/**
 * Mq Factory
 * @authors yanjixiong
 * @date    2016-07-22 09:56:19
 */

var Connection = require('./Connection');
var Channel = require('./Channel');
var Exchange = require('./Exchange');
var Queue = require('./Queue');
var Consume = require('./Consume');
var ExchangeTypes = require('../constant').ExchangeTypes;
var RouteKey = require('../constant').RouteKey;

var config = require('../../config');
var log = require('../../common/logger').getLogger('Core:mq:index');

var ROUTE_KEY = RouteKey.RECEIVE_PA;
var QUEUE_NAME = RouteKey.RECEIVE_PA; // 队列名称

function MQ() {
    this.connection = null;
    this.init();
}

/**
 * 初始化消息队列
 * @return {[type]} [description]
 */
MQ.prototype.init = function init() {
    var self = this;

    // 创建连接
    Connection
        .createConnection(config.rabbitMQ_url)
        .then(function (conn) {

            // 实例中存储当前连接
            self.connection = conn;

            // 监听连接错误
            conn.on('error', function(err) {
                log.error('[mq] connection error ', err);
                self.reconnect();
            });

            log.info('[mq] create connection success');

            // 创建通道
            return Channel
                .createChannel(conn);
        })
        .then(function (ch) {

            // 进程被杀死关闭连接
            process.once('SIGINT', function() {
                log.info('kill by signal SIGINT');
                ch.close();
                self.connection.close();
                self.connection = null;
                process.exit(0);
            });

            ch.on('error', function(error) {
                // ch.close();
                log.error('[mq] channel error: ', error);
            });

            log.info('[mq] create channel success');

            // 创建交换机
            return Exchange
                .assertExchange(ch, config.exchange_name, ExchangeTypes.DIRECT, {durable: false})
                .then(function () {
                    log.info('[mq] assert exchange [%s] [%s]', config.exchange_name, ExchangeTypes.DIRECT);

                    // 创建队列
                    return Queue
                        .assertQueue(ch, QUEUE_NAME, {exclusive: false, durable: false}); // exclusive 是否排它 durable : 是否持久化
                })
                .then(function (queue) {
                    log.info('[mq] assert queue [%s] success', QUEUE_NAME);

                    log.debug(queue);

                    // 绑定队列到交换机
                    return Queue.
                        bindQueue(ch, QUEUE_NAME, config.exchange_name, ROUTE_KEY);
                })
                .then(function() {
                    log.info('[mq] bind queue [%s] to exchange [%s]', QUEUE_NAME, config.exchange_name);

                    // 消费
                    return Consume
                        .consume(self.connection, ch, QUEUE_NAME);
                })
        })
        .catch(function (err) {
            log.error('[mq] Init failed , error: ', err);
            self.reconnect();
        });
};

/**
 * 重新连接
 * @return {[type]} [description]
 */
MQ.prototype.reconnect = function() {
    var self = this;

    log.info('[mq] try reconnect 3 seconds later');

    setTimeout(function () {
        self.init();
        self.reconnectCount++;
    }, 3000);
}

/**
 * 获取连接
 * @return {[type]} [description]
 */
MQ.prototype.getConnection = function getConnection() {
    var self = this;

    if (this.connection) {
        return Promise.resolve(self.connection);
    } else {
        return Connection
            .createConnection(config.rabbitMQ_url)
            .then(function (conn) {
                // 实例中存储当前连接
                self.connection = conn;

                // 进程被杀死关闭连接
                process.once('SIGINT', function() {
                    log.info('kill by signal SIGINT');
                    conn.close();
                    self.connection = null;
                    process.exit(0);
                });

                log.info('[mq] create connection success');

                return Promise.resolve(conn);
            });
    }
}

module.exports = MQ;