var FlightMonitorBox = function() {
	var instance = this;

	this.history = [];
	this.storage = Storage;
	this.init();

	FlightMonitorBox = function() {
		return instance;
	};
};

FlightMonitorBox.prototype.init = function() {
	var flightIdsString = this.storage.get('monitorBox'),
		flightIds = [],
		data;

	this.flights = {};
	this.count = 0;
	
	if (flightIdsString !== null) {
		flightIds = JSON.parse(flightIdsString);
	}

	for (var i = flightIds.length - 1; i >= 0; i--) {
		if (this.storage.get(flightIds[i]) === null) {
			continue;
		}
		data = JSON.parse(this.storage.get(flightIds[i]));

		this.add(
			FlightFactory.getFromId(flightIds[i]).setData(data.flight),
			data.monitor,
			data.lastShowedPrice,
			data.error
		);
	};
	
	return this;
};

FlightMonitorBox.prototype.add = function(flight, monitor, lastShowedPrice, error) {
	var flightId = flight.getId();
	
	if (this.flights[flightId] !== undefined) {
		throw {
			name: 'MonitorDulipcateId',
			message: '重复航班'
		};
	}
	if (this.count >= config.monitor.limit) {
		throw {
			name: 'MonitorLimit',
			message: '最多允许同时关注' + config.monitor.limit + '条航线'
		};
	}

	this.flights[flightId] = {
		flight: flight,
		monitor: monitor,
		lastShowedPrice: lastShowedPrice,
		error: error
	};

	this.count++;
	this.history.push(flightId);
	return this;
};

FlightMonitorBox.prototype.remove = function(id) {
	delete this.flights[id];
	this.storage.remove(id);
	this.count--;
	return this;
};

FlightMonitorBox.prototype.getAll = function() {
	return this.flights;
};

FlightMonitorBox.prototype.getCount = function() {
	return this.count;
};

FlightMonitorBox.prototype.get = function(id) {
	return this.flights[id];
};

FlightMonitorBox.prototype.persistenceOne = function(id) {
	this.storage.set(id, JSON.stringify({
		flight: this.flights[id].flight.data,
		monitor: this.flights[id].monitor,
		lastShowedPrice: this.flights[id].lastShowedPrice,
		error: this.flights[id].error
	}));
};

FlightMonitorBox.prototype.persistence = function() {
	var flightIds = [],
		flightId;

	for (flightId in this.flights) {
		flightIds.push(flightId);
		this.persistenceOne(flightId);
	}

	this.storage.set('monitorBox', JSON.stringify(flightIds));
	this.storage.set('monitorHistory', JSON.stringify(this.history.slice(-20)));
};