const express = require("express");
const socketio = require("socket.io");
const fs=require("fs");
const app = express();
const server = app.listen(3000,()=>{
});
const io = socketio(server);
app.get('/',(req,res)=>{
    fs.readFile('page.html','utf-8',(err,data)=>{
        console.log(err);
        res.send(data);
    });
});
io.on('connection',(socket)=>{
    console.log(socket);
    socket.on('joinRoom',(room,name)=>{
        socket.join(room);
        io.to(room).emit('joinRoom',room,name);
    });
    socket.on('leaveRoom',(room,name)=>{
        socket.leave(room);
        io.to(room).emit("leaveRoom",room,name);
    });
    socket.on('chat',(room, name, msg)=>{
        io.to(room).emit('chat',name,msg);
    });
});
const socket = io.connect();
window.onload = function(){
    loginbtn.onclick = function(){
        login.style.display = "none";
        main.style.display = 'block';
        const name = username.value;
        console.log(rooms.options[0].value);
        console.log(rooms.selectedIndex);
        let room = rooms.options[rooms.selectedIndex].value;
        const socket = io.connect();
        socket.emit('joinRoom',room, name );
        
        rooms.onchange = function(e){
            let el = e.target;
            console.log(el.selectedIndex);
            socket.emit('leaveRoom', room, name);
            room = rooms.options[rooms.selectedIndex].value;
            socket.emit('joinRoom', room, name);
        };
        socket.on('joinRoom',(room,name)=>{
            messages.innerHTML += `
            <li class="join_text">
                야생의 ${name}님이 ${room}에 들어왔어요
            </li>
            `;
        });
        socket.on("leaveRoom",(room,name)=>{
            messages.innerHTML += `
            <li class="leave_text">
                야생의 ${name}님이 ${room}에 나갔어요
            </li>
            `;
        });
        socket.on('chat',(name,msg)=>{
            messages.innerHTML += `
            <li>
                ${name} : ${msg}
            </li>
            `;
        });
           sendbtn.onclick = function(){
        socket.emit('chat',room,name,msg.value);
        msg.value = "";
    };
    };
    
};

책 보면서 채팅방 만드는거 까진 성공했는데
귓속말은 어케 만드냐

socket.to(소켓 아이디).emit(이벤트, 데이터); 이런식으로 하라는데 뭔소린지 모르겠어