/* mediafragment module */

IriSP.MediaFragment = function(Popcorn, config, Serializer) {

  IriSP.Module.call(this, Popcorn, config, Serializer);

  this.mutex = false; /* a mutex because we access the url from two different functions */

  this._Popcorn.listen( "loadedmetadata", IriSP.wrap(this,this.advanceTime));

  this._Popcorn.listen( "pause", IriSP.wrap(this,this.updateTime));

  this._Popcorn.listen( "seeked", IriSP.wrap(this,this.updateTime));

  this._Popcorn.listen( "IriSP.PolemicTweet.click", IriSP.wrap(this,this.updateAnnotation));

  this._Popcorn.listen( "IriSP.SegmentsWidget.click", IriSP.wrap(this,this.updateAnnotation));

  window.onhashchange = IriSP.wrap(this, this.advanceTime);

};

IriSP.MediaFragment.prototype = new IriSP.Module();

IriSP.MediaFragment.prototype.advanceTime = function() {

             var url = window.location.href;

              if ( url.split( "#" )[ 1 ] != null ) {

                  pageoffset = url.split( "#" )[1];

                  if ( pageoffset.substring(0, 2) === "t=") {

                    // timecode 

                    if ( pageoffset.substring( 2 ) != null ) {

                    var offsettime = pageoffset.substring( 2 );

                    this._Popcorn.currentTime( parseFloat( offsettime ) );

                    }

                  } else if ( pageoffset.substring(0, 3) === "id=") {

                    // annotation

                    var annotationId = pageoffset.substring( 3 );

                    // there's no better way than that because

                    // of possible race conditions

                    this._serializer.sync(IriSP.wrap(this, function() {

                          this.lookupAnnotation.call(this, annotationId); 

                          }));

                  }

              }

};

/** handler for the seeked signal. It may have or may have not an argument.

    @param time if not undefined, the time we're seeking to 

*/

IriSP.MediaFragment.prototype.updateTime = function(time) {

  if (this.mutex === true) {

    return;

  }

  var history = window.history;

  if ( !history.pushState ) {

    return false;

  }

  if (IriSP.null_or_undefined(time)) {

    var ntime = this._Popcorn.currentTime().toFixed(2)

  } else {

    var ntime = time.toFixed(2);

  }

  splitArr = window.location.href.split( "#" )

  history.replaceState( {}, "", splitArr[0] + "#t=" + ntime );

};

IriSP.MediaFragment.prototype.updateAnnotation = function(annotationId) {

  var _this = this;

  this.mutex = true;

  var history = window.history;

  if ( !history.pushState ) {

    return false;

  }

  splitArr = window.location.href.split( "#" )

  history.replaceState( {}, "", splitArr[0] + "#id=" + annotationId);

  // reset the mutex afterwards to prevent the module from reacting to his own changes.

  window.setTimeout(function() { _this.mutex = false }, 50);

};

// lookup and seek to the beginning of an annotation

IriSP.MediaFragment.prototype.lookupAnnotation = function(annotationId) {

  var _this = this;

  this.mutex = true;

  var annotation = undefined;

  var annotations = this._serializer._data.annotations;

  var i;

  for (i = 0; i < annotations.length; i++) {

      if (annotations[i].id === annotationId) {

        annotation = annotations[i];

        break;

      }

  }

  if (typeof(annotation) !== "undefined") {

    this._Popcorn.currentTime(annotation.begin / 1000);

    this._Popcorn.trigger("IriSP.Mediafragment.showAnnotation", annotationId);

  }

  window.setTimeout(function() { _this.mutex = false }, 50);

};