/**
 *
 * Simulates an XMLHttpRequest object's methods and properties as returned
 * form the flash polyfill plugin. Used in submitting binary data in browsers that do 
 * not support doing so from JavaScript.
 * NOTE: By default this will look for the flash object in the ext directory. When packaging and deploying the app, copy the <tt>ext/plugins</tt> directory and its contents to your root directory. For custom deployments where just the <tt>FlashPlugin.swf</tt> file gets copied (e.g. to <tt>/resources/FlashPlugin.swf</tt>), make sure to notify the framework of the location of the plugin before making the first attempt to post binary data, e.g. in the <tt>launch</tt> method of your app do:
 * <pre><code>
Ext.flashPluginPath="/resources/FlashPlugin.swf";
 </code></pre>
 *
 * @private
 */
Ext.define('Ext.data.flash.BinaryXhr', {
    
    statics: {
        /**
         * Called by the flash plugin once it's installed and open for business.
         * @private
         */
        flashPluginActivated: function() {
            Ext.data.flash.BinaryXhr.flashPluginActive = true;
            Ext.data.flash.BinaryXhr.flashPlugin = document.getElementById("ext-flash-polyfill");
            Ext.GlobalEvents.fireEvent("flashready"); // let all pending connections know
        },
        
        /**
         * Set to <tt>trut</tt> once the plugin registers and is active.
         * @private
         */
        flashPluginActive: false,
        
        /**
         * Flag to avoid installing the plugin twice.
         * @private
         */
        flashPluginInjected: false,
        
        /**
         * Counts IDs for new connections.
         * @private
         */
        
        connectionIndex: 1,
        
        /**
         * Plcaeholder for active connections.
         * @private
         */
        liveConnections: {},
        
        /**
         * Reference to the actual plugin, once activated.
         * @private
         */
        flashPlugin: null,
        
        /**
         * Called by the flash plugin once the state of one of the active connections changes.
         * @param {Number/number} javascriptId the ID of the connection.
         * @param {number} state the state of the connection. Equivalent to readyState numbers in XHR.
         * @param {Object} data optional object containing the returned data, error and status codes.
         * @private
         */
        onFlashStateChange: function(javascriptId, state, data) {
            var connection;
            // Identify the request this is for
            connection = this.liveConnections[Number(javascriptId)]; // Make sure its a native number
            if (connection) {
                connection.onFlashStateChange(state, data);
            } 
            //<debug>
            else {
                Ext.warn.log("onFlashStateChange for unknown connection ID: " + javascriptId);
            }
            //</debug>
        },
        
        /**
         * Adds the BinaryXhr object to the tracked connection list and assigns it an ID
         * @param {Ext.data.flash.BinaryXhr} conn the connection to register
         * @return {Number} id
         * @private
         */
        registerConnection: function(conn) {
            var i = this.connectionIndex;
            this.conectionIndex = this.connectionIndex + 1;
            this.liveConnections[i] = conn;
            return i;
        },
        
        /**
         * Injects the flash polyfill plugin to allow posting binary data.
         * This is done in two steps: First we load the javascript loader for flash objects, then we call it to inject the flash object.
         * @private
         */
        injectFlashPlugin: function() {
            var me = this,
                flashLoaderPath, flashObjectPath;
                // Generate the following HTML set of tags:
               // + '<div id="ext-flash-polyfill">'
               // + '<p>To view this page ensure that Adobe Flash Player version 11.1.0 or greater is installed, and that the FlashPlugin.swf file was correctly placed in the /resources directory.</p>'
                //+ '<a href="http://www.adobe.com/go/getflashplayer"><img src="' + window.location.protocol + '//www.adobe.com/images/shared/download_buttons/get_flash_player.gif" alt="Get Adobe Flash player" /></a>'
                //+ '</div>'
            
            me.flashPolyfillEl = Ext.getBody().appendChild({
                id: 'ext-flash-polyfill',
                cn: [
                    {
                        tag: 'p',
                        html: 'To view this page ensure that Adobe Flash Player version 11.1.0 or greater is installed.'
                    },
                    {
                        tag: 'a',
                        href: 'http://www.adobe.com/go/getflashplayer',
                        cn: [
                            {
                                tag: 'img',
                                src: window.location.protocol + '//www.adobe.com/images/shared/download_buttons/get_flash_player.gif',
                                alt: 'Get Adobe Flash player'
                            }
                        ]
                    }
                ]
            });
            
            // Now load the flash-loading script
            
            flashLoaderPath = [Ext.Loader.getPath('Ext.data.Connection'), '../../../plugins/flash/swfobject.js'].join('/');
            flashObjectPath = "/plugins/flash/FlashPlugin.swf";
            //<debug>
            flashObjectPath = [Ext.Loader.getPath('Ext.data.Connection'), '../../plugins/flash/FlashPlugin.swf'].join('/');
            //</debug>
            if (Ext.flashPluginPath) {
                flashObjectPath = Ext.flashPluginPath;
            }
            //console.log('LOADING Flash plugin from: ' + flashObjectPath);
            Ext.Loader.loadScript({
                url:flashLoaderPath,
                onLoad: function() {
                    // For version detection, set to min. required Flash Player version, or 0 (or 0.0.0), for no version detection. 
                    var swfVersionStr = "11.4.0";
                    // To use express install, set to playerProductInstall.swf, otherwise the empty string. 
                    var xiSwfUrlStr = "playerProductInstall.swf";
                    var flashvars = {};
                    var params = {};
                    params.quality = "high";
                    params.bgcolor = "#ffffff";
                    params.allowscriptaccess = "sameDomain";
                    params.allowfullscreen = "true";
                    var attributes = {};
                    attributes.id = "ext-flash-polyfill";
                    attributes.name = "polyfill";
                    attributes.align = "middle";
                    swfobject.embedSWF(
                        flashObjectPath, "ext-flash-polyfill", 
                        "0", "0", // no size so it's not visible. 
                        swfVersionStr, xiSwfUrlStr, 
                        flashvars, params, attributes);
                },
                onError: function() {
                    //<debug>
                    Ext.Error.raise("Could not load flash-loader file swfobject.js from " + flashLoader);
                    //</debug>
                },
                scope: me
            });

            Ext.data.flash.BinaryXhr.flashPluginInjected = true;
        }
    },
    
    /**
     * @property {number} readyState The connection's simulated readyState. Note that the only supported values are 0, 1 and 4. States 2 and 3 will never be reported.
     */
    readyState: 0,
    
    /**
     * @property {number} status Connection status code returned by flash or the server.
     */
    status: 0,
    
    
    /**
     * Status text (if any) returned by flash or the server.
     */
    statusText: "",
    
    /**
     * @property {Array} responseBytes The binary bytes returned.
     */
    responseBytes: null,
    
    /**
     * An ID representing this connection with flash.
     * @private
     */
    javascriptId: null,
    
    
    /**
     * Creates a new instance of BinaryXhr.
     */
    constructor: function (config) {
        // first, make sure flash is loading if needed
        if (!Ext.data.flash.BinaryXhr.flashPluginInjected) {
            Ext.data.flash.BinaryXhr.injectFlashPlugin();
        }
        var me = this;

        Ext.apply(me, config);
        me.requestHeaders = {};
    },

    /**
     * Abort this connection. Sets its readyState to 4.
     */
    abort: function () {
        var me = this;
        // if complete, nothing to abort 
        if (me.readyState == 4) {
            //<debug>
            Ext.warn.log("Aborting a connection that's completed its transfer: " + this.url);
            //</debug>
            return;
        }
        // Mark as aborted
        me.aborted = true;
        // Remove ourselves from the listeners if flash isn't active yet
        if (!Ext.data.flash.BinaryXhr.flashPluginActive) {
            Ext.GlobalEvents.removeListener("flashready", me.onFlashReady, me);
            return;
        }
        // Flash is already live, so we should have a javascriptID and should have called flash to get the request going. Cancel:
        Ext.data.flash.BinaryXhr.flashPlugin.abortRequest(me.javascriptId);
        // remove from list
        delete Ext.data.flash.BinaryXhr.liveConnections[me.javascriptId];
    },

    /**
     * As in XMLHttpRequest.
     */
    getAllResponseHeaders: function () {
        var headers = [];
        Ext.Object.each(this.responseHeaders, function (name, value) {
            headers.push(name + ': ' + value);
        });
        return headers.join('\x0d\x0a');
    },

    /**
     * As in XMLHttpRequest.
     */
    getResponseHeader: function (header) {
        var headers = this.responseHeaders;
        return (headers && headers[header]) || null;
    },

    /**
     * As in XMLHttpRequest.
     */
    open: function (method, url, async, user, password) {
        var me = this;
        me.method = method;
        me.url = url;
        me.async = async !== false;
        me.user = user;
        me.password = password;
        
        //<debug>
        if (!me.async) {
            Ext.Error.raise("Binary posts are only supported in async mode: " + url);
        }
        if (me.method != "POST") {
            Ext.log.warn("Binary data can only be sent as a POST request: " + url);
        }
        //</debug>
    },

    /**
     * As in XMLHttpRequest.
     */
    overrideMimeType: function (mimeType) {
        this.mimeType = mimeType;
    },

    /**
     * Initiate the request.
     * @param {Array} body an array of byte values to send.
     */
    send: function (body) {
        var me = this;
        me.body = body;
        if (!Ext.data.flash.BinaryXhr.flashPluginActive) {
            Ext.GlobalEvents.addListener("flashready", me.onFlashReady, me);
        } else {
            this.onFlashReady();
        }
    },
    
    /**
     * Called by send, or once flash is loaded, to actually send the bytes.
     * @private
     */
    onFlashReady: function() {
        var me = this, req, status;
        me.javascriptId = Ext.data.flash.BinaryXhr.registerConnection(me);
        
        // Create the request object we're sending to flash
        req = {
            method: me.method, // ignored since we always POST binary data
            url: me.url,
            user: me.user,
            password: me.password,
            mimeType: me.mimeType,
            requestHeaders: me.requestHeaders,
            body: me.body,
            javascriptId: me.javascriptId
        };
        status = Ext.data.flash.BinaryXhr.flashPlugin.postBinary(req);
    },

    /**
     * Updates readyState and notifies listeners.
     * @private
     */
    setReadyState: function (state) {
        var me = this;
        if (me.readyState != state) {
            me.readyState = state;
            me.onreadystatechange();
        }
    },

    /**
     * As in XMLHttpRequest.
     */
    setRequestHeader: function (header, value) {
        this.requestHeaders[header] = value;
    },

    /**
     * As in XMLHttpRequest.
     */
    onreadystatechange: Ext.emptyFn,

    /**
     * Parses data returned from flash once a connection is done.
     * @param {Object} data the data object send from Flash.
     * @private
     */
    parseData: function (data) {
        var me = this;
        // parse data and set up variables so that listeners can use this XHR
        this.status = data.status || 0; 
        // we get back no response headers, so fake what we know:
        me.responseHeaders = {};
        if (me.mimeType) {
            me.responseHeaders["content-type"] = me.mimeType;
        }
        if (data.reason == "complete") {
            // Transfer complete and data received
            this.responseBytes = data.data;
            me.responseHeaders["content-length"] = data.data.length;
        } else if (data.reason == "error" || data.reason == "securityError") {
            this.statusText = data.text;
            me.responseHeaders["content-length"] = 0; // we don't get the error response data
        }
        //<debug>
        else {
            Ext.Error.raise("Unkown reason code in data: " + data.reason);
        }
        //</debug>
    },

    /**
     * Called once flash calls back with updates about the connection
     * @param {Number} state the readyState of the connection.
     * @param {Object} data optional data object.
     * @private
     */
    onFlashStateChange: function(state, data) {
        var me = this;
        if (state == 4) {
            // parse data and prepare for handing back to initiator
            me.parseData(data);
            // remove from list
            delete Ext.data.flash.BinaryXhr.liveConnections[me.javascriptId];
        }
        me.setReadyState(state); // notify all listeners
    }
    
});
