr.IsEmpty() ||
            (junkScoreStr.ToInteger(&rv) == nsIJunkMailPlugin::IS_HAM_SCORE)) {
          ApplyCommandToIndices(nsMsgViewCommandType::junk,
                                {(nsMsgViewIndex)row});
        } else {
          ApplyCommandToIndices(nsMsgViewCommandType::unjunk,
                                {(nsMsgViewIndex)row});
        }
        NS_ASSERTION(NS_SUCCEEDED(rv),
                     "Converting junkScore to integer failed.");
      }
      break;
    }
    default:
      break;
  }

  return NS_OK;
}

///////////////////////////////////////////////////////////////////////////
// end nsITreeView Implementation Methods
///////////////////////////////////////////////////////////////////////////

NS_IMETHODIMP
nsMsgDBView::Open(nsIMsgFolder* folder, nsMsgViewSortTypeValue sortType,
                  nsMsgViewSortOrderValue sortOrder,
                  nsMsgViewFlagsTypeValue viewFlags, int32_t* pCount) {
  m_viewFlags = viewFlags;
  m_sortOrder = sortOrder;
  m_sortType = sortType;

  nsresult rv;
  nsCOMPtr<nsIMsgAccountManager> accountManager =
      do_GetService("@mozilla.org/messenger/account-manager;1", &rv);

  NS_ENSURE_SUCCESS(rv, rv);
  bool userNeedsToAuthenticate = false;
  // If we're PasswordProtectLocalCache, then we need to find out if the
  // server is authenticated.
  (void)accountManager->GetUserNeedsToAuthenticate(&userNeedsToAuthenticate);
  if (userNeedsToAuthenticate) return NS_MSG_USER_NOT_AUTHENTICATED;

  if (folder) {
    // Search view will have a null folder.
    nsCOMPtr<nsIDBFolderInfo> folderInfo;
    rv = folder->GetDBFolderInfoAndDB(getter_AddRefs(folderInfo),
                                      getter_AddRefs(m_db));
    NS_ENSURE_SUCCESS(rv, rv);
    nsCOMPtr<nsIMsgDBService> msgDBService =
        do_GetService("@mozilla.org/msgDatabase/msgDBService;1", &rv);
    NS_ENSURE_SUCCESS(rv, rv);
    msgDBService->RegisterPendingListener(folder, this);
    m_folder = folder;

    if (!m_viewFolder) {
      // There is never a viewFolder already set except for the single folder
      // saved search case, where the backing folder m_folder is different from
      // the m_viewFolder with its own dbFolderInfo state.
      m_viewFolder = folder;
    }

    SetMRUTimeForFolder(m_viewFolder);

    RestoreSortInfo();

    // Determine if we are in a news folder or not. If yes, we'll show lines
    // instead of size, and special icons in the thread pane.
    nsCOMPtr<nsIMsgIncomingServer> server;
    rv = folder->GetServer(getter_AddRefs(server));
    NS_ENSURE_SUCCESS(rv, rv);
    nsCString type;
    rv = server->GetType(type);
    NS_ENSURE_SUCCESS(rv, rv);

    // I'm not sure this is correct, because XF virtual folders with mixed news
    // and mail can have this set.
    mIsNews = type.LowerCaseEqualsLiteral("nntp");

    // Default to a virtual folder if folder not set, since synthetic search
    // views may not have a folder.
    uint32_t folderFlags = nsMsgFolderFlags::Virtual;
    if (folder) folder->GetFlags(&folderFlags);

    mIsXFVirtual = folderFlags & nsMsgFolderFlags::Virtual;
    if (!mIsXFVirtual && type.LowerCaseEqualsLiteral("rss")) mIsRss = true;

    // Special case nntp --> news since we'll break themes if we try to be
    // consistent.
    if (mIsNews)
      mMessageType.AssignLiteral("news");
    else
      CopyUTF8toUTF16(type, mMessageType);

    GetImapDeleteModel(nullptr);

    nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
    if (prefs) {
      prefs->GetBoolPref("mailnews.sort_threads_by_root", &mSortThreadsByRoot);
      if (mIsNews)
        prefs->GetBoolPref("news.show_size_in_lines", &mShowSizeInLines);
    }
  }

  nsTArray<RefPtr<nsIMsgIdentity>> identities;
  rv = accountManager->GetAllIdentities(identities);
  NS_ENSURE_SUCCESS(rv, rv);

  for (auto identity : identities) {
    if (!identity) continue;

    nsCString email;
    identity->GetEmail(email);
    if (!email.IsEmpty()) {
      ToLowerCaseDropPlusAddessing(email);
      mEmails.PutEntry(email);
    }

    identity->GetReplyTo(email);
    if (!email.IsEmpty()) {
      ToLowerCaseDropPlusAddessing(email);
      mEmails.PutEntry(email);
    }
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::Close() {
  int32_t oldSize = GetSize();
  // This is important, because the tree will ask us for our row count, which
  // gets determined from the number of keys.
  m_keys.Clear();
  // Be consistent.
  m_flags.Clear();
  m_levels.Clear();

  // Clear these out since they no longer apply if we're switching a folder
  mJunkHdrs.Clear();

  // This needs to happen after we remove all the keys, since RowCountChanged()
  // will call our GetRowCount().
  if (mTree) mTree->RowCountChanged(0, -oldSize);
  if (mJSTree) mJSTree->RowCountChanged(0, -oldSize);

  ClearHdrCache();
  if (m_db) {
    m_db->RemoveListener(this);
    m_db = nullptr;
  }
  if (m_folder) {
    nsresult rv;
    nsCOMPtr<nsIMsgDBService> msgDBService =
        do_GetService("@mozilla.org/msgDatabase/msgDBService;1", &rv);
    NS_ENSURE_SUCCESS(rv, rv);
    msgDBService->UnregisterPendingListener(this);
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::OpenWithHdrs(nsIMsgEnumerator* aHeaders,
                          nsMsgViewSortTypeValue aSortType,
                          nsMsgViewSortOrderValue aSortOrder,
                          nsMsgViewFlagsTypeValue aViewFlags, int32_t* aCount) {
  NS_ASSERTION(false, "not implemented");
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP
nsMsgDBView::Init(nsIMessenger* aMessengerInstance, nsIMsgWindow* aMsgWindow,
                  nsIMsgDBViewCommandUpdater* aCmdUpdater) {
  mMessengerWeak = do_GetWeakReference(aMessengerInstance);
  mMsgWindowWeak = do_GetWeakReference(aMsgWindow);
  mCommandUpdater = do_GetWeakReference(aCmdUpdater);
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SetSuppressCommandUpdating(bool aSuppressCommandUpdating) {
  mSuppressCommandUpdating = aSuppressCommandUpdating;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetSuppressCommandUpdating(bool* aSuppressCommandUpdating) {
  *aSuppressCommandUpdating = mSuppressCommandUpdating;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SetSuppressMsgDisplay(bool aSuppressDisplay) {
  mSuppressMsgDisplay = aSuppressDisplay;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetSuppressMsgDisplay(bool* aSuppressDisplay) {
  *aSuppressDisplay = mSuppressMsgDisplay;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetUsingLines(bool* aUsingLines) {
  *aUsingLines = mShowSizeInLines;
  return NS_OK;
}

int CompareViewIndices(const void* v1, const void* v2, void*) {
  nsMsgViewIndex i1 = *(nsMsgViewIndex*)v1;
  nsMsgViewIndex i2 = *(nsMsgViewIndex*)v2;
  return i1 - i2;
}

// Array<nsMsgViewIndex> getIndicesForSelection();
NS_IMETHODIMP
nsMsgDBView::GetIndicesForSelection(nsTArray<nsMsgViewIndex>& indices) {
  indices.Clear();
  if (mTreeSelection) {
    int32_t viewSize = GetSize();
    int32_t count;
    mTreeSelection->GetCount(&count);
    indices.SetCapacity(count);
    int32_t selectionCount;
    mTreeSelection->GetRangeCount(&selectionCount);
    for (int32_t i = 0; i < selectionCount; i++) {
      int32_t startRange = -1;
      int32_t endRange = -1;
      mTreeSelection->GetRangeAt(i, &startRange, &endRange);
      if (startRange >= 0 && startRange < viewSize) {
        for (int32_t rangeIndex = startRange;
             rangeIndex <= endRange && rangeIndex < viewSize; rangeIndex++) {
          indices.AppendElement(rangeIndex);
        }
      }
    }

    NS_ASSERTION(indices.Length() == uint32_t(count),
                 "selection count is wrong");
  } else {
    // If there is no tree selection object then we must be in stand alone
    // message mode. In that case the selected indices are really just the
    // current message key.
    nsMsgViewIndex viewIndex = FindViewIndex(m_currentlyDisplayedMsgKey);
    if (viewIndex != nsMsgViewIndex_None) indices.AppendElement(viewIndex);
  }

  return NS_OK;
}

// Array<nsIMsgDBHdr> getSelectedMsgHdrs();
NS_IMETHODIMP
nsMsgDBView::GetSelectedMsgHdrs(nsTArray<RefPtr<nsIMsgDBHdr>>& aResult) {
  nsMsgViewIndexArray selection;
  aResult.Clear();
  nsresult rv = GetIndicesForSelection(selection);
  NS_ENSURE_SUCCESS(rv, rv);
  return GetHeadersFromSelection(selection, aResult);
}

NS_IMETHODIMP
nsMsgDBView::GetURIsForSelection(nsTArray<nsCString>& uris) {
  uris.Clear();
  AutoTArray<RefPtr<nsIMsgDBHdr>, 1> messages;
  nsresult rv = GetSelectedMsgHdrs(messages);
  NS_ENSURE_SUCCESS(rv, rv);
  uris.SetCapacity(messages.Length());
  for (nsIMsgDBHdr* msgHdr : messages) {
    nsCString tmpUri;
    nsCOMPtr<nsIMsgFolder> folder;
    nsMsgKey msgKey;
    msgHdr->GetMessageKey(&msgKey);
    msgHdr->GetFolder(getter_AddRefs(folder));
    rv = GenerateURIForMsgKey(msgKey, folder, tmpUri);
    NS_ENSURE_SUCCESS(rv, rv);
    uris.AppendElement(tmpUri);
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetURIForViewIndex(nsMsgViewIndex index, nsACString& result) {
  nsresult rv;
  nsCOMPtr<nsIMsgFolder> folder = m_folder;
  if (!folder) {
    rv = GetFolderForViewIndex(index, getter_AddRefs(folder));
    NS_ENSURE_SUCCESS(rv, rv);
  }

  if (index == nsMsgViewIndex_None || index >= m_flags.Length() ||
      m_flags[index] & MSG_VIEW_FLAG_DUMMY) {
    return NS_MSG_INVALID_DBVIEW_INDEX;
  }

  return GenerateURIForMsgKey(m_keys[index], folder, result);
}

NS_IMETHODIMP
nsMsgDBView::DoCommandWithFolder(nsMsgViewCommandTypeValue command,
                                 nsIMsgFolder* destFolder) {
  NS_ENSURE_ARG_POINTER(destFolder);

  nsMsgViewIndexArray selection;
  GetIndicesForSelection(selection);

  nsresult rv = NS_OK;
  switch (command) {
    case nsMsgViewCommandType::copyMessages:
    case nsMsgViewCommandType::moveMessages:
      rv = ApplyCommandToIndicesWithFolder(command, selection, destFolder);
      NoteChange(0, 0, nsMsgViewNotificationCode::none);
      break;
    default:
      NS_ASSERTION(false, "invalid command type");
      rv = NS_ERROR_UNEXPECTED;
      break;
  }

  return rv;
}

NS_IMETHODIMP
nsMsgDBView::DoCommand(nsMsgViewCommandTypeValue command) {
  nsMsgViewIndexArray selection;
  GetIndicesForSelection(selection);

  nsCOMPtr<nsIMsgWindow> msgWindow(do_QueryReferent(mMsgWindowWeak));

  nsresult rv = NS_OK;
  switch (command) {
    case nsMsgViewCommandType::downloadSelectedForOffline:
      return DownloadForOffline(msgWindow, selection);
    case nsMsgViewCommandType::downloadFlaggedForOffline:
      return DownloadFlaggedForOffline(msgWindow);
    case nsMsgViewCommandType::markMessagesRead:
    case nsMsgViewCommandType::markMessagesUnread:
    case nsMsgViewCommandType::toggleMessageRead:
    case nsMsgViewCommandType::flagMessages:
    case nsMsgViewCommandType::unflagMessages:
    case nsMsgViewCommandType::deleteMsg:
    case nsMsgViewCommandType::undeleteMsg:
    case nsMsgViewCommandType::deleteNoTrash:
    case nsMsgViewCommandType::markThreadRead:
    case nsMsgViewCommandType::junk:
    case nsMsgViewCommandType::unjunk:
      rv = ApplyCommandToIndices(command, selection);
      NoteChange(0, 0, nsMsgViewNotificationCode::none);
      break;
    case nsMsgViewCommandType::selectAll:
      if (mTreeSelection) {
        // If in threaded mode, we need to expand all before selecting.
        if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
          rv = ExpandAll();

        mTreeSelection->SelectAll();
        if (mTree) mTree->Invalidate();
        if (mJSTree) mJSTree->Invalidate();
      }
      break;
    case nsMsgViewCommandType::selectThread:
      rv = ExpandAndSelectThread();
      break;
    case nsMsgViewCommandType::selectFlagged:
      if (!mTreeSelection) {
        rv = NS_ERROR_UNEXPECTED;
      } else {
        mTreeSelection->SetSelectEventsSuppressed(true);
        mTreeSelection->ClearSelection();
        // XXX ExpandAll?
        uint32_t numIndices = GetSize();
        for (uint32_t curIndex = 0; curIndex < numIndices; curIndex++) {
          if (m_flags[curIndex] & nsMsgMessageFlags::Marked)
            mTreeSelection->ToggleSelect(curIndex);
        }

        mTreeSelection->SetSelectEventsSuppressed(false);
      }
      break;
    case nsMsgViewCommandType::markAllRead:
      if (m_folder) {
        SetSuppressChangeNotifications(true);
        rv = m_folder->MarkAllMessagesRead(msgWindow);
        SetSuppressChangeNotifications(false);
        if (mTree) mTree->Invalidate();
        if (mJSTree) mJSTree->Invalidate();
      }
      break;
    case nsMsgViewCommandType::toggleThreadWatched:
      rv = ToggleWatched(selection);
      break;
    case nsMsgViewCommandType::expandAll:
      rv = ExpandAll();
      m_viewFlags |= nsMsgViewFlagsType::kExpandAll;
      SetViewFlags(m_viewFlags);
      if (mTree) mTree->Invalidate();
      if (mJSTree) mJSTree->Invalidate();

      break;
    case nsMsgViewCommandType::collapseAll:
      rv = CollapseAll();
      m_viewFlags &= ~nsMsgViewFlagsType::kExpandAll;
      SetViewFlags(m_viewFlags);
      if (mTree) mTree->Invalidate();
      if (mJSTree) mJSTree->Invalidate();

      break;
    default:
      NS_ASSERTION(false, "invalid command type");
      rv = NS_ERROR_UNEXPECTED;
      break;
  }

  return rv;
}

bool nsMsgDBView::ServerSupportsFilterAfterTheFact() {
  // Cross folder virtual folders might not have a folder set.
  if (!m_folder) return false;

  nsCOMPtr<nsIMsgIncomingServer> server;
  nsresult rv = m_folder->GetServer(getter_AddRefs(server));
  // Unexpected.
  if (NS_FAILED(rv)) return false;

  // Filter after the fact is implement using search so if you can't search,
  // you can't filter after the fact.
  bool canSearch;
  rv = server->GetCanSearchMessages(&canSearch);
  // Unexpected.
  if (NS_FAILED(rv)) return false;

  return canSearch;
}

NS_IMETHODIMP
nsMsgDBView::GetCommandStatus(nsMsgViewCommandTypeValue command,
                              bool* selectable_p,
                              nsMsgViewCommandCheckStateValue* selected_p) {
  nsresult rv = NS_OK;

  bool haveSelection;
  int32_t rangeCount;
  nsMsgViewIndexArray selection;
  GetIndicesForSelection(selection);
  // If range count is non-zero, we have at least one item selected, so we
  // have a selection.
  if (mTreeSelection &&
      NS_SUCCEEDED(mTreeSelection->GetRangeCount(&rangeCount)) &&
      rangeCount > 0) {
    haveSelection = NonDummyMsgSelected(selection);
  } else {
    // If we don't have a tree selection we must be in stand alone mode.
    haveSelection = IsValidIndex(m_currentlyDisplayedViewIndex);
  }

  switch (command) {
    case nsMsgViewCommandType::deleteMsg:
    case nsMsgViewCommandType::deleteNoTrash: {
      bool canDelete;
      if (m_folder &&
          NS_SUCCEEDED(m_folder->GetCanDeleteMessages(&canDelete)) &&
          !canDelete) {
        *selectable_p = false;
      } else {
        *selectable_p = haveSelection;
      }
      break;
    }
    case nsMsgViewCommandType::applyFilters:
      // Disable if no messages.
      // XXX todo, check that we have filters, and at least one is enabled.
      *selectable_p = GetSize();
      if (*selectable_p) *selectable_p = ServerSupportsFilterAfterTheFact();

      break;
    case nsMsgViewCommandType::runJunkControls:
      // Disable if no messages.
      // XXX todo, check that we have JMC enabled?
      *selectable_p = GetSize() && JunkControlsEnabled(nsMsgViewIndex_None);
      break;
    case nsMsgViewCommandType::deleteJunk: {
      // Disable if no messages, or if we can't delete (like news and
      // certain imap folders).
      bool canDelete;
      *selectable_p =
          GetSize() && m_folder &&
          NS_SUCCEEDED(m_folder->GetCanDeleteMessages(&canDelete)) && canDelete;
      break;
    }
    case nsMsgViewCommandType::markMessagesRead:
    case nsMsgViewCommandType::markMessagesUnread:
    case nsMsgViewCommandType::toggleMessageRead:
    case nsMsgViewCommandType::flagMessages:
    case nsMsgViewCommandType::unflagMessages:
    case nsMsgViewCommandType::toggleThreadWatched:
    case nsMsgViewCommandType::markThreadRead:
    case nsMsgViewCommandType::downloadSelectedForOffline:
      *selectable_p = haveSelection;
      break;
    case nsMsgViewCommandType::junk:
    case nsMsgViewCommandType::unjunk:
      *selectable_p = haveSelection && !selection.IsEmpty() &&
                      JunkControlsEnabled(selection[0]);
      break;
    case nsMsgViewCommandType::cmdRequiringMsgBody:
      *selectable_p =
          haveSelection && (!WeAreOffline() || OfflineMsgSelected(selection));
      break;
    case nsMsgViewCommandType::downloadFlaggedForOffline:
    case nsMsgViewCommandType::markAllRead:
      *selectable_p = true;
      break;
    default:
      NS_ASSERTION(false, "invalid command type");
      rv = NS_ERROR_FAILURE;
  }

  return rv;
}

// This method needs to be overridden by the various view classes
// that have different kinds of threads. For example, in a
// threaded quick search db view, we'd only want to include children
// of the thread that fit the view (IMO). And when we have threaded
// cross folder views, we would include all the children of the
// cross-folder thread.
nsresult nsMsgDBView::ListCollapsedChildren(
    nsMsgViewIndex viewIndex, nsTArray<RefPtr<nsIMsgDBHdr>>& messageArray) {
  nsCOMPtr<nsIMsgDBHdr> msgHdr;
  nsCOMPtr<nsIMsgThread> thread;
  GetMsgHdrForViewIndex(viewIndex, getter_AddRefs(msgHdr));
  if (!msgHdr) {
    NS_ASSERTION(false, "couldn't find message to expand");
    return NS_MSG_MESSAGE_NOT_FOUND;
  }

  nsresult rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(thread));
  NS_ENSURE_SUCCESS(rv, rv);
  uint32_t numChildren;
  thread->GetNumChildren(&numChildren);
  for (uint32_t i = 1; i < numChildren && NS_SUCCEEDED(rv); i++) {
    nsCOMPtr<nsIMsgDBHdr> msgHdr;
    rv = thread->GetChildHdrAt(i, getter_AddRefs(msgHdr));
    if (msgHdr) {
      messageArray.AppendElement(msgHdr);
    }
  }

  return rv;
}

bool nsMsgDBView::OperateOnMsgsInCollapsedThreads() {
  if (!mJSTree && mTreeSelection) {
    RefPtr<mozilla::dom::XULTreeElement> selTree;
    mTreeSelection->GetTree(getter_AddRefs(selTree));
    // No tree means stand-alone message window.
    if (!selTree) return false;
  }

  nsresult rv = NS_OK;
  nsCOMPtr<nsIPrefBranch> prefBranch(
      do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
  NS_ENSURE_SUCCESS(rv, false);

  bool includeCollapsedMsgs = false;
  prefBranch->GetBoolPref("mail.operate_on_msgs_in_collapsed_threads",
                          &includeCollapsedMsgs);
  return includeCollapsedMsgs;
}

nsresult nsMsgDBView::GetHeadersFromSelection(
    nsTArray<nsMsgViewIndex> const& selection,
    nsTArray<RefPtr<nsIMsgDBHdr>>& hdrs) {
  hdrs.Clear();
  hdrs.SetCapacity(selection.Length());  // Best guess.
  nsresult rv = NS_OK;

  // Don't include collapsed messages if the front end failed to summarize
  // the selection.
  bool includeCollapsedMsgs =
      OperateOnMsgsInCollapsedThreads() && !mSummarizeFailed;

  for (nsMsgViewIndex viewIndex : selection) {
    if (NS_FAILED(rv)) {
      break;
    }
    if (viewIndex == nsMsgViewIndex_None) {
      continue;
    }

    uint32_t viewIndexFlags = m_flags[viewIndex];
    if (viewIndexFlags & MSG_VIEW_FLAG_DUMMY) {
      // If collapsed dummy header selected, list its children.
      if (includeCollapsedMsgs && viewIndexFlags & nsMsgMessageFlags::Elided &&
          m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)
        rv = ListCollapsedChildren(viewIndex, hdrs);

      continue;
    }

    nsCOMPtr<nsIMsgDBHdr> msgHdr;
    rv = GetMsgHdrForViewIndex(viewIndex, getter_AddRefs(msgHdr));
    if (NS_SUCCEEDED(rv) && msgHdr) {
      hdrs.AppendElement(msgHdr);
      if (includeCollapsedMsgs && viewIndexFlags & nsMsgMessageFlags::Elided &&
          viewIndexFlags & MSG_VIEW_FLAG_HASCHILDREN &&
          m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) {
        rv = ListCollapsedChildren(viewIndex, hdrs);
      }
    }
  }

  return rv;
}

nsresult nsMsgDBView::CopyMessages(nsIMsgWindow* window,
                                   nsTArray<nsMsgViewIndex> const& selection,
                                   bool isMove, nsIMsgFolder* destFolder) {
  if (m_deletingRows) {
    NS_ASSERTION(false, "Last move did not complete");
    return NS_OK;
  }

  nsresult rv;
  NS_ENSURE_ARG_POINTER(destFolder);

  AutoTArray<RefPtr<nsIMsgDBHdr>, 1> hdrs;
  rv = GetHeadersFromSelection(selection, hdrs);
  NS_ENSURE_SUCCESS(rv, rv);

  m_deletingRows = isMove && mDeleteModel != nsMsgImapDeleteModels::IMAPDelete;
  if (m_deletingRows) {
    mIndicesToNoteChange.AppendElements(selection);
  }

  nsCOMPtr<nsIMsgCopyService> copyService =
      do_GetService("@mozilla.org/messenger/messagecopyservice;1", &rv);
  NS_ENSURE_SUCCESS(rv, rv);

  return copyService->CopyMessages(m_folder /* source folder */, hdrs,
                                   destFolder, isMove, nullptr /* listener */,
                                   window, true /* allow Undo */);
}

nsresult nsMsgDBView::ApplyCommandToIndicesWithFolder(
    nsMsgViewCommandTypeValue command,
    nsTArray<nsMsgViewIndex> const& selection, nsIMsgFolder* destFolder) {
  nsresult rv = NS_OK;
  NS_ENSURE_ARG_POINTER(destFolder);

  nsCOMPtr<nsIMsgWindow> msgWindow(do_QueryReferent(mMsgWindowWeak));
  switch (command) {
    case nsMsgViewCommandType::copyMessages:
      NS_ASSERTION(!(m_folder == destFolder),
                   "The source folder and the destination folder are the same");
      if (m_folder != destFolder)
        rv = CopyMessages(msgWindow, selection, false /* isMove */, destFolder);

      break;
    case nsMsgViewCommandType::moveMessages:
      NS_ASSERTION(!(m_folder == destFolder),
                   "The source folder and the destination folder are the same");
      if (m_folder != destFolder)
        rv = CopyMessages(msgWindow, selection, true /* isMove */, destFolder);

      break;
    default:
      NS_ASSERTION(false, "unhandled command");
      rv = NS_ERROR_UNEXPECTED;
      break;
  }

  return rv;
}

NS_IMETHODIMP
nsMsgDBView::ApplyCommandToIndices(nsMsgViewCommandTypeValue command,
                                   nsTArray<nsMsgViewIndex> const& selection) {
  if (selection.IsEmpty()) {
    // Return quietly, just in case/
    return NS_OK;
  }

  nsCOMPtr<nsIMsgFolder> folder;
  nsresult rv = GetFolderForViewIndex(selection[0], getter_AddRefs(folder));
  nsCOMPtr<nsIMsgWindow> msgWindow(do_QueryReferent(mMsgWindowWeak));
  if (command == nsMsgViewCommandType::deleteMsg)
    return DeleteMessages(msgWindow, selection, false);

  if (command == nsMsgViewCommandType::deleteNoTrash)
    return DeleteMessages(msgWindow, selection, true);

  nsTArray<nsMsgKey> imapUids;
  nsCOMPtr<nsIMsgImapMailFolder> imapFolder = do_QueryInterface(folder);
  bool thisIsImapFolder = (imapFolder != nullptr);
  nsCOMPtr<nsIJunkMailPlugin> junkPlugin;

  // If this is a junk command, get the junk plugin.
  if (command == nsMsgViewCommandType::junk ||
      command == nsMsgViewCommandType::unjunk) {
    // Get the folder from the first item; we assume that
    // all messages in the view are from the same folder (no
    // more junk status column in the 'search messages' dialog
    // like in earlier versions...).
    nsCOMPtr<nsIMsgIncomingServer> server;
    rv = folder->GetServer(getter_AddRefs(server));
    NS_ENSURE_SUCCESS(rv, rv);

    nsCOMPtr<nsIMsgFilterPlugin> filterPlugin;
    rv = server->GetSpamFilterPlugin(getter_AddRefs(filterPlugin));
    NS_ENSURE_SUCCESS(rv, rv);

    junkPlugin = do_QueryInterface(filterPlugin, &rv);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  folder->EnableNotifications(nsIMsgFolder::allMessageCountNotifications,
                              false);

  // No sense going through the code that handles messages in collasped threads
  // for mark thread read.
  if (command == nsMsgViewCommandType::markThreadRead) {
    for (nsMsgViewIndex viewIndex : selection) {
      SetThreadOfMsgReadByIndex(viewIndex, imapUids, true);
    }
  } else {
    // Turn the selection into an array of msg hdrs. This may include messages
    // in collapsed threads
    AutoTArray<RefPtr<nsIMsgDBHdr>, 1> messages;
    rv = GetHeadersFromSelection(selection, messages);
    NS_ENSURE_SUCCESS(rv, rv);
    uint32_t length = messages.Length();

    if (thisIsImapFolder) {
      imapUids.SetLength(length);
    }

    for (uint32_t i = 0; i < length; i++) {
      nsMsgKey msgKey;
      nsCOMPtr<nsIMsgDBHdr> msgHdr(messages[i]);
      msgHdr->GetMessageKey(&msgKey);
      if (thisIsImapFolder) imapUids[i] = msgKey;

      switch (command) {
        case nsMsgViewCommandType::junk:
          mNumMessagesRemainingInBatch++;
          mJunkHdrs.AppendElement(msgHdr);
          rv = SetMsgHdrJunkStatus(junkPlugin.get(), msgHdr,
                                   nsIJunkMailPlugin::JUNK);
          break;
        case nsMsgViewCommandType::unjunk:
          mNumMessagesRemainingInBatch++;
          mJunkHdrs.AppendElement(msgHdr);
          rv = SetMsgHdrJunkStatus(junkPlugin.get(), msgHdr,
                                   nsIJunkMailPlugin::GOOD);
          break;
        case nsMsgViewCommandType::toggleMessageRead:
        case nsMsgViewCommandType::undeleteMsg:
        case nsMsgViewCommandType::markMessagesRead:
        case nsMsgViewCommandType::markMessagesUnread:
        case nsMsgViewCommandType::unflagMessages:
        case nsMsgViewCommandType::flagMessages:
          // This is completely handled in the code below.
          break;
        default:
          NS_ERROR("unhandled command");
          break;
      }
    }

    switch (command) {
      case nsMsgViewCommandType::toggleMessageRead: {
        if (messages.IsEmpty()) break;

        uint32_t msgFlags;
        messages[0]->GetFlags(&msgFlags);
        folder->MarkMessagesRead(messages,
                                 !(msgFlags & nsMsgMessageFlags::Read));
        break;
      }
      case nsMsgViewCommandType::markMessagesRead:
      case nsMsgViewCommandType::markMessagesUnread:
        folder->MarkMessagesRead(
            messages, command == nsMsgViewCommandType::markMessagesRead);
        break;
      case nsMsgViewCommandType::unflagMessages:
      case nsMsgViewCommandType::flagMessages:
        folder->MarkMessagesFlagged(
            messages, command == nsMsgViewCommandType::flagMessages);
        break;
      default:
        break;
    }

    // Provide junk-related batch notifications.
    if (command == nsMsgViewCommandType::junk ||
        command == nsMsgViewCommandType::unjunk) {
      nsCOMPtr<nsIMsgFolderNotificationService> notifier(
          do_GetService("@mozilla.org/messenger/msgnotificationservice;1"));
      if (notifier) {
        notifier->NotifyMsgsJunkStatusChanged(messages);
      }
    }
  }

  folder->EnableNotifications(nsIMsgFolder::allMessageCountNotifications, true);

  if (thisIsImapFolder) {
    imapMessageFlagsType flags = kNoImapMsgFlag;
    bool addFlags = false;
    nsCOMPtr<nsIMsgWindow> msgWindow(do_QueryReferent(mMsgWindowWeak));
    switch (command) {
      case nsMsgViewCommandType::markThreadRead:
        flags |= kImapMsgSeenFlag;
        addFlags = true;
        break;
      case nsMsgViewCommandType::undeleteMsg:
        flags = kImapMsgDeletedFlag;
        addFlags = false;
        break;
      case nsMsgViewCommandType::junk:
        return imapFolder->StoreCustomKeywords(msgWindow, "Junk"_ns,
                                               "NonJunk"_ns, imapUids, nullptr);
      case nsMsgViewCommandType::unjunk: {
        nsCOMPtr<nsIMsgDBHdr> msgHdr;
        GetHdrForFirstSelectedMessage(getter_AddRefs(msgHdr));
        uint32_t msgFlags = 0;
        if (msgHdr) msgHdr->GetFlags(&msgFlags);

        if (msgFlags & nsMsgMessageFlags::IMAPDeleted)
          imapFolder->StoreImapFlags(kImapMsgDeletedFlag, false, imapUids,
                                     nullptr);

        return imapFolder->StoreCustomKeywords(msgWindow, "NonJunk"_ns,
                                               "Junk"_ns, imapUids, nullptr);
      }
      default:
        break;
    }

    // Can't get here without thisIsImapThreadPane == TRUE.
    if (flags != kNoImapMsgFlag) {
      imapFolder->StoreImapFlags(flags, addFlags, imapUids, nullptr);
    }
  }

  return rv;
}

/**
 * View modifications methods by index.
 */

// This method just removes the specified line from the view. It does
// NOT delete it from the database.
nsresult nsMsgDBView::RemoveByIndex(nsMsgViewIndex index) {
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  m_keys.RemoveElementAt(index);
  m_flags.RemoveElementAt(index);
  m_levels.RemoveElementAt(index);

  // The call to NoteChange() has to happen after we remove the key as
  // NoteChange() will call RowCountChanged() which will call our GetRowCount().
  // An example where view is not the listener - D&D messages.
  if (!m_deletingRows)
    NoteChange(index, -1, nsMsgViewNotificationCode::insertOrDelete);

  return NS_OK;
}

nsresult nsMsgDBView::DeleteMessages(nsIMsgWindow* window,
                                     nsTArray<nsMsgViewIndex> const& selection,
                                     bool deleteStorage) {
  if (m_deletingRows) {
    NS_WARNING("Last delete did not complete");
    return NS_OK;
  }

  nsresult rv;
  AutoTArray<RefPtr<nsIMsgDBHdr>, 1> hdrs;
  rv = GetHeadersFromSelection(selection, hdrs);
  NS_ENSURE_SUCCESS(rv, rv);

  const char* warnCollapsedPref = "mail.warn_on_collapsed_thread_operation";
  const char* warnShiftDelPref = "mail.warn_on_shift_delete";
  const char* warnNewsPref = "news.warn_on_delete";
  const char* warnTrashDelPref = "mail.warn_on_delete_from_trash";
  const char* activePref = nullptr;
  nsString warningName;
  nsCOMPtr<nsIPrefBranch> prefBranch(
      do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
  NS_ENSURE_SUCCESS(rv, rv);

  bool trashFolder = false;
  rv = m_folder->GetFlag(nsMsgFolderFlags::Trash, &trashFolder);
  NS_ENSURE_SUCCESS(rv, rv);

  if (trashFolder) {
    bool pref = false;
    prefBranch->GetBoolPref(warnTrashDelPref, &pref);
    if (pref) {
      activePref = warnTrashDelPref;
      warningName.AssignLiteral("confirmMsgDelete.deleteFromTrash.desc");
    }
  }

  if (!activePref && (selection.Length() != hdrs.Length())) {
    bool pref = false;
    prefBranch->GetBoolPref(warnCollapsedPref, &pref);
    if (pref) {
      activePref = warnCollapsedPref;
      warningName.AssignLiteral("confirmMsgDelete.collapsed.desc");
    }
  }

  if (!activePref && deleteStorage && !trashFolder) {
    bool pref = false;
    prefBranch->GetBoolPref(warnShiftDelPref, &pref);
    if (pref) {
      activePref = warnShiftDelPref;
      warningName.AssignLiteral("confirmMsgDelete.deleteNoTrash.desc");
    }
  }

  if (!activePref && mIsNews) {
    bool pref = false;
    prefBranch->GetBoolPref(warnNewsPref, &pref);
    if (pref) {
      activePref = warnNewsPref;
      warningName.AssignLiteral("confirmMsgDelete.deleteNoTrash.desc");
    }
  }

  if (activePref) {
    nsCOMPtr<nsIPrompt> dialog;

    nsCOMPtr<nsIWindowWatcher> wwatch(
        do_GetService(NS_WINDOWWATCHER_CONTRACTID, &rv));
    NS_ENSURE_SUCCESS(rv, rv);

    rv = wwatch->GetNewPrompter(0, getter_AddRefs(dialog));
    NS_ENSURE_SUCCESS(rv, rv);
    // "Don't ask..." - unchecked by default.
    bool dontAsk = false;
    int32_t buttonPressed = 0;

    nsString dialogTitle;
    nsString confirmString;
    nsString checkboxText;
    nsString buttonApplyNowText;
    GetString(u"confirmMsgDelete.title", dialogTitle);
    GetString(u"confirmMsgDelete.dontAsk.label", checkboxText);
    GetString(u"confirmMsgDelete.delete.label", buttonApplyNowText);

    GetString(warningName.get(), confirmString);

    const uint32_t buttonFlags =
        (nsIPrompt::BUTTON_TITLE_IS_STRING * nsIPrompt::BUTTON_POS_0) +
        (nsIPrompt::BUTTON_TITLE_CANCEL * nsIPrompt::BUTTON_POS_1);

    rv = dialog->ConfirmEx(dialogTitle.get(), confirmString.get(), buttonFlags,
                           buttonApplyNowText.get(), nullptr, nullptr,
                           checkboxText.get(), &dontAsk, &buttonPressed);
    NS_ENSURE_SUCCESS(rv, rv);
    if (buttonPressed) return NS_ERROR_FAILURE;

    if (dontAsk) prefBranch->SetBoolPref(activePref, false);
  }

  if (!deleteStorage) {
    rv = m_folder->MarkMessagesRead(hdrs, true);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  if (mDeleteModel != nsMsgImapDeleteModels::IMAPDelete) {
    m_deletingRows = true;
  }

  if (m_deletingRows) {
    mIndicesToNoteChange.AppendElements(selection);
  }

  rv = m_folder->DeleteMessages(hdrs, window, deleteStorage, false, nullptr,
                                true /* allow Undo */);
  if (NS_FAILED(rv)) {
    m_deletingRows = false;
  }

  return rv;
}

nsresult nsMsgDBView::DownloadForOffline(
    nsIMsgWindow* window, nsTArray<nsMsgViewIndex> const& selection) {
  nsresult rv = NS_OK;
  nsTArray<RefPtr<nsIMsgDBHdr>> messages;
  for (nsMsgViewIndex viewIndex : selection) {
    nsMsgKey key = m_keys[viewIndex];
    nsCOMPtr<nsIMsgDBHdr> msgHdr;
    rv = m_db->GetMsgHdrForKey(key, getter_AddRefs(msgHdr));
    NS_ENSURE_SUCCESS(rv, rv);
    if (msgHdr) {
      uint32_t flags;
      msgHdr->GetFlags(&flags);
      if (!(flags & nsMsgMessageFlags::Offline)) {
        messages.AppendElement(msgHdr);
      }
    }
  }

  m_folder->DownloadMessagesForOffline(messages, window);
  return rv;
}

nsresult nsMsgDBView::DownloadFlaggedForOffline(nsIMsgWindow* window) {
  nsresult rv = NS_OK;
  nsTArray<RefPtr<nsIMsgDBHdr>> messages;
  nsCOMPtr<nsIMsgEnumerator> enumerator;
  rv = GetMessageEnumerator(getter_AddRefs(enumerator));
  if (NS_SUCCEEDED(rv) && enumerator) {
    bool hasMore;
    while (NS_SUCCEEDED(rv = enumerator->HasMoreElements(&hasMore)) &&
           hasMore) {
      nsCOMPtr<nsIMsgDBHdr> header;
      rv = enumerator->GetNext(getter_AddRefs(header));
      if (header && NS_SUCCEEDED(rv)) {
        uint32_t flags;
        header->GetFlags(&flags);
        if ((flags & nsMsgMessageFlags::Marked) &&
            !(flags & nsMsgMessageFlags::Offline)) {
          messages.AppendElement(header);
        }
      }
    }
  }

  m_folder->DownloadMessagesForOffline(messages, window);
  return rv;
}

// Read/unread handling.
nsresult nsMsgDBView::ToggleReadByIndex(nsMsgViewIndex index) {
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  return SetReadByIndex(index, !(m_flags[index] & nsMsgMessageFlags::Read));
}

nsresult nsMsgDBView::SetReadByIndex(nsMsgViewIndex index, bool read) {
  nsresult rv;

  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  if (read) {
    OrExtraFlag(index, nsMsgMessageFlags::Read);
    // MarkRead() will clear this flag in the db and then call OnKeyChange(),
    // but because we are the instigator of the change we'll ignore the change.
    // So we need to clear it in m_flags to keep the db and m_flags in sync.
    AndExtraFlag(index, ~nsMsgMessageFlags::New);
  } else {
    AndExtraFlag(index, ~nsMsgMessageFlags::Read);
  }

  nsCOMPtr<nsIMsgDatabase> dbToUse;
  rv = GetDBForViewIndex(index, getter_AddRefs(dbToUse));
  NS_ENSURE_SUCCESS(rv, rv);

  rv = dbToUse->MarkRead(m_keys[index], read, this);
  NoteChange(index, 1, nsMsgViewNotificationCode::changed);
  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) {
    nsMsgViewIndex threadIndex = GetThreadIndex(index);
    if (threadIndex != index)
      NoteChange(threadIndex, 1, nsMsgViewNotificationCode::changed);
  }

  return rv;
}

nsresult nsMsgDBView::SetThreadOfMsgReadByIndex(
    nsMsgViewIndex index, nsTArray<nsMsgKey>& keysMarkedRead, bool /*read*/) {
  nsresult rv;

  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  rv = MarkThreadOfMsgRead(m_keys[index], index, keysMarkedRead, true);
  return rv;
}

nsresult nsMsgDBView::SetFlaggedByIndex(nsMsgViewIndex index, bool mark) {
  nsresult rv;

  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  nsCOMPtr<nsIMsgDatabase> dbToUse;
  rv = GetDBForViewIndex(index, getter_AddRefs(dbToUse));
  NS_ENSURE_SUCCESS(rv, rv);

  if (mark)
    OrExtraFlag(index, nsMsgMessageFlags::Marked);
  else
    AndExtraFlag(index, ~nsMsgMessageFlags::Marked);

  rv = dbToUse->MarkMarked(m_keys[index], mark, this);
  NoteChange(index, 1, nsMsgViewNotificationCode::changed);
  return rv;
}

nsresult nsMsgDBView::SetMsgHdrJunkStatus(nsIJunkMailPlugin* aJunkPlugin,
                                          nsIMsgDBHdr* aMsgHdr,
                                          nsMsgJunkStatus aNewClassification) {
  // Get the old junk score.
  nsCString junkScoreStr;
  nsresult rv = aMsgHdr->GetStringProperty("junkscore", junkScoreStr);

  // And the old origin.
  nsCString oldOriginStr;
  rv = aMsgHdr->GetStringProperty("junkscoreorigin", oldOriginStr);

  // If this was not classified by the user, say so.
  nsMsgJunkStatus oldUserClassification;
  if (oldOriginStr.get()[0] != 'u') {
    oldUserClassification = nsIJunkMailPlugin::UNCLASSIFIED;
  } else {
    // Otherwise, pass the actual user classification.
    if (junkScoreStr.IsEmpty())
      oldUserClassification = nsIJunkMailPlugin::UNCLASSIFIED;
    else if (junkScoreStr.ToInteger(&rv) == nsIJunkMailPlugin::IS_SPAM_SCORE)
      oldUserClassification = nsIJunkMailPlugin::JUNK;
    else
      oldUserClassification = nsIJunkMailPlugin::GOOD;

    NS_ASSERTION(NS_SUCCEEDED(rv), "Converting junkScore to integer failed.");
  }

  // Get the URI for this message so we can pass it to the plugin.
  nsCString uri;
  nsMsgKey msgKey;
  nsCOMPtr<nsIMsgFolder> folder;
  nsCOMPtr<nsIMsgDatabase> db;
  aMsgHdr->GetMessageKey(&msgKey);
  rv = aMsgHdr->GetFolder(getter_AddRefs(folder));
  NS_ENSURE_SUCCESS(rv, rv);
  GenerateURIForMsgKey(msgKey, folder, uri);
  NS_ENSURE_SUCCESS(rv, rv);
  rv = folder->GetMsgDatabase(getter_AddRefs(db));
  NS_ENSURE_SUCCESS(rv, rv);

  // Tell the plugin about this change, so that it can (potentially)
  // adjust its database appropriately.
  nsCOMPtr<nsIMsgWindow> msgWindow(do_QueryReferent(mMsgWindowWeak));
  rv = aJunkPlugin->SetMessageClassification(
      uri, oldUserClassification, aNewClassification, msgWindow, this);
  NS_ENSURE_SUCCESS(rv, rv);

  // This routine is only reached if the user someone touched the UI
  // and told us the junk status of this message.
  // Set origin first so that listeners on the junkscore will
  // know the correct origin.
  rv = db->SetStringProperty(msgKey, "junkscoreorigin", "user"_ns);
  NS_ASSERTION(NS_SUCCEEDED(rv), "SetStringPropertyByIndex failed");

  // Set the junk score on the message itself.
  nsAutoCString msgJunkScore;
  msgJunkScore.AppendInt(aNewClassification == nsIJunkMailPlugin::JUNK
                             ? nsIJunkMailPlugin::IS_SPAM_SCORE
                             : nsIJunkMailPlugin::IS_HAM_SCORE);
  db->SetStringProperty(msgKey, "junkscore", msgJunkScore);
  NS_ENSURE_SUCCESS(rv, rv);

  return rv;
}

nsresult nsMsgDBView::GetFolderFromMsgURI(const nsACString& aMsgURI,
                                          nsIMsgFolder** aFolder) {
  NS_IF_ADDREF(*aFolder = m_folder);
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::OnMessageClassified(const nsACString& aMsgURI,
                                 nsMsgJunkStatus aClassification,
                                 uint32_t aJunkPercent)

{
  // Note: we know all messages in a batch have the same
  // classification, since unlike OnMessageClassified
  // methods in other classes (such as nsLocalMailFolder
  // and nsImapMailFolder), this class, nsMsgDBView, currently
  // only triggers message classifications due to a command to
  // mark some of the messages in the view as junk, or as not
  // junk - so the classification is dictated to the filter,
  // not suggested by it.
  //
  // For this reason the only thing we (may) have to do is
  // perform the action on all of the junk messages.

  uint32_t numJunk = mJunkHdrs.Length();
  NS_ASSERTION(aClassification == nsIJunkMailPlugin::GOOD || numJunk,
               "the classification of a manually-marked junk message has "
               "been classified as junk, yet there seem to be no such "
               "outstanding messages");

  // Is this the last message in the batch?
  if (--mNumMessagesRemainingInBatch == 0 && numJunk > 0) {
    PerformActionsOnJunkMsgs(aClassification == nsIJunkMailPlugin::JUNK);
    mJunkHdrs.Clear();
  }

  return NS_OK;
}

nsresult nsMsgDBView::PerformActionsOnJunkMsgs(bool msgsAreJunk) {
  uint32_t numJunkHdrs = mJunkHdrs.Length();
  if (!numJunkHdrs) {
    NS_ERROR("no indices of marked-as-junk messages to act on");
    return NS_OK;
  }

  nsCOMPtr<nsIMsgFolder> srcFolder;
  mJunkHdrs[0]->GetFolder(getter_AddRefs(srcFolder));

  bool moveMessages, changeReadState;
  nsCOMPtr<nsIMsgFolder> targetFolder;

  nsresult rv = DetermineActionsForJunkChange(msgsAreJunk, srcFolder,
                                              moveMessages, changeReadState,
                                              getter_AddRefs(targetFolder));
  NS_ENSURE_SUCCESS(rv, rv);

  // Nothing to do, bail out.
  if (!(moveMessages || changeReadState)) return NS_OK;

  if (changeReadState) {
    // Notes on marking junk as read:
    // 1. There are 2 occasions on which junk messages are marked as
    //    read: after a manual marking (here and in the front end) and after
    //    automatic classification by the bayesian filter (see code for local
    //    mail folders and for imap mail folders). The server-specific
    //    markAsReadOnSpam pref only applies to the latter, the former is
    //    controlled by "mailnews.ui.junk.manualMarkAsJunkMarksRead".
    // 2. Even though move/delete on manual mark may be
    //    turned off, we might still need to mark as read.

    rv = srcFolder->MarkMessagesRead(mJunkHdrs, msgsAreJunk);
    NoteChange(0, 0, nsMsgViewNotificationCode::none);
    NS_ASSERTION(NS_SUCCEEDED(rv),
                 "marking marked-as-junk messages as read failed");
  }

  if (moveMessages) {
    // Check if one of the messages to be junked is actually selected.
    // If more than one message being junked, one must be selected.
    // If no tree selection at all, must be in stand-alone message window.
    bool junkedMsgSelected = numJunkHdrs > 1 || !mTreeSelection;
    for (nsMsgViewIndex junkIndex = 0;
         !junkedMsgSelected && junkIndex < numJunkHdrs; junkIndex++) {
      nsMsgViewIndex hdrIndex = FindHdr(mJunkHdrs[junkIndex]);
      if (hdrIndex != nsMsgViewIndex_None)
        mTreeSelection->IsSelected(hdrIndex, &junkedMsgSelected);
    }

    // If a junked msg is selected, tell the FE to call
    // SetNextMessageAfterDelete() because a delete is coming.
    if (junkedMsgSelected) {
      nsCOMPtr<nsIMsgDBViewCommandUpdater> commandUpdater(
          do_QueryReferent(mCommandUpdater));
      if (commandUpdater) {
        rv = commandUpdater->UpdateNextMessageAfterDelete();
        NS_ENSURE_SUCCESS(rv, rv);
      }
    }

    nsCOMPtr<nsIMsgWindow> msgWindow(do_QueryReferent(mMsgWindowWeak));
    if (targetFolder) {
      nsCOMPtr<nsIMsgCopyService> copyService =
          do_GetService("@mozilla.org/messenger/messagecopyservice;1", &rv);
      NS_ENSURE_SUCCESS(rv, rv);

      rv = copyService->CopyMessages(srcFolder, mJunkHdrs, targetFolder, true,
                                     nullptr, msgWindow, true);
    } else if (msgsAreJunk) {
      if (mDeleteModel == nsMsgImapDeleteModels::IMAPDelete) {
        // Unfortunately the DeleteMessages in this case is interpreted by
        // IMAP as a delete toggle. So what we have to do is to assemble a
        // new delete array, keeping only those that are not deleted.
        nsTArray<RefPtr<nsIMsgDBHdr>> hdrsToDelete;
        for (nsIMsgDBHdr* msgHdr : mJunkHdrs) {
          if (msgHdr) {
            uint32_t flags;
            msgHdr->GetFlags(&flags);
            if (!(flags & nsMsgMessageFlags::IMAPDeleted)) {
              hdrsToDelete.AppendElement(msgHdr);
            }
          }
        }

        if (!hdrsToDelete.IsEmpty())
          rv = srcFolder->DeleteMessages(hdrsToDelete, msgWindow, false, false,
                                         nullptr, true);
      } else {
        rv = srcFolder->DeleteMessages(mJunkHdrs, msgWindow, false, false,
                                       nullptr, true);
      }
    } else if (mDeleteModel == nsMsgImapDeleteModels::IMAPDelete) {
      nsCOMPtr<nsIMsgImapMailFolder> imapFolder(do_QueryInterface(srcFolder));
      nsTArray<nsMsgKey> imapUids(numJunkHdrs);
      for (nsIMsgDBHdr* msgHdr : mJunkHdrs) {
        nsMsgKey key;
        msgHdr->GetMessageKey(&key);
        imapUids.AppendElement(key);
      }

      imapFolder->StoreImapFlags(kImapMsgDeletedFlag, false, imapUids, nullptr);
    }

    NoteChange(0, 0, nsMsgViewNotificationCode::none);

    NS_ASSERTION(NS_SUCCEEDED(rv),
                 "move or deletion of message marked-as-junk/non junk failed");
  }

  return rv;
}

nsresult nsMsgDBView::DetermineActionsForJunkChange(
    bool msgsAreJunk, nsIMsgFolder* srcFolder, bool& moveMessages,
    bool& changeReadState, nsIMsgFolder** targetFolder) {
  // There are two possible actions which may be performed
  // on messages marked as spam: marking as read and moving
  // somewhere. When a message is marked as non junk,
  // it may be moved to the inbox, and marked unread.
  moveMessages = false;
  changeReadState = false;

  // The 'somewhere', junkTargetFolder, can be a folder,
  // but if it remains null we'll delete the messages.
  *targetFolder = nullptr;

  uint32_t folderFlags;
  srcFolder->GetFlags(&folderFlags);

  nsCOMPtr<nsIMsgIncomingServer> server;
  nsresult rv = srcFolder->GetServer(getter_AddRefs(server));
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIPrefBranch> prefBranch(
      do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
  NS_ENSURE_SUCCESS(rv, rv);

  // Handle the easy case of marking a junk message as good first.
  // Set the move target folder to the inbox, if any.
  if (!msgsAreJunk) {
    if (folderFlags & nsMsgFolderFlags::Junk) {
      prefBranch->GetBoolPref("mail.spam.markAsNotJunkMarksUnRead",
                              &changeReadState);
      nsCOMPtr<nsIMsgFolder> rootMsgFolder;
      rv = server->GetRootMsgFolder(getter_AddRefs(rootMsgFolder));
      NS_ENSURE_SUCCESS(rv, rv);
      rootMsgFolder->GetFolderWithFlags(nsMsgFolderFlags::Inbox, targetFolder);
      moveMessages = *targetFolder != nullptr;
    }

    return NS_OK;
  }

  nsCOMPtr<nsISpamSettings> spamSettings;
  rv = server->GetSpamSettings(getter_AddRefs(spamSettings));
  NS_ENSURE_SUCCESS(rv, rv);

  // When the user explicitly marks a message as junk, we can mark it as read,
  // too. This is independent of the "markAsReadOnSpam" pref, which applies
  // only to automatically-classified messages.
  // Note that this behaviour should match the one in the front end for marking
  // as junk via toolbar/context menu.
  prefBranch->GetBoolPref("mailnews.ui.junk.manualMarkAsJunkMarksRead",
                          &changeReadState);

  // Now let's determine whether we'll be taking the second action,
  // the move / deletion (and also determine which of these two).
  bool manualMark;
  (void)spamSettings->GetManualMark(&manualMark);
  if (!manualMark) return NS_OK;

  int32_t manualMarkMode;
  (void)spamSettings->GetManualMarkMode(&manualMarkMode);
  NS_ASSERTION(manualMarkMode == nsISpamSettings::MANUAL_MARK_MODE_MOVE ||
                   manualMarkMode == nsISpamSettings::MANUAL_MARK_MODE_DELETE,
               "bad manual mark mode");

  if (manualMarkMode == nsISpamSettings::MANUAL_MARK_MODE_MOVE) {
    // If this is a junk folder (not only "the" junk folder for this account)
    // don't do the move.
    if (folderFlags & nsMsgFolderFlags::Junk) return NS_OK;

    nsCString spamFolderURI;
    rv = spamSettings->GetSpamFolderURI(spamFolderURI);
    NS_ENSURE_SUCCESS(rv, rv);

    NS_ASSERTION(!spamFolderURI.IsEmpty(),
                 "spam folder URI is empty, can't move");
    if (!spamFolderURI.IsEmpty()) {
      rv = FindFolder(spamFolderURI, targetFolder);
      NS_ENSURE_SUCCESS(rv, rv);
      if (*targetFolder) {
        moveMessages = true;
      } else {
        // XXX TODO: GetOrCreateJunkFolder will only create a folder with
        // localized name "Junk" regardless of spamFolderURI. So if someone
        // sets the junk folder to an existing folder of a different name,
        // then deletes that folder, this will fail to create the correct
        // folder.
        rv = GetOrCreateJunkFolder(spamFolderURI, nullptr /* aListener */);
        if (NS_SUCCEEDED(rv))
          rv = GetExistingFolder(spamFolderURI, targetFolder);

        NS_ASSERTION(NS_SUCCEEDED(rv), "GetOrCreateJunkFolder failed");
      }
    }

    return NS_OK;
  }

  // At this point manualMarkMode == nsISpamSettings::MANUAL_MARK_MODE_DELETE).

  // If this is in the trash, let's not delete.
  if (folderFlags & nsMsgFolderFlags::Trash) return NS_OK;

  return srcFolder->GetCanDeleteMessages(&moveMessages);
}

// Reversing threads involves reversing the threads but leaving the
// expanded messages ordered relative to the thread, so we
// make a copy of each array and copy them over.
void nsMsgDBView::ReverseThreads() {
  nsTArray<uint32_t> newFlagArray;
  nsTArray<nsMsgKey> newKeyArray;
  nsTArray<uint8_t> newLevelArray;

  uint32_t viewSize = GetSize();
  uint32_t startThread = viewSize;
  uint32_t nextThread = viewSize;
  uint32_t destIndex = 0;

  newKeyArray.SetLength(m_keys.Length());
  newFlagArray.SetLength(m_flags.Length());
  newLevelArray.SetLength(m_levels.Length());

  while (startThread) {
    startThread--;

    if (m_flags[startThread] & MSG_VIEW_FLAG_ISTHREAD) {
      for (uint32_t sourceIndex = startThread; sourceIndex < nextThread;
           sourceIndex++) {
        newKeyArray[destIndex] = m_keys[sourceIndex];
        newFlagArray[destIndex] = m_flags[sourceIndex];
        newLevelArray[destIndex] = m_levels[sourceIndex];
        destIndex++;
      }
      // Because we're copying in reverse order.
      nextThread = startThread;
    }
  }

  m_keys.SwapElements(newKeyArray);
  m_flags.SwapElements(newFlagArray);
  m_levels.SwapElements(newLevelArray);
}

void nsMsgDBView::ReverseSort() {
  uint32_t topIndex = GetSize();

  nsCOMArray<nsIMsgFolder>* folders = GetFolders();

  // Go up half the array swapping values.
  for (uint32_t bottomIndex = 0; bottomIndex < --topIndex; bottomIndex++) {
    // Swap flags.
    uint32_t tempFlags = m_flags[bottomIndex];
    m_flags[bottomIndex] = m_flags[topIndex];
    m_flags[topIndex] = tempFlags;

    // Swap keys.
    nsMsgKey tempKey = m_keys[bottomIndex];
    m_keys[bottomIndex] = m_keys[topIndex];
    m_keys[topIndex] = tempKey;

    if (folders) {
      // Swap folders -- needed when search is done across multiple folders.
      nsIMsgFolder* bottomFolder = folders->ObjectAt(bottomIndex);
      nsIMsgFolder* topFolder = folders->ObjectAt(topIndex);
      folders->ReplaceObjectAt(topFolder, bottomIndex);
      folders->ReplaceObjectAt(bottomFolder, topIndex);
    }

    // No need to swap elements in m_levels; since we only call
    // ReverseSort in non-threaded mode, m_levels are all the same.
  }
}

int nsMsgDBView::FnSortIdKey(const IdKey* pItem1, const IdKey* pItem2,
                             viewSortInfo* sortInfo) {
  int32_t retVal = 0;

  nsIMsgDatabase* db = sortInfo->db;

  mozilla::DebugOnly<nsresult> rv =
      db->CompareCollationKeys(pItem1->key, pItem2->key, &retVal);
  NS_ASSERTION(NS_SUCCEEDED(rv), "compare failed");

  if (retVal) return sortInfo->ascendingSort ? retVal : -retVal;

  return sortInfo->view->SecondaryCompare(pItem1->id, pItem1->folder,
                                          pItem2->id, pItem2->folder, sortInfo);
}

int nsMsgDBView::FnSortIdUint32(const IdUint32* pItem1, const IdUint32* pItem2,
                                viewSortInfo* sortInfo) {
  if (pItem1->dword > pItem2->dword) {
    return (sortInfo->ascendingSort) ? 1 : -1;
  }

  if (pItem1->dword < pItem2->dword) {
    return (sortInfo->ascendingSort) ? -1 : 1;
  }

  return sortInfo->view->SecondaryCompare(pItem1->id, pItem1->folder,
                                          pItem2->id, pItem2->folder, sortInfo);
}

// XXX are these still correct?
// To compensate for memory alignment required for systems such as HP-UX, these
// values must be 4 bytes aligned. Don't break this when modifying the
// constants.
const int kMaxSubjectKey = 160;
const int kMaxLocationKey = 160;  // Also used for account.
const int kMaxAuthorKey = 160;
const int kMaxRecipientKey = 80;

// There are cases when pFieldType is not set:
// one case returns NS_ERROR_UNEXPECTED;
// the other case now return NS_ERROR_NULL_POINTER (this is only when
// colHandler below is null, but is very unlikely).
// The latter case used to return NS_OK, which was incorrect.
nsresult nsMsgDBView::GetFieldTypeAndLenForSort(
    nsMsgViewSortTypeValue sortType, uint16_t* pMaxLen, eFieldType* pFieldType,
    nsIMsgCustomColumnHandler* colHandler) {
  NS_ENSURE_ARG_POINTER(pMaxLen);
  NS_ENSURE_ARG_POINTER(pFieldType);

  switch (sortType) {
    case nsMsgViewSortType::bySubject:
      *pFieldType = kCollationKey;
      *pMaxLen = kMaxSubjectKey;
      break;
    case nsMsgViewSortType::byAccount:
    case nsMsgViewSortType::byTags:
    case nsMsgViewSortType::byLocation:
      *pFieldType = kCollationKey;
      *pMaxLen = kMaxLocationKey;
      break;
    case nsMsgViewSortType::byRecipient:
    case nsMsgViewSortType::byCorrespondent:
      *pFieldType = kCollationKey;
      *pMaxLen = kMaxRecipientKey;
      break;
    case nsMsgViewSortType::byAuthor:
      *pFieldType = kCollationKey;
      *pMaxLen = kMaxAuthorKey;
      break;
    case nsMsgViewSortType::byDate:
    case nsMsgViewSortType::byReceived:
    case nsMsgViewSortType::byPriority:
    case nsMsgViewSortType::byThread:
    case nsMsgViewSortType::byId:
    case nsMsgViewSortType::bySize:
    case nsMsgViewSortType::byFlagged:
    case nsMsgViewSortType::byUnread:
    case nsMsgViewSortType::byStatus:
    case nsMsgViewSortType::byJunkStatus:
    case nsMsgViewSortType::byAttachments:
      *pFieldType = kU32;
      *pMaxLen = 0;
      break;
    case nsMsgViewSortType::byCustom: {
      if (colHandler == nullptr) {
        NS_WARNING("colHandler is null. *pFieldType is not set.");
        return NS_ERROR_NULL_POINTER;
      }

      bool isString;
      colHandler->IsString(&isString);

      if (isString) {
        *pFieldType = kCollationKey;
        // 80 - do we need a separate k?
        *pMaxLen = kMaxRecipientKey;
      } else {
        *pFieldType = kU32;
        *pMaxLen = 0;
      }
      break;
    }
    case nsMsgViewSortType::byNone:
      // Bug 901948.
      return NS_ERROR_INVALID_ARG;
    default: {
      nsAutoCString message("unexpected switch value: sortType=");
      message.AppendInt(sortType);
      NS_WARNING(message.get());
      return NS_ERROR_UNEXPECTED;
    }
  }

  return NS_OK;
}

#define MSG_STATUS_MASK \
  (nsMsgMessageFlags::Replied | nsMsgMessageFlags::Forwarded)

nsresult nsMsgDBView::GetStatusSortValue(nsIMsgDBHdr* msgHdr,
                                         uint32_t* result) {
  NS_ENSURE_ARG_POINTER(msgHdr);
  NS_ENSURE_ARG_POINTER(result);

  uint32_t messageFlags;
  nsresult rv = msgHdr->GetFlags(&messageFlags);
  NS_ENSURE_SUCCESS(rv, rv);

  if (messageFlags & nsMsgMessageFlags::New) {
    // Happily, new by definition stands alone.
    *result = 0;
    return NS_OK;
  }

  switch (messageFlags & MSG_STATUS_MASK) {
    case nsMsgMessageFlags::Replied:
      *result = 2;
      break;
    case nsMsgMessageFlags::Forwarded | nsMsgMessageFlags::Replied:
      *result = 1;
      break;
    case nsMsgMessageFlags::Forwarded:
      *result = 3;
      break;
    default:
      *result = (messageFlags & nsMsgMessageFlags::Read) ? 4 : 5;
      break;
  }

  return NS_OK;
}

nsresult nsMsgDBView::GetLongField(nsIMsgDBHdr* msgHdr,
                                   nsMsgViewSortTypeValue sortType,
                                   uint32_t* result,
                                   nsIMsgCustomColumnHandler* colHandler) {
  nsresult rv;
  NS_ENSURE_ARG_POINTER(msgHdr);
  NS_ENSURE_ARG_POINTER(result);

  bool isRead;
  uint32_t bits;

  switch (sortType) {
    case nsMsgViewSortType::bySize:
      rv = (mShowSizeInLines) ? msgHdr->GetLineCount(result)
                              : msgHdr->GetMessageSize(result);
      break;
    case nsMsgViewSortType::byPriority:
      nsMsgPriorityValue priority;
      rv = msgHdr->GetPriority(&priority);
      // Treat "none" as "normal" when sorting.
      if (priority == nsMsgPriority::none) priority = nsMsgPriority::normal;

      // We want highest priority to have lowest value
      // so ascending sort will have highest priority first.
      *result = nsMsgPriority::highest - priority;
      break;
    case nsMsgViewSortType::byStatus:
      rv = GetStatusSortValue(msgHdr, result);
      break;
    case nsMsgViewSortType::byFlagged:
      bits = 0;
      rv = msgHdr->GetFlags(&bits);
      // Make flagged come out on top.
      *result = !(bits & nsMsgMessageFlags::Marked);
      break;
    case nsMsgViewSortType::byUnread:
      rv = msgHdr->GetIsRead(&isRead);
      if (NS_SUCCEEDED(rv)) *result = !isRead;

      break;
    case nsMsgViewSortType::byJunkStatus: {
      nsCString junkScoreStr;
      rv = msgHdr->GetStringProperty("junkscore", junkScoreStr);
      // Unscored messages should come before messages that are scored
      // junkScoreStr is "", and "0" - "100"; normalize to 0 - 101.
      *result = junkScoreStr.IsEmpty() ? (0) : atoi(junkScoreStr.get()) + 1;
      break;
    }
    case nsMsgViewSortType::byAttachments:
      bits = 0;
      rv = msgHdr->GetFlags(&bits);
      *result = !(bits & nsMsgMessageFlags::Attachment);
      break;
    case nsMsgViewSortType::byDate:
      // When sorting threads by date, we may want the date of the newest msg
      // in the thread.
      if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay &&
          !(m_viewFlags & nsMsgViewFlagsType::kGroupBySort) &&
          !mSortThreadsByRoot) {
        nsCOMPtr<nsIMsgThread> thread;
        rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(thread));
        if (NS_SUCCEEDED(rv)) {
          thread->GetNewestMsgDate(result);
          break;
        }
      }
      rv = msgHdr->GetDateInSeconds(result);
      break;
    case nsMsgViewSortType::byReceived:
      // When sorting threads by received date, we may want the received date
      // of the newest msg in the thread.
      if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay &&
          !(m_viewFlags & nsMsgViewFlagsType::kGroupBySort) &&
          !mSortThreadsByRoot) {
        nsCOMPtr<nsIMsgThread> thread;
        rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(thread));
        NS_ENSURE_SUCCESS(rv, rv);
        thread->GetNewestMsgDate(result);
      } else {
        // Already in seconds.
        rv = msgHdr->GetUint32Property("dateReceived", result);
        if (*result == 0)
          // Use Date instead, we have no Received property
          rv = msgHdr->GetDateInSeconds(result);
      }
      break;
    case nsMsgViewSortType::byCustom:
      if (colHandler != nullptr) {
        colHandler->GetSortLongForRow(msgHdr, result);
        rv = NS_OK;
      } else {
        NS_ASSERTION(false,
                     "should not be here (Sort Type: byCustom (Long), but no "
                     "custom handler)");
        rv = NS_ERROR_UNEXPECTED;
      }
      break;
    case nsMsgViewSortType::byNone:
      // Bug 901948.
      return NS_ERROR_INVALID_ARG;

    case nsMsgViewSortType::byId:
      // Handled by caller, since caller knows the key.
    default:
      NS_ERROR("should not be here");
      rv = NS_ERROR_UNEXPECTED;
      break;
  }

  NS_ENSURE_SUCCESS(rv, rv);
  return NS_OK;
}

MsgViewSortColumnInfo::MsgViewSortColumnInfo(
    const MsgViewSortColumnInfo& other) {
  mSortType = other.mSortType;
  mSortOrder = other.mSortOrder;
  mCustomColumnName = other.mCustomColumnName;
  mColHandler = other.mColHandler;
}

bool MsgViewSortColumnInfo::operator==(
    const MsgViewSortColumnInfo& other) const {
  return (mSortType == nsMsgViewSortType::byCustom)
             ? mCustomColumnName.Equals(other.mCustomColumnName)
             : mSortType == other.mSortType;
}

nsresult nsMsgDBView::EncodeColumnSort(nsString& columnSortString) {
  for (uint32_t i = 0; i < m_sortColumns.Length(); i++) {
    MsgViewSortColumnInfo& sortInfo = m_sortColumns[i];
    columnSortString.Append((char)sortInfo.mSortType);
    columnSortString.Append((char)sortInfo.mSortOrder + '0');
    if (sortInfo.mSortType == nsMsgViewSortType::byCustom) {
      columnSortString.Append(sortInfo.mCustomColumnName);
      columnSortString.Append((char16_t)'\r');
    }
  }

  return NS_OK;
}

nsresult nsMsgDBView::DecodeColumnSort(nsString& columnSortString) {
  const char16_t* stringPtr = columnSortString.BeginReading();
  while (*stringPtr) {
    MsgViewSortColumnInfo sortColumnInfo;
    sortColumnInfo.mSortType = (nsMsgViewSortTypeValue)*stringPtr++;
    sortColumnInfo.mSortOrder = (nsMsgViewSortOrderValue)(*stringPtr++) - '0';
    if (sortColumnInfo.mSortType == nsMsgViewSortType::byCustom) {
      while (*stringPtr && *stringPtr != '\r')
        sortColumnInfo.mCustomColumnName.Append(*stringPtr++);

      sortColumnInfo.mColHandler =
          GetColumnHandler(sortColumnInfo.mCustomColumnName);

      // Advance past '\r'.
      if (*stringPtr) stringPtr++;
    }

    m_sortColumns.AppendElement(sortColumnInfo);
  }

  return NS_OK;
}

//  Secondary Sort Key: when you select a column to sort, that
//  becomes the new Primary sort key, and all previous sort keys
//  become secondary. For example, if you first click on Date,
//  the messages are sorted by Date; then click on From, and now the
//  messages are sorted by From, and for each value of From the
//  messages are in Date order.

void nsMsgDBView::PushSort(const MsgViewSortColumnInfo& newSort) {
  // Handle byNone (bug 901948) ala a mail/base/modules/DBViewerWrapper.jsm
  // where we don't push the secondary sort type if it's ::byNone;
  // (and secondary sort type is NOT the same as the first sort type
  // there). This code should behave the same way.

  // We don't expect to be passed sort type ::byNone,
  // but if we are it's safe to ignore it.
  if (newSort.mSortType == nsMsgViewSortType::byNone) return;

  // byId is a unique key (misnamed as Order Received). If we are sorting byId,
  // we don't need to keep any secondary sort keys.
  if (newSort.mSortType == nsMsgViewSortType::byId) m_sortColumns.Clear();

  m_sortColumns.RemoveElement(newSort);
  m_sortColumns.InsertElementAt(0, newSort);
  if (m_sortColumns.Length() > kMaxNumSortColumns)
    m_sortColumns.RemoveElementAt(kMaxNumSortColumns);
}

nsresult nsMsgDBView::GetCollationKey(nsIMsgDBHdr* msgHdr,
                                      nsMsgViewSortTypeValue sortType,
                                      nsTArray<uint8_t>& result,
                                      nsIMsgCustomColumnHandler* colHandler) {
  nsresult rv = NS_ERROR_UNEXPECTED;
  NS_ENSURE_ARG_POINTER(msgHdr);

  switch (sortType) {
    case nsMsgViewSortType::bySubject:
      rv = msgHdr->GetSubjectCollationKey(result);
      break;
    case nsMsgViewSortType::byLocation:
      rv = GetLocationCollationKey(msgHdr, result);
      break;
    case nsMsgViewSortType::byRecipient: {
      nsString recipients;
      rv = FetchRecipients(msgHdr, recipients);
      if (NS_SUCCEEDED(rv)) {
        nsCOMPtr<nsIMsgDatabase> dbToUse = m_db;
        // Probably a search view.
        if (!dbToUse) {
          rv = GetDBForHeader(msgHdr, getter_AddRefs(dbToUse));
          NS_ENSURE_SUCCESS(rv, rv);
        }
        rv = dbToUse->CreateCollationKey(recipients, result);
      }
      break;
    }
    case nsMsgViewSortType::byAuthor: {
      rv = msgHdr->GetAuthorCollationKey(result);
      nsString author;
      rv = FetchAuthor(msgHdr, author);
      if (NS_SUCCEEDED(rv)) {
        nsCOMPtr<nsIMsgDatabase> dbToUse = m_db;
        // Probably a search view.
        if (!dbToUse) {
          rv = GetDBForHeader(msgHdr, getter_AddRefs(dbToUse));
          NS_ENSURE_SUCCESS(rv, rv);
        }

        rv = dbToUse->CreateCollationKey(author, result);
      }
      break;
    }
    case nsMsgViewSortType::byAccount:
    case nsMsgViewSortType::byTags: {
      nsString str;
      nsCOMPtr<nsIMsgDatabase> dbToUse = m_db;

      if (!dbToUse)
        // Probably a search view.
        GetDBForViewIndex(0, getter_AddRefs(dbToUse));

      rv = (sortType == nsMsgViewSortType::byAccount)
               ? FetchAccount(msgHdr, str)
               : FetchTags(msgHdr, str);
      if (NS_SUCCEEDED(rv) && dbToUse)
        rv = dbToUse->CreateCollationKey(str, result);

      break;
    }
    case nsMsgViewSortType::byCustom:
      if (colHandler != nullptr) {
        nsAutoString strKey;
        rv = colHandler->GetSortStringForRow(msgHdr, strKey);
        NS_ASSERTION(NS_SUCCEEDED(rv),
                     "failed to get sort string for custom row");
        nsAutoString strTemp(strKey);

        nsCOMPtr<nsIMsgDatabase> dbToUse = m_db;
        // Probably a search view.
        if (!dbToUse) {
          rv = GetDBForHeader(msgHdr, getter_AddRefs(dbToUse));
          NS_ENSURE_SUCCESS(rv, rv);
        }
        rv = dbToUse->CreateCollationKey(strKey, result);
      } else {
        NS_ERROR(
            "should not be here (Sort Type: byCustom (String), but no custom "
            "handler)");
        rv = NS_ERROR_UNEXPECTED;
      }
      break;
    case nsMsgViewSortType::byCorrespondent: {
      nsString value;
      if (IsOutgoingMsg(msgHdr))
        rv = FetchRecipients(msgHdr, value);
      else
        rv = FetchAuthor(msgHdr, value);

      if (NS_SUCCEEDED(rv)) {
        nsCOMPtr<nsIMsgDatabase> dbToUse = m_db;
        // Probably a search view.
        if (!dbToUse) {
          rv = GetDBForHeader(msgHdr, getter_AddRefs(dbToUse));
          NS_ENSURE_SUCCESS(rv, rv);
        }

        rv = dbToUse->CreateCollationKey(value, result);
      }
      break;
    }
    default:
      rv = NS_ERROR_UNEXPECTED;
      break;
  }

  // Bailing out with failure will stop the sort and leave us in
  // a bad state. Try to continue on, instead.
  NS_ASSERTION(NS_SUCCEEDED(rv), "failed to get the collation key");
  if (NS_FAILED(rv)) {
    result.Clear();
  }

  return NS_OK;
}

// As the location collation key is created getting folder from the msgHdr,
// it is defined in this file and not from the db.
nsresult nsMsgDBView::GetLocationCollationKey(nsIMsgDBHdr* msgHdr,
                                              nsTArray<uint8_t>& result) {
  nsCOMPtr<nsIMsgFolder> folder;

  nsresult rv = msgHdr->GetFolder(getter_AddRefs(folder));
  NS_ENSURE_SUCCESS(rv, rv);
  nsCOMPtr<nsIMsgDatabase> dbToUse;
  rv = folder->GetMsgDatabase(getter_AddRefs(dbToUse));
  NS_ENSURE_SUCCESS(rv, rv);

  nsString locationString;
  rv = folder->GetPrettyName(locationString);
  NS_ENSURE_SUCCESS(rv, rv);

  return dbToUse->CreateCollationKey(locationString, result);
}

nsresult nsMsgDBView::SaveSortInfo(nsMsgViewSortTypeValue sortType,
                                   nsMsgViewSortOrderValue sortOrder) {
  if (m_viewFolder) {
    nsCOMPtr<nsIDBFolderInfo> folderInfo;
    nsCOMPtr<nsIMsgDatabase> db;
    nsresult rv = m_viewFolder->GetDBFolderInfoAndDB(getter_AddRefs(folderInfo),
                                                     getter_AddRefs(db));
    if (NS_SUCCEEDED(rv) && folderInfo) {
      // Save off sort type and order, view type and flags.
      folderInfo->SetSortType(sortType);
      folderInfo->SetSortOrder(sortOrder);

      nsString sortColumnsString;
      rv = EncodeColumnSort(sortColumnsString);
      NS_ENSURE_SUCCESS(rv, rv);
      folderInfo->SetProperty("sortColumns", sortColumnsString);
    }
  }

  return NS_OK;
}

nsresult nsMsgDBView::RestoreSortInfo() {
  if (!m_viewFolder) return NS_OK;

  nsCOMPtr<nsIDBFolderInfo> folderInfo;
  nsCOMPtr<nsIMsgDatabase> db;
  nsresult rv = m_viewFolder->GetDBFolderInfoAndDB(getter_AddRefs(folderInfo),
                                                   getter_AddRefs(db));
  if (NS_SUCCEEDED(rv) && folderInfo) {
    // Restore m_sortColumns from db.
    nsString sortColumnsString;
    folderInfo->GetProperty("sortColumns", sortColumnsString);
    DecodeColumnSort(sortColumnsString);
    if (m_sortColumns.Length() > 1) {
      m_secondarySort = m_sortColumns[1].mSortType;
      m_secondarySortOrder = m_sortColumns[1].mSortOrder;
      m_secondaryCustomColumn = m_sortColumns[1].mCustomColumnName;
    }

    // Restore curCustomColumn from db.
    folderInfo->GetProperty("customSortCol", m_curCustomColumn);
  }

  return NS_OK;
}

// Called by msgDBView::Sort, at which point any persisted active custom
// columns must be registered. If not, reset their m_sortColumns entries
// to byDate; Sort will fill in values if necessary based on new user sort.
void nsMsgDBView::EnsureCustomColumnsValid() {
  if (!m_sortColumns.Length()) return;

  for (uint32_t i = 0; i < m_sortColumns.Length(); i++) {
    if (m_sortColumns[i].mSortType == nsMsgViewSortType::byCustom &&
        m_sortColumns[i].mColHandler == nullptr) {
      m_sortColumns[i].mSortType = nsMsgViewSortType::byDate;
      m_sortColumns[i].mCustomColumnName.Truncate();
      // There are only two...
      if (i == 0 && m_sortType != nsMsgViewSortType::byCustom)
        SetCurCustomColumn(EmptyString());
      if (i == 1) m_secondaryCustomColumn.Truncate();
    }
  }
}

int32_t nsMsgDBView::SecondaryCompare(nsMsgKey key1, nsIMsgFolder* folder1,
                                      nsMsgKey key2, nsIMsgFolder* folder2,
                                      viewSortInfo* comparisonContext) {
  nsMsgViewSortTypeValue sortType = comparisonContext->view->m_secondarySort;
  bool isAscendingSort = comparisonContext->view->m_secondarySortOrder ==
                         nsMsgViewSortOrder::ascending;

  // We need to make sure that in the case of the secondary sort field also
  // matching, we don't recurse.
  if (comparisonContext->isSecondarySort ||
      sortType == nsMsgViewSortType::byId) {
    if (key1 > key2) {
      return isAscendingSort ? 1 : -1;
    }

    if (key1 < key2) {
      return isAscendingSort ? -1 : 1;
    }

    return 0;
  }

  nsCOMPtr<nsIMsgDBHdr> hdr1, hdr2;
  nsresult rv = folder1->GetMessageHeader(key1, getter_AddRefs(hdr1));
  NS_ENSURE_SUCCESS(rv, 0);
  rv = folder2->GetMessageHeader(key2, getter_AddRefs(hdr2));
  NS_ENSURE_SUCCESS(rv, 0);
  IdKey EntryInfo1, EntryInfo2;

  uint16_t maxLen;
  eFieldType fieldType;

  // Get the custom column handler for the *secondary* sort and pass it first
  // to GetFieldTypeAndLenForSort to get the fieldType and then either
  // GetCollationKey or GetLongField.
  nsIMsgCustomColumnHandler* colHandler = nullptr;
  if (sortType == nsMsgViewSortType::byCustom &&
      comparisonContext->view->m_sortColumns.Length() > 1) {
    colHandler = comparisonContext->view->m_sortColumns[1].mColHandler;
  }

  // The following may leave fieldType undefined.
  // In this case, we can return 0 right away since
  // it is the value returned in the default case of
  // switch (fieldType) statement below.
  rv = GetFieldTypeAndLenForSort(sortType, &maxLen, &fieldType, colHandler);
  NS_ENSURE_SUCCESS(rv, 0);

  hdr1->GetMessageKey(&EntryInfo1.id);
  hdr2->GetMessageKey(&EntryInfo2.id);

  // Set up new viewSortInfo data for our secondary comparison.
  viewSortInfo ctx = {
      .view = comparisonContext->view,
      .db = comparisonContext->db,
      .isSecondarySort = true,  // To avoid recursing back here!
      .ascendingSort = isAscendingSort,
  };

  switch (fieldType) {
    case kCollationKey:
      rv = GetCollationKey(hdr1, sortType, EntryInfo1.key, colHandler);
      NS_ASSERTION(NS_SUCCEEDED(rv), "failed to create collation key");
      rv = GetCollationKey(hdr2, sortType, EntryInfo2.key, colHandler);
      NS_ASSERTION(NS_SUCCEEDED(rv), "failed to create collation key");

      return FnSortIdKey(&EntryInfo1, &EntryInfo2, &ctx);
    case kU32:
      if (sortType == nsMsgViewSortType::byId) {
        EntryInfo1.dword = EntryInfo1.id;
        EntryInfo2.dword = EntryInfo2.id;
      } else {
        GetLongField(hdr1, sortType, &EntryInfo1.dword, colHandler);
        GetLongField(hdr2, sortType, &EntryInfo2.dword, colHandler);
      }
      return FnSortIdUint32(&EntryInfo1, &EntryInfo2, &ctx);
    default:
      return 0;
  }
}

NS_IMETHODIMP nsMsgDBView::Sort(nsMsgViewSortTypeValue sortType,
                                nsMsgViewSortOrderValue sortOrder) {
  EnsureCustomColumnsValid();

  // If we're doing a stable sort, we can't just reverse the messages.
  // Check also that the custom column we're sorting on hasn't changed.
  // Otherwise, to be on the safe side, resort.
  // Note: m_curCustomColumn is the desired (possibly new) custom column name,
  // while m_sortColumns[0].mCustomColumnName is the name for the last completed
  // sort, since these are persisted after each sort.
  if (m_sortType == sortType && m_sortValid &&
      (sortType != nsMsgViewSortType::byCustom ||
       (sortType == nsMsgViewSortType::byCustom && m_sortColumns.Length() &&
        m_sortColumns[0].mCustomColumnName.Equals(m_curCustomColumn))) &&
      m_sortColumns.Length() < 2) {
    // Same as it ever was. Do nothing.
    if (m_sortOrder == sortOrder) return NS_OK;

    // For secondary sort, remember the sort order on a per column basis.
    if (m_sortColumns.Length()) m_sortColumns[0].mSortOrder = sortOrder;

    SaveSortInfo(sortType, sortOrder);
    if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) {
      ReverseThreads();
    } else {
      ReverseSort();
    }

    m_sortOrder = sortOrder;
    // We just reversed the sort order, we still need to invalidate the view.
    return NS_OK;
  }

  if (sortType == nsMsgViewSortType::byThread) return NS_OK;

  // If a sortType has changed, or the sortType is byCustom and a column has
  // changed, this is the new primary sortColumnInfo.
  // Note: m_curCustomColumn is the desired (possibly new) custom column name,
  // while m_sortColumns[0].mCustomColumnName is the name for the last completed
  // sort, since these are persisted after each sort.
  if (m_sortType != sortType ||
      (sortType == nsMsgViewSortType::byCustom && m_sortColumns.Length() &&
       !m_sortColumns[0].mCustomColumnName.Equals(m_curCustomColumn))) {
    // For secondary sort, remember the sort order of the original primary sort!
    if (m_sortColumns.Length()) m_sortColumns[0].mSortOrder = m_sortOrder;

    MsgViewSortColumnInfo sortColumnInfo;
    sortColumnInfo.mSortType = sortType;
    sortColumnInfo.mSortOrder = sortOrder;
    if (sortType == nsMsgViewSortType::byCustom) {
      GetCurCustomColumn(sortColumnInfo.mCustomColumnName);
      sortColumnInfo.mColHandler = GetCurColumnHandler();
    }

    PushSort(sortColumnInfo);
  } else {
    // For primary sort, remember the sort order on a per column basis.
    if (m_sortColumns.Length()) m_sortColumns[0].mSortOrder = sortOrder;
  }

  if (m_sortColumns.Length() > 1) {
    m_secondarySort = m_sortColumns[1].mSortType;
    m_secondarySortOrder = m_sortColumns[1].mSortOrder;
    m_secondaryCustomColumn = m_sortColumns[1].mCustomColumnName;
  }

  SaveSortInfo(sortType, sortOrder);
  // Figure out how much memory we'll need, and then malloc it.
  uint16_t maxLen;
  eFieldType fieldType;

  // Get the custom column handler for the primary sort and pass it first
  // to GetFieldTypeAndLenForSort to get the fieldType and then either
  // GetCollationKey or GetLongField.
  nsIMsgCustomColumnHandler* colHandler = GetCurColumnHandler();

  // If we did not obtain proper fieldType, it needs to be checked
  // because the subsequent code does not handle it very well.
  nsresult rv =
      GetFieldTypeAndLenForSort(sortType, &maxLen, &fieldType, colHandler);

  // Don't sort if the field type is not supported: Bug 901948.
  if (NS_FAILED(rv)) return NS_OK;

  nsTArray<void*> ptrs;
  uint32_t arraySize = GetSize();

  if (!arraySize) return NS_OK;

  nsCOMArray<nsIMsgFolder>* folders = GetFolders();
  nsCOMPtr<nsIMsgDatabase> dbToUse = m_db;
  // Probably a search view.
  if (!dbToUse) {
    GetDBForViewIndex(0, getter_AddRefs(dbToUse));
    if (!dbToUse) return NS_ERROR_FAILURE;
  }

  viewSortInfo qsPrivateData{
      .view = this,
      .db = dbToUse,
      .isSecondarySort = false,
      .ascendingSort = (sortOrder == nsMsgViewSortOrder::ascending),
  };

  switch (fieldType) {
    case kCollationKey: {
      // Sort on a non-numeric field. We'll be calculating a collation key for
      // each message.
      nsTArray<IdKey> entries;
      entries.SetLength(arraySize);
      nsTArray<IdKey*> pPtrBase;
      pPtrBase.SetLength(arraySize);
      for (uint32_t i = 0; i < arraySize; ++i) {
        IdKey* info = &entries[i];
        pPtrBase[i] = info;
        info->id = m_keys[i];
        info->bits = m_flags[i];
        info->dword = 0;
        info->folder = folders ? folders->ObjectAt(i) : m_folder.get();
        nsCOMPtr<nsIMsgDBHdr> msgHdr;
        rv = GetMsgHdrForViewIndex(i, getter_AddRefs(msgHdr));
        NS_ASSERTION(NS_SUCCEEDED(rv) && msgHdr, "header not found");
        NS_ENSURE_SUCCESS(rv, rv);
        rv = GetCollationKey(msgHdr, sortType, info->key, colHandler);
        NS_ENSURE_SUCCESS(rv, rv);
      }

      // Perform the sort.
      std::sort(pPtrBase.begin(), pPtrBase.end(),
                [&qsPrivateData](const auto& lhs, const auto& rhs) {
                  return FnSortIdKey(lhs, rhs, &qsPrivateData) < 0;
                });

      // Now update the view state to reflect the new order.
      for (uint32_t i = 0; i < arraySize; ++i) {
        m_keys[i] = pPtrBase[i]->id;
        m_flags[i] = pPtrBase[i]->bits;
        if (folders) folders->ReplaceObjectAt(pPtrBase[i]->folder, i);
      }
      m_sortType = sortType;
      m_sortOrder = sortOrder;
      m_sortValid = true;
      return NS_OK;
    }
    case kU32: {
      // Sort on a numeric field.
      nsTArray<IdUint32> entries;
      entries.SetLength(arraySize);
      nsTArray<IdUint32*> pPtrBase;
      pPtrBase.SetLength(arraySize);
      for (uint32_t i = 0; i < arraySize; ++i) {
        IdUint32* info = &entries[i];
        pPtrBase[i] = info;
        info->id = m_keys[i];
        info->bits = m_flags[i];
        info->folder = folders ? folders->ObjectAt(i) : m_folder.get();
        if (sortType == nsMsgViewSortType::byId) {
          info->dword = info->id;  // No msgHdr required.
        } else {
          nsCOMPtr<nsIMsgDBHdr> msgHdr;
          rv = GetMsgHdrForViewIndex(i, getter_AddRefs(msgHdr));
          NS_ASSERTION(NS_SUCCEEDED(rv) && msgHdr, "header not found");
          NS_ENSURE_SUCCESS(rv, rv);
          rv = GetLongField(msgHdr, sortType, &info->dword, colHandler);
          NS_ENSURE_SUCCESS(rv, rv);
        }
      }

      // Perform the sort.
      std::sort(pPtrBase.begin(), pPtrBase.end(),
                [&qsPrivateData](const auto& lhs, const auto& rhs) {
                  return FnSortIdUint32(lhs, rhs, &qsPrivateData) < 0;
                });

      // Now update the view state to reflect the new order.
      for (uint32_t i = 0; i < arraySize; ++i) {
        m_keys[i] = pPtrBase[i]->id;
        m_flags[i] = pPtrBase[i]->bits;
        if (folders) folders->ReplaceObjectAt(pPtrBase[i]->folder, i);
      }
      m_sortType = sortType;
      m_sortOrder = sortOrder;
      m_sortValid = true;
      return NS_OK;
    }
    default:
      // If we get this far, we've got a bad fieldType.
      return NS_ERROR_UNEXPECTED;
  }
}

nsMsgViewIndex nsMsgDBView::GetIndexOfFirstDisplayedKeyInThread(
    nsIMsgThread* threadHdr, bool allowDummy) {
  nsMsgViewIndex retIndex = nsMsgViewIndex_None;
  uint32_t childIndex = 0;
  // We could speed up the unreadOnly view by starting our search with the first
  // unread message in the thread. Sometimes, that will be wrong, however, so
  // let's skip it until we're sure it's necessary.
  //  (m_viewFlags & nsMsgViewFlagsType::kUnreadOnly)
  //    ? threadHdr->GetFirstUnreadKey(m_db) : threadHdr->GetChildAt(0);
  uint32_t numThreadChildren;
  threadHdr->GetNumChildren(&numThreadChildren);
  while (retIndex == nsMsgViewIndex_None && childIndex < numThreadChildren) {
    nsCOMPtr<nsIMsgDBHdr> childHdr;
    threadHdr->GetChildHdrAt(childIndex++, getter_AddRefs(childHdr));
    if (childHdr) retIndex = FindHdr(childHdr, 0, allowDummy);
  }

  return retIndex;
}

nsresult nsMsgDBView::GetFirstMessageHdrToDisplayInThread(
    nsIMsgThread* threadHdr, nsIMsgDBHdr** result) {
  nsresult rv;

  if (m_viewFlags & nsMsgViewFlagsType::kUnreadOnly)
    rv = threadHdr->GetFirstUnreadChild(result);
  else
    rv = threadHdr->GetChildHdrAt(0, result);

  return rv;
}

// Find the view index of the thread containing the passed msgKey, if
// the thread is in the view. MsgIndex is passed in as a shortcut if
// it turns out the msgKey is the first message in the thread,
// then we can avoid looking for the msgKey.
nsMsgViewIndex nsMsgDBView::ThreadIndexOfMsg(
    nsMsgKey msgKey, nsMsgViewIndex msgIndex /* = nsMsgViewIndex_None */,
    int32_t* pThreadCount /* = NULL */, uint32_t* pFlags /* = NULL */) {
  if (!(m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay))
    return nsMsgViewIndex_None;

  nsCOMPtr<nsIMsgDBHdr> msgHdr;
  nsresult rv = m_db->GetMsgHdrForKey(msgKey, getter_AddRefs(msgHdr));
  NS_ENSURE_SUCCESS(rv, nsMsgViewIndex_None);
  return ThreadIndexOfMsgHdr(msgHdr, msgIndex, pThreadCount, pFlags);
}

nsMsgViewIndex nsMsgDBView::GetThreadIndex(nsMsgViewIndex msgIndex) {
  if (!IsValidIndex(msgIndex)) return nsMsgViewIndex_None;

  // Scan up looking for level 0 message.
  while (m_levels[msgIndex] && msgIndex) --msgIndex;

  return msgIndex;
}

nsMsgViewIndex nsMsgDBView::ThreadIndexOfMsgHdr(nsIMsgDBHdr* msgHdr,
                                                nsMsgViewIndex msgIndex,
                                                int32_t* pThreadCount,
                                                uint32_t* pFlags) {
  nsCOMPtr<nsIMsgThread> threadHdr;
  nsresult rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(threadHdr));
  NS_ENSURE_SUCCESS(rv, nsMsgViewIndex_None);

  nsMsgViewIndex retIndex = nsMsgViewIndex_None;

  if (threadHdr != nullptr) {
    if (msgIndex == nsMsgViewIndex_None) msgIndex = FindHdr(msgHdr, 0, true);

    // Hdr is not in view, need to find by thread.
    if (msgIndex == nsMsgViewIndex_None) {
      msgIndex = GetIndexOfFirstDisplayedKeyInThread(threadHdr, true);
      // nsMsgKey threadKey = (msgIndex == nsMsgViewIndex_None) ? nsMsgKey_None
      // :
      //                                                          GetAt(msgIndex);
      if (pFlags) threadHdr->GetFlags(pFlags);
    }

    nsMsgViewIndex startOfThread = msgIndex;
    while ((int32_t)startOfThread >= 0 && m_levels[startOfThread] != 0)
      startOfThread--;

    retIndex = startOfThread;
    if (pThreadCount) {
      int32_t numChildren = 0;
      nsMsgViewIndex threadIndex = startOfThread;
      do {
        threadIndex++;
        numChildren++;
      } while (threadIndex < m_levels.Length() && m_levels[threadIndex] != 0);

      *pThreadCount = numChildren;
    }
  }

  return retIndex;
}

nsMsgKey nsMsgDBView::GetKeyOfFirstMsgInThread(nsMsgKey key) {
  // Just report no key for any failure. This can occur when a
  // message is deleted from a threaded view.
  nsCOMPtr<nsIMsgThread> pThread;
  nsCOMPtr<nsIMsgDBHdr> msgHdr;
  nsresult rv = m_db->GetMsgHdrForKey(key, getter_AddRefs(msgHdr));
  if (NS_FAILED(rv)) return nsMsgKey_None;

  rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(pThread));
  if (NS_FAILED(rv)) return nsMsgKey_None;

  nsMsgKey firstKeyInThread = nsMsgKey_None;

  if (!pThread) return firstKeyInThread;

  // ### dmb UnreadOnly - this is wrong. But didn't seem to matter in 4.x
  pThread->GetChildKeyAt(0, &firstKeyInThread);
  return firstKeyInThread;
}

NS_IMETHODIMP
nsMsgDBView::GetKeyAt(nsMsgViewIndex index, nsMsgKey* result) {
  NS_ENSURE_ARG(result);
  *result = GetAt(index);
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetFlagsAt(nsMsgViewIndex aIndex, uint32_t* aResult) {
  NS_ENSURE_ARG(aResult);
  if (!IsValidIndex(aIndex)) return NS_MSG_INVALID_DBVIEW_INDEX;

  *aResult = m_flags[aIndex];
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetMsgHdrAt(nsMsgViewIndex aIndex, nsIMsgDBHdr** aResult) {
  NS_ENSURE_ARG(aResult);
  if (!IsValidIndex(aIndex)) return NS_MSG_INVALID_DBVIEW_INDEX;

  return GetMsgHdrForViewIndex(aIndex, aResult);
}

nsMsgViewIndex nsMsgDBView::FindHdr(nsIMsgDBHdr* msgHdr,
                                    nsMsgViewIndex startIndex,
                                    bool allowDummy) {
  nsMsgKey msgKey;
  msgHdr->GetMessageKey(&msgKey);
  nsMsgViewIndex viewIndex = m_keys.IndexOf(msgKey, startIndex);
  if (viewIndex == nsMsgViewIndex_None) return viewIndex;

  // If we're supposed to allow dummies, and the previous index is a dummy that
  // is not elided, then it must be the dummy corresponding to our node and
  // we should return that instead.
  if (allowDummy && viewIndex &&
      (m_flags[viewIndex - 1] & MSG_VIEW_FLAG_DUMMY) &&
      !(m_flags[viewIndex - 1] & nsMsgMessageFlags::Elided)) {
    viewIndex--;
  } else if (!allowDummy && m_flags[viewIndex] & MSG_VIEW_FLAG_DUMMY) {
    // We're not allowing dummies, and we found a dummy, look again
    // one past the dummy.
    return m_keys.IndexOf(msgKey, viewIndex + 1);
  }

  // Check that the message we found matches the message we were looking for.
  if (viewIndex != nsMsgViewIndex_None) {
    nsCOMPtr<nsIMsgDBHdr> foundMsgHdr;
    nsresult rv = GetMsgHdrForViewIndex(viewIndex, getter_AddRefs(foundMsgHdr));
    if (NS_FAILED(rv) || foundMsgHdr != msgHdr) {
      viewIndex = nsMsgViewIndex_None;
    }
  }

  return viewIndex;
}

nsMsgViewIndex nsMsgDBView::FindKey(nsMsgKey key, bool expand) {
  nsMsgViewIndex retIndex = nsMsgViewIndex_None;
  retIndex = (nsMsgViewIndex)(m_keys.IndexOf(key));
  // For dummy headers, try to expand if the caller says so. And if the thread
  // is expanded, ignore the dummy header and return the real header index.
  if (retIndex != nsMsgViewIndex_None &&
      m_flags[retIndex] & MSG_VIEW_FLAG_DUMMY &&
      !(m_flags[retIndex] & nsMsgMessageFlags::Elided)) {
    return (nsMsgViewIndex)m_keys.IndexOf(key, retIndex + 1);
  }

  if (key != nsMsgKey_None &&
      (retIndex == nsMsgViewIndex_None ||
       m_flags[retIndex] & MSG_VIEW_FLAG_DUMMY) &&
      expand && m_db) {
    nsMsgKey threadKey = GetKeyOfFirstMsgInThread(key);
    if (threadKey != nsMsgKey_None) {
      nsMsgViewIndex threadIndex = FindKey(threadKey, false);
      if (threadIndex != nsMsgViewIndex_None) {
        uint32_t flags = m_flags[threadIndex];
        if ((flags & nsMsgMessageFlags::Elided &&
             NS_SUCCEEDED(ExpandByIndex(threadIndex, nullptr))) ||
            flags & MSG_VIEW_FLAG_DUMMY) {
          retIndex = (nsMsgViewIndex)m_keys.IndexOf(key, threadIndex + 1);
        }
      }
    }
  }

  return retIndex;
}

nsresult nsMsgDBView::GetThreadCount(nsMsgViewIndex index,
                                     uint32_t* pThreadCount) {
  nsCOMPtr<nsIMsgDBHdr> msgHdr;
  nsresult rv = GetMsgHdrForViewIndex(index, getter_AddRefs(msgHdr));
  NS_ENSURE_SUCCESS(rv, rv);
  nsCOMPtr<nsIMsgThread> pThread;
  rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(pThread));
  if (NS_SUCCEEDED(rv) && pThread != nullptr)
    rv = pThread->GetNumChildren(pThreadCount);

  return rv;
}

// This counts the number of messages in an expanded thread, given the
// index of the first message in the thread.
int32_t nsMsgDBView::CountExpandedThread(nsMsgViewIndex index) {
  int32_t numInThread = 0;
  nsMsgViewIndex startOfThread = index;
  while ((int32_t)startOfThread >= 0 && m_levels[startOfThread] != 0)
    startOfThread--;

  nsMsgViewIndex threadIndex = startOfThread;
  do {
    threadIndex++;
    numInThread++;
  } while (threadIndex < m_levels.Length() && m_levels[threadIndex] != 0);

  return numInThread;
}

// Returns the number of lines that would be added (> 0) or removed (< 0)
// if we were to try to expand/collapse the passed index.
nsresult nsMsgDBView::ExpansionDelta(nsMsgViewIndex index,
                                     int32_t* expansionDelta) {
  uint32_t numChildren;
  nsresult rv;

  *expansionDelta = 0;
  if (index >= ((nsMsgViewIndex)m_keys.Length()))
    return NS_MSG_MESSAGE_NOT_FOUND;

  char flags = m_flags[index];

  if (!(m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)) return NS_OK;

  // The client can pass in the key of any message
  // in a thread and get the expansion delta for the thread.

  if (flags & nsMsgMessageFlags::Elided) {
    rv = GetThreadCount(index, &numChildren);
    NS_ENSURE_SUCCESS(rv, rv);
    *expansionDelta = numChildren - 1;
  } else {
    numChildren = CountExpandedThread(index);
    *expansionDelta = -(int32_t)(numChildren - 1);
  }

  return NS_OK;
}

nsresult nsMsgDBView::ToggleExpansion(nsMsgViewIndex index,
                                      uint32_t* numChanged) {
  nsresult rv;
  NS_ENSURE_ARG(numChanged);
  *numChanged = 0;
  nsMsgViewIndex threadIndex = GetThreadIndex(index);
  if (threadIndex == nsMsgViewIndex_None) {
    NS_ASSERTION(false, "couldn't find thread");
    return NS_MSG_MESSAGE_NOT_FOUND;
  }

  int32_t flags = m_flags[threadIndex];

  // If not a thread, or doesn't have children, no expand/collapse.
  // If we add sub-thread expand collapse, this will need to be relaxed.
  if (!(flags & MSG_VIEW_FLAG_ISTHREAD) || !(flags & MSG_VIEW_FLAG_HASCHILDREN))
    return NS_MSG_MESSAGE_NOT_FOUND;

  if (flags & nsMsgMessageFlags::Elided)
    rv = ExpandByIndex(threadIndex, numChanged);
  else
    rv = CollapseByIndex(threadIndex, numChanged);

  // If we collaps/uncollapse a thread, this changes the selected URIs.
  SelectionChangedXPCOM();
  return rv;
}

nsresult nsMsgDBView::ExpandAndSelectThread() {
  nsresult rv;

  NS_ASSERTION(mTreeSelection, "no tree selection");
  if (!mTreeSelection) return NS_ERROR_UNEXPECTED;

  int32_t index;
  rv = mTreeSelection->GetCurrentIndex(&index);
  NS_ENSURE_SUCCESS(rv, rv);

  rv = ExpandAndSelectThreadByIndex(index, false);
  NS_ENSURE_SUCCESS(rv, rv);
  return NS_OK;
}

nsresult nsMsgDBView::ExpandAndSelectThreadByIndex(nsMsgViewIndex index,
                                                   bool augment) {
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  nsresult rv;

  nsMsgViewIndex threadIndex;
  bool inThreadedMode = (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay);

  if (inThreadedMode) {
    nsCOMPtr<nsIMsgDBHdr> msgHdr;
    rv = GetMsgHdrForViewIndex(index, getter_AddRefs(msgHdr));
    NS_ENSURE_SUCCESS(rv, rv);
    threadIndex = ThreadIndexOfMsgHdr(msgHdr, index);
    if (threadIndex == nsMsgViewIndex_None) {
      NS_ASSERTION(false, "couldn't find thread");
      return NS_MSG_MESSAGE_NOT_FOUND;
    }
  } else {
    threadIndex = index;
  }

  int32_t flags = m_flags[threadIndex];
  int32_t count = 0;

  if (inThreadedMode && flags & MSG_VIEW_FLAG_ISTHREAD &&
      flags & MSG_VIEW_FLAG_HASCHILDREN) {
    // If closed, expand this thread.
    if (flags & nsMsgMessageFlags::Elided) {
      uint32_t numExpanded;
      rv = ExpandByIndex(threadIndex, &numExpanded);
      NS_ENSURE_SUCCESS(rv, rv);
    }

    // Get the number of messages in the expanded thread so we know how many
    // to select.
    count = CountExpandedThread(threadIndex);
  } else {
    count = 1;
  }

  NS_ASSERTION(count > 0, "bad count");

  // Update the selection.

  NS_ASSERTION(mTreeSelection, "no tree selection");
  if (!mTreeSelection) return NS_ERROR_UNEXPECTED;

  // The count should be 1 or greater. If there was only one message in the
  // thread, we just select it. If more, we select all of them.
  mTreeSelection->RangedSelect(threadIndex + count - 1, threadIndex, augment);
  return NS_OK;
}

nsresult nsMsgDBView::ExpandAll() {
  if (mTree) mTree->BeginUpdateBatch();
  if (mJSTree) mJSTree->BeginUpdateBatch();

  for (int32_t i = GetSize() - 1; i >= 0; i--) {
    uint32_t numExpanded;
    uint32_t flags = m_flags[i];
    if (flags & nsMsgMessageFlags::Elided) ExpandByIndex(i, &numExpanded);
  }

  if (mTree) mTree->EndUpdateBatch();
  if (mJSTree) mJSTree->EndUpdateBatch();

  SelectionChangedXPCOM();
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetThreadContainingMsgHdr(nsIMsgDBHdr* msgHdr,
                                       nsIMsgThread** pThread) {
  NS_ENSURE_ARG_POINTER(msgHdr);
  NS_ENSURE_ARG_POINTER(pThread);
  if (!m_db) return NS_ERROR_FAILURE;
  return m_db->GetThreadContainingMsgHdr(msgHdr, pThread);
}

nsresult nsMsgDBView::ExpandByIndex(nsMsgViewIndex index,
                                    uint32_t* pNumExpanded) {
  if ((uint32_t)index >= m_keys.Length()) return NS_MSG_MESSAGE_NOT_FOUND;

  uint32_t flags = m_flags[index];
  uint32_t numExpanded = 0;

  NS_ASSERTION(flags & nsMsgMessageFlags::Elided,
               "can't expand an already expanded thread");
  flags &= ~nsMsgMessageFlags::Elided;

  nsCOMPtr<nsIMsgDBHdr> msgHdr;
  nsCOMPtr<nsIMsgThread> pThread;
  nsresult rv = GetThreadContainingIndex(index, getter_AddRefs(pThread));
  NS_ENSURE_SUCCESS(rv, rv);
  if (m_viewFlags & nsMsgViewFlagsType::kUnreadOnly) {
    // Keep top level hdr in thread, even though read.
    if (flags & nsMsgMessageFlags::Read) {
      m_levels.AppendElement(0);
    }

    rv = ListUnreadIdsInThread(pThread, index, &numExpanded);
  } else {
    rv = ListIdsInThread(pThread, index, &numExpanded);
  }

  if (numExpanded > 0) {
    m_flags[index] = flags;
    NoteChange(index, 1, nsMsgViewNotificationCode::changed);
  }

  NoteChange(index + 1, numExpanded, nsMsgViewNotificationCode::insertOrDelete);

  if (pNumExpanded != nullptr) *pNumExpanded = numExpanded;

  return rv;
}

nsresult nsMsgDBView::CollapseAll() {
  if (mJSTree) mJSTree->BeginUpdateBatch();
  for (uint32_t i = 0; i < GetSize(); i++) {
    uint32_t numExpanded;
    uint32_t flags = m_flags[i];
    if (!(flags & nsMsgMessageFlags::Elided) &&
        (flags & MSG_VIEW_FLAG_HASCHILDREN))
      CollapseByIndex(i, &numExpanded);
  }

  if (mJSTree) mJSTree->EndUpdateBatch();
  SelectionChangedXPCOM();
  return NS_OK;
}

nsresult nsMsgDBView::CollapseByIndex(nsMsgViewIndex index,
                                      uint32_t* pNumCollapsed) {
  nsresult rv;
  int32_t flags = m_flags[index];
  int32_t rowDelta = 0;

  if (flags & nsMsgMessageFlags::Elided ||
      !(m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) ||
      !(flags & MSG_VIEW_FLAG_HASCHILDREN)) {
    return NS_OK;
  }

  if (index > m_keys.Length()) return NS_MSG_MESSAGE_NOT_FOUND;

  rv = ExpansionDelta(index, &rowDelta);
  NS_ENSURE_SUCCESS(rv, rv);

  flags |= nsMsgMessageFlags::Elided;

  m_flags[index] = flags;
  NoteChange(index, 1, nsMsgViewNotificationCode::changed);

  // Don't count first header in thread.
  int32_t numRemoved = -rowDelta;
  if (index + 1 + numRemoved > m_keys.Length()) {
    NS_ERROR("trying to remove too many rows");
    numRemoved -= (index + 1 + numRemoved) - m_keys.Length();
    if (numRemoved <= 0) return NS_MSG_MESSAGE_NOT_FOUND;
  }

  // Start at first id after thread.
  RemoveRows(index + 1, numRemoved);
  if (pNumCollapsed != nullptr) *pNumCollapsed = numRemoved;

  NoteChange(index + 1, rowDelta, nsMsgViewNotificationCode::insertOrDelete);

  return rv;
}

nsresult nsMsgDBView::OnNewHeader(nsIMsgDBHdr* newHdr, nsMsgKey aParentKey,
                                  bool /*ensureListed*/) {
  nsresult rv = NS_OK;
  // Views can override this behaviour, which is to append to view.
  // This is the mail behaviour, but threaded views will want
  // to insert in order...
  if (newHdr) rv = AddHdr(newHdr);

  return rv;
}

NS_IMETHODIMP
nsMsgDBView::GetThreadContainingIndex(nsMsgViewIndex index,
                                      nsIMsgThread** resultThread) {
  nsCOMPtr<nsIMsgDBHdr> msgHdr;
  nsresult rv = GetMsgHdrForViewIndex(index, getter_AddRefs(msgHdr));
  NS_ENSURE_SUCCESS(rv, rv);
  return GetThreadContainingMsgHdr(msgHdr, resultThread);
}

nsMsgViewIndex nsMsgDBView::GetIndexForThread(nsIMsgDBHdr* msgHdr) {
  // Take advantage of the fact that we're already sorted
  // and find the insert index via a binary search, though expanded threads
  // make that tricky.

  nsMsgViewIndex highIndex = m_keys.Length();
  nsMsgViewIndex lowIndex = 0;
  IdKey EntryInfo1, EntryInfo2;

  nsresult rv;
  uint16_t maxLen;
  eFieldType fieldType;

  // Get the custom column handler for the primary sort and pass it first
  // to GetFieldTypeAndLenForSort to get the fieldType and then either
  // GetCollationKey or GetLongField.
  nsIMsgCustomColumnHandler* colHandler = GetCurColumnHandler();

  // The following may leave fieldType undefined.
  // In this case, we can return highIndex right away since
  // it is the value returned in the default case of
  // switch (fieldType) statement below.
  rv = GetFieldTypeAndLenForSort(m_sortType, &maxLen, &fieldType, colHandler);
  NS_ENSURE_SUCCESS(rv, highIndex);

  int retStatus = 0;
  msgHdr->GetMessageKey(&EntryInfo1.id);
  msgHdr->GetFolder(&EntryInfo1.folder);
  EntryInfo1.folder->Release();

  viewSortInfo comparisonContext{
      .view = this,
      .isSecondarySort = false,
      .ascendingSort = (m_sortOrder == nsMsgViewSortOrder::ascending),
  };

  nsCOMPtr<nsIMsgDatabase> hdrDB;
  EntryInfo1.folder->GetMsgDatabase(getter_AddRefs(hdrDB));
  comparisonContext.db = hdrDB.get();
  switch (fieldType) {
    case kCollationKey:
      rv = GetCollationKey(msgHdr, m_sortType, EntryInfo1.key, colHandler);
      NS_ASSERTION(NS_SUCCEEDED(rv), "failed to create collation key");
      break;
    case kU32:
      if (m_sortType == nsMsgViewSortType::byId) {
        EntryInfo1.dword = EntryInfo1.id;
      } else {
        GetLongField(msgHdr, m_sortType, &EntryInfo1.dword, colHandler);
      }

      break;
    default:
      return highIndex;
  }

  while (highIndex > lowIndex) {
    nsMsgViewIndex tryIndex = (lowIndex + highIndex) / 2;
    // Need to adjust tryIndex if it's not a thread.
    while (m_levels[tryIndex] && tryIndex) tryIndex--;

    if (tryIndex < lowIndex) {
      NS_ERROR("try index shouldn't be less than low index");
      break;
    }

    EntryInfo2.id = m_keys[tryIndex];
    GetFolderForViewIndex(tryIndex, &EntryInfo2.folder);
    EntryInfo2.folder->Release();

    nsCOMPtr<nsIMsgDBHdr> tryHdr;
    nsCOMPtr<nsIMsgDatabase> db;
    // ### this should get the db from the folder...
    GetDBForViewIndex(tryIndex, getter_AddRefs(db));
    if (db) db->GetMsgHdrForKey(EntryInfo2.id, getter_AddRefs(tryHdr));

    if (!tryHdr) break;

    if (tryHdr == msgHdr) {
      NS_WARNING("didn't expect header to already be in view");
      highIndex = tryIndex;
      break;
    }

    if (fieldType == kCollationKey) {
      rv = GetCollationKey(tryHdr, m_sortType, EntryInfo2.key, colHandler);
      NS_ASSERTION(NS_SUCCEEDED(rv), "failed to create collation key");

      retStatus = FnSortIdKey(&EntryInfo1, &EntryInfo2, &comparisonContext);
    } else if (fieldType == kU32) {
      if (m_sortType == nsMsgViewSortType::byId) {
        EntryInfo2.dword = EntryInfo2.id;
      } else {
        GetLongField(tryHdr, m_sortType, &EntryInfo2.dword, colHandler);
      }

      retStatus = FnSortIdUint32(&EntryInfo1, &EntryInfo2, &comparisonContext);
    }

    if (retStatus == 0) {
      highIndex = tryIndex;
      break;
    }

    if (retStatus < 0) {
      highIndex = tryIndex;
      // We already made sure tryIndex was at a thread at the top of the loop.
    } else {
      lowIndex = tryIndex + 1;
      while (lowIndex < GetSize() && m_levels[lowIndex]) lowIndex++;
    }
  }

  return highIndex;
}

nsMsgViewIndex nsMsgDBView::GetInsertIndexHelper(
    nsIMsgDBHdr* msgHdr, nsTArray<nsMsgKey>& keys,
    nsCOMArray<nsIMsgFolder>* folders, nsMsgViewSortOrderValue sortOrder,
    nsMsgViewSortTypeValue sortType) {
  nsMsgViewIndex highIndex = keys.Length();
  nsMsgViewIndex lowIndex = 0;
  IdKey EntryInfo1, EntryInfo2;

  nsresult rv;
  uint16_t maxLen;
  eFieldType fieldType;

  // Get the custom column handler for the primary sort and pass it first
  // to GetFieldTypeAndLenForSort to get the fieldType and then either
  // GetCollationKey or GetLongField.
  nsIMsgCustomColumnHandler* colHandler = GetCurColumnHandler();

  // The following may leave fieldType undefined.
  // In this case, we can return highIndex right away since
  // it is the value returned in the default case of
  // switch (fieldType) statement below.
  rv = GetFieldTypeAndLenForSort(sortType, &maxLen, &fieldType, colHandler);
  NS_ENSURE_SUCCESS(rv, highIndex);

  int retStatus = 0;
  msgHdr->GetMessageKey(&EntryInfo1.id);
  msgHdr->GetFolder(&EntryInfo1.folder);
  EntryInfo1.folder->Release();

  viewSortInfo comparisonContext{
      .view = this,
      .isSecondarySort = false,
      .ascendingSort = (sortOrder == nsMsgViewSortOrder::ascending),
  };

  rv = EntryInfo1.folder->GetMsgDatabase(&comparisonContext.db);
  NS_ENSURE_SUCCESS(rv, highIndex);
  comparisonContext.db->Release();

  switch (fieldType) {
    case kCollationKey:
      rv = GetCollationKey(msgHdr, sortType, EntryInfo1.key, colHandler);
      NS_ASSERTION(NS_SUCCEEDED(rv), "failed to create collation key");
      break;
    case kU32:
      if (sortType == nsMsgViewSortType::byId) {
        EntryInfo1.dword = EntryInfo1.id;
      } else {
        GetLongField(msgHdr, sortType, &EntryInfo1.dword, colHandler);
      }

      break;
    default:
      return highIndex;
  }

  while (highIndex > lowIndex) {
    nsMsgViewIndex tryIndex = (lowIndex + highIndex - 1) / 2;
    EntryInfo2.id = keys[tryIndex];
    EntryInfo2.folder = folders ? folders->ObjectAt(tryIndex) : m_folder.get();

    nsCOMPtr<nsIMsgDBHdr> tryHdr;
    EntryInfo2.folder->GetMessageHeader(EntryInfo2.id, getter_AddRefs(tryHdr));
    if (!tryHdr) break;

    if (fieldType == kCollationKey) {
      rv = GetCollationKey(tryHdr, sortType, EntryInfo2.key, colHandler);
      NS_ASSERTION(NS_SUCCEEDED(rv), "failed to create collation key");

      retStatus = FnSortIdKey(&EntryInfo1, &EntryInfo2, &comparisonContext);
    } else if (fieldType == kU32) {
      if (sortType == nsMsgViewSortType::byId) {
        EntryInfo2.dword = EntryInfo2.id;
      } else {
        GetLongField(tryHdr, sortType, &EntryInfo2.dword, colHandler);
      }

      retStatus = FnSortIdUint32(&EntryInfo1, &EntryInfo2, &comparisonContext);
    }

    if (retStatus == 0) {
      highIndex = tryIndex;
      break;
    }

    if (retStatus < 0) {
      highIndex = tryIndex;
    } else {
      lowIndex = tryIndex + 1;
    }
  }

  return highIndex;
}

nsMsgViewIndex nsMsgDBView::GetInsertIndex(nsIMsgDBHdr* msgHdr) {
  if (!GetSize()) return 0;

  if ((m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) != 0 &&
      !(m_viewFlags & nsMsgViewFlagsType::kGroupBySort) &&
      m_sortOrder != nsMsgViewSortType::byId) {
    return GetIndexForThread(msgHdr);
  }

  return GetInsertIndexHelper(msgHdr, m_keys, GetFolders(), m_sortOrder,
                              m_sortType);
}

nsresult nsMsgDBView::AddHdr(nsIMsgDBHdr* msgHdr, nsMsgViewIndex* resultIndex) {
  uint32_t flags = 0;
#ifdef DEBUG_bienvenu
  NS_ASSERTION(m_keys.Length() == m_flags.Length() &&
                   (int)m_keys.Length() == m_levels.Length(),
               "view arrays out of sync!");
#endif

  if (resultIndex) *resultIndex = nsMsgViewIndex_None;

  if (!GetShowingIgnored()) {
    nsCOMPtr<nsIMsgThread> thread;
    GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(thread));
    if (thread) {
      thread->GetFlags(&flags);
      if (flags & nsMsgMessageFlags::Ignored) return NS_OK;
    }

    bool ignored;
    msgHdr->GetIsKilled(&ignored);
    if (ignored) return NS_OK;
  }

  nsMsgKey msgKey, threadId;
  nsMsgKey threadParent;
  msgHdr->GetMessageKey(&msgKey);
  msgHdr->GetThreadId(&threadId);
  msgHdr->GetThreadParent(&threadParent);

  msgHdr->GetFlags(&flags);
  // XXX this isn't quite right, is it?
  // Should be checking that our thread parent key is none?
  if (threadParent == nsMsgKey_None) flags |= MSG_VIEW_FLAG_ISTHREAD;

  nsMsgViewIndex insertIndex = GetInsertIndex(msgHdr);
  if (insertIndex == nsMsgViewIndex_None) {
    // If unreadonly, level is 0 because we must be the only msg in the thread.
    int32_t levelToAdd = 0;

    if (m_sortOrder == nsMsgViewSortOrder::ascending) {
      InsertMsgHdrAt(GetSize(), msgHdr, msgKey, flags, levelToAdd);
      if (resultIndex) *resultIndex = GetSize() - 1;

      // The call to NoteChange() has to happen after we add the key as
      // NoteChange() will call RowCountChanged() which will call our
      // GetRowCount().
      NoteChange(GetSize() - 1, 1, nsMsgViewNotificationCode::insertOrDelete);
    } else {
      InsertMsgHdrAt(0, msgHdr, msgKey, flags, levelToAdd);
      if (resultIndex) *resultIndex = 0;

      // The call to NoteChange() has to happen after we insert the key as
      // NoteChange() will call RowCountChanged() which will call our
      // GetRowCount().
      NoteChange(0, 1, nsMsgViewNotificationCode::insertOrDelete);
    }

    m_sortValid = false;
  } else {
    InsertMsgHdrAt(insertIndex, msgHdr, msgKey, flags, 0);
    if (resultIndex) *resultIndex = insertIndex;

    // The call to NoteChange() has to happen after we add the key as
    // NoteChange() will call RowCountChanged() which will call our
    // GetRowCount().
    NoteChange(insertIndex, 1, nsMsgViewNotificationCode::insertOrDelete);
  }

  OnHeaderAddedOrDeleted();
  return NS_OK;
}

bool nsMsgDBView::WantsThisThread(nsIMsgThread* /*threadHdr*/) {
  // Default is to want all threads.
  return true;
}

nsMsgViewIndex nsMsgDBView::FindParentInThread(
    nsMsgKey parentKey, nsMsgViewIndex startOfThreadViewIndex) {
  nsCOMPtr<nsIMsgDBHdr> msgHdr;
  while (parentKey != nsMsgKey_None) {
    nsMsgViewIndex parentIndex =
        m_keys.IndexOf(parentKey, startOfThreadViewIndex);
    if (parentIndex != nsMsgViewIndex_None) return parentIndex;

    if (NS_FAILED(m_db->GetMsgHdrForKey(parentKey, getter_AddRefs(msgHdr))))
      break;

    msgHdr->GetThreadParent(&parentKey);
  }

  return startOfThreadViewIndex;
}

nsresult nsMsgDBView::ListIdsInThreadOrder(nsIMsgThread* threadHdr,
                                           nsMsgKey parentKey, uint32_t level,
                                           nsMsgViewIndex* viewIndex,
                                           uint32_t* pNumListed) {
  nsCOMPtr<nsIMsgEnumerator> msgEnumerator;
  nsresult rv =
      threadHdr->EnumerateMessages(parentKey, getter_AddRefs(msgEnumerator));
  NS_ENSURE_SUCCESS(rv, rv);
  uint32_t numChildren;
  (void)threadHdr->GetNumChildren(&numChildren);
  NS_ASSERTION(numChildren, "Empty thread in view/db");
  // Bogus, but harmless.
  if (!numChildren) return NS_OK;

  // Account for the existing thread root.
  numChildren--;

  // Skip the first one.
  bool hasMore;
  while (NS_SUCCEEDED(msgEnumerator->HasMoreElements(&hasMore)) && hasMore) {
    nsCOMPtr<nsIMsgDBHdr> msgHdr;
    rv = msgEnumerator->GetNext(getter_AddRefs(msgHdr));
    NS_ENSURE_SUCCESS(rv, rv);
    if (*pNumListed == numChildren) {
      MOZ_ASSERT_UNREACHABLE("thread corrupt in db");
      // If we've listed more messages than are in the thread, then the db
      // is corrupt, and we should invalidate it.
      // We'll use this rv to indicate there's something wrong with the db
      // though for now it probably won't get paid attention to.
      m_db->SetSummaryValid(false);
      return NS_MSG_ERROR_FOLDER_SUMMARY_OUT_OF_DATE;
    }

    if (!(m_viewFlags & nsMsgViewFlagsType::kShowIgnored)) {
      bool ignored;
      msgHdr->GetIsKilled(&ignored);
      // We are not going to process subthreads, horribly invalidating the
      // numChildren characteristic.
      if (ignored) continue;
    }

    nsMsgKey msgKey;
    uint32_t msgFlags, newFlags;
    msgHdr->GetMessageKey(&msgKey);
    msgHdr->GetFlags(&msgFlags);
    AdjustReadFlag(msgHdr, &msgFlags);
    SetMsgHdrAt(msgHdr, *viewIndex, msgKey, msgFlags & ~MSG_VIEW_FLAGS, level);
    // Turn off thread or elided bit if they got turned on (maybe from new
    // only view?)
    msgHdr->AndFlags(~(MSG_VIEW_FLAG_ISTHREAD | nsMsgMessageFlags::Elided),
                     &newFlags);
    (*pNumListed)++;
    (*viewIndex)++;
    rv = ListIdsInThreadOrder(threadHdr, msgKey, level + 1, viewIndex,
                              pNumListed);
    NS_ENSURE_SUCCESS(rv, rv);
  }
  return NS_OK;
}

void nsMsgDBView::InsertEmptyRows(nsMsgViewIndex viewIndex, int32_t numRows) {
  m_keys.InsertElementsAt(viewIndex, numRows, 0);
  m_flags.InsertElementsAt(viewIndex, numRows, 0);
  m_levels.InsertElementsAt(viewIndex, numRows, 1);
}

void nsMsgDBView::RemoveRows(nsMsgViewIndex viewIndex, int32_t numRows) {
  m_keys.RemoveElementsAt(viewIndex, numRows);
  m_flags.RemoveElementsAt(viewIndex, numRows);
  m_levels.RemoveElementsAt(viewIndex, numRows);
}

NS_IMETHODIMP
nsMsgDBView::InsertTreeRows(nsMsgViewIndex aIndex, uint32_t aNumRows,
                            nsMsgKey aKey, nsMsgViewFlagsTypeValue aFlags,
                            uint32_t aLevel, nsIMsgFolder* aFolder) {
  if (GetSize() < aIndex) return NS_ERROR_UNEXPECTED;

  nsCOMArray<nsIMsgFolder>* folders = GetFolders();
  if (folders) {
    // In a search/xfvf view only, a folder is required.
    NS_ENSURE_ARG_POINTER(aFolder);
    for (size_t i = 0; i < aNumRows; i++)
      // Insert into m_folders.
      if (!folders->InsertObjectAt(aFolder, aIndex + i))
        return NS_ERROR_UNEXPECTED;
  }

  m_keys.InsertElementsAt(aIndex, aNumRows, aKey);
  m_flags.InsertElementsAt(aIndex, aNumRows, aFlags);
  m_levels.InsertElementsAt(aIndex, aNumRows, aLevel);
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::RemoveTreeRows(nsMsgViewIndex aIndex, uint32_t aNumRows) {
  // Prevent a crash if attempting to remove rows which don't exist.
  if (GetSize() < aIndex + aNumRows) return NS_ERROR_UNEXPECTED;

  nsMsgDBView::RemoveRows(aIndex, aNumRows);

  nsCOMArray<nsIMsgFolder>* folders = GetFolders();
  if (folders)
    // In a search/xfvf view only, remove from m_folders.
    if (!folders->RemoveObjectsAt(aIndex, aNumRows)) return NS_ERROR_UNEXPECTED;

  return NS_OK;
}

nsresult nsMsgDBView::ListIdsInThread(nsIMsgThread* threadHdr,
                                      nsMsgViewIndex startOfThreadViewIndex,
                                      uint32_t* pNumListed) {
  NS_ENSURE_ARG(threadHdr);
  // These children ids should be in thread order.
  nsresult rv = NS_OK;
  uint32_t i;
  nsMsgViewIndex viewIndex = startOfThreadViewIndex + 1;
  *pNumListed = 0;

  uint32_t numChildren;
  threadHdr->GetNumChildren(&numChildren);
  NS_ASSERTION(numChildren, "Empty thread in view/db");
  if (!numChildren) return NS_OK;

  // Account for the existing thread root.
  numChildren--;
  InsertEmptyRows(viewIndex, numChildren);

  // ### need to rework this when we implemented threading in group views.
  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay &&
      !(m_viewFlags & nsMsgViewFlagsType::kGroupBySort)) {
    nsMsgKey parentKey = m_keys[startOfThreadViewIndex];
    // If the thread is bigger than the hdr cache, expanding the thread
    // can be slow. Increasing the hdr cache size will help a fair amount.
    uint32_t hdrCacheSize;
    m_db->GetMsgHdrCacheSize(&hdrCacheSize);
    if (numChildren > hdrCacheSize) m_db->SetMsgHdrCacheSize(numChildren);

    // If this fails, *pNumListed will be 0, and we'll fall back to just
    // enumerating the messages in the thread below.
    rv = ListIdsInThreadOrder(threadHdr, parentKey, 1, &viewIndex, pNumListed);
    if (numChildren > hdrCacheSize) m_db->SetMsgHdrCacheSize(hdrCacheSize);
  }

  if (!*pNumListed) {
    uint32_t ignoredHeaders = 0;
    // If we're not threaded, just list em out in db order.
    for (i = 1; i <= numChildren; i++) {
      nsCOMPtr<nsIMsgDBHdr> msgHdr;
      threadHdr->GetChildHdrAt(i, getter_AddRefs(msgHdr));

      if (msgHdr != nullptr) {
        if (!(m_viewFlags & nsMsgViewFlagsType::kShowIgnored)) {
          bool killed;
          msgHdr->GetIsKilled(&killed);
          if (killed) {
            ignoredHeaders++;
            continue;
          }
        }

        nsMsgKey msgKey;
        uint32_t msgFlags, newFlags;
        msgHdr->GetMessageKey(&msgKey);
        msgHdr->GetFlags(&msgFlags);
        AdjustReadFlag(msgHdr, &msgFlags);
        SetMsgHdrAt(msgHdr, viewIndex, msgKey, msgFlags & ~MSG_VIEW_FLAGS, 1);
        // Here, we're either flat, or we're grouped - in either case,
        // level is 1. Turn off thread or elided bit if they got turned on
        // (maybe from new only view?).
        if (i > 0)
          msgHdr->AndFlags(
              ~(MSG_VIEW_FLAG_ISTHREAD | nsMsgMessageFlags::Elided), &newFlags);

        (*pNumListed)++;
        viewIndex++;
      }
    }

    if (ignoredHeaders + *pNumListed < numChildren) {
      MOZ_ASSERT_UNREACHABLE("thread corrupt in db");
      // If we've listed fewer messages than are in the thread, then the db
      // is corrupt, and we should invalidate it.
      // We'll use this rv to indicate there's something wrong with the db
      // though for now it probably won't get paid attention to.
      m_db->SetSummaryValid(false);
      rv = NS_MSG_ERROR_FOLDER_SUMMARY_OUT_OF_DATE;
    }
  }

  // We may have added too many elements (i.e., subthreads were cut).
  // XXX Fix for cross folder view case.
  if (*pNumListed < numChildren)
    RemoveRows(viewIndex, numChildren - *pNumListed);

  return rv;
}

int32_t nsMsgDBView::FindLevelInThread(nsIMsgDBHdr* msgHdr,
                                       nsMsgViewIndex startOfThread,
                                       nsMsgViewIndex viewIndex) {
  nsCOMPtr<nsIMsgDBHdr> curMsgHdr = msgHdr;
  nsMsgKey msgKey;
  msgHdr->GetMessageKey(&msgKey);

  // Look through the ancestors of the passed in msgHdr in turn, looking for
  // them in the view, up to the start of the thread. If we find an ancestor,
  // then our level is one greater than the level of the ancestor.
  while (curMsgHdr) {
    nsMsgKey parentKey;
    curMsgHdr->GetThreadParent(&parentKey);
    if (parentKey == nsMsgKey_None) break;

    // Scan up to find view index of ancestor, if any.
    for (nsMsgViewIndex indexToTry = viewIndex;
         indexToTry && indexToTry-- >= startOfThread;) {
      if (m_keys[indexToTry] == parentKey) return m_levels[indexToTry] + 1;
    }

    // If msgHdr's key is its parentKey, we'll loop forever, so protect
    // against that corruption.
    if (msgKey == parentKey || NS_FAILED(m_db->GetMsgHdrForKey(
                                   parentKey, getter_AddRefs(curMsgHdr)))) {
      NS_ERROR(
          "msgKey == parentKey, or GetMsgHdrForKey failed, this used to be an "
          "infinite loop condition");
      curMsgHdr = nullptr;
    } else {
      // Need to update msgKey so the check for a msgHdr with matching
      // key+parentKey will work after first time through loop.
      curMsgHdr->GetMessageKey(&msgKey);
    }
  }

  return 1;
}

// XXX Can this be combined with GetIndexForThread??
nsMsgViewIndex nsMsgDBView::GetThreadRootIndex(nsIMsgDBHdr* msgHdr) {
  if (!msgHdr) {
    NS_WARNING("null msgHdr parameter");
    return nsMsgViewIndex_None;
  }

  // Take advantage of the fact that we're already sorted
  // and find the thread root via a binary search.

  nsMsgViewIndex highIndex = m_keys.Length();
  nsMsgViewIndex lowIndex = 0;
  IdKey EntryInfo1, EntryInfo2;

  nsresult rv;
  uint16_t maxLen;
  eFieldType fieldType;

  // Get the custom column handler for the primary sort and pass it first
  // to GetFieldTypeAndLenForSort to get the fieldType and then either
  // GetCollationKey or GetLongField.
  nsIMsgCustomColumnHandler* colHandler = GetCurColumnHandler();

  // The following may leave fieldType undefined.
  // In this case, we can return highIndex right away since
  // it is the value returned in the default case of
  // switch (fieldType) statement below.
  rv = GetFieldTypeAndLenForSort(m_sortType, &maxLen, &fieldType, colHandler);
  NS_ENSURE_SUCCESS(rv, highIndex);

  int retStatus = 0;
  msgHdr->GetMessageKey(&EntryInfo1.id);
  msgHdr->GetFolder(&EntryInfo1.folder);
  EntryInfo1.folder->Release();

  viewSortInfo comparisonContext{
      .view = this,
      .isSecondarySort = false,
      .ascendingSort = (m_sortOrder == nsMsgViewSortOrder::ascending),
  };

  nsCOMPtr<nsIMsgDatabase> hdrDB;
  EntryInfo1.folder->GetMsgDatabase(getter_AddRefs(hdrDB));
  comparisonContext.db = hdrDB.get();

  switch (fieldType) {
    case kCollationKey:
      rv = GetCollationKey(msgHdr, m_sortType, EntryInfo1.key, colHandler);
      NS_ASSERTION(NS_SUCCEEDED(rv), "failed to create collation key");
      break;
    case kU32:
      if (m_sortType == nsMsgViewSortType::byId) {
        EntryInfo1.dword = EntryInfo1.id;
      } else {
        GetLongField(msgHdr, m_sortType, &EntryInfo1.dword, colHandler);
      }

      break;
    default:
      return highIndex;
  }

  while (highIndex > lowIndex) {
    nsMsgViewIndex tryIndex = (lowIndex + highIndex) / 2;
    // Need to adjust tryIndex if it's not a thread.
    while (m_levels[tryIndex] && tryIndex) tryIndex--;

    if (tryIndex < lowIndex) {
      NS_ERROR("try index shouldn't be less than low index");
      break;
    }

    EntryInfo2.id = m_keys[tryIndex];
    GetFolderForViewIndex(tryIndex, &EntryInfo2.folder);
    EntryInfo2.folder->Release();

    nsCOMPtr<nsIMsgDBHdr> tryHdr;
    nsCOMPtr<nsIMsgDatabase> db;
    // ### this should get the db from the folder...
    GetDBForViewIndex(tryIndex, getter_AddRefs(db));
    if (db) db->GetMsgHdrForKey(EntryInfo2.id, getter_AddRefs(tryHdr));

    if (!tryHdr) break;

    if (tryHdr == msgHdr) {
      highIndex = tryIndex;
      break;
    }

    if (fieldType == kCollationKey) {
      rv = GetCollationKey(tryHdr, m_sortType, EntryInfo2.key, colHandler);
      NS_ASSERTION(NS_SUCCEEDED(rv), "failed to create collation key");
      retStatus = FnSortIdKey(&EntryInfo1, &EntryInfo2, &comparisonContext);
    } else if (fieldType == kU32) {
      if (m_sortType == nsMsgViewSortType::byId) {
        EntryInfo2.dword = EntryInfo2.id;
      } else {
        GetLongField(tryHdr, m_sortType, &EntryInfo2.dword, colHandler);
      }

      retStatus = FnSortIdUint32(&EntryInfo1, &EntryInfo2, &comparisonContext);
    }

    if (retStatus == 0) {
      highIndex = tryIndex;
      break;
    }

    if (retStatus < 0) {
      highIndex = tryIndex;
      // We already made sure tryIndex was at a thread at the top of the loop.
    } else {
      lowIndex = tryIndex + 1;
      while (lowIndex < GetSize() && m_levels[lowIndex]) lowIndex++;
    }
  }

  nsCOMPtr<nsIMsgDBHdr> resultHdr;
  GetMsgHdrForViewIndex(highIndex, getter_AddRefs(resultHdr));

  if (resultHdr != msgHdr) {
    NS_WARNING("didn't find hdr");
    highIndex = FindHdr(msgHdr);
#ifdef DEBUG_David_Bienvenu
    if (highIndex != nsMsgViewIndex_None) {
      NS_WARNING("but find hdr did");
      printf("level of found hdr = %d\n", m_levels[highIndex]);
      ValidateSort();
    }
#endif
    return highIndex;
  }

  return msgHdr == resultHdr ? highIndex : nsMsgViewIndex_None;
}

#ifdef DEBUG_David_Bienvenu

void nsMsgDBView::InitEntryInfoForIndex(nsMsgViewIndex i, IdKey& EntryInfo) {
  nsresult rv;
  uint16_t maxLen;
  eFieldType fieldType;

  // Get the custom column handler for the primary sort and pass it first
  // to GetFieldTypeAndLenForSort to get the fieldType and then either
  // GetCollationKey or GetLongField.
  nsIMsgCustomColumnHandler* colHandler = GetCurColumnHandler();

  // The following may leave fieldType undefined.
  rv = GetFieldTypeAndLenForSort(m_sortType, &maxLen, &fieldType, colHandler);
  NS_ASSERTION(NS_SUCCEEDED(rv), "failed to obtain fieldType");

  nsCOMPtr<nsIMsgDBHdr> msgHdr;
  GetMsgHdrForViewIndex(i, getter_AddRefs(msgHdr));

  msgHdr->GetMessageKey(&EntryInfo.id);
  msgHdr->GetFolder(&EntryInfo.folder);
  EntryInfo.folder->Release();

  nsCOMPtr<nsIMsgDatabase> hdrDB;
  EntryInfo.folder->GetMsgDatabase(getter_AddRefs(hdrDB));
  switch (fieldType) {
    case kCollationKey:
      rv = GetCollationKey(msgHdr, m_sortType, EntryInfo.key, colHandler);
      NS_ASSERTION(NS_SUCCEEDED(rv), "failed to create collation key");
      break;
    case kU32:
      if (m_sortType == nsMsgViewSortType::byId)
        EntryInfo.dword = EntryInfo.id;
      else
        GetLongField(msgHdr, m_sortType, &EntryInfo.dword, colHandler);

      break;
    default:
      NS_ERROR("invalid field type");
  }
}

void nsMsgDBView::ValidateSort() {
  IdKey EntryInfo1, EntryInfo2;
  nsCOMPtr<nsIMsgDBHdr> hdr1, hdr2;

  uint16_t maxLen;
  eFieldType fieldType;

  // Get the custom column handler for the primary sort and pass it first
  // to GetFieldTypeAndLenForSort to get the fieldType and then either
  // GetCollationKey or GetLongField.
  nsIMsgCustomColumnHandler* colHandler = GetCurColumnHandler();

  // It is not entirely clear what we should do since,
  // if fieldType is not available, there is no way to know
  // how to compare the field to check for sorting.
  // So we bomb out here. It is OK since this is debug code
  // inside  #ifdef DEBUG_David_Bienvenu
  nsresult rv =
      GetFieldTypeAndLenForSort(m_sortType, &maxLen, &fieldType, colHandler);
  NS_ASSERTION(NS_SUCCEEDED(rv), "failed to obtain fieldType");

  viewSortInfo comparisonContext;
  comparisonContext.view = this;
  comparisonContext.isSecondarySort = false;
  comparisonContext.ascendingSort =
      (m_sortOrder == nsMsgViewSortOrder::ascending);
  nsCOMPtr<nsIMsgDatabase> db;
  GetDBForViewIndex(0, getter_AddRefs(db));
  // This is only for comparing collation keys - it could be any db.
  comparisonContext.db = db.get();

  for (nsMsgViewIndex i = 0; i < m_keys.Length();) {
    // Ignore non threads.
    if (m_levels[i]) {
      i++;
      continue;
    }

    // Find next header.
    nsMsgViewIndex j = i + 1;
    while (j < m_keys.Length() && m_levels[j]) j++;

    if (j == m_keys.Length()) break;

    InitEntryInfoForIndex(i, EntryInfo1);
    InitEntryInfoForIndex(j, EntryInfo2);
    const void *pValue1 = &EntryInfo1, *pValue2 = &EntryInfo2;
    int retStatus = 0;
    if (fieldType == kCollationKey)
      retStatus = FnSortIdKey(&pValue1, &pValue2, &comparisonContext);
    else if (fieldType == kU32)
      retStatus = FnSortIdUint32(&pValue1, &pValue2, &comparisonContext);

    if (retStatus &&
        (retStatus < 0) == (m_sortOrder == nsMsgViewSortOrder::ascending)) {
      NS_ERROR("view not sorted correctly");
      break;
    }
    // j is the new i.
    i = j;
  }
}

#endif

nsresult nsMsgDBView::ListUnreadIdsInThread(
    nsIMsgThread* threadHdr, nsMsgViewIndex startOfThreadViewIndex,
    uint32_t* pNumListed) {
  NS_ENSURE_ARG(threadHdr);
  // These children ids should be in thread order.
  nsMsgViewIndex viewIndex = startOfThreadViewIndex + 1;
  *pNumListed = 0;
  nsMsgKey topLevelMsgKey = m_keys[startOfThreadViewIndex];

  uint32_t numChildren;
  threadHdr->GetNumChildren(&numChildren);
  uint32_t i;
  for (i = 0; i < numChildren; i++) {
    nsCOMPtr<nsIMsgDBHdr> msgHdr;
    threadHdr->GetChildHdrAt(i, getter_AddRefs(msgHdr));
    if (msgHdr != nullptr) {
      if (!(m_viewFlags & nsMsgViewFlagsType::kShowIgnored)) {
        bool killed;
        msgHdr->GetIsKilled(&killed);
        if (killed) continue;
      }

      nsMsgKey msgKey;
      uint32_t msgFlags;
      msgHdr->GetMessageKey(&msgKey);
      msgHdr->GetFlags(&msgFlags);
      bool isRead = AdjustReadFlag(msgHdr, &msgFlags);
      if (!isRead) {
        // Just make sure flag is right in db.
        m_db->MarkHdrRead(msgHdr, false, nullptr);
        if (msgKey != topLevelMsgKey) {
          InsertMsgHdrAt(
              viewIndex, msgHdr, msgKey, msgFlags,
              FindLevelInThread(msgHdr, startOfThreadViewIndex, viewIndex));
          viewIndex++;
          (*pNumListed)++;
        }
      }
    }
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::OnHdrFlagsChanged(nsIMsgDBHdr* aHdrChanged, uint32_t aOldFlags,
                               uint32_t aNewFlags,
                               nsIDBChangeListener* aInstigator) {
  // If we're not the instigator, update flags if this key is in our view.
  if (aInstigator != this) {
    NS_ENSURE_ARG_POINTER(aHdrChanged);
    nsMsgKey msgKey;
    aHdrChanged->GetMessageKey(&msgKey);
    nsMsgViewIndex index = FindHdr(aHdrChanged);
    if (index != nsMsgViewIndex_None) {
      uint32_t viewOnlyFlags =
          m_flags[index] & (MSG_VIEW_FLAGS | nsMsgMessageFlags::Elided);

      // XXX what about saving the old view only flags, like IsThread and
      // HasChildren?
      // I think we'll want to save those away.
      m_flags[index] = aNewFlags | viewOnlyFlags;
      // Tell the view the extra flag changed, so it can
      // update the previous view, if any.
      OnExtraFlagChanged(index, aNewFlags);
      NoteChange(index, 1, nsMsgViewNotificationCode::changed);
    }

    uint32_t deltaFlags = (aOldFlags ^ aNewFlags);
    if (deltaFlags & (nsMsgMessageFlags::Read | nsMsgMessageFlags::New)) {
      nsMsgViewIndex threadIndex =
          ThreadIndexOfMsgHdr(aHdrChanged, index, nullptr, nullptr);

      // May need to fix thread counts.
      if (threadIndex != nsMsgViewIndex_None && threadIndex != index)
        NoteChange(threadIndex, 1, nsMsgViewNotificationCode::changed);
    }
  }

  // Don't need to propagate notifications, right?
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::OnHdrDeleted(nsIMsgDBHdr* aHdrChanged, nsMsgKey aParentKey,
                          int32_t aFlags, nsIDBChangeListener* aInstigator) {
  nsMsgViewIndex deletedIndex = FindHdr(aHdrChanged);
  if (IsValidIndex(deletedIndex)) {
    // Check if this message is currently selected. If it is, tell the frontend
    // to be prepared for a delete.
    nsCOMPtr<nsIMsgDBViewCommandUpdater> commandUpdater(
        do_QueryReferent(mCommandUpdater));
    bool isMsgSelected = false;
    if (mTreeSelection && commandUpdater) {
      mTreeSelection->IsSelected(deletedIndex, &isMsgSelected);
      if (isMsgSelected) commandUpdater->UpdateNextMessageAfterDelete();
    }

    RemoveByIndex(deletedIndex);

    if (isMsgSelected) {
      // Now tell the front end that the delete happened.
      commandUpdater->SelectedMessageRemoved();
    }
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::OnHdrAdded(nsIMsgDBHdr* aHdrChanged, nsMsgKey aParentKey,
                        int32_t aFlags, nsIDBChangeListener* aInstigator) {
  return OnNewHeader(aHdrChanged, aParentKey, false);
  // Probably also want to pass that parent key in, since we went to the
  // trouble of figuring out what it is.
}

NS_IMETHODIMP
nsMsgDBView::OnHdrPropertyChanged(nsIMsgDBHdr* aHdrToChange,
                                  const nsACString& property, bool aPreChange,
                                  uint32_t* aStatus,
                                  nsIDBChangeListener* aInstigator) {
  if (aPreChange) return NS_OK;

  if (aHdrToChange) {
    nsMsgViewIndex index = FindHdr(aHdrToChange);
    if (index != nsMsgViewIndex_None)
      NoteChange(index, 1, nsMsgViewNotificationCode::changed);
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::OnParentChanged(nsMsgKey aKeyChanged, nsMsgKey oldParent,
                             nsMsgKey newParent,
                             nsIDBChangeListener* aInstigator) {
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::OnAnnouncerGoingAway(nsIDBChangeAnnouncer* instigator) {
  if (m_db) {
    m_db->RemoveListener(this);
    m_db = nullptr;
  }

  int32_t saveSize = GetSize();
  ClearHdrCache();

  // This is important, because the tree will ask us for our
  // row count, which get determine from the number of keys.
  m_keys.Clear();
  // Be consistent.
  m_flags.Clear();
  m_levels.Clear();

  // Tell the tree all the rows have gone away.
  if (mTree) mTree->RowCountChanged(0, -saveSize);
  if (mJSTree) mJSTree->RowCountChanged(0, -saveSize);

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::OnEvent(nsIMsgDatabase* aDB, const char* aEvent) {
  if (!strcmp(aEvent, "DBOpened")) m_db = aDB;

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::OnReadChanged(nsIDBChangeListener* aInstigator) { return NS_OK; }

NS_IMETHODIMP
nsMsgDBView::OnJunkScoreChanged(nsIDBChangeListener* aInstigator) {
  return NS_OK;
}

void nsMsgDBView::ClearHdrCache() {
  m_cachedHdr = nullptr;
  m_cachedMsgKey = nsMsgKey_None;
}

NS_IMETHODIMP
nsMsgDBView::SetSuppressChangeNotifications(bool aSuppressChangeNotifications) {
  mSuppressChangeNotification = aSuppressChangeNotifications;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetSuppressChangeNotifications(
    bool* aSuppressChangeNotifications) {
  NS_ENSURE_ARG_POINTER(aSuppressChangeNotifications);
  *aSuppressChangeNotifications = mSuppressChangeNotification;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::NoteChange(nsMsgViewIndex firstLineChanged, int32_t numChanged,
                        nsMsgViewNotificationCodeValue changeType) {
  if ((mTree || mJSTree) && !mSuppressChangeNotification) {
    switch (changeType) {
      case nsMsgViewNotificationCode::changed:
        if (mTree)
          mTree->InvalidateRange(firstLineChanged,
                                 firstLineChanged + numChanged - 1);
        if (mJSTree)
          mJSTree->InvalidateRange(firstLineChanged,
                                   firstLineChanged + numChanged - 1);
        break;
      case nsMsgViewNotificationCode::insertOrDelete:
        if (numChanged < 0) mRemovingRow = true;

        // The caller needs to have adjusted m_keys before getting here, since
        // RowCountChanged() will call our GetRowCount().
        if (mTree) mTree->RowCountChanged(firstLineChanged, numChanged);
        if (mJSTree) mJSTree->RowCountChanged(firstLineChanged, numChanged);
        mRemovingRow = false;
        [[fallthrough]];
      case nsMsgViewNotificationCode::all:
        ClearHdrCache();
        break;
    }
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetSortOrder(nsMsgViewSortOrderValue* aSortOrder) {
  NS_ENSURE_ARG_POINTER(aSortOrder);
  *aSortOrder = m_sortOrder;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetSortType(nsMsgViewSortTypeValue* aSortType) {
  NS_ENSURE_ARG_POINTER(aSortType);
  *aSortType = m_sortType;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SetSortType(nsMsgViewSortTypeValue aSortType) {
  m_sortType = aSortType;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetViewType(nsMsgViewTypeValue* aViewType) {
  NS_ERROR("you should be overriding this");
  return NS_ERROR_UNEXPECTED;
}

NS_IMETHODIMP
nsMsgDBView::GetSecondarySortOrder(nsMsgViewSortOrderValue* aSortOrder) {
  NS_ENSURE_ARG_POINTER(aSortOrder);
  *aSortOrder = m_secondarySortOrder;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SetSecondarySortOrder(nsMsgViewSortOrderValue aSortOrder) {
  m_secondarySortOrder = aSortOrder;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetSecondarySortType(nsMsgViewSortTypeValue* aSortType) {
  NS_ENSURE_ARG_POINTER(aSortType);
  *aSortType = m_secondarySort;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SetSecondarySortType(nsMsgViewSortTypeValue aSortType) {
  m_secondarySort = aSortType;
  return NS_OK;
}

nsresult nsMsgDBView::PersistFolderInfo(nsIDBFolderInfo** dbFolderInfo) {
  nsresult rv = m_db->GetDBFolderInfo(dbFolderInfo);
  NS_ENSURE_SUCCESS(rv, rv);
  // Save off sort type and order, view type and flags.
  (*dbFolderInfo)->SetSortType(m_sortType);
  (*dbFolderInfo)->SetSortOrder(m_sortOrder);
  (*dbFolderInfo)->SetViewFlags(m_viewFlags);
  nsMsgViewTypeValue viewType;
  GetViewType(&viewType);
  (*dbFolderInfo)->SetViewType(viewType);
  return rv;
}

NS_IMETHODIMP
nsMsgDBView::GetViewFlags(nsMsgViewFlagsTypeValue* aViewFlags) {
  NS_ENSURE_ARG_POINTER(aViewFlags);
  *aViewFlags = m_viewFlags;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SetViewFlags(nsMsgViewFlagsTypeValue aViewFlags) {
  // If we're turning off threaded display, we need to expand all so that all
  // messages will be displayed.
  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay &&
      !(aViewFlags & nsMsgViewFlagsType::kThreadedDisplay)) {
    ExpandAll();
    // Invalidate the sort so sorting will do something.
    m_sortValid = false;
  }

  m_viewFlags = aViewFlags;

  if (m_viewFolder) {
    nsCOMPtr<nsIMsgDatabase> db;
    nsCOMPtr<nsIDBFolderInfo> folderInfo;
    nsresult rv = m_viewFolder->GetDBFolderInfoAndDB(getter_AddRefs(folderInfo),
                                                     getter_AddRefs(db));
    NS_ENSURE_SUCCESS(rv, rv);
    return folderInfo->SetViewFlags(aViewFlags);
  } else
    return NS_OK;
}

nsresult nsMsgDBView::MarkThreadOfMsgRead(nsMsgKey msgId,
                                          nsMsgViewIndex msgIndex,
                                          nsTArray<nsMsgKey>& idsMarkedRead,
                                          bool bRead) {
  nsCOMPtr<nsIMsgThread> threadHdr;
  nsresult rv = GetThreadContainingIndex(msgIndex, getter_AddRefs(threadHdr));
  NS_ENSURE_SUCCESS(rv, rv);

  nsMsgViewIndex threadIndex;

  NS_ASSERTION(threadHdr, "threadHdr is null");
  if (!threadHdr) return NS_MSG_MESSAGE_NOT_FOUND;

  nsCOMPtr<nsIMsgDBHdr> firstHdr;
  rv = threadHdr->GetChildHdrAt(0, getter_AddRefs(firstHdr));
  NS_ENSURE_SUCCESS(rv, rv);
  nsMsgKey firstHdrId;
  firstHdr->GetMessageKey(&firstHdrId);
  if (msgId != firstHdrId)
    threadIndex = GetIndexOfFirstDisplayedKeyInThread(threadHdr);
  else
    threadIndex = msgIndex;

  return MarkThreadRead(threadHdr, threadIndex, idsMarkedRead, bRead);
}

nsresult nsMsgDBView::MarkThreadRead(nsIMsgThread* threadHdr,
                                     nsMsgViewIndex threadIndex,
                                     nsTArray<nsMsgKey>& idsMarkedRead,
                                     bool bRead) {
  uint32_t numChildren;
  threadHdr->GetNumChildren(&numChildren);
  idsMarkedRead.SetCapacity(numChildren);
  for (int32_t childIndex = 0; childIndex < (int32_t)numChildren;
       childIndex++) {
    nsCOMPtr<nsIMsgDBHdr> msgHdr;
    threadHdr->GetChildHdrAt(childIndex, getter_AddRefs(msgHdr));
    NS_ASSERTION(msgHdr, "msgHdr is null");
    if (!msgHdr) continue;

    bool isRead;
    nsMsgKey hdrMsgId;
    msgHdr->GetMessageKey(&hdrMsgId);
    nsCOMPtr<nsIMsgDatabase> db;
    nsresult rv = GetDBForHeader(msgHdr, getter_AddRefs(db));
    NS_ENSURE_SUCCESS(rv, rv);
    db->IsRead(hdrMsgId, &isRead);

    if (isRead != bRead) {
      // MarkHdrRead will change the unread count on the thread.
      db->MarkHdrRead(msgHdr, bRead, nullptr);
      // Insert at the front. Should we insert at the end?
      idsMarkedRead.InsertElementAt(0, hdrMsgId);
    }
  }

  return NS_OK;
}

bool nsMsgDBView::AdjustReadFlag(nsIMsgDBHdr* msgHdr, uint32_t* msgFlags) {
  // If we're a cross-folder view, just bail on this.
  if (GetFolders()) return *msgFlags & nsMsgMessageFlags::Read;

  bool isRead = false;
  nsMsgKey msgKey;
  msgHdr->GetMessageKey(&msgKey);
  m_db->IsRead(msgKey, &isRead);
  // Just make sure flag is right in db.
#ifdef DEBUG_David_Bienvenu
  NS_ASSERTION(isRead == ((*msgFlags & nsMsgMessageFlags::Read) != 0),
               "msgFlags out of sync");
#endif
  if (isRead)
    *msgFlags |= nsMsgMessageFlags::Read;
  else
    *msgFlags &= ~nsMsgMessageFlags::Read;

  m_db->MarkHdrRead(msgHdr, isRead, nullptr);
  return isRead;
}

// Starting from startIndex, performs the passed in navigation, including
// any marking read needed, and returns the resultId and resultIndex of the
// destination of the navigation.  If no message is found in the view,
// it returns a resultId of nsMsgKey_None and an resultIndex of
// nsMsgViewIndex_None.
NS_IMETHODIMP
nsMsgDBView::ViewNavigate(nsMsgNavigationTypeValue motion, nsMsgKey* pResultKey,
                          nsMsgViewIndex* pResultIndex,
                          nsMsgViewIndex* pThreadIndex, bool wrap) {
  NS_ENSURE_ARG_POINTER(pResultKey);
  NS_ENSURE_ARG_POINTER(pResultIndex);
  NS_ENSURE_ARG_POINTER(pThreadIndex);

  int32_t currentIndex;
  nsMsgViewIndex startIndex;

  if (!mTreeSelection) {
    // We must be in stand alone message mode.
    currentIndex = FindViewIndex(m_currentlyDisplayedMsgKey);
  } else {
    nsresult rv = mTreeSelection->GetCurrentIndex(&currentIndex);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  startIndex = currentIndex;
  return nsMsgDBView::NavigateFromPos(motion, startIndex, pResultKey,
                                      pResultIndex, pThreadIndex, wrap);
}

nsresult nsMsgDBView::NavigateFromPos(nsMsgNavigationTypeValue motion,
                                      nsMsgViewIndex startIndex,
                                      nsMsgKey* pResultKey,
                                      nsMsgViewIndex* pResultIndex,
                                      nsMsgViewIndex* pThreadIndex, bool wrap) {
  nsresult rv = NS_OK;
  nsMsgKey resultThreadKey;
  nsMsgViewIndex curIndex;
  nsMsgViewIndex lastIndex =
      (GetSize() > 0) ? (nsMsgViewIndex)GetSize() - 1 : nsMsgViewIndex_None;
  nsMsgViewIndex threadIndex = nsMsgViewIndex_None;

  // If there aren't any messages in the view, bail out.
  if (GetSize() <= 0) {
    *pResultIndex = nsMsgViewIndex_None;
    *pResultKey = nsMsgKey_None;
    return NS_OK;
  }
  *pResultKey = nsMsgKey_None;

  switch (motion) {
    case nsMsgNavigationType::firstMessage:
      *pResultIndex = 0;
      *pResultKey = m_keys[0];
      break;
    case nsMsgNavigationType::nextMessage:
      // Return same index and id on next on last message.
      *pResultIndex = std::min(startIndex + 1, lastIndex);
      *pResultKey = m_keys[*pResultIndex];
      break;
    case nsMsgNavigationType::previousMessage:
      if (startIndex != nsMsgViewIndex_None && startIndex > 0) {
        *pResultIndex = startIndex - 1;
      }
      if (IsValidIndex(*pResultIndex)) *pResultKey = m_keys[*pResultIndex];
      break;
    case nsMsgNavigationType::lastMessage:
      *pResultIndex = lastIndex;
      *pResultKey = m_keys[*pResultIndex];
      break;
    case nsMsgNavigationType::firstFlagged:
      rv = FindFirstFlagged(pResultIndex);
      if (IsValidIndex(*pResultIndex)) *pResultKey = m_keys[*pResultIndex];
      break;
    case nsMsgNavigationType::nextFlagged:
      rv = FindNextFlagged(startIndex + 1, pResultIndex);
      if (IsValidIndex(*pResultIndex)) *pResultKey = m_keys[*pResultIndex];
      break;
    case nsMsgNavigationType::previousFlagged:
      rv = FindPrevFlagged(startIndex, pResultIndex);
      if (IsValidIndex(*pResultIndex)) *pResultKey = m_keys[*pResultIndex];
      break;
    case nsMsgNavigationType::firstNew:
      rv = FindFirstNew(pResultIndex);
      if (IsValidIndex(*pResultIndex)) *pResultKey = m_keys[*pResultIndex];
      break;
    case nsMsgNavigationType::firstUnreadMessage:
      startIndex = nsMsgViewIndex_None;
      // Note fall through - is this motion ever used?
      [[fallthrough]];
    case nsMsgNavigationType::nextUnreadMessage:
      for (curIndex = (startIndex == nsMsgViewIndex_None) ? 0 : startIndex;
           curIndex <= lastIndex && lastIndex != nsMsgViewIndex_None;
           curIndex++) {
        uint32_t flags = m_flags[curIndex];
        // Don't return start index since navigate should move.
        if (!(flags & (nsMsgMessageFlags::Read | MSG_VIEW_FLAG_DUMMY)) &&
            (curIndex != startIndex)) {
          *pResultIndex = curIndex;
          *pResultKey = m_keys[*pResultIndex];
          break;
        }

        // Check for collapsed thread with new children.
        if ((m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) &&
            flags & MSG_VIEW_FLAG_ISTHREAD &&
            flags & nsMsgMessageFlags::Elided) {
          nsCOMPtr<nsIMsgThread> threadHdr;
          GetThreadContainingIndex(curIndex, getter_AddRefs(threadHdr));
          NS_ENSURE_SUCCESS(rv, rv);

          NS_ASSERTION(threadHdr, "threadHdr is null");
          if (!threadHdr) continue;

          uint32_t numUnreadChildren;
          threadHdr->GetNumUnreadChildren(&numUnreadChildren);
          if (numUnreadChildren > 0) {
            uint32_t numExpanded;
            ExpandByIndex(curIndex, &numExpanded);
            lastIndex += numExpanded;
            if (pThreadIndex) *pThreadIndex = curIndex;
          }
        }
      }

      if (curIndex > lastIndex) {
        // Wrap around by starting at index 0.
        if (wrap) {
          nsMsgKey startKey = GetAt(startIndex);
          rv = NavigateFromPos(nsMsgNavigationType::nextUnreadMessage,
                               nsMsgViewIndex_None, pResultKey, pResultIndex,
                               pThreadIndex, false);

          if (*pResultKey == startKey) {
            // wrapped around and found start message!
            *pResultIndex = nsMsgViewIndex_None;
            *pResultKey = nsMsgKey_None;
          }
        } else {
          *pResultIndex = nsMsgViewIndex_None;
          *pResultKey = nsMsgKey_None;
        }
      }
      break;
    case nsMsgNavigationType::previousUnreadMessage:
      if (!IsValidIndex(startIndex)) break;

      rv = FindPrevUnread(m_keys[startIndex], pResultKey, &resultThreadKey);
      if (NS_SUCCEEDED(rv)) {
        *pResultIndex = FindViewIndex(*pResultKey);
        if (*pResultKey != resultThreadKey &&
            (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay)) {
          threadIndex = GetThreadIndex(*pResultIndex);
          if (*pResultIndex == nsMsgViewIndex_None) {
            nsCOMPtr<nsIMsgThread> threadHdr;
            nsCOMPtr<nsIMsgDBHdr> msgHdr;
            rv = m_db->GetMsgHdrForKey(*pResultKey, getter_AddRefs(msgHdr));
            NS_ENSURE_SUCCESS(rv, rv);
            rv = GetThreadContainingMsgHdr(msgHdr, getter_AddRefs(threadHdr));
            NS_ENSURE_SUCCESS(rv, rv);

            NS_ASSERTION(threadHdr, "threadHdr is null");
            if (threadHdr) break;

            uint32_t numUnreadChildren;
            threadHdr->GetNumUnreadChildren(&numUnreadChildren);
            if (numUnreadChildren > 0) {
              uint32_t numExpanded;
              ExpandByIndex(threadIndex, &numExpanded);
            }

            *pResultIndex = FindViewIndex(*pResultKey);
          }
        }

        if (pThreadIndex) *pThreadIndex = threadIndex;
      }
      break;
    case nsMsgNavigationType::lastUnreadMessage:
      break;
    case nsMsgNavigationType::nextUnreadThread:
      if (startIndex != nsMsgViewIndex_None) {
        ApplyCommandToIndices(nsMsgViewCommandType::markThreadRead,
                              {startIndex});
      }

      return NavigateFromPos(nsMsgNavigationType::nextUnreadMessage, startIndex,
                             pResultKey, pResultIndex, pThreadIndex, true);
    case nsMsgNavigationType::toggleThreadKilled: {
      bool resultKilled;
      nsMsgViewIndexArray selection;
      GetIndicesForSelection(selection);
      ToggleIgnored(selection, &threadIndex, &resultKilled);
      if (resultKilled) {
        return NavigateFromPos(nsMsgNavigationType::nextUnreadThread,
                               threadIndex, pResultKey, pResultIndex,
                               pThreadIndex, true);
      } else {
        *pResultIndex = nsMsgViewIndex_None;
        *pResultKey = nsMsgKey_None;
        return NS_OK;
      }
    }
    case nsMsgNavigationType::toggleSubthreadKilled: {
      bool resultKilled;
      nsMsgViewIndexArray selection;
      GetIndicesForSelection(selection);
      ToggleMessageKilled(selection, &threadIndex, &resultKilled);
      if (resultKilled) {
        return NavigateFromPos(nsMsgNavigationType::nextUnreadMessage,
                               threadIndex, pResultKey, pResultIndex,
                               pThreadIndex, true);
      } else {
        *pResultIndex = nsMsgViewIndex_None;
        *pResultKey = nsMsgKey_None;
        return NS_OK;
      }
    }
    // Check where navigate says this will take us. If we have the message
    // in the view, return it. Otherwise, return an error.
    case nsMsgNavigationType::back:
    case nsMsgNavigationType::forward:
      // Handled purely in JS.
      *pResultIndex = nsMsgViewIndex_None;
      *pResultKey = nsMsgKey_None;
      break;
    default:
      NS_ERROR("unsupported motion");
      break;
  }

  return NS_OK;
}

// Note that these routines do NOT expand collapsed threads! This mimics the
// old behaviour, but it's also because we don't remember whether a thread
// contains a flagged message the same way we remember if a thread contains
// new messages. It would be painful to dive down into each collapsed thread
// to update navigate status. We could cache this info, but it would still be
// expensive the first time this status needs to get updated.
nsresult nsMsgDBView::FindNextFlagged(nsMsgViewIndex startIndex,
                                      nsMsgViewIndex* pResultIndex) {
  nsMsgViewIndex lastIndex = (nsMsgViewIndex)GetSize() - 1;
  nsMsgViewIndex curIndex;

  *pResultIndex = nsMsgViewIndex_None;

  if (GetSize() > 0) {
    for (curIndex = startIndex; curIndex <= lastIndex; curIndex++) {
      uint32_t flags = m_flags[curIndex];
      if (flags & nsMsgMessageFlags::Marked) {
        *pResultIndex = curIndex;
        break;
      }
    }
  }

  return NS_OK;
}

nsresult nsMsgDBView::FindFirstNew(nsMsgViewIndex* pResultIndex) {
  if (m_db) {
    nsMsgKey firstNewKey = nsMsgKey_None;
    m_db->GetFirstNew(&firstNewKey);
    *pResultIndex = (firstNewKey != nsMsgKey_None) ? FindKey(firstNewKey, true)
                                                   : nsMsgViewIndex_None;
  }

  return NS_OK;
}

nsresult nsMsgDBView::FindPrevUnread(nsMsgKey startKey, nsMsgKey* pResultKey,
                                     nsMsgKey* resultThreadId) {
  nsMsgViewIndex startIndex = FindViewIndex(startKey);
  nsMsgViewIndex curIndex = startIndex;
  nsresult rv = NS_MSG_MESSAGE_NOT_FOUND;

  if (startIndex == nsMsgViewIndex_None) return NS_MSG_MESSAGE_NOT_FOUND;

  *pResultKey = nsMsgKey_None;
  if (resultThreadId) *resultThreadId = nsMsgKey_None;

  for (; (int)curIndex >= 0 && (*pResultKey == nsMsgKey_None); curIndex--) {
    uint32_t flags = m_flags[curIndex];
    if (curIndex != startIndex && flags & MSG_VIEW_FLAG_ISTHREAD &&
        flags & nsMsgMessageFlags::Elided) {
      NS_ERROR("fix this");
      // nsMsgKey threadId = m_keys[curIndex];
      // rv = m_db->GetUnreadKeyInThread(threadId, pResultKey, resultThreadId);
      if (NS_SUCCEEDED(rv) && (*pResultKey != nsMsgKey_None)) break;
    }

    if (!(flags & (nsMsgMessageFlags::Read | MSG_VIEW_FLAG_DUMMY)) &&
        (curIndex != startIndex)) {
      *pResultKey = m_keys[curIndex];
      rv = NS_OK;
      break;
    }
  }

  // Found unread message but we don't know the thread.
  NS_ASSERTION(!(*pResultKey != nsMsgKey_None && resultThreadId &&
                 *resultThreadId == nsMsgKey_None),
               "fix this");
  return rv;
}

nsresult nsMsgDBView::FindFirstFlagged(nsMsgViewIndex* pResultIndex) {
  return FindNextFlagged(0, pResultIndex);
}

nsresult nsMsgDBView::FindPrevFlagged(nsMsgViewIndex startIndex,
                                      nsMsgViewIndex* pResultIndex) {
  nsMsgViewIndex curIndex;

  *pResultIndex = nsMsgViewIndex_None;

  if (GetSize() > 0 && IsValidIndex(startIndex)) {
    curIndex = startIndex;
    do {
      if (curIndex != 0) curIndex--;

      uint32_t flags = m_flags[curIndex];
      if (flags & nsMsgMessageFlags::Marked) {
        *pResultIndex = curIndex;
        break;
      }
    } while (curIndex != 0);
  }

  return NS_OK;
}

bool nsMsgDBView::IsValidIndex(nsMsgViewIndex index) {
  return index != nsMsgViewIndex_None &&
         (index < (nsMsgViewIndex)m_keys.Length());
}

nsresult nsMsgDBView::OrExtraFlag(nsMsgViewIndex index, uint32_t orflag) {
  uint32_t flag;
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  flag = m_flags[index];
  flag |= orflag;
  m_flags[index] = flag;
  OnExtraFlagChanged(index, flag);
  return NS_OK;
}

nsresult nsMsgDBView::AndExtraFlag(nsMsgViewIndex index, uint32_t andflag) {
  uint32_t flag;
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  flag = m_flags[index];
  flag &= andflag;
  m_flags[index] = flag;
  OnExtraFlagChanged(index, flag);
  return NS_OK;
}

nsresult nsMsgDBView::SetExtraFlag(nsMsgViewIndex index, uint32_t extraflag) {
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  m_flags[index] = extraflag;
  OnExtraFlagChanged(index, extraflag);
  return NS_OK;
}

nsresult nsMsgDBView::ToggleIgnored(nsTArray<nsMsgViewIndex> const& selection,
                                    nsMsgViewIndex* resultIndex,
                                    bool* resultToggleState) {
  nsCOMPtr<nsIMsgThread> thread;

  // Ignored state is toggled based on the first selected thread.
  nsMsgViewIndex threadIndex =
      GetThreadFromMsgIndex(selection[0], getter_AddRefs(thread));
  NS_ENSURE_STATE(thread);
  uint32_t threadFlags;
  thread->GetFlags(&threadFlags);
  uint32_t ignored = threadFlags & nsMsgMessageFlags::Ignored;

  // Process threads in reverse order.
  // Otherwise collapsing the threads will invalidate the indices.
  threadIndex = nsMsgViewIndex_None;
  uint32_t numIndices = selection.Length();
  while (numIndices) {
    numIndices--;
    if (selection[numIndices] < threadIndex) {
      threadIndex =
          GetThreadFromMsgIndex(selection[numIndices], getter_AddRefs(thread));
      thread->GetFlags(&threadFlags);
      if ((threadFlags & nsMsgMessageFlags::Ignored) == ignored)
        SetThreadIgnored(thread, threadIndex, !ignored);
    }
  }

  if (resultIndex) *resultIndex = threadIndex;

  if (resultToggleState) *resultToggleState = !ignored;

  return NS_OK;
}

nsresult nsMsgDBView::ToggleMessageKilled(
    nsTArray<nsMsgViewIndex> const& selection, nsMsgViewIndex* resultIndex,
    bool* resultToggleState) {
  NS_ENSURE_ARG_POINTER(resultToggleState);

  nsCOMPtr<nsIMsgDBHdr> header;
  // Ignored state is toggled based on the first selected message.
  nsresult rv = GetMsgHdrForViewIndex(selection[0], getter_AddRefs(header));
  NS_ENSURE_SUCCESS(rv, rv);

  uint32_t msgFlags;
  header->GetFlags(&msgFlags);
  uint32_t ignored = msgFlags & nsMsgMessageFlags::Ignored;

  // Process messages in reverse order.
  // Otherwise the indices may be invalidated.
  nsMsgViewIndex msgIndex = nsMsgViewIndex_None;
  uint32_t numIndices = selection.Length();
  while (numIndices) {
    numIndices--;
    if (selection[numIndices] < msgIndex) {
      msgIndex = selection[numIndices];
      rv = GetMsgHdrForViewIndex(msgIndex, getter_AddRefs(header));
      NS_ENSURE_SUCCESS(rv, rv);
      header->GetFlags(&msgFlags);
      if ((msgFlags & nsMsgMessageFlags::Ignored) == ignored)
        SetSubthreadKilled(header, msgIndex, !ignored);
    }
  }

  if (resultIndex) *resultIndex = msgIndex;

  if (resultToggleState) *resultToggleState = !ignored;

  return NS_OK;
}

nsMsgViewIndex nsMsgDBView::GetThreadFromMsgIndex(nsMsgViewIndex index,
                                                  nsIMsgThread** threadHdr) {
  if (threadHdr == nullptr) return nsMsgViewIndex_None;
  nsMsgKey msgKey = GetAt(index);

  nsresult rv = GetThreadContainingIndex(index, threadHdr);
  NS_ENSURE_SUCCESS(rv, nsMsgViewIndex_None);

  if (*threadHdr == nullptr) return nsMsgViewIndex_None;

  nsMsgKey threadKey;
  (*threadHdr)->GetThreadKey(&threadKey);
  nsMsgViewIndex threadIndex;
  if (msgKey != threadKey)
    threadIndex = GetIndexOfFirstDisplayedKeyInThread(*threadHdr);
  else
    threadIndex = index;
  return threadIndex;
}

nsresult nsMsgDBView::ToggleWatched(nsTArray<nsMsgViewIndex> const& selection) {
  MOZ_ASSERT(!selection.IsEmpty());
  nsCOMPtr<nsIMsgThread> thread;

  // Watched state is toggled based on the first selected thread.
  nsMsgViewIndex threadIndex =
      GetThreadFromMsgIndex(selection[0], getter_AddRefs(thread));
  NS_ENSURE_STATE(thread);
  uint32_t threadFlags;
  thread->GetFlags(&threadFlags);
  uint32_t watched = threadFlags & nsMsgMessageFlags::Watched;

  // Process threads in reverse order for consistency with ToggleIgnored.
  threadIndex = nsMsgViewIndex_None;
  uint32_t numIndices = selection.Length();
  while (numIndices) {
    numIndices--;
    if (selection[numIndices] < threadIndex) {
      threadIndex =
          GetThreadFromMsgIndex(selection[numIndices], getter_AddRefs(thread));
      thread->GetFlags(&threadFlags);
      if ((threadFlags & nsMsgMessageFlags::Watched) == watched)
        SetThreadWatched(thread, threadIndex, !watched);
    }
  }

  return NS_OK;
}

nsresult nsMsgDBView::SetThreadIgnored(nsIMsgThread* thread,
                                       nsMsgViewIndex threadIndex,
                                       bool ignored) {
  if (!IsValidIndex(threadIndex)) return NS_MSG_INVALID_DBVIEW_INDEX;

  NoteChange(threadIndex, 1, nsMsgViewNotificationCode::changed);
  if (ignored) {
    nsTArray<nsMsgKey> idsMarkedRead;
    MarkThreadRead(thread, threadIndex, idsMarkedRead, true);
    CollapseByIndex(threadIndex, nullptr);
  }

  if (!m_db) return NS_ERROR_FAILURE;

  return m_db->MarkThreadIgnored(thread, m_keys[threadIndex], ignored, this);
}

nsresult nsMsgDBView::SetSubthreadKilled(nsIMsgDBHdr* header,
                                         nsMsgViewIndex msgIndex,
                                         bool ignored) {
  if (!IsValidIndex(msgIndex)) return NS_MSG_INVALID_DBVIEW_INDEX;

  NoteChange(msgIndex, 1, nsMsgViewNotificationCode::changed);

  if (!m_db) return NS_ERROR_FAILURE;

  nsresult rv = m_db->MarkHeaderKilled(header, ignored, this);
  NS_ENSURE_SUCCESS(rv, rv);

  if (ignored) {
    nsCOMPtr<nsIMsgThread> thread;
    nsresult rv;
    rv = GetThreadContainingMsgHdr(header, getter_AddRefs(thread));
    // So we didn't mark threads read.
    if (NS_FAILED(rv)) return NS_OK;

    uint32_t children, current;
    thread->GetNumChildren(&children);

    nsMsgKey headKey;
    header->GetMessageKey(&headKey);

    for (current = 0; current < children; current++) {
      nsMsgKey newKey;
      thread->GetChildKeyAt(current, &newKey);
      if (newKey == headKey) break;
    }

    // Process all messages, starting with this message.
    for (; current < children; current++) {
      nsCOMPtr<nsIMsgDBHdr> nextHdr;
      bool isKilled;

      thread->GetChildHdrAt(current, getter_AddRefs(nextHdr));
      nextHdr->GetIsKilled(&isKilled);

      // Ideally, the messages should stop processing here.
      // However, the children are ordered not by thread...
      if (isKilled) nextHdr->MarkRead(true);
    }
  }

  return NS_OK;
}

nsresult nsMsgDBView::SetThreadWatched(nsIMsgThread* thread,
                                       nsMsgViewIndex index, bool watched) {
  if (!IsValidIndex(index)) return NS_MSG_INVALID_DBVIEW_INDEX;

  nsresult rv = m_db->MarkThreadWatched(thread, m_keys[index], watched, this);
  NoteChange(index, 1, nsMsgViewNotificationCode::changed);
  return rv;
}

NS_IMETHODIMP
nsMsgDBView::GetMsgFolder(nsIMsgFolder** aMsgFolder) {
  NS_ENSURE_ARG_POINTER(aMsgFolder);
  NS_IF_ADDREF(*aMsgFolder = m_folder);
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SetViewFolder(nsIMsgFolder* aMsgFolder) {
  m_viewFolder = aMsgFolder;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetViewFolder(nsIMsgFolder** aMsgFolder) {
  NS_ENSURE_ARG_POINTER(aMsgFolder);
  NS_IF_ADDREF(*aMsgFolder = m_viewFolder);
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetNumSelected(uint32_t* aNumSelected) {
  NS_ENSURE_ARG_POINTER(aNumSelected);

  if (!mTreeSelection) {
    // No tree selection can mean we're in the stand alone mode.
    *aNumSelected = (m_currentlyDisplayedMsgKey != nsMsgKey_None) ? 1 : 0;
    return NS_OK;
  }

  bool includeCollapsedMsgs = OperateOnMsgsInCollapsedThreads();

  // We call this a lot from the front end JS, so make it fast.
  nsresult rv = mTreeSelection->GetCount((int32_t*)aNumSelected);
  if (!*aNumSelected || !includeCollapsedMsgs ||
      !(m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay))
    return rv;

  int32_t numSelectedIncludingCollapsed = *aNumSelected;
  nsMsgViewIndexArray selection;
  GetIndicesForSelection(selection);
  int32_t numIndices = selection.Length();
  // Iterate over the selection, counting up the messages in collapsed
  // threads.
  for (int32_t i = 0; i < numIndices; i++) {
    if (m_flags[selection[i]] & nsMsgMessageFlags::Elided) {
      int32_t collapsedCount;
      ExpansionDelta(selection[i], &collapsedCount);
      numSelectedIncludingCollapsed += collapsedCount;
    }
  }

  *aNumSelected = numSelectedIncludingCollapsed;
  return rv;
}

NS_IMETHODIMP
nsMsgDBView::GetNumMsgsInView(int32_t* aNumMsgs) {
  NS_ENSURE_ARG_POINTER(aNumMsgs);
  return (m_folder) ? m_folder->GetTotalMessages(false, aNumMsgs)
                    : NS_ERROR_FAILURE;
}

/**
 * @note For the IMAP delete model, this applies to both deleting and
 *       undeleting a message.
 */
NS_IMETHODIMP
nsMsgDBView::GetMsgToSelectAfterDelete(nsMsgViewIndex* msgToSelectAfterDelete) {
  NS_ENSURE_ARG_POINTER(msgToSelectAfterDelete);
  *msgToSelectAfterDelete = nsMsgViewIndex_None;

  bool isMultiSelect = false;
  int32_t startFirstRange = nsMsgViewIndex_None;
  int32_t endFirstRange = nsMsgViewIndex_None;
  if (!mTreeSelection) {
    // If we don't have a tree selection then we must be in stand alone mode.
    // return the index of the current message key as the first selected index.
    *msgToSelectAfterDelete = FindViewIndex(m_currentlyDisplayedMsgKey);
  } else {
    int32_t selectionCount;
    int32_t startRange;
    int32_t endRange;
    nsresult rv = mTreeSelection->GetRangeCount(&selectionCount);
    NS_ENSURE_SUCCESS(rv, rv);
    for (int32_t i = 0; i < selectionCount; i++) {
      rv = mTreeSelection->GetRangeAt(i, &startRange, &endRange);
      NS_ENSURE_SUCCESS(rv, rv);

      // Save off the first range in case we need it later.
      if (i == 0) {
        startFirstRange = startRange;
        endFirstRange = endRange;
      } else {
        // If the tree selection is goofy (eg adjacent or overlapping ranges),
        // complain about it, but don't try and cope.  Just live with the fact
        // that one of the deleted messages is going to end up selected.
        NS_WARNING_ASSERTION(
            endFirstRange != startRange,
            "goofy tree selection state: two ranges are adjacent!");
      }

      *msgToSelectAfterDelete =
          std::min(*msgToSelectAfterDelete, (nsMsgViewIndex)startRange);
    }

    // Multiple selection either using Ctrl, Shift, or one of the affordances
    // to select an entire thread.
    isMultiSelect = (selectionCount > 1 || (endRange - startRange) > 0);
  }

  if (*msgToSelectAfterDelete == nsMsgViewIndex_None) return NS_OK;

  nsCOMPtr<nsIMsgFolder> folder;
  GetMsgFolder(getter_AddRefs(folder));
  nsCOMPtr<nsIMsgImapMailFolder> imapFolder = do_QueryInterface(folder);
  bool thisIsImapFolder = (imapFolder != nullptr);
  // Need to update the imap-delete model, can change more than once in a
  // session.
  if (thisIsImapFolder) GetImapDeleteModel(nullptr);

  // If mail.delete_matches_sort_order is true,
  // for views sorted in descending order (newest at the top), make
  // msgToSelectAfterDelete advance in the same direction as the sort order.
  bool deleteMatchesSort = false;
  if (m_sortOrder == nsMsgViewSortOrder::descending &&
      *msgToSelectAfterDelete) {
    nsresult rv;
    nsCOMPtr<nsIPrefBranch> prefBranch(
        do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
    NS_ENSURE_SUCCESS(rv, rv);
    prefBranch->GetBoolPref("mail.delete_matches_sort_order",
                            &deleteMatchesSort);
  }

  if (mDeleteModel == nsMsgImapDeleteModels::IMAPDelete) {
    if (isMultiSelect) {
      if (deleteMatchesSort)
        *msgToSelectAfterDelete = startFirstRange - 1;
      else
        *msgToSelectAfterDelete = endFirstRange + 1;
    } else {
      if (deleteMatchesSort)
        *msgToSelectAfterDelete -= 1;
      else
        *msgToSelectAfterDelete += 1;
    }
  } else if (deleteMatchesSort) {
    *msgToSelectAfterDelete -= 1;
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetRemoveRowOnMoveOrDelete(bool* aRemoveRowOnMoveOrDelete) {
  NS_ENSURE_ARG_POINTER(aRemoveRowOnMoveOrDelete);
  nsCOMPtr<nsIMsgImapMailFolder> imapFolder = do_QueryInterface(m_folder);
  if (!imapFolder) {
    *aRemoveRowOnMoveOrDelete = true;
    return NS_OK;
  }

  // Need to update the imap-delete model, can change more than once in a
  // session.
  GetImapDeleteModel(nullptr);

  // Unlike the other imap delete models, "mark as deleted" does not remove
  // rows on delete (or move).
  *aRemoveRowOnMoveOrDelete =
      (mDeleteModel != nsMsgImapDeleteModels::IMAPDelete);
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetCurrentlyDisplayedMessage(
    nsMsgViewIndex* currentlyDisplayedMessage) {
  NS_ENSURE_ARG_POINTER(currentlyDisplayedMessage);
  *currentlyDisplayedMessage = FindViewIndex(m_currentlyDisplayedMsgKey);
  return NS_OK;
}

// If nothing selected, return an NS_ERROR.
NS_IMETHODIMP
nsMsgDBView::GetHdrForFirstSelectedMessage(nsIMsgDBHdr** hdr) {
  NS_ENSURE_ARG_POINTER(hdr);

  nsresult rv;
  nsMsgKey key;
  rv = GetKeyForFirstSelectedMessage(&key);
  // Don't assert, it is legal for nothing to be selected.
  if (NS_FAILED(rv)) return rv;

  if (key == nsMsgKey_None) {
    *hdr = nullptr;
    return NS_OK;
  }

  if (!m_db) return NS_MSG_MESSAGE_NOT_FOUND;

  rv = m_db->GetMsgHdrForKey(key, hdr);
  NS_ENSURE_SUCCESS(rv, rv);
  return NS_OK;
}

// If nothing selected, return an NS_ERROR.
NS_IMETHODIMP
nsMsgDBView::GetURIForFirstSelectedMessage(nsACString& uri) {
  nsresult rv;
  nsMsgViewIndex viewIndex;
  rv = GetViewIndexForFirstSelectedMsg(&viewIndex);
  // Don't assert, it is legal for nothing to be selected.
  if (NS_FAILED(rv)) return rv;

  return GetURIForViewIndex(viewIndex, uri);
}

NS_IMETHODIMP
nsMsgDBView::OnDeleteCompleted(bool aSucceeded) {
  if (m_deletingRows && aSucceeded) {
    uint32_t numIndices = mIndicesToNoteChange.Length();
    if (numIndices && (mTree || mJSTree)) {
      if (numIndices > 1) mIndicesToNoteChange.Sort();

      // The call to NoteChange() has to happen after we are done removing the
      // keys as NoteChange() will call RowCountChanged() which will call our
      // GetRowCount().
      if (numIndices > 1) {
        if (mTree) mTree->BeginUpdateBatch();
        if (mJSTree) mJSTree->BeginUpdateBatch();
      }

      for (uint32_t i = 0; i < numIndices; i++)
        NoteChange(mIndicesToNoteChange[i], -1,
                   nsMsgViewNotificationCode::insertOrDelete);

      if (numIndices > 1) {
        if (mTree) mTree->EndUpdateBatch();
        if (mJSTree) mJSTree->EndUpdateBatch();
      }
    }

    mIndicesToNoteChange.Clear();
  }

  m_deletingRows = false;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetDb(nsIMsgDatabase** aDB) {
  NS_ENSURE_ARG_POINTER(aDB);
  NS_IF_ADDREF(*aDB = m_db);
  return NS_OK;
}

bool nsMsgDBView::OfflineMsgSelected(
    nsTArray<nsMsgViewIndex> const& selection) {
  nsCOMPtr<nsIMsgLocalMailFolder> localFolder = do_QueryInterface(m_folder);
  if (localFolder) {
    return true;
  }

  for (nsMsgViewIndex viewIndex : selection) {
    // For cross-folder saved searches, we need to check if any message
    // is in a local folder.
    if (!m_folder) {
      nsCOMPtr<nsIMsgFolder> folder;
      GetFolderForViewIndex(viewIndex, getter_AddRefs(folder));
      nsCOMPtr<nsIMsgLocalMailFolder> localFolder = do_QueryInterface(folder);
      if (localFolder) {
        return true;
      }
    }

    uint32_t flags = m_flags[viewIndex];
    if ((flags & nsMsgMessageFlags::Offline)) {
      return true;
    }
  }

  return false;
}

bool nsMsgDBView::NonDummyMsgSelected(
    nsTArray<nsMsgViewIndex> const& selection) {
  bool includeCollapsedMsgs = OperateOnMsgsInCollapsedThreads();

  for (nsMsgViewIndex viewIndex : selection) {
    uint32_t flags = m_flags[viewIndex];
    // We now treat having a collapsed dummy message selected as if
    // the whole group was selected so we can apply commands to the group.
    if (!(flags & MSG_VIEW_FLAG_DUMMY) ||
        (flags & nsMsgMessageFlags::Elided && includeCollapsedMsgs)) {
      return true;
    }
  }

  return false;
}

NS_IMETHODIMP
nsMsgDBView::GetViewIndexForFirstSelectedMsg(nsMsgViewIndex* aViewIndex) {
  NS_ENSURE_ARG_POINTER(aViewIndex);
  // If we don't have a tree selection we must be in stand alone mode...
  if (!mTreeSelection) {
    *aViewIndex = m_currentlyDisplayedViewIndex;
    return NS_OK;
  }

  int32_t startRange;
  int32_t endRange;
  nsresult rv = mTreeSelection->GetRangeAt(0, &startRange, &endRange);
  // Don't assert, it is legal for nothing to be selected.
  if (NS_FAILED(rv)) return rv;

  // Check that the first index is valid, it may not be if nothing is selected.
  if (startRange < 0 || uint32_t(startRange) >= GetSize())
    return NS_ERROR_UNEXPECTED;

  *aViewIndex = startRange;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetKeyForFirstSelectedMessage(nsMsgKey* key) {
  NS_ENSURE_ARG_POINTER(key);
  // If we don't have a tree selection we must be in stand alone mode...
  if (!mTreeSelection) {
    *key = m_currentlyDisplayedMsgKey;
    return NS_OK;
  }

  int32_t selectionCount;
  mTreeSelection->GetRangeCount(&selectionCount);
  if (selectionCount == 0) {
    *key = nsMsgKey_None;
    return NS_OK;
  }

  int32_t startRange;
  int32_t endRange;
  nsresult rv = mTreeSelection->GetRangeAt(0, &startRange, &endRange);
  // Don't assert, it is legal for nothing to be selected.
  if (NS_FAILED(rv)) return rv;

  // Check that the first index is valid, it may not be if nothing is selected.
  if (startRange < 0 || uint32_t(startRange) >= GetSize())
    return NS_ERROR_UNEXPECTED;

  if (m_flags[startRange] & MSG_VIEW_FLAG_DUMMY)
    return NS_MSG_INVALID_DBVIEW_INDEX;

  *key = m_keys[startRange];
  return NS_OK;
}

nsCOMArray<nsIMsgFolder>* nsMsgDBView::GetFolders() { return nullptr; }

nsresult nsMsgDBView::AdjustRowCount(int32_t rowCountBeforeSort,
                                     int32_t rowCountAfterSort) {
  int32_t rowChange = rowCountAfterSort - rowCountBeforeSort;

  if (rowChange) {
    // This is not safe to use when you have a selection.
    // RowCountChanged() will call AdjustSelection().
    uint32_t numSelected = 0;
    GetNumSelected(&numSelected);
    NS_ASSERTION(
        numSelected == 0,
        "it is not save to call AdjustRowCount() when you have a selection");

    if (mTree) mTree->RowCountChanged(0, rowChange);
    if (mJSTree) mJSTree->RowCountChanged(0, rowChange);
  }

  return NS_OK;
}

nsresult nsMsgDBView::GetImapDeleteModel(nsIMsgFolder* folder) {
  nsresult rv = NS_OK;
  nsCOMPtr<nsIMsgIncomingServer> server;
  // For the search view.
  if (folder)
    folder->GetServer(getter_AddRefs(server));
  else if (m_folder)
    m_folder->GetServer(getter_AddRefs(server));

  nsCOMPtr<nsIImapIncomingServer> imapServer = do_QueryInterface(server, &rv);
  if (NS_SUCCEEDED(rv) && imapServer) imapServer->GetDeleteModel(&mDeleteModel);

  return rv;
}

//
// CanDrop
//
// Can't drop on the thread pane.
//
NS_IMETHODIMP
nsMsgDBView::CanDrop(int32_t index, int32_t orient,
                     mozilla::dom::DataTransfer* dataTransfer, bool* _retval) {
  NS_ENSURE_ARG_POINTER(_retval);
  *_retval = false;

  return NS_OK;
}

//
// Drop
//
// Can't drop on the thread pane.
//
NS_IMETHODIMP
nsMsgDBView::Drop(int32_t row, int32_t orient,
                  mozilla::dom::DataTransfer* dataTransfer) {
  return NS_OK;
}

//
// IsSorted
//
// ...
//
NS_IMETHODIMP
nsMsgDBView::IsSorted(bool* _retval) {
  *_retval = false;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SelectFolderMsgByKey(nsIMsgFolder* aFolder, nsMsgKey aKey) {
  NS_ENSURE_ARG_POINTER(aFolder);
  if (aKey == nsMsgKey_None) return NS_ERROR_FAILURE;

  // This is OK for non search views.

  nsMsgViewIndex viewIndex = FindKey(aKey, true /* expand */);

  if (mTree) mTreeSelection->SetCurrentIndex(viewIndex);

  // Make sure the current message is once again visible in the thread pane
  // so we don't have to go search for it in the thread pane.
  if (mTree && viewIndex != nsMsgViewIndex_None) {
    mTreeSelection->Select(viewIndex);
    mTree->EnsureRowIsVisible(viewIndex);
  }

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::SelectMsgByKey(nsMsgKey aKey) {
  NS_ASSERTION(aKey != nsMsgKey_None, "bad key");
  if (aKey == nsMsgKey_None) return NS_OK;

  // Use SaveAndClearSelection()
  // and RestoreSelection() so that we'll clear the current selection
  // but pass in a different key array so that we'll
  // select (and load) the desired message.

  AutoTArray<nsMsgKey, 1> preservedSelection;
  nsresult rv = SaveAndClearSelection(nullptr, preservedSelection);
  NS_ENSURE_SUCCESS(rv, rv);

  // Now, restore our desired selection.
  AutoTArray<nsMsgKey, 1> keyArray;
  keyArray.AppendElement(aKey);

  // If the key was not found
  // (this can happen with "remember last selected message")
  // nothing will be selected.
  rv = RestoreSelection(aKey, keyArray);
  NS_ENSURE_SUCCESS(rv, rv);
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::CloneDBView(nsIMessenger* aMessengerInstance,
                         nsIMsgWindow* aMsgWindow,
                         nsIMsgDBViewCommandUpdater* aCmdUpdater,
                         nsIMsgDBView** _retval) {
  nsMsgDBView* newMsgDBView = new nsMsgDBView();

  nsresult rv =
      CopyDBView(newMsgDBView, aMessengerInstance, aMsgWindow, aCmdUpdater);
  NS_ENSURE_SUCCESS(rv, rv);

  NS_IF_ADDREF(*_retval = newMsgDBView);
  return NS_OK;
}

nsresult nsMsgDBView::CopyDBView(nsMsgDBView* aNewMsgDBView,
                                 nsIMessenger* aMessengerInstance,
                                 nsIMsgWindow* aMsgWindow,
                                 nsIMsgDBViewCommandUpdater* aCmdUpdater) {
  NS_ENSURE_ARG_POINTER(aNewMsgDBView);
  if (aMsgWindow) {
    aNewMsgDBView->mMsgWindowWeak = do_GetWeakReference(aMsgWindow);
    aMsgWindow->SetOpenFolder(m_viewFolder ? m_viewFolder : m_folder);
  }

  aNewMsgDBView->mMessengerWeak = do_GetWeakReference(aMessengerInstance);
  aNewMsgDBView->mCommandUpdater = do_GetWeakReference(aCmdUpdater);
  aNewMsgDBView->m_folder = m_folder;
  aNewMsgDBView->m_viewFlags = m_viewFlags;
  aNewMsgDBView->m_sortOrder = m_sortOrder;
  aNewMsgDBView->m_sortType = m_sortType;
  aNewMsgDBView->m_curCustomColumn = m_curCustomColumn;
  aNewMsgDBView->m_secondarySort = m_secondarySort;
  aNewMsgDBView->m_secondarySortOrder = m_secondarySortOrder;
  aNewMsgDBView->m_secondaryCustomColumn = m_secondaryCustomColumn;
  aNewMsgDBView->m_db = m_db;
  if (m_db) aNewMsgDBView->m_db->AddListener(aNewMsgDBView);

  aNewMsgDBView->mIsNews = mIsNews;
  aNewMsgDBView->mIsRss = mIsRss;
  aNewMsgDBView->mIsXFVirtual = mIsXFVirtual;
  aNewMsgDBView->mShowSizeInLines = mShowSizeInLines;
  aNewMsgDBView->mDeleteModel = mDeleteModel;
  aNewMsgDBView->m_flags = m_flags.Clone();
  aNewMsgDBView->m_levels = m_levels.Clone();
  aNewMsgDBView->m_keys = m_keys.Clone();

  aNewMsgDBView->m_customColumnHandlerIDs = m_customColumnHandlerIDs.Clone();
  aNewMsgDBView->m_customColumnHandlers.AppendObjects(m_customColumnHandlers);

  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::GetSearchSession(nsIMsgSearchSession** aSession) {
  NS_ASSERTION(false, "should be overridden by child class");
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP
nsMsgDBView::SetSearchSession(nsIMsgSearchSession* aSession) {
  NS_ASSERTION(false, "should be overridden by child class");
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP
nsMsgDBView::GetSupportsThreading(bool* aResult) {
  NS_ENSURE_ARG_POINTER(aResult);
  *aResult = true;
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::FindIndexFromKey(nsMsgKey aMsgKey, bool aExpand,
                              nsMsgViewIndex* aIndex) {
  NS_ENSURE_ARG_POINTER(aIndex);
  *aIndex = FindKey(aMsgKey, aExpand);
  return NS_OK;
}

NS_IMETHODIMP
nsMsgDBView::FindIndexOfMsgHdr(nsIMsgDBHdr* aMsgHdr, bool aExpand,
                               nsMsgViewIndex* aIndex) {
  NS_ENSURE_ARG(aMsgHdr);
  NS_ENSURE_ARG_POINTER(aIndex);

  if (m_viewFlags & nsMsgViewFlagsType::kThreadedDisplay) {
    nsMsgViewIndex threadIndex = ThreadIndexOfMsgHdr(aMsgHdr);
    if (threadIndex != nsMsgViewIndex_None) {
      if (aExpand && (m_flags[threadIndex] & nsMsgMessageFlags::Elided))
        ExpandByIndex(threadIndex, nullptr);

      *aIndex = FindHdr(aMsgHdr, threadIndex);
    } else {
      *aIndex = nsMsgViewIndex_None;
    }
  } else {
    *aIndex = FindHdr(aMsgHdr);
  }

  return NS_OK;
}

static void getDateFormatPref(nsIPrefBranch* _prefBranch,
                              const char* _prefLocalName,
                              nsDateFormatSelectorComm& _format) {
  // Read.
  int32_t nFormatSetting(0);
  nsresult result = _prefBranch->GetIntPref(_prefLocalName, &nFormatSetting);
  if (NS_SUCCEEDED(result)) {
    // Translate.
    nsDateFormatSelectorComm res;
    res = static_cast<nsDateFormatSelectorComm>(nFormatSetting);
    // Transfer if valid.
    if (res >= kDateFormatNone && res <= kDateFormatShort)
      _format = res;
    else if (res == kDateFormatWeekday)
      _format = res;
  }
}

nsresult nsMsgDBView::InitDisplayFormats() {
  m_dateFormatsInitialized = true;

  nsresult rv = NS_OK;
  nsCOMPtr<nsIPrefService> prefs =
      do_GetService(NS_PREFSERVICE_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);
  nsCOMPtr<nsIPrefBranch> dateFormatPrefs;
  rv = prefs->GetBranch("mail.ui.display.dateformat.",
                        getter_AddRefs(dateFormatPrefs));
  NS_ENSURE_SUCCESS(rv, rv);

  getDateFormatPref(dateFormatPrefs, "default", m_dateFormatDefault);
  getDateFormatPref(dateFormatPrefs, "thisweek", m_dateFormatThisWeek);
  getDateFormatPref(dateFormatPrefs, "today", m_dateFormatToday);
  return rv;
}

void nsMsgDBView::SetMRUTimeForFolder(nsIMsgFolder* folder) {
  uint32_t seconds;
  PRTime2Seconds(PR_Now(), &seconds);
  nsAutoCString nowStr;
  nowStr.AppendInt(seconds);
  folder->SetStringProperty(MRU_TIME_PROPERTY, nowStr);
}

nsMsgDBView::nsMsgViewHdrEnumerator::nsMsgViewHdrEnumerator(nsMsgDBView* view) {
  // We need to clone the view because the caller may clear the
  // current view immediately. It also makes it easier to expand all
  // if we're working on a copy.
  nsCOMPtr<nsIMsgDBView> clonedView;
  view->CloneDBView(nullptr, nullptr, nullptr, getter_AddRefs(clonedView));
  m_view = static_cast<nsMsgDBView*>(clonedView.get());
  // Make sure we enumerate over collapsed threads by expanding all.
  m_view->ExpandAll();
  m_curHdrIndex = 0;
}

nsMsgDBView::nsMsgViewHdrEnumerator::~nsMsgViewHdrEnumerator() {
  if (m_view) m_view->Close();
}

NS_IMETHODIMP
nsMsgDBView::nsMsgViewHdrEnumerator::GetNext(nsIMsgDBHdr** aItem) {
  NS_ENSURE_ARG_POINTER(aItem);

  if (m_curHdrIndex >= m_view->GetSize()) return NS_ERROR_FAILURE;

  // Ignore dummy header. We won't have empty groups, so
  // we know the view index is good.
  if (m_view->m_flags[m_curHdrIndex] & MSG_VIEW_FLAG_DUMMY) ++m_curHdrIndex;

  nsCOMPtr<nsIMsgDBHdr> nextHdr;

  nsresult rv =
      m_view->GetMsgHdrForViewIndex(m_curHdrIndex++, getter_AddRefs(nextHdr));
  nextHdr.forget(aItem);
  return rv;
}

NS_IMETHODIMP
nsMsgDBView::nsMsgViewHdrEnumerator::HasMoreElements(bool* aResult) {
  NS_ENSURE_ARG_POINTER(aResult);
  *aResult = m_curHdrIndex < m_view->GetSize();
  return NS_OK;
}

nsresult nsMsgDBView::GetViewEnumerator(nsIMsgEnumerator** enumerator) {
  NS_IF_ADDREF(*enumerator = new nsMsgViewHdrEnumerator(this));
  return (*enumerator) ? NS_OK : NS_ERROR_OUT_OF_MEMORY;
}

nsresult nsMsgDBView::GetDBForHeader(nsIMsgDBHdr* msgHdr, nsIMsgDatabase** db) {
  nsCOMPtr<nsIMsgFolder> folder;
  nsresult rv = msgHdr->GetFolder(getter_AddRefs(folder));
  NS_ENSURE_SUCCESS(rv, rv);
  return folder->GetMsgDatabase(db);
}

/**
 * Determine whether junk commands should be enabled on this view.
 * Junk commands are always enabled for mail. For nntp and rss, they
 * may be selectively enabled using an inherited folder property.
 *
 * @param  aViewIndex  view index of the message to check
 * @return             true if junk controls should be enabled
 */
bool nsMsgDBView::JunkControlsEnabled(nsMsgViewIndex aViewIndex) {
  // For normal mail, junk commands are always enabled.
  if (!(mIsNews || mIsRss || mIsXFVirtual)) return true;

  // We need to check per message or folder.
  nsCOMPtr<nsIMsgFolder> folder = m_folder;
  if (!folder && IsValidIndex(aViewIndex))
    GetFolderForViewIndex(aViewIndex, getter_AddRefs(folder));

  if (folder) {
    // Check if this is a mail message in search folders.
    if (mIsXFVirtual) {
      nsCOMPtr<nsIMsgIncomingServer> server;
      folder->GetServer(getter_AddRefs(server));
      nsAutoCString type;
      if (server) server->GetType(type);

      if (!(type.LowerCaseEqualsLiteral("nntp") ||
            type.LowerCaseEqualsLiteral("rss")))
        return true;
    }

    // For rss and news, check the inherited folder property.
    nsAutoCString junkEnableOverride;
    folder->GetInheritedStringProperty("dobayes.mailnews@mozilla.org#junk",
                                       junkEnableOverride);
    if (junkEnableOverride.EqualsLiteral("true")) return true;
  }

  return false;
}