// Copyright: Hiroshi Ichikawa <http://gimite.net/en/>
// License: New BSD License
// Reference: http://dev.w3.org/html5/websockets/
// Reference: http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol

(function() {
  
  if (window.WebSocket) return;

  var console = window.console;
  if (!console || !console.log || !console.error) {
    console = {log: function(){ }, error: function(){ }};
  }
  
  if (!swfobject.hasFlashPlayerVersion("10.0.0")) {
    console.error("Flash Player >= 10.0.0 is required.");
    return;
  }
  if (location.protocol == "file:") {
    console.error(
      "WARNING: web-socket-js doesn't work in file:///... URL " +
      "unless you set Flash Security Settings properly. " +
      "Open the page via Web server i.e. http://...");
  }

  /**
   * This class represents a faux web socket.
   * @param {string} url
   * @param {string} protocol
   * @param {string} proxyHost
   * @param {int} proxyPort
   * @param {string} headers
   */
  WebSocket = function(url, protocol, proxyHost, proxyPort, headers) {
    var self = this;
    self.__id = WebSocket.__nextId++;
    WebSocket.__instances[self.__id] = self;
    self.readyState = WebSocket.CONNECTING;
    self.bufferedAmount = 0;
    // Uses setTimeout() to make sure __createFlash() runs after the caller sets ws.onopen etc.
    // Otherwise, when onopen fires immediately, onopen is called before it is set.
    setTimeout(function() {
      WebSocket.__addTask(function() {
        WebSocket.__flash.create(
            self.__id, url, protocol, proxyHost || null, proxyPort || 0, headers || null);
      });
    }, 0);
  };

  /**
   * Send data to the web socket.
   * @param {string} data  The data to send to the socket.
   * @return {boolean}  True for success, false for failure.
   */
  WebSocket.prototype.send = function(data) {
    if (this.readyState == WebSocket.CONNECTING) {
      throw "INVALID_STATE_ERR: Web Socket connection has not been established";
    }
    // We use encodeURIComponent() here, because FABridge doesn't work if
    // the argument includes some characters. We don't use escape() here
    // because of this:
    // https://developer.mozilla.org/en/Core_JavaScript_1.5_Guide/Functions#escape_and_unescape_Functions
    // But it looks decodeURIComponent(encodeURIComponent(s)) doesn't
    // preserve all Unicode characters either e.g. "\uffff" in Firefox.
    // Note by wtritch: Hopefully this will not be necessary using ExternalInterface.  Will require
    // additional testing.
    var result = WebSocket.__flash.send(this.__id, encodeURIComponent(data));
    if (result < 0) { // success
      return true;
    } else {
      this.bufferedAmount += result;
      return false;
    }
  };

  /**
   * Close this web socket gracefully.
   */
  WebSocket.prototype.close = function() {
    if (this.readyState == WebSocket.CLOSED || this.readyState == WebSocket.CLOSING) {
      return;
    }
    this.readyState = WebSocket.CLOSING;
    WebSocket.__flash.close(this.__id);
  };

  /**
   * Implementation of {@link <a href="http://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-registration">DOM 2 EventTarget Interface</a>}
   *
   * @param {string} type
   * @param {function} listener
   * @param {boolean} useCapture !NB Not implemented yet
   * @return void
   */
  WebSocket.prototype.addEventListener = function(type, listener, useCapture) {
    if (!('__events' in this)) {
      this.__events = {};
    }
    if (!(type in this.__events)) {
      this.__events[type] = [];
      if ('function' == typeof this['on' + type]) {
        this.__events[type].defaultHandler = this['on' + type];
        this['on' + type] = this.__createEventHandler(this, type);
      }
    }
    this.__events[type].push(listener);
  };

  /**
   * Implementation of {@link <a href="http://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-registration">DOM 2 EventTarget Interface</a>}
   *
   * @param {string} type
   * @param {function} listener
   * @param {boolean} useCapture NB! Not implemented yet
   * @return void
   */
  WebSocket.prototype.removeEventListener = function(type, listener, useCapture) {
    if (!('__events' in this)) {
      this.__events = {};
    }
    if (!(type in this.__events)) return;
    for (var i = this.__events.length; i > -1; --i) {
      if (listener === this.__events[type][i]) {
        this.__events[type].splice(i, 1);
        break;
      }
    }
  };

  /**
   * Implementation of {@link <a href="http://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-registration">DOM 2 EventTarget Interface</a>}
   *
   * @param {WebSocketEvent} event
   * @return void
   */
  WebSocket.prototype.dispatchEvent = function(event) {
    if (!('__events' in this)) throw 'UNSPECIFIED_EVENT_TYPE_ERR';
    if (!(event.type in this.__events)) throw 'UNSPECIFIED_EVENT_TYPE_ERR';
  
    for (var i = 0, l = this.__events[event.type].length; i < l; ++ i) {
      this.__events[event.type][i](event);
      if (event.cancelBubble) break;
    }
  
    if (false !== event.returnValue &&
      'function' == typeof this.__events[event.type].defaultHandler)
    {
      this.__events[event.type].defaultHandler(event);
    }
  };

  /**
   * Handle an event from flash.  Do any websocket-specific
   * handling before passing the event off to the event handlers.
   * @param {Object} event
   */
  WebSocket.prototype.__handleEvent = function(event) {
    if ("readyState" in event) {
      this.readyState = event.readyState;
    }
  
    try {
      if (event.type == "open") {
        this.onopen && this.onopen();
      } else if (event.type == "close") {
        this.onclose && this.onclose();
      } else if (event.type == "error") {
        this.onerror && this.onerror(event);
      } else if (event.type == "message") {
        if (this.onmessage) {
          var data = decodeURIComponent(event.message);
          var e;
          if (window.MessageEvent && !window.opera) {
            e = document.createEvent("MessageEvent");
            e.initMessageEvent("message", false, false, data, null, null, window, null);
          } else {
            // IE and Opera, the latter one truncates the data parameter after any 0x00 bytes.
            e = {data: data};
          }
          this.onmessage(e);
        }
        
      } else {
        throw "unknown event type: " + event.type;
      }
    } catch (e) {
      console.error(e.toString());
    }
  };
  
  /**
   * @param {object} object
   * @param {string} type
   */
  WebSocket.prototype.__createEventHandler = function(object, type) {
    return function(data) {
      var event = new WebSocketEvent();
      event.initEvent(type, true, true);
      event.target = event.currentTarget = object;
      for (var key in data) {
        event[key] = data[key];
      }
      object.dispatchEvent(event, arguments);
    };
  };

  /**
   * Define the WebSocket readyState enumeration.
   */
  WebSocket.CONNECTING = 0;
  WebSocket.OPEN = 1;
  WebSocket.CLOSING = 2;
  WebSocket.CLOSED = 3;

  WebSocket.__flash = null;
  WebSocket.__instances = {};
  WebSocket.__tasks = [];
  WebSocket.__nextId = 0;
  
  /**
   * Loads WebSocketMain.swf and creates WebSocketMain object in Flash.
   */
  WebSocket.__initialize = function() {
    if (WebSocket.__flash) return;
    
    if (WebSocket.__swfLocation) {
      // For backword compatibility.
      window.WEB_SOCKET_SWF_LOCATION = WebSocket.__swfLocation;
    }
    if (!window.WEB_SOCKET_SWF_LOCATION) {
      console.error("[WebSocket] set WEB_SOCKET_SWF_LOCATION to location of WebSocketMain.swf");
      return;
    }
    var container = document.createElement("div");
    container.id = "webSocketContainer";
    // Hides Flash box. We cannot use display: none or visibility: hidden because it prevents
    // Flash from loading at least in IE. So we move it out of the screen at (-100, -100).
    // But this even doesn't work with Flash Lite (e.g. in Droid Incredible). So with Flash
    // Lite, we put it at (0, 0). This shows 1x1 box visible at left-top corner but this is
    // the best we can do as far as we know now.
    container.style.position = "absolute";
    if (WebSocket.__isFlashLite()) {
      container.style.left = "0px";
      container.style.top = "0px";
    } else {
      container.style.left = "-100px";
      container.style.top = "-100px";
    }
    var holder = document.createElement("div");
    holder.id = "webSocketFlash";
    container.appendChild(holder);
    document.body.appendChild(container);
    // See this article for hasPriority:
    // http://help.adobe.com/en_US/as3/mobile/WS4bebcd66a74275c36cfb8137124318eebc6-7ffd.html
    swfobject.embedSWF(
      WEB_SOCKET_SWF_LOCATION,
      "webSocketFlash",
      "1" /* width */,
      "1" /* height */,
      "10.0.0" /* SWF version */,
      null,
      null,
      {hasPriority: true, swliveconnect : true, allowScriptAccess: "always"},
      null,
      function(e) {
        if (!e.success) {
          console.error("[WebSocket] swfobject.embedSWF failed");
        }
      });
  };
  
  /**
   * Load a new flash security policy file.
   * @param {string} url
   */
  WebSocket.loadFlashPolicyFile = function(url){
    WebSocket.__addTask(function() {
      WebSocket.__flash.loadManualPolicyFile(url);
    });
  };

  /**
   * Called by flash to notify js that it's fully loaded and ready
   * for communication.
   */
  WebSocket.__onFlashInitialized = function() {
    // We need to set a timeout here to avoid round-trip calls
    // to flash during the initialization process.
    setTimeout(function() {
      WebSocket.__flash = document.getElementById("webSocketFlash");
      WebSocket.__flash.setCallerUrl(location.href);
      WebSocket.__flash.setDebug(!!window.WEB_SOCKET_DEBUG);
      for (var i = 0; i < WebSocket.__tasks.length; ++i) {
        WebSocket.__tasks[i]();
      }
      WebSocket.__tasks = [];
    }, 0);
  };
  
  /**
   * Called by flash to dispatch an event to a web socket.
   * @param {object} eventObj  A web socket event dispatched from flash.
   */
  WebSocket.__onFlashEvent = function() {
    setTimeout(function() {
      // Gets events using receiveEvents() instead of getting it from event object
      // of Flash event. This is to make sure to keep message order.
      // It seems sometimes Flash events don't arrive in the same order as they are sent.
      var events = WebSocket.__flash.receiveEvents();
      for (var i = 0; i < events.length; ++i) {
        WebSocket.__instances[events[i].webSocketId].__handleEvent(events[i]);
      }
    }, 0);
    return true;
  };
  
  // called from Flash
  WebSocket.__log = function(message) {
    console.log(decodeURIComponent(message));
  };
  
  // called from Flash
  WebSocket.__error = function(message) {
    console.error(decodeURIComponent(message));
  };
  
  WebSocket.__addTask = function(task) {
    if (WebSocket.__flash) {
      task();
    } else {
      WebSocket.__tasks.push(task);
    }
  };
  
  /**
   * Test if the browser is running flash lite.
   * @return {boolean} True if flash lite is running, false otherwise.
   */
  WebSocket.__isFlashLite = function() {
    if (!window.navigator || !window.navigator.mimeTypes) {
      return false;
    }
    var mimeType = window.navigator.mimeTypes["application/x-shockwave-flash"];
    if (!mimeType || !mimeType.enabledPlugin || !mimeType.enabledPlugin.filename) {
      return false;
    }
    return mimeType.enabledPlugin.filename.match(/flashlite/i) ? true : false;
  };
  
  /**
   * Basic implementation of {@link <a href="http://www.w3.org/TR/DOM-Level-2-Events/events.html#Events-interface">DOM 2 EventInterface</a>}
   *
   * @class
   * @constructor
   */
  function WebSocketEvent(){}
  
  /**
   *
   * @type boolean
   */
  WebSocketEvent.prototype.cancelable = true;
  
  /**
  *
  * @type boolean
  */
  WebSocketEvent.prototype.cancelBubble = false;
  
  /**
  *
  * @return void
  */
  WebSocketEvent.prototype.preventDefault = function() {
    if (this.cancelable) {
      this.returnValue = false;
    }
  };
  
  /**
  *
  * @return void
  */
  WebSocketEvent.prototype.stopPropagation = function() {
    this.cancelBubble = true;
  };

  /**
  *
  * @param {string} eventTypeArg
  * @param {boolean} canBubbleArg
  * @param {boolean} cancelableArg
  * @return void
  */
  WebSocketEvent.prototype.initEvent = function(eventTypeArg, canBubbleArg, cancelableArg) {
    this.type = eventTypeArg;
    this.cancelable = cancelableArg;
    this.timeStamp = new Date();
  };

  if (!window.WEB_SOCKET_DISABLE_AUTO_INITIALIZATION) {
    if (window.addEventListener) {
      window.addEventListener("load", function(){
        WebSocket.__initialize();
      }, false);
    } else {
      window.attachEvent("onload", function(){
        WebSocket.__initialize();
      });
    }
  }
  
})();