import MqttClient from '@/utils/mqtt.js';


class MqHelper {
	constructor() {
		this.instance = null;
		this.subTopics=[];
	}

	timeout(ms) {
		if (!ms) {
			ms = 200;
		}
		return new Promise((succ, err) => {
			setTimeout(() => {
				err({
					code: -1,
					errMsg: '超时了'
				})
			}, ms);
		});

	}
	//打开mq连接,topics:要订阅的主题列表格式{topic:'主题',callback:fn}或此格式的数组
	init(topics) {
		let connect = () => {
			return new Promise((resolve, reject) => {
				this.instance = new MqttClient();
				this.instance.connect((res) => {
					if(topics){
						console.error("连接成功开始订阅消息",topics);
						setTimeout(this.subscribes, 50, topics)	
					}
					
					resolve();
				});
			});
		}

		let p1 = connect();
		let p2 = this.timeout(500);

		return new Promise((resolve, reject) => {
			Promise.race([p1, p2]).then(()=>{
				resolve()
			}).catch(ex=>{
				this.instance=null;
				reject(ex);
			});
		});

	}
	//订阅消息{topic:'主题名称',callback:fn(payload,receive)}
	subscribes(topics) {
		return new Promise((resolve,reject)=>{
			
		
		if(!this.instance || !topics){
			reject();
			return;
		}
		if (!Array.isArray(topics)) {
			topics = [topics];
		}
		for (let i = 0; i < topics.length; i++) {
			let item = topics[i];
			let f=this.subTopics.find(v=>{
				return v.topic===item.topic;
			});
			if(!f){
				this.subTopics.push(item);
			}
			this.instance.subscribe(item.topic, (payload, receive) => {			
				try {
					console.log("开始处理回调")
					item.callback({payload:payload,receive:receive});
					console.log("处理回调成功")
				} catch (err) {
					console.error("订阅消息回调出现异常,",err);
				}
			});
			
			console.error("订阅消息成功");
		}
		resolve();
		});
		
	}
	//取消订阅消息 单个或者数组
	unSubscribes(topics){
		if(!this.instance || !topics){
			return;
		}
		if (!Array.isArray(topics)) {
			topics = [topics];
		}
		
		for (let i = 0; i < topics.length; i++) {
			let item = topics[i];
			this.instance.unsubscribe(item.topic);
			this.subTopics.find((v,index)=>{
				if(v.topic===item.topic){
					this.subTopics.splice(index,1);
					return true;
				}
				return false;
			});
		}
		
	}
	//发送消息，主题 消息内容  是否保留消息
	sendData(topic,msg,retained){
		return new Promise((resolve,reject)=>{
			if(!this.instance || !topic){
				reject("MQTT未连接或无主题无法发布消息")
				return
			}
			if(msg===null || msg===undefined){
				reject("msg无内容")
				return;
			}
			
			if(!retained){
				retained=false;
			}else{
				retained=true;
			}
			
			try {
				let flag = this.instance.publish(topic, msg, retained);
				if (flag) {
					resolve({
						code: 200,
						msg: 'MQTT直连发送成功'
					});
					return;
				}
				
				reject("MQTT未连接，无法发布消息");
			} catch (error) {
				
				reject(error);
			}
		});
		
		
	}
	//断开连接
	disconnect(){
		if(!this.instance){
			return
		}
		this.instance.disconnect()
	}
	
}



export default {
	getMqTool: function(found, receive) {
	
			let instance = new MqHelper();

		

		return instance;
	}
}