/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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/. */

#if !defined(MediaMetadataManager_h__)
#define MediaMetadataManager_h__

#include "mozilla/LinkedList.h"

#include "nsAutoPtr.h"
#include "AbstractMediaDecoder.h"
#include "TimeUnits.h"
#include "VideoUtils.h"

namespace mozilla {

// A struct that contains the metadata of a media, and the time at which those
// metadata should start to be reported.
class TimedMetadata : public LinkedListElement<TimedMetadata> {
public:
  // The time, in microseconds, at which those metadata should be available.
  media::TimeUnit mPublishTime;
  // The metadata. The ownership is transfered to the element when dispatching to
  // the main threads.
  nsAutoPtr<MetadataTags> mTags;
  // The media info, including the info of audio tracks and video tracks.
  // The ownership is transfered to MediaDecoder when dispatching to the
  // main thread.
  nsAutoPtr<MediaInfo> mInfo;
};

// This class encapsulate the logic to give the metadata from the reader to
// the content, at the right time.
class MediaMetadataManager
{
public:
  ~MediaMetadataManager() {
    TimedMetadata* element;
    while((element = mMetadataQueue.popFirst()) != nullptr) {
      delete element;
    }
  }

  void QueueMetadata(TimedMetadata* aMetadata) {
    mMetadataQueue.insertBack(aMetadata);
  }

  void DispatchMetadataIfNeeded(AbstractMediaDecoder* aDecoder, const media::TimeUnit& aCurrentTime) {
    TimedMetadata* metadata = mMetadataQueue.getFirst();
    while (metadata && aCurrentTime >= metadata->mPublishTime) {
      // Remove all media tracks from the list first.
      nsCOMPtr<nsIRunnable> removeTracksEvent =
        new RemoveMediaTracksEventRunner(aDecoder);
      NS_DispatchToMainThread(removeTracksEvent);

      nsCOMPtr<nsIRunnable> metadataUpdatedEvent =
        new MetadataUpdatedEventRunner(aDecoder,
                                       metadata->mInfo,
                                       metadata->mTags);
      NS_DispatchToMainThread(metadataUpdatedEvent);
      delete mMetadataQueue.popFirst();
      metadata = mMetadataQueue.getFirst();
    }
  }

protected:
  LinkedList<TimedMetadata> mMetadataQueue;
};

} // namespace mozilla

#endif
