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diff --git a/dom/media/mediacontrol/MediaStatusManager.h b/dom/media/mediacontrol/MediaStatusManager.h
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+/* 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 DOM_MEDIA_MEDIACONTROL_MEDIASTATUSMANAGER_H_
+#define DOM_MEDIA_MEDIACONTROL_MEDIASTATUSMANAGER_H_
+
+#include "MediaControlKeySource.h"
+#include "MediaEventSource.h"
+#include "MediaPlaybackStatus.h"
+#include "mozilla/dom/MediaMetadata.h"
+#include "mozilla/dom/MediaSessionBinding.h"
+#include "mozilla/Maybe.h"
+#include "nsTHashMap.h"
+#include "nsISupportsImpl.h"
+
+namespace mozilla::dom {
+
+class MediaSessionInfo {
+ public:
+  MediaSessionInfo() = default;
+
+  explicit MediaSessionInfo(MediaMetadataBase& aMetadata) {
+    mMetadata.emplace(aMetadata);
+  }
+
+  MediaSessionInfo(MediaMetadataBase& aMetadata,
+                   MediaSessionPlaybackState& aState) {
+    mMetadata.emplace(aMetadata);
+    mDeclaredPlaybackState = aState;
+  }
+
+  static MediaSessionInfo EmptyInfo() { return MediaSessionInfo(); }
+
+  static uint32_t GetActionBitMask(MediaSessionAction aAction) {
+    return 1 << static_cast<uint8_t>(aAction);
+  }
+
+  void EnableAction(MediaSessionAction aAction) {
+    mSupportedActions |= GetActionBitMask(aAction);
+  }
+
+  void DisableAction(MediaSessionAction aAction) {
+    mSupportedActions &= ~GetActionBitMask(aAction);
+  }
+
+  bool IsActionSupported(MediaSessionAction aAction) const {
+    return mSupportedActions & GetActionBitMask(aAction);
+  }
+
+  // These attributes are all propagated from the media session in the content
+  // process.
+  Maybe<MediaMetadataBase> mMetadata;
+  MediaSessionPlaybackState mDeclaredPlaybackState =
+      MediaSessionPlaybackState::None;
+  // Use bitwise to store the supported actions.
+  uint32_t mSupportedActions = 0;
+};
+
+/**
+ * IMediaInfoUpdater is an interface which provides methods to update the media
+ * related information that happens in the content process.
+ */
+class IMediaInfoUpdater {
+  NS_INLINE_DECL_PURE_VIRTUAL_REFCOUNTING
+
+  // Use this method to update controlled media's playback state and the
+  // browsing context where controlled media exists. When notifying the state
+  // change, we MUST follow the following rules.
+  // (1) `eStart` MUST be the first state and `eStop` MUST be the last state
+  // (2) Do not notify same state again
+  // (3) `ePaused` can only be notified after notifying `ePlayed`.
+  virtual void NotifyMediaPlaybackChanged(uint64_t aBrowsingContextId,
+                                          MediaPlaybackState aState) = 0;
+
+  // Use this method to update the audible state of controlled media, and MUST
+  // follow the following rules in which `audible` and `inaudible` should be a
+  // pair. `inaudible` should always be notified after `audible`. When audible
+  // media paused, `inaudible` should be notified
+  // Eg. (O) `audible` -> `inaudible` -> `audible` -> `inaudible`
+  //     (X) `inaudible` -> `audible`    [notify `inaudible` before `audible`]
+  //     (X) `audible` -> `audible`      [notify `audible` twice]
+  //     (X) `audible` -> (media pauses) [forgot to notify `inaudible`]
+  virtual void NotifyMediaAudibleChanged(uint64_t aBrowsingContextId,
+                                         MediaAudibleState aState) = 0;
+
+  // Use this method to update media session's declared playback state for the
+  // specific media session.
+  virtual void SetDeclaredPlaybackState(uint64_t aBrowsingContextId,
+                                        MediaSessionPlaybackState aState) = 0;
+
+  // Use these methods to update controller's media session list. We'd use it
+  // when media session is created/destroyed in the content process.
+  virtual void NotifySessionCreated(uint64_t aBrowsingContextId) = 0;
+  virtual void NotifySessionDestroyed(uint64_t aBrowsingContextId) = 0;
+
+  // Use this method to update the metadata for the specific media session.
+  virtual void UpdateMetadata(uint64_t aBrowsingContextId,
+                              const Maybe<MediaMetadataBase>& aMetadata) = 0;
+
+  // Use this method to update the picture in picture mode state of controlled
+  // media, and it's safe to notify same state again.
+  virtual void SetIsInPictureInPictureMode(uint64_t aBrowsingContextId,
+                                           bool aIsInPictureInPictureMode) = 0;
+
+  // Use these methods to update the supported media session action for the
+  // specific media session. For a media session from a given browsing context,
+  // do not re-enable the same action, or disable the action without enabling it
+  // before.
+  virtual void EnableAction(uint64_t aBrowsingContextId,
+                            MediaSessionAction aAction) = 0;
+  virtual void DisableAction(uint64_t aBrowsingContextId,
+                             MediaSessionAction aAction) = 0;
+
+  // Use this method when media enters or leaves the fullscreen.
+  virtual void NotifyMediaFullScreenState(uint64_t aBrowsingContextId,
+                                          bool aIsInFullScreen) = 0;
+
+  // Use this method when media session update its position state.
+  virtual void UpdatePositionState(uint64_t aBrowsingContextId,
+                                   const PositionState& aState) = 0;
+};
+
+/**
+ * MediaStatusManager would decide the media related status which can represents
+ * the whole tab. The status includes the playback status, tab's metadata and
+ * the active media session ID if it exists.
+ *
+ * We would use `IMediaInfoUpdater` methods to update the media playback related
+ * information and then use `MediaPlaybackStatus` to determine the final
+ * playback state.
+ *
+ * The metadata would be the one from the active media session, or the default
+ * one. This class would determine which media session is an active media
+ * session [1] whithin a tab. It tracks all alive media sessions within a tab
+ * and store their metadata which could be used to show on the virtual media
+ * control interface. In addition, we can use it to get the current media
+ * metadata even if there is no media session existing. However, the meaning of
+ * active media session here is not equal to the definition from the spec [1].
+ * We just choose the session which is the active one inside the tab, the global
+ * active media session among different tabs would be the one inside the main
+ * controller which is determined by MediaControlService.
+ *
+ * [1] https://w3c.github.io/mediasession/#active-media-session
+ */
+class MediaStatusManager : public IMediaInfoUpdater {
+ public:
+  explicit MediaStatusManager(uint64_t aBrowsingContextId);
+
+  // IMediaInfoUpdater's methods
+  void NotifyMediaPlaybackChanged(uint64_t aBrowsingContextId,
+                                  MediaPlaybackState aState) override;
+  void NotifyMediaAudibleChanged(uint64_t aBrowsingContextId,
+                                 MediaAudibleState aState) override;
+  void SetDeclaredPlaybackState(uint64_t aSessionContextId,
+                                MediaSessionPlaybackState aState) override;
+  void NotifySessionCreated(uint64_t aSessionContextId) override;
+  void NotifySessionDestroyed(uint64_t aSessionContextId) override;
+  void UpdateMetadata(uint64_t aSessionContextId,
+                      const Maybe<MediaMetadataBase>& aMetadata) override;
+  void EnableAction(uint64_t aBrowsingContextId,
+                    MediaSessionAction aAction) override;
+  void DisableAction(uint64_t aBrowsingContextId,
+                     MediaSessionAction aAction) override;
+  void UpdatePositionState(uint64_t aBrowsingContextId,
+                           const PositionState& aState) override;
+
+  // Return active media session's metadata if active media session exists and
+  // it has already set its metadata. Otherwise, return default media metadata
+  // which is based on website's title and favicon.
+  MediaMetadataBase GetCurrentMediaMetadata() const;
+
+  bool IsMediaAudible() const;
+  bool IsMediaPlaying() const;
+  bool IsAnyMediaBeingControlled() const;
+
+  // These events would be notified when the active media session's certain
+  // property changes.
+  MediaEventSource<MediaMetadataBase>& MetadataChangedEvent() {
+    return mMetadataChangedEvent;
+  }
+
+  MediaEventSource<PositionState>& PositionChangedEvent() {
+    return mPositionStateChangedEvent;
+  }
+
+  MediaEventSource<MediaSessionPlaybackState>& PlaybackChangedEvent() {
+    return mPlaybackStateChangedEvent;
+  }
+
+  // Return the actual playback state.
+  MediaSessionPlaybackState PlaybackState() const;
+
+  // When page title changes, we might need to update it on the default
+  // metadata as well.
+  void NotifyPageTitleChanged();
+
+ protected:
+  ~MediaStatusManager() = default;
+
+  // This event would be notified when the active media session changes its
+  // supported actions.
+  MediaEventSource<nsTArray<MediaSessionAction>>&
+  SupportedActionsChangedEvent() {
+    return mSupportedActionsChangedEvent;
+  }
+
+  uint64_t mTopLevelBrowsingContextId;
+
+  // Within a tab, the Id of the browsing context which has already created a
+  // media session and owns the audio focus within a tab.
+  Maybe<uint64_t> mActiveMediaSessionContextId;
+
+  void ClearActiveMediaSessionContextIdIfNeeded();
+
+ private:
+  nsString GetDefaultFaviconURL() const;
+  nsString GetDefaultTitle() const;
+  MediaMetadataBase CreateDefaultMetadata() const;
+  bool IsInPrivateBrowsing() const;
+  void FillMissingTitleAndArtworkIfNeeded(MediaMetadataBase& aMetadata) const;
+
+  bool IsSessionOwningAudioFocus(uint64_t aBrowsingContextId) const;
+  void SetActiveMediaSessionContextId(uint64_t aBrowsingContextId);
+  void HandleAudioFocusOwnerChanged(Maybe<uint64_t>& aBrowsingContextId);
+
+  void NotifySupportedKeysChangedIfNeeded(uint64_t aBrowsingContextId);
+
+  // Return a copyable array filled with the supported media session actions.
+  // Use copyable array so that we can use the result as a parameter for the
+  // media event.
+  CopyableTArray<MediaSessionAction> GetSupportedActions() const;
+
+  void StoreMediaSessionContextIdOnWindowContext();
+
+  // When the amount of playing media changes, we would use this function to
+  // update the guessed playback state.
+  void SetGuessedPlayState(MediaSessionPlaybackState aState);
+
+  // Whenever the declared playback state or the guessed playback state changes,
+  // we should recompute actual playback state to know if we need to update the
+  // virtual control interface.
+  void UpdateActualPlaybackState();
+
+  // Return the active media session's declared playback state. If the active
+  // media session doesn't exist, return  'None' instead.
+  MediaSessionPlaybackState GetCurrentDeclaredPlaybackState() const;
+
+  // This state can match to the `guessed playback state` in the spec [1], it
+  // indicates if we have any media element playing within the tab which this
+  // controller belongs to. But currently we only take media elements into
+  // account, which is different from the way the spec recommends. In addition,
+  // We don't support web audio and plugin and not consider audible state of
+  // media.
+  // [1] https://w3c.github.io/mediasession/#guessed-playback-state
+  MediaSessionPlaybackState mGuessedPlaybackState =
+      MediaSessionPlaybackState::None;
+
+  // This playback state would be the final playback which can be used to know
+  // if the controller is playing or not.
+  // https://w3c.github.io/mediasession/#actual-playback-state
+  MediaSessionPlaybackState mActualPlaybackState =
+      MediaSessionPlaybackState::None;
+
+  nsTHashMap<nsUint64HashKey, MediaSessionInfo> mMediaSessionInfoMap;
+  MediaEventProducer<MediaMetadataBase> mMetadataChangedEvent;
+  MediaEventProducer<nsTArray<MediaSessionAction>>
+      mSupportedActionsChangedEvent;
+  MediaEventProducer<PositionState> mPositionStateChangedEvent;
+  MediaEventProducer<MediaSessionPlaybackState> mPlaybackStateChangedEvent;
+  MediaPlaybackStatus mPlaybackStatusDelegate;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // DOM_MEDIA_MEDIACONTROL_MEDIASTATUSMANAGER_H_