var SpeedTest = function() {
};
SpeedTest.prototype = {
  runCount: 2                 // how many times we want to run the test for
  ,imgUrl: "http://www.sportozona.lt/admin/jscripts/test.jpg"    // Where the image is located at
  ,size: 59917                // bytes
  ,run: function( options ) {
    this.results = []; // reset the results
    this.callback = ( options && options.onEnd ) ? options.onEnd : null;
    this.runTrial(0, options);
  }
  ,runTrial: function(i, options ) {
    var imgUrl = this.imgUrl + "?r=" + Math.random();
    var me = this;
    var testImage = new Image();
    testImage.onload = function() { 
      me.results[i].endTime = ( new Date() ).getTime();
      me.results[i].runTime = me.results[i].endTime - me.results[i].startTime;
      if ( i < me.runCount - 1 )
        me.runTrial( i + 1 ); // run the next trial 
      else
      {
        // Execute the callback
        if( me.callback )
          me.callback( me.getResults());
      }
    };
    this.results[i] = { startTime: ( new Date() ).getTime() };
    testImage.src = imgUrl;
  }
  ,getResults: function() {
    var totalRunTime = 0;
    for( var i = 0; i < this.runCount; i++ )
    {
      if( !this.results || !this.results[i].endTime )
        return null; // exit if we found no endTime.  --> test's not done yet
      else
        totalRunTime += this.results[i].runTime;
    }
    var avgRunTime = totalRunTime / this.runCount;
    return { 
      avgRunTime: avgRunTime
      ,Kbps: ( this.size * 8 / 1024 / ( avgRunTime / 1000 ) )
      ,KBps: ( this.size / 1024 / ( avgRunTime / 1000 ) )
    };
  }
}