//   asset_loader.js

//   Script by Nephilim
//   http://nephilim.blogspot.com/2007/09/preloading-both-images-and-scripts-in.html


//   This object handles all the assets for the page.

//   First, the master list of application assets to preload.
//   All images are considered to be optional unless required is set to 1.
//   All scripts are considered to be required unless optional is set to 1.



var assets = {

   //   List images here.
   //   Each image is an associative array with:
   //      id: an identifier
   //      url: a url to load the image from (can be relative)
   //      required: (optional) if '1', calls failure callback
   //         if there is an error loading this image
   //         (Thus, all images default to being optional.)

   images: [
      { id: 'filmLoad', url: 'film/filmLoad1.jpg', required: 1 },
      { id: 'filmLoad', url: 'film/filmLoad2.jpg', required: 1 },
      { id: 'filmLoad', url: 'film/filmLoad3.jpg', required: 1 },
      { id: 'filmLoad', url: 'film/filmLoad4.jpg', required: 1 },
      
            
      
      { id: 'boxa1', url: 'film/menuimages/blue5_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow6_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/green3.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red1.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red5_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/blue1.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/blue2.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow7_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/blue3_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/green2_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow6.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/blue4.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red2_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/green4.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red7_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/green4_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red6.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red4.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red2.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow4_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow1_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow7.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow5.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/green1.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/blue2_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/green2.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/blue3.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/green3_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/blue1_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red1_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow3_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow5_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red3_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow2_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow2.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/blue4_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow1.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red7.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red5.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/blue5.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red3.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red4_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow3.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/yellow4.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/green1_on.jpg', required: 1 },
      { id: 'boxa1', url: 'film/menuimages/red6_on.jpg', required: 1 },

   ],

   //   List scripts here.
   //   Each script is an associative array with:
   //      id: an identifier
   //      url: a url to load the script from (can be relative)
   //      optional: (optional) if '1', does not call failure callback
   //         if there is an error loading this script
   //         (Thus, all scripts default to being required.)

   scripts: [
      { id: 'buildroll', url: 'js/buildroll.js' },
   ]

};

//   The preloader object.
//   This object handles the job of preloading everything.
//   Usage:
//
//      preLoader.startLoading( preloadSuccess, preloadFailure, preloadStatus );
//
//   Where:
//      preloadSuccess: the function to call when preloading was successful
//      preloadFailure: the function to call when preloading failed
//      preloadStatus:  the function to call to report status of preloading in progress
//
//   Scripts grabbed in this manner are eval()'d by Prototype.

var preLoader = {
   errors: { images: 0, scripts: 0 },
   errortext: '',
   progress: 0,
   startLoading: function( completeCallback, errorCallback, statusCallback ) {
      this.success = completeCallback;
      this.failure = errorCallback;
      this.status = statusCallback;
      this.loadNextImage();
   },
   
//   images   
   loadNextImage: function() {
      if (this.progress >= assets.images.length) {
         this.progress = 0;
         this.loadNextScript();
         return;
      }
      imageObject = new Image();
      imageObject.onload = function() { preLoader.imageLoaded(); }
      imageObject.onerror = function() { preLoader.imageError(); }
      imageObject.src = assets.images[ this.progress ].url;
      assets.images[ this.progress ].image = imageObject;
   },
   imageLoaded: function() {
      var perc = Math.round((this.progress + 1) * 100 / assets.images.length);
      assets.images[ this.progress ].success = 1;
      this.preloaderMessage( perc, 'Loading Images', assets.images[ this.progress ].url );
      this.progress++;
      this.loadNextImage();
   },
   imageError: function() {
      var perc = Math.round((this.progress + 1) * 100 / assets.images.length);
      assets.images[ this.progress ].success = 0;
      this.errors.images++;
      this.errortext += '<div>Error loading ' + assets.images[ this.progress ].url + '</div>';
      this.preloaderMessage( perc, 'Loading Images', assets.images[ this.progress ].url );
      if (assets.images[ this.progress ].required == 1) return this.failure();
      this.progress++;
      this.loadNextImage();
   },

//   scripts   
   loadNextScript: function() {
      if (this.progress >= assets.scripts.length) {
         this.progress = 0;
         this.success();
         return;
      }
      this.ajax = new Ajax.Request( assets.scripts[ this.progress ].url, {
         method: 'get',
         onSuccess: function(transport) {
            preLoader.scriptLoaded();
         },
         onFailure: function(transport) {
            preLoader.scriptError();
         }
      });
   },
   scriptLoaded: function() {
      var perc = Math.round((this.progress + 1) * 100 / assets.scripts.length);
      assets.scripts[ this.progress ].success = 1;
      this.preloaderMessage( perc, 'Loading Scripts', assets.scripts[ this.progress ].url );
      this.progress++;
      this.loadNextScript();
   },
   scriptError: function() {
      var perc = Math.round((this.progress + 1) * 100 / assets.scripts.length);
      assets.scripts[ this.progress ].success = 0;
      this.errors.scripts++;
      this.errortext += '<div>Error loading ' + assets.scripts[ this.progress ].url + '</div>';
      this.preloaderMessage( perc, 'Loading Scripts', assets.scripts[ this.progress ].url );
      if (assets.scripts[ this.progress ].optional != 1) return this.failure();
      this.progress++;
      this.loadNextScript();
   },
   preloaderMessage: function( perc, header, msg ) {
   
      this.status( perc, header, msg, this.errortext );
      
   }

};