/* 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/. */

#ifndef nsHtml5TreeOpExecutor_h
#define nsHtml5TreeOpExecutor_h

#include "nsAtom.h"
#include "nsTraceRefcnt.h"
#include "nsHtml5TreeOperation.h"
#include "nsHtml5SpeculativeLoad.h"
#include "nsTArray.h"
#include "nsContentSink.h"
#include "nsNodeInfoManager.h"
#include "nsHtml5DocumentMode.h"
#include "nsIScriptElement.h"
#include "nsIParser.h"
#include "nsAHtml5TreeOpSink.h"
#include "nsHtml5TreeOpStage.h"
#include "nsIURI.h"
#include "nsTHashSet.h"
#include "nsHashKeys.h"
#include "mozilla/LinkedList.h"
#include "nsHtml5DocumentBuilder.h"
#include "nsCharsetSource.h"

class nsHtml5Parser;
class nsHtml5StreamParser;
class nsIContent;
namespace mozilla {
namespace dom {
class Document;
}
}  // namespace mozilla

class nsHtml5TreeOpExecutor final
    : public nsHtml5DocumentBuilder,
      public nsIContentSink,
      public nsAHtml5TreeOpSink,
      public mozilla::LinkedListElement<nsHtml5TreeOpExecutor> {
  friend class nsHtml5FlushLoopGuard;
  typedef mozilla::dom::ReferrerPolicy ReferrerPolicy;
  using Encoding = mozilla::Encoding;
  template <typename T>
  using NotNull = mozilla::NotNull<T>;

 public:
  NS_DECL_ISUPPORTS_INHERITED

 private:
#ifdef DEBUG_NS_HTML5_TREE_OP_EXECUTOR_FLUSH
  static uint32_t sAppendBatchMaxSize;
  static uint32_t sAppendBatchSlotsExamined;
  static uint32_t sAppendBatchExaminations;
  static uint32_t sLongestTimeOffTheEventLoop;
  static uint32_t sTimesFlushLoopInterrupted;
#endif

  /**
   * Whether EOF needs to be suppressed
   */
  bool mSuppressEOF;

  bool mReadingFromStage;
  nsTArray<nsHtml5TreeOperation> mOpQueue;
  nsHtml5StreamParser* mStreamParser;

  /**
   * URLs already preloaded/preloading.
   */
  nsTHashSet<nsCString> mPreloadedURLs;

  nsCOMPtr<nsIURI> mSpeculationBaseURI;

  nsCOMPtr<nsIURI> mViewSourceBaseURI;

  /**
   * Whether the parser has started
   */
  bool mStarted;

  nsHtml5TreeOpStage mStage;

  bool mRunFlushLoopOnStack;

  bool mCallContinueInterruptedParsingIfEnabled;

  /**
   * Whether this executor has already complained about matters related
   * to character encoding declarations.
   */
  bool mAlreadyComplainedAboutCharset;

  /**
   * Whether this executor has already complained about the tree being too
   * deep.
   */
  bool mAlreadyComplainedAboutDeepTree;

 public:
  nsHtml5TreeOpExecutor();

 protected:
  virtual ~nsHtml5TreeOpExecutor();

 public:
  // nsIContentSink

  /**
   * Unimplemented. For interface compat only.
   */
  NS_IMETHOD WillParse() override;

  NS_IMETHOD WillBuildModel(nsDTDMode /* unused */) override {
    return WillBuildModel();
  }
  nsresult WillBuildModel();

  /**
   * Emits EOF.
   */
  NS_IMETHOD DidBuildModel(bool aTerminated) override;

  /**
   * Forwards to nsContentSink
   */
  NS_IMETHOD WillInterrupt() override;

  /**
   * Unimplemented. For interface compat only.
   */
  void WillResume() override;

  virtual nsIContentSink* AsExecutor() override { return this; }

  virtual void InitialTranslationCompleted() override;

  /**
   * Sets the parser.
   */
  NS_IMETHOD SetParser(nsParserBase* aParser) override;

  /**
   * No-op for backwards compat.
   */
  virtual void FlushPendingNotifications(mozilla::FlushType aType) override;

  /**
   * Don't call. For interface compat only.
   */
  virtual void SetDocumentCharset(NotNull<const Encoding*> aEncoding) override {
    MOZ_ASSERT_UNREACHABLE("No one should call this.");
  }

  /**
   * Returns the document.
   */
  virtual nsISupports* GetTarget() override;

  virtual void ContinueInterruptedParsingAsync() override;

  bool IsScriptExecuting() override { return IsScriptExecutingImpl(); }

  // Not from interface

  void SetStreamParser(nsHtml5StreamParser* aStreamParser) {
    mStreamParser = aStreamParser;
  }

  void InitializeDocWriteParserState(nsAHtml5TreeBuilderState* aState,
                                     int32_t aLine);

  bool IsScriptEnabled();

  virtual nsresult MarkAsBroken(nsresult aReason) override;

  void StartLayout(bool* aInterrupted);

  void PauseDocUpdate(bool* aInterrupted);

  void FlushSpeculativeLoads();

  void RunFlushLoop();

  nsresult FlushDocumentWrite();

  void CommitToInternalEncoding();

  [[nodiscard]] bool TakeOpsFromStage();

  void MaybeSuspend();

  void Start();

  void SetDocumentCharsetAndSource(NotNull<const Encoding*> aEncoding,
                                   nsCharsetSource aCharsetSource);

  void UpdateCharsetSource(nsCharsetSource aCharsetSource);

  void NeedsCharsetSwitchTo(NotNull<const Encoding*> aEncoding, int32_t aSource,
                            uint32_t aLineNumber);

  void MaybeComplainAboutCharset(const char* aMsgId, bool aError,
                                 uint32_t aLineNumber);

  void ComplainAboutBogusProtocolCharset(mozilla::dom::Document* aDoc,
                                         bool aUnrecognized);

  void MaybeComplainAboutDeepTree(uint32_t aLineNumber);

  bool HasStarted() { return mStarted; }

  bool IsFlushing() { return mFlushState >= eInFlush; }

#ifdef DEBUG
  bool IsInFlushLoop() { return mRunFlushLoopOnStack; }
#endif

  void RunScript(nsIContent* aScriptElement);

  /**
   * Flush the operations from the tree operations from the argument
   * queue unconditionally. (This is for the main thread case.)
   */
  [[nodiscard]] virtual bool MoveOpsFrom(
      nsTArray<nsHtml5TreeOperation>& aOpQueue) override;

  void ClearOpQueue();

  void RemoveFromStartOfOpQueue(size_t aNumberOfOpsToRemove);

  inline size_t OpQueueLength() { return mOpQueue.Length(); }

  nsHtml5TreeOpStage* GetStage() { return &mStage; }

  void StartReadingFromStage() { mReadingFromStage = true; }

  void StreamEnded();

#ifdef DEBUG
  void AssertStageEmpty() { mStage.AssertEmpty(); }
#endif

  nsIURI* GetViewSourceBaseURI();

  void PreloadScript(const nsAString& aURL, const nsAString& aCharset,
                     const nsAString& aType, const nsAString& aCrossOrigin,
                     const nsAString& aMedia, const nsAString& aIntegrity,
                     ReferrerPolicy aReferrerPolicy, bool aScriptFromHead,
                     bool aAsync, bool aDefer, bool aNoModule,
                     bool aLinkPreload);

  void PreloadStyle(const nsAString& aURL, const nsAString& aCharset,
                    const nsAString& aCrossOrigin, const nsAString& aMedia,
                    const nsAString& aReferrerPolicy,
                    const nsAString& aIntegrity, bool aLinkPreload);

  void PreloadImage(const nsAString& aURL, const nsAString& aCrossOrigin,
                    const nsAString& aMedia, const nsAString& aSrcset,
                    const nsAString& aSizes,
                    const nsAString& aImageReferrerPolicy, bool aLinkPreload,
                    const mozilla::TimeStamp& aInitTimestamp);

  void PreloadOpenPicture();

  void PreloadEndPicture();

  void PreloadPictureSource(const nsAString& aSrcset, const nsAString& aSizes,
                            const nsAString& aType, const nsAString& aMedia);

  void PreloadFont(const nsAString& aURL, const nsAString& aCrossOrigin,
                   const nsAString& aMedia, const nsAString& aReferrerPolicy);

  void PreloadFetch(const nsAString& aURL, const nsAString& aCrossOrigin,
                    const nsAString& aMedia, const nsAString& aReferrerPolicy);

  void SetSpeculationBase(const nsAString& aURL);

  void UpdateReferrerInfoFromMeta(const nsAString& aMetaReferrer);

  void AddSpeculationCSP(const nsAString& aCSP);

  void AddBase(const nsAString& aURL);

 private:
  nsHtml5Parser* GetParser();

  bool IsExternalViewSource();

  /**
   * Get a nsIURI for an nsString if the URL hasn't been preloaded yet.
   */
  already_AddRefed<nsIURI> ConvertIfNotPreloadedYet(const nsAString& aURL);

  /**
   * The above, plus also checks that the media attribute applies.
   */
  already_AddRefed<nsIURI> ConvertIfNotPreloadedYetAndMediaApplies(
      const nsAString& aURL, const nsAString& aMedia);

  /** Returns whether the given media attribute applies to mDocument */
  bool MediaApplies(const nsAString& aMedia);

  /**
   * The base URI we would use for current preload operations
   */
  nsIURI* BaseURIForPreload();

  /**
   * Returns true if we haven't preloaded this URI yet, and adds it to the
   * list of preloaded URIs
   */
  bool ShouldPreloadURI(nsIURI* aURI);

  ReferrerPolicy GetPreloadReferrerPolicy(const nsAString& aReferrerPolicy);

  ReferrerPolicy GetPreloadReferrerPolicy(ReferrerPolicy aReferrerPolicy);
};

#endif  // nsHtml5TreeOpExecutor_h