'use strict';
const Service = require('egg').Service;

class RabbitmqService extends Service {

  constructor(ctx) {
    super(ctx);
    this.exType = 'topic';
    this.durable = true;
  }

  // 发送消息
  async sendQueueMsg(ex, routeKey, msg, parm) {
    const { mq } = this.ctx;
    if (mq) {
      await mq.topic(ex, routeKey, msg, parm);
    } else {
      this.ctx.logger.error('!!!!!!没有配置MQ插件!!!!!!');
    }
  }

  // 接收消息
  async receiveQueueMsg(ex) {
    const self = this;
    const { mq } = self.ctx;
    if (mq) {
      const ch = await mq.conn.createChannel();
      try {
        await ch.assertExchange(ex, self.exType, { durable: self.durable });
        const q = await ch.assertQueue('', { exclusive: true });
        // 队列绑定 exchange
        await ch.bindQueue(q.queue, ex, '*');
        ch.consume(q.queue, msg => {
          const result = msg.content.toString();
          const headers = msg.properties.headers;
          // 插入待办事项到数据库中。
        }, { noAck: true });
      } catch (e) {
        await ch.close();
      }
    } else {
      this.ctx.logger.error('!!!!!!没有配置MQ插件!!!!!!');
    }
  }

}

module.exports = RabbitmqService;