// src/utils/socket.js
import { ElMessage } from 'element-plus'
import { ROOTPATH2 } from '../comment/httpUrl.js'

let WSS = null              // 全局唯一 WebSocket 实例
let heartTimer = null       // 心跳定时器
let reconnectTimer = null   // 重连定时器
let reconnectCount = 0      // 当前重连次数
const MAX_RECONNECT = 10    // 最大重连次数
const RECONNECT_INTERVAL = 3000 // 重连间隔 3 秒
let manuallyClosed = false

/**
 * 连接 WebSocket
 * @param {string} userId 当前用户 ID
 * @param {object} store Vuex store 实例
 * @param {object} router Vue Router 实例
 */
export function connectSocket(userId, store, router) {
    if (!userId) return
    manuallyClosed = false

    // 若已有连接则关闭旧连接
    if (WSS) {
        try { WSS.close() } catch { }
    }

    // 生成 tabId
    let tabId = sessionStorage.getItem('tabId')
    if (!tabId) {
        tabId = Date.now() + '_' + Math.random().toString(36).slice(2)
        sessionStorage.setItem('tabId', tabId)
    }

    const wsUrl = `${ROOTPATH2}${userId}?tabId=${tabId}`
    WSS = new WebSocket(wsUrl)
    console.log('WebSocket 连接中:', wsUrl)

    /** 连接成功 */
    WSS.onopen = () => {
        console.log('WebSocket 已连接:', wsUrl)
        reconnectCount = 0

        // 启动心跳
        if (heartTimer) clearInterval(heartTimer)
        heartTimer = setInterval(() => {
            if (WSS && WSS.readyState === WebSocket.OPEN) {
                WSS.send('HeartBeat')
            }
        }, 5000)
    }

    /** 接收消息 */
    WSS.onmessage = (event) => {
        console.log('收到消息:', event.data)
        if (event.data === 'HeartBeat' || event.data === 'Pong') return;
        let msg
        try {
            msg = JSON.parse(event.data)
        } catch (e) {
            console.warn('非 JSON 消息:', event.data)
            return
        }

        if (msg.type === 'kickOut') {
            ElMessage({
                message: msg.content || '您的账号已在其他设备登录',
                type: 'warning',
                duration: 1500
            })
            localStorage.removeItem('token')
            localStorage.removeItem('userId')
            localStorage.removeItem('userType')
            localStorage.removeItem('companyId')

            if (store) store.dispatch('SET_DATA')
            if (router) router.push({ name: 'login' })
        }
    }

    /** 错误处理 */
    WSS.onerror = (err) => {
        console.error('WebSocket 错误:', err)
    }

    /** 连接关闭 */
    WSS.onclose = () => {
        console.log('WebSocket 已关闭')

        if (heartTimer) clearInterval(heartTimer)
        WSS = null

        // 自动重连
        if (!manuallyClosed) {
            if (reconnectCount < MAX_RECONNECT) {
                reconnectCount++
                console.warn(`WebSocket 断开，尝试第 ${reconnectCount} 次重连...`)
                reconnectTimer = setTimeout(() => {
                    connectSocket(userId, store, router)
                }, RECONNECT_INTERVAL)
            } else {
                console.error('达到最大重连次数，停止重连')
            }
        }
    }
}

/** 获取 WebSocket 实例 */
export function getSocket() {
    return WSS
}

/** 发送消息 */
export function sendSocketMsg(data) {
    if (WSS && WSS.readyState === WebSocket.OPEN) {
        WSS.send(data)
    } else {
        console.warn('WebSocket 未连接，尝试重连后再发送')
    }
}

/** 关闭连接 */
export function closeSocket() {
    manuallyClosed = true
    if (heartTimer) clearInterval(heartTimer)
    if (reconnectTimer) clearTimeout(reconnectTimer)
    if (WSS) {
        try { WSS.close() } catch { }
        WSS = null
    }
}