/*

Copyright (c) 2009, Yahoo! Inc. All rights reserved.

Code licensed under the BSD License:

http://developer.yahoo.net/yui/license.txt

version: 3.0.0b1

build: 1163

*/

YUI.add('cookie', function(Y) {

/**

 * Utilities for cookie management

 * @module cookie

 */

    //shortcuts

    var L       = Y.Lang,

        O       = Y.Object,

        NULL    = null,

        //shortcuts to functions

        isString    = L.isString,

        isObject    = L.isObject,

        isUndefined = L.isUndefined,

        isFunction  = L.isFunction,

        encode      = encodeURIComponent,

        decode      = decodeURIComponent,

        //shortcut to document

        doc         = Y.config.doc;

    /*

     * Throws an error message.

     */

    function error(message){

        throw new TypeError(message);

    }        

    /*

     * Checks the validity of a cookie name.

     */

    function validateCookieName(name){

        if (!isString(name) || name === ""){

            error("Cookie name must be a non-empty string.");

        }               

    }

    /*

     * Checks the validity of a subcookie name.

     */    

    function validateSubcookieName(subName){

        if (!isString(subName) || subName === ""){

            error("Subcookie name must be a non-empty string.");

        }    

    }

    /**

     * Cookie utility.

     * @class Cookie

     * @static

     */

    Y.Cookie = {

        //-------------------------------------------------------------------------

        // Private Methods

        //-------------------------------------------------------------------------

        /**

         * Creates a cookie string that can be assigned into document.cookie.

         * @param {String} name The name of the cookie.

         * @param {String} value The value of the cookie.

         * @param {Boolean} encodeValue True to encode the value, false to leave as-is.

         * @param {Object} options (Optional) Options for the cookie.

         * @return {String} The formatted cookie string.

         * @method _createCookieString

         * @private

         * @static

         */

        _createCookieString : function (name /*:String*/, value /*:Variant*/, encodeValue /*:Boolean*/, options /*:Object*/) /*:String*/ {

            options = options || {};

            var text /*:String*/ = encode(name) + "=" + (encodeValue ? encode(value) : value),

                expires = options.expires,

                path    = options.path,

                domain  = options.domain;

            if (isObject(options)){

                //expiration date

                if (expires instanceof Date){

                    text += "; expires=" + expires.toUTCString();

                }

                //path

                if (isString(path) && path !== ""){

                    text += "; path=" + path;

                }

                //domain

                if (isString(domain) && domain !== ""){

                    text += "; domain=" + domain;

                }

                //secure

                if (options.secure === true){

                    text += "; secure";

                }

            }

            return text;

        },

        /**

         * Formats a cookie value for an object containing multiple values.

         * @param {Object} hash An object of key-value pairs to create a string for.

         * @return {String} A string suitable for use as a cookie value.

         * @method _createCookieHashString

         * @private

         * @static

         */

        _createCookieHashString : function (hash /*:Object*/) /*:String*/ {

            if (!isObject(hash)){

                error("Cookie._createCookieHashString(): Argument must be an object.");

            }

            var text /*:Array*/ = [];

            O.each(hash, function(value, key){

                if (!isFunction(value) && !isUndefined(value)){

                    text.push(encode(key) + "=" + encode(String(value)));

                }            

            });

            return text.join("&");

        },

        /**

         * Parses a cookie hash string into an object.

         * @param {String} text The cookie hash string to parse (format: n1=v1&n2=v2).

         * @return {Object} An object containing entries for each cookie value.

         * @method _parseCookieHash

         * @private

         * @static

         */

        _parseCookieHash : function (text) {

            var hashParts   = text.split("&"),

                hashPart    = NULL,

                hash        = {};

            if (text.length){

                for (var i=0, len=hashParts.length; i < len; i++){

                    hashPart = hashParts[i].split("=");

                    hash[decode(hashPart[0])] = decode(hashPart[1]);

                }

            }

            return hash;          

        },

        /**

         * Parses a cookie string into an object representing all accessible cookies.

         * @param {String} text The cookie string to parse.

         * @param {Boolean} shouldDecode (Optional) Indicates if the cookie values should be decoded or not. Default is true.

         * @return {Object} An object containing entries for each accessible cookie.

         * @method _parseCookieString

         * @private

         * @static

         */

        _parseCookieString : function (text /*:String*/, shouldDecode /*:Boolean*/) /*:Object*/ {

            var cookies /*:Object*/ = {};        

            if (isString(text) && text.length > 0) {

                var decodeValue = (shouldDecode === false ? function(s){return s;} : decode),  

                    cookieParts = text.split(/;\s/g),

                    cookieName  = NULL,

                    cookieValue = NULL,

                    cookieNameValue = NULL;

                for (var i=0, len=cookieParts.length; i < len; i++){

                    //check for normally-formatted cookie (name-value)

                    cookieNameValue = cookieParts[i].match(/([^=]+)=/i);

                    if (cookieNameValue instanceof Array){

                        try {

                            cookieName = decode(cookieNameValue[1]);

                            cookieValue = decodeValue(cookieParts[i].substring(cookieNameValue[1].length+1));

                        } catch (ex){

                            //intentionally ignore the cookie - the encoding is wrong

                        }

                    } else {

                        //means the cookie does not have an "=", so treat it as a boolean flag

                        cookieName = decode(cookieParts[i]);

                        cookieValue = "";

                    }

                    cookies[cookieName] = cookieValue;

                }

            }

            return cookies;

        },    

        //-------------------------------------------------------------------------

        // Public Methods

        //-------------------------------------------------------------------------

        /**

         * Determines if the cookie with the given name exists. This is useful for

         * Boolean cookies (those that do not follow the name=value convention).

         * @param {String} name The name of the cookie to check.

         * @return {Boolean} True if the cookie exists, false if not.

         * @method exists

         * @static

         */

        exists: function(name) {

            validateCookieName(name);   //throws error

            var cookies = this._parseCookieString(doc.cookie, true);

            return cookies.hasOwnProperty(name);

        },    

        /**

         * Returns the cookie value for the given name.

         * @param {String} name The name of the cookie to retrieve.

         * @param {Function|Object} options (Optional) An object containing one or more

         *      cookie options: raw (true/false) and converter (a function).

         *      The converter function is run on the value before returning it. The

         *      function is not used if the cookie doesn't exist. The function can be

         *      passed instead of the options object for backwards compatibility. When

         *      raw is set to true, the cookie value is not URI decoded.

         * @return {Variant} If no converter is specified, returns a string or null if

         *      the cookie doesn't exist. If the converter is specified, returns the value

         *      returned from the converter or null if the cookie doesn't exist.

         * @method get

         * @static

         */

        get : function (name, options) {

            validateCookieName(name);   //throws error                        

            var cookies,

                cookie,

                converter;

            //if options is a function, then it's the converter

            if (isFunction(options)) {

                converter = options;

                options = {};

            } else if (isObject(options)) {

                converter = options.converter;

            } else {

                options = {};

            }

            cookies = this._parseCookieString(doc.cookie, !options.raw);

            cookie = cookies[name];

            //should return null, not undefined if the cookie doesn't exist

            if (isUndefined(cookie)) {

                return NULL;

            }

            if (!isFunction(converter)){

                return cookie;

            } else {

                return converter(cookie);

            }

        },

        /**

         * Returns the value of a subcookie.

         * @param {String} name The name of the cookie to retrieve.

         * @param {String} subName The name of the subcookie to retrieve.

         * @param {Function} converter (Optional) A function to run on the value before returning

         *      it. The function is not used if the cookie doesn't exist.

         * @return {Variant} If the cookie doesn't exist, null is returned. If the subcookie

         *      doesn't exist, null if also returned. If no converter is specified and the

         *      subcookie exists, a string is returned. If a converter is specified and the

         *      subcookie exists, the value returned from the converter is returned.

         * @method getSub

         * @static

         */

        getSub : function (name /*:String*/, subName /*:String*/, converter /*:Function*/) /*:Variant*/ {

            var hash /*:Variant*/ = this.getSubs(name);  

            if (hash !== NULL) {

                validateSubcookieName(subName);   //throws error

                if (isUndefined(hash[subName])){

                    return NULL;

                }            

                if (!isFunction(converter)){

                    return hash[subName];

                } else {

                    return converter(hash[subName]);

                }

            } else {

                return NULL;

            }

        },

        /**

         * Returns an object containing name-value pairs stored in the cookie with the given name.

         * @param {String} name The name of the cookie to retrieve.

         * @return {Object} An object of name-value pairs if the cookie with the given name

         *      exists, null if it does not.

         * @method getSubs

         * @static

         */

        getSubs : function (name) {

            validateCookieName(name);   //throws error

            var cookies = this._parseCookieString(doc.cookie, false);

            if (isString(cookies[name])){

                return this._parseCookieHash(cookies[name]);

            }

            return NULL;

        },

        /**

         * Removes a cookie from the machine by setting its expiration date to

         * sometime in the past.

         * @param {String} name The name of the cookie to remove.

         * @param {Object} options (Optional) An object containing one or more

         *      cookie options: path (a string), domain (a string), 

         *      and secure (true/false). The expires option will be overwritten

         *      by the method.

         * @return {String} The created cookie string.

         * @method remove

         * @static

         */

        remove : function (name, options) {

            validateCookieName(name);   //throws error

            //set options

            options = Y.merge(options || {}, {

                expires: new Date(0)

            });

            //set cookie

            return this.set(name, "", options);

        },

        /**

         * Removes a sub cookie with a given name.

         * @param {String} name The name of the cookie in which the subcookie exists.

         * @param {String} subName The name of the subcookie to remove.

         * @param {Object} options (Optional) An object containing one or more

         *      cookie options: path (a string), domain (a string), expires (a Date object),

         *      removeIfEmpty (true/false), and secure (true/false). This must be the same

         *      settings as the original subcookie.

         * @return {String} The created cookie string.

         * @method removeSub

         * @static

         */

        removeSub : function(name, subName, options) {

            validateCookieName(name);   //throws error

            validateSubcookieName(subName);   //throws error

            options = options || {};

            //get all subcookies for this cookie

            var subs = this.getSubs(name);

            //delete the indicated subcookie

            if (isObject(subs) && subs.hasOwnProperty(subName)){

                delete subs[subName];

                if (!options.removeIfEmpty) {

                    //reset the cookie

                    return this.setSubs(name, subs, options);

                } else {

                    //reset the cookie if there are subcookies left, else remove

                    for (var key in subs){

                        if (subs.hasOwnProperty(key) && !isFunction(subs[key]) && !isUndefined(subs[key])){

                            return this.setSubs(name, subs, options);

                        }

                    }

                    return this.remove(name, options);

                }                

            } else {

                return "";

            }

        },

        /**

         * Sets a cookie with a given name and value.

         * @param {String} name The name of the cookie to set.

         * @param {Variant} value The value to set for the cookie.