const net = require('net') // 实现了底层通信接口；http模块是专门用来做http服务的
const MyTransform = require('./myTransform.js') // 添加后缀提高加载速度

// 创建服务端实例
const server = net.createServer()

let overageBuffer = null // 存储没处理完的数据
let ts = new MyTransform()

const RORT = 1234
const HOST = 'localhost'

server.listen(RORT, HOST)

server.on('listening', () => { // 调用listen方法后触发
    console.log(`服务端已经开启在${HOST}: ${RORT}`);
})

// 接收消息
server.on('connection', (socket) => { // 每有一个新连接建立都会走这里
    socket.on('data', (chunk) => {
        if (overageBuffer) {
            chunk = Buffer.concat([overageBuffer, chunk])
        }
        let packageLen = 0
        while (packageLen = ts.getPackageLen(chunk)) {
            const packageCon = chunk.slice(0, packageLen)
            // console.log(packageCon); // <Buffer 00 00 00 0a e5 ae a2 e6 88 b7 e7 ab af 31>
            chunk = chunk.slice(packageLen) // 因为是循环，截掉上一次拿到的内容
            const ret = ts.decode(packageCon)
            socket.write(ts.encode(ret.body, ret.serialNum))
            console.log(ret);
        }
        overageBuffer = chunk
        // const msg = chunk.toString()
        // console.log(msg); // 您好客户端1您好客户端2客户端3客户端4
        // socket.write(Buffer.from('您好' + msg))
    })
})

server.on('close', () => {
    console.log('服务端关闭了');
})

server.on('error', (err) => {
    if (err.code == 'EADDRINUSE') {
        console.log('地址正在被使用'); // 可做重启操作
    } else {
        console.log(err);
    }
})