var video, transcriptDiv;

var tracks, trackElems, tracksURLs = [];

var buttonEnglish, buttonDeutsch, buttonEnglishChapters;

​

window.onload = function() {

  console.log("init");

  // when the page is loaded

  video = document.querySelector("#myVideo");

  transcriptDiv = document.querySelector("#transcript");

  // The tracks as HTML elements

  trackElems = document.querySelectorAll("track");

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

    var currentTrackElem = trackElems[i];

    tracksURLs[i] = currentTrackElem.src;

  }

  buttonEnglish = document.querySelector("#buttonEnglish");

  buttonDeutsch = document.querySelector("#buttonDeutsch");

  buttonEnglishChapters = document.querySelector("#buttonEnglishChapters");

  // we enable the buttons and show transcript

  buttonEnglish.disabled = false;

  buttonDeutsch.disabled = false;

    buttonEnglishChapters.disabled = false;

  // The tracks as JS objects

  tracks = video.textTracks;

};

​

function loadTranscript(lang, kind) {

  // clear current transcript

  clearTranscriptDiv();

  // set all track mode to disabled. We will only activate the

  // one whose content will be displayed as transcript

  if(kind !== 'chapters')

      disableAllTracks(); // if displaying chapters, do not

                          // disable all tracks

  // Locate the track with language = lang

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

    // current track

    var track = tracks[i];

    var trackAsHtmlElem = trackElems[i];

    if((track.language === lang) && (track.kind === kind)) {

      track.mode="showing";

​

      if(trackAsHtmlElem.readyState === 2) {

        // the track has already been loaded

        displayCues(track);

      } else {

        displayCuesAfterTrackLoaded(trackAsHtmlElem, track);

      }

/*      track.addEventListener("cuechange", function(e) {

        var cue = this.activeCues[0];

        console.log("cue change");

        var transcriptText = document.getElementById(cue.id);

        transcriptText.classList.add("current");

      });

      */

    }

  } 

}

​

function displayCuesAfterTrackLoaded(trackElem, track) {

  // Create a listener that will be called only when the track has

  // been loaded

  trackElem.addEventListener('load', function(e) {

      console.log("track loaded");

      displayCues(track);

   });

}

function disableAllTracks() {

    for(var i = 0; i < tracks.length; i++) 

      tracks[i].mode = "disabled";

}

​

function displayCues(track) {

    var cues = track.cues;

    //append all the subtitle texts to 

      for(var i=0, len = cues.length; i < len; i++) {

        var cue = cues[i];

        addCueListeners(cue);

​

        var voices = getVoices(cue.text);

        var transText="";

        if (voices.length > 0) {

            for (var j = 0; j < voices.length; j++) { // how many voices ?

                transText += voices[j].voice + ': ' + removeHTML(voices[j].text);

            }

          } else 

             transText = cue.text; // not a voice text

        var clickableTransText = "<li class='cues' id=" + cue.id +  " onclick='jumpTo(" + cue.startTime + ");'" + ">" + transText + "</li>";

​

        addToTranscriptDiv(clickableTransText);

      }

  }

​

function getVoices(speech) {  // takes a text content and check if there are voices 

  var voices = [];            // inside

  var pos = speech.indexOf('<v'); // voices are like <v michel> ....

  while (pos != -1) {

    endVoice = speech.indexOf('>');

    var voice = speech.substring(pos + 2, endVoice).trim();

    var endSpeech = speech.indexOf('</v>');

    var text = speech.substring(endVoice + 1, endSpeech);

    voices.push({

       'voice': voice,

       'text': text

    });

    speech = speech.substring(endSpeech + 4);

    pos = speech.indexOf('<v');

  }

  return voices;

}

​

function removeHTML(text) {

  var div = document.createElement('div');

  div.innerHTML = text;

  return div.textContent || div.innerText || '';

}

function jumpTo(time) {

  video.currentTime = time;

  video.play();

}

​

function clearTranscriptDiv() {

  transcriptDiv.innerHTML = "";

}

​

function addToTranscriptDiv(htmlText) {

  transcriptDiv.innerHTML += htmlText;

}

​

function addCueListeners(cue) {

  cue.onenter = function(){

    console.log('enter id=' + this.id);

    var transcriptText = document.getElementById(this.id);

    transcriptText.classList.add("current");

  };

​

  cue.onexit = function(){

    console.log('exit id=' + cue.id);

   var transcriptText = document.getElementById(this.id); transcriptText.classList.remove("current");

  };

}

​