/**
 * Ensure global ga Google Analytics queue has been initialized.
 * @type {Array}
 */
// var ga = ga || function(){};

function merge(stream1, stream2) {
  return stream1.merge(stream2);
}

function eventStream(eventName) {
  return jQuery(window).asEventStream(eventName);
}

// A map to player state codes from their human-readable sting equivalents.
// https://developers.google.com/youtube/js_api_reference
var PLAYER_CODES = {
  beginning: -1,
  completed: 0,
  play: 1,
  pause: 2,
  buffer: 3,
  video: 5
};

var DECAY = 5000; // milliseconds
var EVENT_NAMES = ["focus", "click", "scroll", "mousemove", "touchstart", "touchend", "touchcancel", "touchleave", "touchmove"];
var URL = [location.protocol, '//', location.host, location.pathname].join('');

var playerEventStream = new Bacon.Bus();

var isPlaying = playerEventStream
    .scan({}, function(states, event) {
      var update = {};
      var id = event.target.getIframe().id;
      update[id] = event.data;
      return _.assign(states, update);
    })
    .map(_.values)
    .map(_.partialRight(_.contains, PLAYER_CODES.play));

var playerEvents = function(id) {
  var events = new Bacon.Bus();
  var player = new YT.Player(id, {
    events: {
      'onReady': onPlayerReady,
      'onStateChange': onPlayerStateChange
    }
  });
  return events;
};

var isFocused = eventStream("focus").map(true)
    .merge(eventStream("blur").map(false))
    .toProperty(true);

var streams = _.map(EVENT_NAMES, eventStream);
var interactionStream = _.reduce(streams, merge);
var activityStream = interactionStream.merge(playerEventStream);

var recentlyActive = activityStream
    .map(true)
    .flatMapLatest(function() {
      return Bacon.once(true).merge(Bacon.once(false).delay(DECAY));
    })
    .toProperty(false);

var isActive = (recentlyActive.and(isFocused)).or(isPlaying);

var secondsActive = Bacon.mergeAll(isActive.changes(), isActive.sample(1000))
  .map(function(isActive) {
    return {
      isActive: isActive,
      timestamp: new Date().getTime()
    };
  })
  .slidingWindow(2,2)
  .filter(function(span) { return span[0].isActive; })
  .map(function(span) { return span[1].timestamp - span[0].timestamp; })
  .scan(0, function(x,y) { return x + y;})
  .map(function(x) { return x / 1000; }) // milliseconds
  .map(Math.floor)
  .skipDuplicates();
  
var sendGaEvent = secondsActive
  .map(function(x) { 
    if(!(x % 5)){ return x;}
  });

////////////////////////////////////////
// this is included from youtube.ga.js
////////////////////////////////////////

var current_player;
function onPlayerReady(event) {
    yt_vid_url = event.target.getVideoUrl();
    yt_id = extractParamFromUri(yt_vid_url, 'v');
    yt_video_title = yt_vid_url; // just in case we can't grab the title in time
    yt_api_url = "//apps.opensocietyfoundations.org/shield/yt/" + yt_id + "/"
    jQuery.getJSON(yt_api_url, function(data) {
        yt_video_title = data.items[0].snippet.title;
    });
    
    // save player for reference later
    current_player = event.target;
    
    // Reattach events
    playerEventStream.plug(playerEvents("player"));
    
    if (typeof time_track != "undefined"){ 
        clearTimeout(time_track);
    }
    
    timer_count = 0;
    played = 0;
    
  }
  
// when player state changes
  var time_track;
  var played = 0;
  function onPlayerStateChange(event) {
  
    playerEventStream.push(event);
  
    if (event.data == YT.PlayerState.PLAYING && !YT.PlayerState.ENDED) { 
       time_track = setInterval(gaTrackDuration, 1000 );
    } else {
       clearTimeout(time_track);
    }
    
    // track plays
    if (event.data == 1 && played == 0) {
      gaTrackEvent('Video','Play', yt_video_title, true);
      gaTrackEvent('video play', yt_video_title, URL, true);
      opTrackVideo('videoPlay');
      played = 1;
    }

    // track completes
    if (event.data == 0) {
      gaTrackEvent('Video','End', yt_video_title, true);
      gaTrackEvent('video end', yt_video_title, URL, true);
      opTrackVideo('videoEnd');
    }
    
  }
  
  function opTrackVideo(aAct) {
    if (typeof window.optimizely != "undefined"){
      window['optimizely'].push(["trackEvent", aAct]);
    }
  }
  
  var timer_count = 0;
  function gaTrackDuration() {
      timer_count++;
      if(timer_count % 10 == 0 && (timer_count <= 600)){
          gaTrackEvent('Video', 'Duration', yt_video_title + ': ' + timer_count, true);
          gaTrackEvent('video duration', timer_count, URL, true);
      }
  }

jQuery(function() {

  // Include You Tube API if we have a video on page
  if (jQuery('iframe[src*="youtube"]#player').length > 0){
    
    var player = {
    loadAPI: function() {
        if (typeof(YT) == 'undefined' || typeof(YT.Player) == 'undefined') {
            window.onYouTubePlayerAPIReady = function() {
                player.loadPlayer();
            };
            jQuery.getScript('https://www.youtube.com/player_api');
        } else {
            player.loadPlayer();
        }
    },
    loadPlayer: function() {
        
        // Create YT player and attach events
        playerEventStream.plug(playerEvents("player"));

      }
    };

    player.loadAPI();
    
    // stop player if switching videos
    jQuery('.vids a').click( function(event) {
        if (typeof(current_player) != 'undefined'){
            current_player.stopVideo();
        }
    });
  
  }
  
  // Send ga event for event 5 seconds active on page
  sendGaEvent.onValue(function(x) { 
    if(x && x <= 600){
        gaTrackEvent('attention', x, URL, true);
    }
  });

});