import EventEmitter from 'eventemitter3'
import { OPTIONS } from './config'
import mqtt from 'mqtt'

export class UranusMqtt extends EventEmitter {
	constructor(url, options) {
		super()
		this._url = url || ''
		this._options = options
		this._client = null
		this._hasInit = false
	}

	initMqtt = () => {
		// 仅初始化一次
		if (this._hasInit) return
		// 建立连接
		this._client = mqtt.connect(this._url, {
			...OPTIONS,
			...this._options,
		})
		this._hasInit = true
		if (this._client) {
			this._client.on('reconnect', this._onReconnect)

			// 消息监听
			this._client.on('message', this._onMessage)

			// 连接关闭
			this._client.on('close', this._onClose)

			// 连接异常
			this._client.on('error', this._onError)
		}
	}

	// 发布
	publishMqtt = (topic, body, opts) => {
		if (!this._client?.connected) {
			this.initMqtt()
		}
		this._client?.publish(topic, body, opts || {}, (error, packet) => {
			if (error) {
				window.console.error('mqtt publish error,', error, packet)
			}
		})
	}

	// 订阅
	subscribeMqtt = topic => {
		if (!this._client?.connected) {
			this.initMqtt()
		}
		window.console.log('subscribeMqtt>>>>>', topic)
		this._client?.subscribe(topic, (error, granted) => {
			window.console.log('mqtt subscribe,', error, granted)
		})
	}

	// 取消订阅
	unsubscribeMqtt = topic => {
		window.console.log('mqtt unsubscribeMqtt,', topic)
		this._client?.unsubscribe(topic)
	}

	// 关闭 mqtt 客户端
	destroyed = () => {
		window.console.log('mqtt 销毁')
		this._client?.end()
	}

	_onReconnect = () => {
		if (this._client) {
			window.console.error('mqtt reconnect,')
		}
	}

	_onMessage = (topic, payload, packet) => {
		this.emit('onMessageMqtt', { topic, payload, packet })
	}

	_onClose = () => {
		// 连接异常关闭会自动重连
		window.console.error('mqtt close,')
		this.emit('onStatus', {
			status: 'close',
		})
	}

	_onError = error => {
		// 连接错误会自动重连
		window.console.error('mqtt error,', error)
		this.emit('onStatus', {
			status: 'error',
			data: error,
		})
	}
}