// store jQuery output containers
var $output = $('#output');
var $tweet = $('#tweet');

// configure # of albums to display
var limit = 20;

// initialize PubNub
var pubnub = PUBNUB.init({
  subscribe_key: 'sub-c-78806dd4-42a6-11e4-aed8-02ee2ddab7fe'
});

// retrieve the last link provided in a tweet
var findLink = function(tweet) {  
  
  console.log(tweet);
  
  if(tweet.entities.hasOwnProperty('urls')) {

    var links = tweet.entities.urls; 
    var link = false;

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

      if (
        links[i].expanded_url.indexOf('spoti.fi') > 0 ||
        links[i].expanded_url.indexOf('spotify.com') > 0
      ) {
        link = links[i].expanded_url;
      }

    }

    return link;
    
  } else {
    return false;
  }
  
};

// create a hashtable for Album objects
var albums = {};

// this object represents an album Album and tweet
var Album = function(tweet, link) {
  
  var self = this;
  
  self.render = function(image) {
    
    var $html = $('\
      <a class="album" href="' +  link + '" target="_blank"> \
        <img src="' + image + '" class="animated flipInY"> \
      </a>');

    var tweet_html = '<a href="//twitter.com/' + tweet.user.screen_name + '/status/' + tweet.id + '" ">' + tweet.text + '</a>';
    
    $html.hover(function(){
      $tweet.html(tweet_html).show();
    }, function(){
      $tweet.hide();
    });
    
    var num_albums = $('.album');

    if(num_albums.length < limit) {
    
      // we haven't populated the page yet, append
      $output.append($html);
    
    } else {
      
      // take a random album element and replace it with this one 
      var randomel = Math.floor((Math.random() * num_albums.length ) + 1);
      var $replace = $('.album:nth-child(' + randomel + ')');

      $replace.addClass('animated flipOutY').one('webkitAnimationEnd mozAnimationEnd MSAnimationEnd oanimationend animationend', function() {
        $(this).replaceWith($html);
      });

    }
    
  };
  
};

// this is a function turns an array of tweets into Album objects
var handleTweets = function(tweets) {

  // create an array of links from provided tweets
  var links = [];
  for(var i = 0; i < tweets.length; i++) {

    var link = findLink(tweets[i]);
    
    if(link) {

      links.push(link);

      // maps the link to a Album object
      albums[link] = new Album(tweets[i], link);

    }

  }

  // pass the array of links to embedly where album information is retrieved
 $.embedly.extract(links, {key: 'e8214d5cec7844388e11c4413689986b'}).progress(function(data){

    var image = data.images[0];
    
    if(typeof image !== 'undefined' && (image.width / image.height == 1)) { 
      
      // use the link to render the Album
      albums[data.original_url].render(image.url);
    
    }

  });

};

// populate the page with the last x tweets
pubnub.history({
  channel: 'pubnub-twitter-spotify',
  count: limit * 1.5,
  callback: function(data){
    handleTweets(data[0]);
  },
});

// render tweets in real time
pubnub.subscribe({
  channel: 'pubnub-twitter-spotify',
  message: function(tweet) { 
    handleTweets([tweet]);
  }
});