////////////////////////////////////////////////////////////////////////////////
// Convenience Functions (mini library)
// Functions not specific to video or VideoJS and could probably be replaced with a library like jQuery
////////////////////////////////////////////////////////////////////////////////

VideoJS.extend({

  addClass: function(element, classToAdd){
    if ((" "+element.className+" ").indexOf(" "+classToAdd+" ") == -1) { 
      element.className = element.className === "" ? classToAdd : element.className + " " + classToAdd; 
    }
  },
  removeClass: function(element, classToRemove){
    if (element.className.indexOf(classToRemove) == -1) { return; }
    var classNames = element.className.split(/\s+/);
    classNames.splice(classNames.lastIndexOf(classToRemove),1);
    element.className = classNames.join(" ");
  },
  createElement: function(tagName, attributes){
    return this.merge(document.createElement(tagName), attributes);
  },

  // Attempt to block the ability to select text while dragging controls
  blockTextSelection: function(){
    document.body.focus();
    document.onselectstart = function () { return false; };
  },
  // Turn off text selection blocking
  unblockTextSelection: function(){ document.onselectstart = function () { return true; }; },

  // Return seconds as MM:SS
  formatTime: function(secs) {
    var seconds = Math.round(secs);
    var minutes = Math.floor(seconds / 60);
    minutes = (minutes >= 10) ? minutes : "0" + minutes;
    seconds = Math.floor(seconds % 60);
    seconds = (seconds >= 10) ? seconds : "0" + seconds;
    return minutes + ":" + seconds;
  },

  // Return the relative horizonal position of an event as a value from 0-1
  getRelativePosition: function(x, relativeElement){
    return Math.max(0, Math.min(1, (x - this.findPosX(relativeElement)) / relativeElement.offsetWidth));
  },
  // Get an objects position on the page
  findPosX: function(obj) {
    var curleft = obj.offsetLeft;
    while(obj = obj.offsetParent) {
      curleft += obj.offsetLeft;
    }
    return curleft;
  },
  getComputedStyleValue: function(element, style){
    return window.getComputedStyle(element, null).getPropertyValue(style);
  },

  round: function(num, dec) {
    if (!dec) { dec = 0; }
    return Math.round(num*Math.pow(10,dec))/Math.pow(10,dec);
  },
  
  addListener: function(element, type, handler){
    if (element.addEventListener) {
      element.addEventListener(type, handler, false);
    } else if (element.attachEvent) {
      element.attachEvent("on"+type, handler);
    }
  },
  removeListener: function(element, type, handler){
    if (element.removeEventListener) {
      element.removeEventListener(type, handler, false);
    } else if (element.attachEvent) {
      element.detachEvent("on"+type, handler);
    }
  },

  get: function(url, onSuccess){
    if (typeof XMLHttpRequest == "undefined") {
      XMLHttpRequest = function () {
        try { return new ActiveXObject("Msxml2.XMLHTTP.6.0"); } catch (e) {}
        try { return new ActiveXObject("Msxml2.XMLHTTP.3.0"); } catch (f) {}
        try { return new ActiveXObject("Msxml2.XMLHTTP"); } catch (g) {}
        //Microsoft.XMLHTTP points to Msxml2.XMLHTTP.3.0 and is redundant
        throw new Error("This browser does not support XMLHttpRequest.");
      };
    }
    var request = new XMLHttpRequest();
    request.open("GET",url);
    request.onreadystatechange = function() {
      if (request.readyState == 4 && request.status == 200) {
        onSuccess(request.responseText);
      }
    }.context(this);
    request.send();
  },

  trim: function(string){ return string.toString().replace(/^\s+/, "").replace(/\s+$/, ""); },

  // DOM Ready functionality adapted from jQuery. http://jquery.com/
  bindDOMReady: function(){
    if (document.readyState === "complete") {
      return VideoJS.onDOMReady();
    }
    if (document.addEventListener) {
      document.addEventListener("DOMContentLoaded", VideoJS.DOMContentLoaded, false);
      window.addEventListener("load", VideoJS.onDOMReady, false);
    } else if (document.attachEvent) {
      document.attachEvent("onreadystatechange", VideoJS.DOMContentLoaded);
      window.attachEvent("onload", VideoJS.onDOMReady);
    }
  },

  DOMContentLoaded: function(){
    if (document.addEventListener) {
      document.removeEventListener( "DOMContentLoaded", VideoJS.DOMContentLoaded, false);
      VideoJS.onDOMReady();
    } else if ( document.attachEvent ) {
      if ( document.readyState === "complete" ) {
        document.detachEvent("onreadystatechange", VideoJS.DOMContentLoaded);
        VideoJS.onDOMReady();
      }
    }
  },

  // Functions to be run once the DOM is loaded
  DOMReadyList: [],
  addToDOMReady: function(fn){
    if (VideoJS.DOMIsReady) {
      fn.call(document);
    } else {
      VideoJS.DOMReadyList.push(fn);
    }
  },

  DOMIsReady: false,
  onDOMReady: function(){
    if (VideoJS.DOMIsReady) { return; }
    if (!document.body) { return setTimeout(VideoJS.onDOMReady, 13); }
    VideoJS.DOMIsReady = true;
    if (VideoJS.DOMReadyList) {
      for (var i=0; i<VideoJS.DOMReadyList.length; i++) {
        VideoJS.DOMReadyList[i].call(document);
      }
      VideoJS.DOMReadyList = null;
    }
  }
});
VideoJS.bindDOMReady();

// Allows for binding context to functions
// when using in event listeners and timeouts
Function.prototype.context = function(obj){
  var method = this,
  temp = function(){
    return method.apply(obj, arguments);
  };
  return temp;
};

// Like context, in that it creates a closure
// But insteaad keep "this" intact, and passes the var as the second argument of the function
// Need for event listeners where you need to know what called the event
// Only use with event callbacks
Function.prototype.evtContext = function(obj){
  var method = this,
  temp = function(){
    var origContext = this;
    return method.call(obj, arguments[0], origContext);
  };
  return temp;
};

// Removeable Event listener with Context
// Replaces the original function with a version that has context
// So it can be removed using the original function name.
// In order to work, a version of the function must already exist in the player/prototype
Function.prototype.rEvtContext = function(obj, funcParent){
  if (this.hasContext === true) { return this; }
  if (!funcParent) { funcParent = obj; }
  for (var attrname in funcParent) {
    if (funcParent[attrname] == this) {
      funcParent[attrname] = this.evtContext(obj);
      funcParent[attrname].hasContext = true;
      return funcParent[attrname];
    }
  }
  return this.evtContext(obj);
};