function Session(async) {
	var session = {
		character: JSON.parse(localStorage.getItem('character')),
		game: JSON.parse(localStorage.getItem('game')),
		options: JSON.parse(localStorage.getItem('options')) || defaultOptions()
	};

	return {
		get: get,
		set: set,
		syncGame: syncGame,
		update: update
	};

	function defaultOptions() {
		var o = {
			layout: {
				'a': 'A',
				'b': 'B',
				'ArrowLeft': 'Left',
				'ArrowRight': 'Right',
				'ArrowUp': 'Up',
				'ArrowDown': 'Down',
				'Enter': 'Start',
				' ': 'Select'
			},
			textSpeed: 'medium'
		};
		save('options', o);
		return o;
	}

	function get(path, obj) {
		obj = obj || session;
		if(Array.isArray(path)) {
			if(path.length == 0) {
				return obj;
			} else {
				var key = path.shift();
				return get(path, obj[key]);
			}
		} else {
			return obj[path];
		}
	}

	function save(key, value) {
		if(key != undefined) {
			localStorage.setItem(key, JSON.stringify(value || session[key]));
		} else {
			for(var key in session) {
				save(key);
			}
		}
	}

	function set(newSession) {
		for(var key in newSession) {
			session[key] = newSession[key];
			save(key);
		}
	}

	function syncGame() {
		return async.bind(
			messaging.receive(function(message) {
				return message.tag == "Game";
			}),
			function(message) {
				session.game = message.contents;
				return async.wrap();
			}
		);
	}

	function update(newSession) {
		for(var key in newSession) {
			merge(session[key], newSession[key]);
			save(key);
		}
	}

	function merge(a, b) {
		for(var key in b) {
			var value = b[key];
			if(typeof value == "object") {
				if(Array.isArray(value)) {
					a[key] = [];
					for(var i = 0; i < value.length; i++) {
						a[key][i] = value[i];
					}
				} else {
					merge(a[key], value);
				}
			} else {
				if(value !== undefined) {
					a[key] = value;
				} else {
					delete a[key];
				}
			}
		}
	}

}