/*
 * Ext JS Library 2.0 Copyright(c) 2006-2007, Ext JS, LLC. licensing@extjs.com
 * 
 * http://extjs.com/license
 */

/**
 * @class Ext.state.Provider Abstract base class for state provider
 *        implementations. This class provides methods for encoding and decoding
 *        <b>typed</b> variables including dates and defines the Provider
 *        interface.
 */
Ext.state.Provider = function() {
	/**
	 * @event statechange Fires when a state change occurs.
	 * @param {Provider}
	 *            this This state provider
	 * @param {String}
	 *            key The state key which was changed
	 * @param {String}
	 *            value The encoded value for the state
	 */
	this.addEvents("statechange");
	this.state = {};
	Ext.state.Provider.superclass.constructor.call(this);
};
Ext.extend(Ext.state.Provider, Ext.util.Observable, {
			/**
			 * Returns the current value for a key
			 * 
			 * @param {String}
			 *            name The key name
			 * @param {Mixed}
			 *            defaultValue A default value to return if the key's
			 *            value is not found
			 * @return {Mixed} The state data
			 */
			get : function(name, defaultValue) {
				return typeof this.state[name] == "undefined"
						? defaultValue
						: this.state[name];
			},

			/**
			 * Clears a value from the state
			 * 
			 * @param {String}
			 *            name The key name
			 */
			clear : function(name) {
				delete this.state[name];
				this.fireEvent("statechange", this, name, null);
			},

			/**
			 * Sets the value for a key
			 * 
			 * @param {String}
			 *            name The key name
			 * @param {Mixed}
			 *            value The value to set
			 */
			set : function(name, value) {
				this.state[name] = value;
				// console.log(value);
				this.fireEvent("statechange", this, name, value);
			},

			/**
			 * Decodes a string previously encoded with {@link #encodeValue}.
			 * 
			 * @param {String}
			 *            value The value to decode
			 * @return {Mixed} The decoded value
			 */
			decodeValue : function(cookie) {
				var re = /^(a|n|d|b|s|o)\:(.*)$/;
				var matches = re.exec(unescape(cookie));
				if (!matches || !matches[1])
					return; // non state cookie
				var type = matches[1];
				var v = matches[2];
				switch (type) {
					case "n" :
						return parseFloat(v);
					case "d" :
						return new Date(Date.parse(v));
					case "b" :
						return (v == "1");
					case "a" :
						var all = [];
						var values = v.split("^");
						for (var i = 0, len = values.length; i < len; i++) {
							all.push(this.decodeValue(values[i]));
						}
						return all;
					case "o" :
						var all = {};
						var values = v.split("^");
						for (var i = 0, len = values.length; i < len; i++) {
							var kv = values[i].split("=");
							all[kv[0]] = this.decodeValue(kv[1]);
						}
						return all;
					default :
						return v;
				}
			},

			/**
			 * Encodes a value including type information. Decode with
			 * {@link #decodeValue}.
			 * 
			 * @param {Mixed}
			 *            value The value to encode
			 * @return {String} The encoded value
			 */
			encodeValue : function(v) {
				var enc;
				if (typeof v == "number") {
					enc = "n:" + v;
				} else if (typeof v == "boolean") {
					enc = "b:" + (v ? "1" : "0");
				} else if (v instanceof Date) {
					enc = "d:" + v.toGMTString();
				} else if (v instanceof Array) {
					var flat = "";
					for (var i = 0, len = v.length; i < len; i++) {
						flat += this.encodeValue(v[i]);
						if (i != len - 1)
							flat += "^";
					}
					enc = "a:" + flat;
				} else if (typeof v == "object") {
					var flat = "";
					for (var key in v) {
						if (typeof v[key] != "function" && v[key] !== undefined) {
							flat += key + "=" + this.encodeValue(v[key]) + "^";
						}
					}
					enc = "o:" + flat.substring(0, flat.length - 1);
				} else {
					enc = "s:" + v;
				}
				return escape(enc);
			}
		});