index.js

//node packages
const express = require('express');
const app = express();
const http = require('http');
const { mongo, default: mongoose } = require('mongoose');
const server = http.createServer(app);
const { Server } = require("socket.io");
const io = new Server(server);
const bodyParser = require('body-parser');
const registerRoute = require('./routes/register');
const loginRoute = require('./routes/login');
const fs = require('fs');
const activeUsers = new Map();
const authenticationRoute = require('./routes/auth');
const { response } = require('express');
const { resolve } = require('path');


//DB Connection
mongoose.connect("mongodb://127.0.0.1:27017/cloudComputing");

app.use(bodyParser.json());
//Routes
app.use('/register', registerRoute);
app.use('/login', loginRoute);
app.use('/authenticate', authenticationRoute)

//Views
app.get('/', (req, res) => {
  res.sendFile(__dirname + '/views/start.html');
}); 

app.get('/chatroom', (req, res) => {
  res.sendFile(__dirname + '/views/index.html');
});

app.get('/register', (req, res) => {
  res.sendFile(__dirname + '/views/register.html');
}); 

app.get('/login', (req, res) => {
  res.sendFile(__dirname + '/views/login.html');
});


io.on('connection', (socket) => {
  
  // Triggered by emit() from client, when entering the chatroom
  // SocketID => name
  socket.on('userLogin', async function(response) {
    await addUserToActiveUsers(response, socket);
    
  });
  
  // when disconnecting from chatroom
  socket.on('disconnect', async function(response) {
    await deleteUserFromActiveUsers(response, socket);

  });
});


/**
* Summary:
* Function to add a user to map of users, who are currently online.
*
* Description:
* Function will take the username from response and append it together with the socketID to map activeUsers.
* after appending, ip.emit() will send the updated userlist to all users who are currently online.
*
* @param {socket} socket
* @param {Object} response
* @triggers io.emit() 'updateUserlist' event
* @listens  socket.on() 'userLogin' event
*/
async function addUserToActiveUsers(response, socket) {

  return new Promise(resolve => {

    activeUsers.set(socket.id, response.name);
    
    var userArr = Array.from(activeUsers.values());
    
    io.emit('updateUserlist', {
      userList : userArr
    });
  });
}


/**
* Summary:
* Function to delete a user from the map of users, who are currently online.
*
* Description:
* Function will take the socketID from the socket, of the client, who is disconneting.
* The socketID and its value (username) will be deleted from map activeUsers.
* After deleting the socketID and username io.emit() is called and the upodated userList is sent to all users who are currently online.
*
* @param {socket} socket
* @param {Object} response
* @triggers io.emit() 'updateUserlist' event
* @listens  socket.on() 'disconnect' event
*/
async function deleteUserFromActiveUsers(response, socket) {

  return new Promise(resolve => {
    activeUsers.delete(socket.id);
    var userArr = Array.from(activeUsers.values());

    io.emit('updateUserlist', {
      userList : userArr
    });
  });
}


/**
* Summary:
* Function for forwarding chat messages.
*
* Description:
* Function will take the username of the sender and the message from the response.
* Server will append the current time and call io.emit() 'chat message' event.
* Json with the message, username of sender and current time is sent to all users who are currently online.
*
* 
* @param {Object} response
* @triggers io.emit() 'chat message' event
* @listens  socket.on() 'chat message' event
*/
io.on('connection', (socket) => {
  socket.on('chat message', (response) =>{
      var msg = response.msg;
      var name = response.name;
      var dateTime = new Date().toTimeString();

      io.emit('chat message', {
        msg : msg,
        name : name,
        dateTime: dateTime
      });
  })
});

/**
* Summary:
* Function for forwarding private chat messages.
*
* Description:
* Function will take the username of the sender, the private message, the name of the receiver  from the response.
* Server will append the current time and call io.emit() 'chat message' event.
* 
*
* 
* @param {Object} response
* @triggers io.emit() 'chat message' event
* @listens  socket.on() 'chat message' event
*/
io.on('connection', (socket) => {
  socket.on('private message', (response) => {

    var private_msg = response.msg;
    var receiver = response.receiver;
    var sender = response.name;
    var array = Array.from(activeUsers);
    var dateTime = new Date().toTimeString();

    for(var i = 0; i<array.length; i++) {
      if(array[i][1] == receiver){
        io.emit(receiver, {
          msg : private_msg,
          sender : sender,
          receiver: receiver,
          dateTime: dateTime
          })
        io.emit(sender, {
          msg : private_msg,
          sender : sender,
          receiver: receiver,
          dateTime: dateTime
        })
      return 0;
        }
      }
    io.emit(sender, {
      status: 401
    })
    })

  socket.on('groupMessage', (response) => {
    
    let sender = response.name;
    let receivers = response.receivers;
    let groupMsg = response.groupMsg;
    var dateTime = new Date().toTimeString();

    console.log("receivers", receivers[0]);
    console.log("groupmsg", groupMsg);

    let a = activeUsers.values;

    console.log("sender", sender);

    for (let i = 0; i<receivers.length; i++) {
      io.emit(receivers[i].trim(), {
        msg: groupMsg,
        sender: sender,
        receiver: receivers,
        dateTime: dateTime
      })
    }
    io.emit(sender, {
      msg: groupMsg,
      sender: sender,
      receiver: receivers,
      dateTime: dateTime
    })
  })
})

async function getKeyFromVal(receiver){
  return new Promise( () => {
    var array = Array.from(activeUsers);
    console.log("usersArray: " + array);
    var receiverSocketId;
    for (var i = 0; i<array.length; i++){
      console.log("array[i] ", array[i][0]);
      if(array[i][1] == receiver) {
        receiverSocketId = array[i][0];
        resolve(receiverSocketId);
      } else {
        resolve("false");
      }
    }
  })
}

//Logs message from Socket to Console
io.on('connection', (socket) => {
  socket.on('chat message', (response) => {
    var msg = response.msg;
  });
});

//Send Image File
io.on("connection", (socket) => {
  socket.on('sendImage', (file, callback) => {
    io.emit('image', file);
  });
});

//Send Video File
io.on("connection", (socket) => {
  socket.on('sendVideo', (file, callback) => {
    io.emit('video', file);
  });
});

//Send Audio File
io.on("connection", (socket) => {
  socket.on('sendAudio', (file, callback) => {
    io.emit('audio', file);
  });
});

server.listen(3000, () => {
  console.log('listening on Port :3000');
});


module.exports = {activeUsers};