// const { WebSocketServer} = require('ws');
// const { createServer } = require('http');
// 借助babel-node使用import方式导入模块
import { WebSocketServer } from 'ws';
import { createServer } from 'http';
const os = require('os');
const httpServer = createServer();

const createWebSocketServer = (httpServer) => {
    const wss = new WebSocketServer({
        noServer: true
    })
    
    // 握手事件
    httpServer.on('upgrade', (req, socket, head) => {
        if (req.headers['sec-websocket-protocol'] === 'conn') { 
            wss.handleUpgrade(req, socket, head, (ws) => {
                wss.emit('connection', ws, req)
            })
        }
    })
    
    // 连接事件
    wss.on('connection', (ws) => {
        console.log('新的连接')
        ws.send(JSON.stringify({
            type: 'connected' // 主题
        }))
        // 监听客户端发来的数据
        ws.on('message', (data, isBinary) => {
            const receiveData = isBinary ? data : data.toString()
            console.log('客户端发来的数据', receiveData)
        })
    })
    
    // 监听错误事件
    wss.on('error', (e) => {
        const { code } = e;
        if (code !== 'EADDRINUSE') { // 非端口被占用
            console.error(`websocker error:\n${e.stack || e.message}`)
        }
    })

    return {
        send(message) { // 给客户端发消息
            wss.clients.forEach(ws => {
                if (ws.readyState === 1) {
                    ws.send(message)
                }
            })
        },
        close() { // 关闭ws服务
            wss.close()
        },
        wss
    }
}

const ws = createWebSocketServer(httpServer)

// 发送消息
const sendMessage = (type, data) => {
    ws.send(JSON.stringify({type, data}))
}

setInterval(() => {
    sendMessage('console', `服务端定时向客户端发送消息，时间：${new Date().toLocaleString()}`)
}, 3000)

// 获取本机ip地址
function getIpAddress() {
    let interfaces = os.networkInterfaces();
    for(let devName in interfaces) {
        let iface = interfaces[devName];
        for(let i = 0; i < iface.length; i++){
            let alias = iface[i];
            if(alias.family === "IPv4" && alias.address !== "127.0.0.1" && !alias.internal){
                return alias.address;
            }
        }
    }
}
const port = 3000

httpServer.listen(port, getIpAddress(), () => {
    console.log(`服务器开启: ws://${getIpAddress()}:${port}`)
})