117 lines
3.7 KiB
JavaScript
117 lines
3.7 KiB
JavaScript
import { useState, useEffect } from 'react';
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import mqtt from 'mqtt';
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import { getMqttUrl, getMqttCredentials, MQTT_TOPIC_COMMAND, MQTT_TOPIC_TICK } from '../config';
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/* =========================================================
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MQTT 客户端（mqtt.js）—— 后端控制通道
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订阅 opc/display/command（页面/媒体/卡片控制）与 opc/dashboard/tick（数据快照）
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断线自动重连；未连接时静默降级（页面仍可本地操作）
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========================================================= */
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let client = null;
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let status = 'connecting'; // connecting | connected | offline
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let clientId = null;
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const listeners = new Set();
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function notifyStatus() {
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window.dispatchEvent(new CustomEvent('dpm:mqtt-status', { detail: { status } }));
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}
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/* 每个连接生成全局唯一 client_id（独立客户端 ID 铁律）：
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优先 crypto.randomUUID（WebView2/现代浏览器），回退时间戳+双段高熵随机 */
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function makeClientId() {
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try {
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if (window.crypto && typeof window.crypto.randomUUID === 'function') {
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return `dpm-screen-${crypto.randomUUID().replace(/-/g, '')}`;
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}
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} catch { /* 继续回退 */ }
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return `dpm-screen-${Date.now().toString(36)}-${Math.random().toString(16).slice(2, 12)}-${Math.random().toString(16).slice(2, 10)}`;
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}
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export function connectMqtt() {
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if (client) return;
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try {
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// 独立客户端 ID：避免多屏/多实例/多标签页同 ID 被 broker 互相踢下线
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clientId = makeClientId();
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// 连接时惰性读取 MQTT 地址/账号：打包部署时 main.jsx 引导已从后端 /api/config 覆盖
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const { username, password } = getMqttCredentials();
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client = mqtt.connect(getMqttUrl(), {
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reconnectPeriod: 3000,
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connectTimeout: 8000,
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clientId,
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clean: true,
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username: username || undefined,
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password: password || undefined,
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});
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client.on('connect', () => {
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status = 'connected';
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notifyStatus();
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// 客户端只监听自己唯一的频道 opc/display/command/<clientId>（+ 数据 tick）。
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// 不再订阅全局命令频道 → 后端按客户端路由时，他屏的指令绝收不到。
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client.subscribe([MQTT_TOPIC_TICK, `${MQTT_TOPIC_COMMAND}/${clientId}`], { qos: 1 });
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});
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client.on('reconnect', () => {
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status = 'connecting';
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notifyStatus();
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});
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client.on('close', () => {
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status = 'offline';
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notifyStatus();
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});
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client.on('error', () => {
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status = 'offline';
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notifyStatus();
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});
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client.on('message', (topic, payload) => {
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let data = null;
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try {
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data = JSON.parse(payload.toString());
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} catch {
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return;
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}
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listeners.forEach((fn) => fn(topic, data));
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});
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} catch (e) {
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status = 'offline';
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notifyStatus();
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}
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}
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export function getMqttStatus() {
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return status;
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}
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/** 当前连接的稳定 client_id */
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export function getClientId() {
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return clientId;
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}
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/** 发布消息（大屏心跳等） */
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export function publishMqtt(topic, payload) {
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if (!client || status !== 'connected') return false;
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try {
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client.publish(topic, JSON.stringify(payload), { qos: 1 });
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return true;
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} catch (e) {
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return false;
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}
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}
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/** 订阅 MQTT 消息，返回取消订阅函数 */
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export function onMqttMessage(fn) {
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listeners.add(fn);
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return () => listeners.delete(fn);
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}
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/** React Hook：MQTT 连接状态 */
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export function useMqttStatus() {
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const [s, setS] = useState(status);
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useEffect(() => {
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connectMqtt();
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const on = (e) => setS(e.detail.status);
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window.addEventListener('dpm:mqtt-status', on);
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return () => window.removeEventListener('dpm:mqtt-status', on);
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}, []);
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return s;
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}
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