var Reflux = require('reflux');

var actions = require('../actions/inputHistory');

var HISTORY_MAX_LENGTH = 128;

var history = [];
var index = -1;
var stored = localStorage.inputHistory;

if (stored) {
	history = JSON.parse(stored);
}

function getState() {
	if (index !== -1) {
		return history[index];
	}
	return null;
}

var inputHistoryStore = Reflux.createStore({
	init() {
		this.listenToMany(actions);
	},

	add(line) {
		if (line.trim() && line !== history[0]) {
			history.unshift(line);

			if (history.length > HISTORY_MAX_LENGTH) {
				history.pop();
			}

			localStorage.inputHistory = JSON.stringify(history);
		}
	},

	reset() {
		if (index !== -1) {
			index = -1;
			this.trigger(history[index]);
		}
	},

	increment() {
		if (index !== history.length - 1) {
			index++;
			this.trigger(history[index]);
		}
	},

	decrement() {
		if (index !== -1) {
			index--;
			this.trigger(history[index]);
		}
	},

	getInitialState: getState,
	getState
});

module.exports = inputHistoryStore;