dojo.provide("dojox.storage.CookieStorageProvider");

dojo.require("dojox.storage.Provider");
dojo.require("dojox.storage.manager");
dojo.require("dojo.cookie");

dojo.declare("dojox.storage.CookieStorageProvider", 
[ dojox.storage.Provider ], {

	store: null,
	cookieName: 'dojoxStorageCookie',
	storageLife: 730, // in days
	
	initialize: function(){
		
		this.store = dojo.fromJson(dojo.cookie(this.cookieName)) || {};

		this.initialized = true;
		dojox.storage.manager.loaded();	
	},
	
	isAvailable: function(){ /*Boolean*/
		return dojo.cookie.isSupported();
	},

	put: function(	/*string*/ key,
					/*object*/ value, 
					/*function*/ resultsHandler,
					/*string?*/ namespace){
		
		this._assertIsValidKey(key);
		
		namespace = namespace||this.DEFAULT_NAMESPACE;
		this._assertIsValidNamespace(namespace);
		
		fullKey = this.getFullKey(key,namespace);
		
		this.store[fullKey] = dojo.toJson(value);
		this._save();
		
		var success = dojo.toJson(this.store) === dojo.cookie(this.cookieName);
		
		if(!success){
			this.remove(key,namespace);
		}
		
		if(resultsHandler){
			resultsHandler(success ? this.SUCCESS : this.FAILED, key, null, namespace);
		}
	
	},

	get: function(/*string*/ key, /*string?*/ namespace){ /*Object*/
		this._assertIsValidKey(key);
		
		namespace = namespace||this.DEFAULT_NAMESPACE;
		this._assertIsValidNamespace(namespace);
		
		// get our full key name, which is namespace + key
		key = this.getFullKey(key, namespace);
		
		return this.store[key] ? dojo.fromJson(this.store[key]) : null;
	},

	getKeys: function(/*string?*/ namespace){ /*Array*/
		namespace = namespace||this.DEFAULT_NAMESPACE;
		this._assertIsValidNamespace(namespace);
		
		namespace = '__'+namespace+'_'
		
		var keys = [];
		for(var currentKey in this.store){
			if(this._beginsWith(currentKey,namespace)){
				currentKey = currentKey.substring(namespace.length);
				keys.push(currentKey);
			}
		}
		
		return keys;
	},
	
	clear: function(/*string?*/ namespace){
		
		namespace = namespace||this.DEFAULT_NAMESPACE;
		this._assertIsValidNamespace(namespace);

		namespace = '__'+namespace+'_'

		for(var currentKey in this.store){
			if(this._beginsWith(currentKey,namespace)){
				delete(this.store[currentKey]);
			}
		}
		
		this._save();
	},
  
	remove: function(/*string*/ key, /*string?*/ namespace){
		namespace = namespace||this.DEFAULT_NAMESPACE;
		this._assertIsValidNamespace(namespace);
		
		this._assertIsValidKey(key);
		key = this.getFullKey(key, namespace);
		
		delete this.store[key];
		this._save();
	},
	
	getNamespaces: function(){ /*string[]*/
		// There must be a better way than
		// to execute a regex on *every*
		// item in the store.
		
		var results = [ this.DEFAULT_NAMESPACE];
		
		var found = {};
		found[this.DEFAULT_NAMESPACE] = true;
		var tester = /^__([^_]*)_/;
		
		for(var currentKey in this.store){
			if(tester.test(currentKey) == true){
				var currentNS = currentKey.match(tester)[1];
				if(typeof found[currentNS] == "undefined"){
					found[currentNS] = true;
					results.push(currentNS);
				}
			}
		}
		
		return results;
	},

	isPermanent: function(){ /*Boolean*/
		return true;
	},

	getMaximumSize: function(){ /* mixed */
		return 4;
	},

	hasSettingsUI: function(){ /*Boolean*/
		return false;
	},
	
	isValidKey: function(/*string*/ keyName){ /*Boolean*/
		if(keyName === null || keyName === undefined){
			return false;
		}
			
		return /^[0-9A-Za-z_-]*$/.test(keyName);
	},
	
	isValidNamespace: function(/*string*/ keyName){ /*Boolean*/
		// we *must* prevent namespaces from having
		// underscores - else lookup of namespaces
		// via RegEx (e.g. in getNamespaces ) would
		// return wrong results.
		// 
		// The only way around this would be to
		// disallow underscores in keys.
		
		if(keyName === null || keyName === undefined){
			return false;
		}
			
		return /^[0-9A-Za-z-]*$/.test(keyName);
	},
	
	getFullKey: function(key, namespace){
		// checks for valid namespace and
		// key are already performed.
		return "__" + namespace + "_" + key;
	},
	
	_save: function(){
		dojo.cookie(this.cookieName,dojo.toJson(this.store),{expires: this.storageLife});
	},
	
	_beginsWith: function(/* string */ haystack, /* string */ needle) {
		if(needle.length > haystack.length) {
			return false;
		}
		return haystack.substring(0,needle.length) === needle;
	},
	
	_assertIsValidNamespace: function(/* string */ namespace){
		if(this.isValidNamespace(namespace) === false){
			throw new Error("Invalid namespace given: " + namespace);
		}
	},
	
	_assertIsValidKey: function(/* string */ key){
		if(this.isValidKey(key) === false){
			throw new Error("Invalid key given: " + key);
		}
	}
});

dojox.storage.manager.register("dojox.storage.CookieStorageProvider", new dojox.storage.CookieStorageProvider());