/* -*- Mode: C++; tab-width: 8; 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/. */

/*
  nsPluginsDirWin.cpp

  Windows implementation of the nsPluginsDir/nsPluginsFile classes.

  by Alex Musil
 */

#include "mozilla/ArrayUtils.h"  // ArrayLength
#include "mozilla/DebugOnly.h"
#include "mozilla/Printf.h"

#include "nsPluginsDir.h"
#include "prlink.h"
#include "plstr.h"

#include "windows.h"
#include "winbase.h"

#include "nsString.h"
#include "nsIFile.h"
#include "nsUnicharUtils.h"

using namespace mozilla;

/* Local helper functions */

static char* GetKeyValue(void* verbuf, const WCHAR* key, UINT language,
                         UINT codepage) {
  WCHAR keybuf[64];  // plenty for the template below, with the longest key
                     // we use (currently "FileDescription")
  const WCHAR keyFormat[] = L"\\StringFileInfo\\%04X%04X\\%ls";
  WCHAR* buf = nullptr;
  UINT blen;

  if (_snwprintf_s(keybuf, ArrayLength(keybuf), _TRUNCATE, keyFormat, language,
                   codepage, key) < 0) {
    MOZ_ASSERT_UNREACHABLE("plugin info key too long for buffer!");
    return nullptr;
  }

  if (::VerQueryValueW(verbuf, keybuf, (void**)&buf, &blen) == 0 ||
      buf == nullptr || blen == 0) {
    return nullptr;
  }

  return PL_strdup(NS_ConvertUTF16toUTF8(buf, blen).get());
}

static char* GetVersion(void* verbuf) {
  VS_FIXEDFILEINFO* fileInfo;
  UINT fileInfoLen;

  ::VerQueryValueW(verbuf, L"\\", (void**)&fileInfo, &fileInfoLen);

  if (fileInfo) {
    return mozilla::Smprintf("%ld.%ld.%ld.%ld",
                             HIWORD(fileInfo->dwFileVersionMS),
                             LOWORD(fileInfo->dwFileVersionMS),
                             HIWORD(fileInfo->dwFileVersionLS),
                             LOWORD(fileInfo->dwFileVersionLS))
        .release();
  }

  return nullptr;
}

// Returns a boolean indicating if the key's value contains a string
// entry equal to "1" or "0". No entry for the key returns false.
static bool GetBooleanFlag(void* verbuf, const WCHAR* key, UINT language,
                           UINT codepage) {
  char* flagStr = GetKeyValue(verbuf, key, language, codepage);
  if (!flagStr) {
    return false;
  }
  bool result = (PL_strncmp("1", flagStr, 1) == 0);
  PL_strfree(flagStr);
  return result;
}

static uint32_t CalculateVariantCount(char* mimeTypes) {
  uint32_t variants = 1;

  if (!mimeTypes) return 0;

  char* index = mimeTypes;
  while (*index) {
    if (*index == '|') variants++;

    ++index;
  }
  return variants;
}

static char** MakeStringArray(uint32_t variants, char* data) {
  // The number of variants has been calculated based on the mime
  // type array. Plugins are not explicitely required to match
  // this number in two other arrays: file extention array and mime
  // description array, and some of them actually don't.
  // We should handle such situations gracefully

  if ((variants <= 0) || !data) return nullptr;

  char** array = (char**)calloc(variants, sizeof(char*));
  if (!array) return nullptr;

  char* start = data;

  for (uint32_t i = 0; i < variants; i++) {
    char* p = PL_strchr(start, '|');
    if (p) *p = 0;

    array[i] = PL_strdup(start);

    if (!p) {
      // nothing more to look for, fill everything left
      // with empty strings and break
      while (++i < variants) array[i] = PL_strdup("");

      break;
    }

    start = ++p;
  }
  return array;
}

static void FreeStringArray(uint32_t variants, char** array) {
  if ((variants == 0) || !array) return;

  for (uint32_t i = 0; i < variants; i++) {
    if (array[i]) {
      PL_strfree(array[i]);
      array[i] = nullptr;
    }
  }
  free(array);
}

static bool CanLoadPlugin(char16ptr_t aBinaryPath) {
#if defined(_M_IX86) || defined(_M_X64) || defined(_M_IA64)
  bool canLoad = false;

  HANDLE file =
      CreateFileW(aBinaryPath, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE,
                  nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
  if (file != INVALID_HANDLE_VALUE) {
    HANDLE map = CreateFileMappingW(file, nullptr, PAGE_READONLY, 0,
                                    GetFileSize(file, nullptr), nullptr);
    if (map != nullptr) {
      LPVOID mapView = MapViewOfFile(map, FILE_MAP_READ, 0, 0, 0);
      if (mapView != nullptr) {
        if (((IMAGE_DOS_HEADER*)mapView)->e_magic == IMAGE_DOS_SIGNATURE) {
          long peImageHeaderStart = (((IMAGE_DOS_HEADER*)mapView)->e_lfanew);
          if (peImageHeaderStart != 0L) {
            DWORD arch =
                (((IMAGE_NT_HEADERS*)((LPBYTE)mapView + peImageHeaderStart))
                     ->FileHeader.Machine);
#  ifdef _M_IX86
            canLoad = (arch == IMAGE_FILE_MACHINE_I386);
#  elif defined(_M_X64)
            canLoad = (arch == IMAGE_FILE_MACHINE_AMD64);
#  elif defined(_M_IA64)
            canLoad = (arch == IMAGE_FILE_MACHINE_IA64);
#  endif
          }
        }
        UnmapViewOfFile(mapView);
      }
      CloseHandle(map);
    }
    CloseHandle(file);
  }

  return canLoad;
#else
  // Assume correct binaries for unhandled cases.
  return true;
#endif
}

/* nsPluginsDir implementation */

// The file name must be in the form "np*.dll"
bool nsPluginsDir::IsPluginFile(nsIFile* file) {
  nsAutoString path;
  if (NS_FAILED(file->GetPath(path))) return false;

  // this is most likely a path, so skip to the filename
  auto filename = Substring(path, path.RFindChar('\\') + 1);
  // The file name must have at least one character between "np" and ".dll".
  if (filename.Length() < 7) {
    return false;
  }

  ToLowerCase(filename);
  if (StringBeginsWith(filename, u"np"_ns) &&
      StringEndsWith(filename, u".dll"_ns)) {
    // don't load OJI-based Java plugins
    if (StringBeginsWith(filename, u"npoji"_ns) ||
        StringBeginsWith(filename, u"npjava"_ns))
      return false;
    return true;
  }

  return false;
}

/* nsPluginFile implementation */

nsPluginFile::nsPluginFile(nsIFile* file) : mPlugin(file) {
  // nada
}

nsPluginFile::~nsPluginFile() {
  // nada
}

/**
 * Loads the plugin into memory using NSPR's shared-library loading
 * mechanism. Handles platform differences in loading shared libraries.
 */
nsresult nsPluginFile::LoadPlugin(PRLibrary** outLibrary) {
  if (!mPlugin) return NS_ERROR_NULL_POINTER;

  nsAutoString pluginFilePath;
  mPlugin->GetPath(pluginFilePath);

  nsAutoString pluginFolderPath = pluginFilePath;
  int32_t idx = pluginFilePath.RFindChar('\\');
  pluginFolderPath.SetLength(idx);

  BOOL restoreOrigDir = FALSE;
  WCHAR aOrigDir[MAX_PATH + 1];
  DWORD dwCheck = GetCurrentDirectoryW(MAX_PATH, aOrigDir);
  NS_ASSERTION(dwCheck <= MAX_PATH + 1, "Error in Loading plugin");

  if (dwCheck <= MAX_PATH + 1) {
    restoreOrigDir = SetCurrentDirectoryW(pluginFolderPath.get());
    NS_ASSERTION(restoreOrigDir, "Error in Loading plugin");
  }

  // Temporarily add the current directory back to the DLL load path.
  SetDllDirectory(nullptr);

  nsresult rv = mPlugin->Load(outLibrary);
  if (NS_FAILED(rv)) *outLibrary = nullptr;

  SetDllDirectory(L"");

  if (restoreOrigDir) {
    DebugOnly<BOOL> bCheck = SetCurrentDirectoryW(aOrigDir);
    NS_ASSERTION(bCheck, "Error in Loading plugin");
  }

  return rv;
}

/**
 * Obtains all of the information currently available for this plugin.
 */
nsresult nsPluginFile::GetPluginInfo(nsPluginInfo& info,
                                     PRLibrary** outLibrary) {
  *outLibrary = nullptr;

  nsresult rv = NS_OK;
  DWORD zerome, versionsize;
  void* verbuf = nullptr;

  if (!mPlugin) return NS_ERROR_NULL_POINTER;

  nsAutoString fullPath;
  if (NS_FAILED(rv = mPlugin->GetPath(fullPath))) return rv;

  if (!CanLoadPlugin(fullPath.get())) return NS_ERROR_FAILURE;

  nsAutoString fileName;
  if (NS_FAILED(rv = mPlugin->GetLeafName(fileName))) return rv;

  LPCWSTR lpFilepath = fullPath.get();

  versionsize = ::GetFileVersionInfoSizeW(lpFilepath, &zerome);

  if (versionsize > 0) verbuf = malloc(versionsize);
  if (!verbuf) return NS_ERROR_OUT_OF_MEMORY;

  if (::GetFileVersionInfoW(lpFilepath, 0, versionsize, verbuf)) {
    // TODO: get appropriately-localized info from plugin file
    UINT lang = 1033;  // language = English, 0x409
    UINT cp = 1252;    // codepage = Western, 0x4E4
    info.fName = GetKeyValue(verbuf, L"ProductName", lang, cp);
    info.fDescription = GetKeyValue(verbuf, L"FileDescription", lang, cp);
    info.fSupportsAsyncRender =
        GetBooleanFlag(verbuf, L"AsyncDrawingSupport", lang, cp);

    char* mimeType = GetKeyValue(verbuf, L"MIMEType", lang, cp);
    char* mimeDescription = GetKeyValue(verbuf, L"FileOpenName", lang, cp);
    char* extensions = GetKeyValue(verbuf, L"FileExtents", lang, cp);

    info.fVariantCount = CalculateVariantCount(mimeType);
    info.fMimeTypeArray = MakeStringArray(info.fVariantCount, mimeType);
    info.fMimeDescriptionArray =
        MakeStringArray(info.fVariantCount, mimeDescription);
    info.fExtensionArray = MakeStringArray(info.fVariantCount, extensions);
    info.fFullPath = PL_strdup(NS_ConvertUTF16toUTF8(fullPath).get());
    info.fFileName = PL_strdup(NS_ConvertUTF16toUTF8(fileName).get());
    info.fVersion = GetVersion(verbuf);

    PL_strfree(mimeType);
    PL_strfree(mimeDescription);
    PL_strfree(extensions);
  } else {
    rv = NS_ERROR_FAILURE;
  }

  free(verbuf);

  return rv;
}

nsresult nsPluginFile::FreePluginInfo(nsPluginInfo& info) {
  if (info.fName) PL_strfree(info.fName);

  if (info.fDescription) PL_strfree(info.fDescription);

  if (info.fMimeTypeArray)
    FreeStringArray(info.fVariantCount, info.fMimeTypeArray);

  if (info.fMimeDescriptionArray)
    FreeStringArray(info.fVariantCount, info.fMimeDescriptionArray);

  if (info.fExtensionArray)
    FreeStringArray(info.fVariantCount, info.fExtensionArray);

  if (info.fFullPath) PL_strfree(info.fFullPath);

  if (info.fFileName) PL_strfree(info.fFileName);

  if (info.fVersion) free(info.fVersion);

  ZeroMemory((void*)&info, sizeof(info));

  return NS_OK;
}