index.js

const io= require("socket.io")(8800,{
    cors:{
        origin:"http://teamsbackendsocket:3000",
        methods: [ "GET", "POST" ]

    },

}
    );
 let users = [];

 const addUser = (userId,socketId) =>{
  !users.some(user=>user.userId ===userId) &&

  users.push({userId,socketId});

 
};
const removeUser = (socketId) =>{
    users =users.filter(user =>user.socketId !==socketId)

};
const getUser =(userId) =>{
    return users.find(user=>user.userId === userId);


}
    io.on("connection",(socket)=>{
     
        //adding web rtc shit 
        socket.emit("me", socket.id);


	socket.on("callUser", ({ userToCall, signalData, from, name }) => {
		io.to(userToCall).emit("callUser", { signal: signalData, from, name });
	});

	socket.on("answerCall", (data) => {
		io.to(data.to).emit("callAccepted", data.signal)
	});

        //when connect 
        console.log("a user connected.")
        //take userId and socketId from user 
        socket.on("addUser",userId =>{
            addUser(userId,socket.id);

         io.emit("getUsers",users);
        });
        //send and get message
        socket.on("sendMessage",({senderId,receiverId,text})=>{
           const user = getUser(receiverId);
           io.to(user.socketId).emit("getMessage",{
               senderId,
               text,


           });

        })

//when disconnect
        socket.on("disconnect",() =>{
            socket.broadcast.emit("callEnded")

            console.log("for chat log : below");
            console.log("a user disconnected");
            removeUser(socket.id);
            io.emit("getUsers",users);


        });
        
    });