// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

'use strict';

/** @suppress {duplicate} */
var remoting = remoting || {};

/**
 * @param {HTMLMediaElement} videoTag <video> tag to render to.
 * @constructor
 */
remoting.MediaSourceRenderer = function(videoTag) {
  /** @type {HTMLMediaElement} */
  this.video_ = videoTag;

  /** @type {MediaSource} */
  this.mediaSource_ = null;

  /** @type {SourceBuffer} */
  this.sourceBuffer_ = null;

  /** @type {!Array.<ArrayBuffer>} Queue of pending buffers that haven't been
   * processed . */
  this.buffers_ = [];
}

/**
 * @param {string} format Format of the stream.
 */
remoting.MediaSourceRenderer.prototype.reset = function(format) {
  // Create a new MediaSource instance.
  this.sourceBuffer_ = null;
  this.mediaSource_ = new MediaSource();
  this.mediaSource_.addEventListener('sourceopen',
                                     this.onSourceOpen_.bind(this, format));
  this.mediaSource_.addEventListener('sourceclose', function(e) {
    console.error("MediaSource closed unexpectedly.");
  });
  this.mediaSource_.addEventListener('sourceended', function(e) {
    console.error("MediaSource ended unexpectedly.");
  });

  // Start playback from new MediaSource.
  this.video_.src =
      /** @type {string} */(
          window.URL.createObjectURL(/** @type {!Blob} */(this.mediaSource_)));
  this.video_.play();
}

/**
 * @param {string} format
 * @private
 */
remoting.MediaSourceRenderer.prototype.onSourceOpen_ = function(format) {
  this.sourceBuffer_ =
      this.mediaSource_.addSourceBuffer(format);

  this.sourceBuffer_.addEventListener(
      'updateend', this.processPendingData_.bind(this));
  this.processPendingData_();
}

/**
 * @private
 */
remoting.MediaSourceRenderer.prototype.processPendingData_ = function() {
  if (this.sourceBuffer_) {
    while (this.buffers_.length > 0 && !this.sourceBuffer_.updating) {
      // TODO(sergeyu): Figure out the way to determine when a frame is rendered
      // and use it to report performance statistics.
      this.sourceBuffer_.appendBuffer(
          /** @type {ArrayBuffer} */(this.buffers_.shift()));
    }
  }
}

/**
 * @param {ArrayBuffer} data
 */
remoting.MediaSourceRenderer.prototype.onIncomingData = function(data) {
  this.buffers_.push(data);
  this.processPendingData_();
}