OmarElGabry/chat.io

'use strict';

var config     = require('../config');
var redis     = require('redis').createClient;
var adapter = require('socket.io-redis');

var Room = require('../models/room');

/**
 * Encapsulates all code for emitting and listening to socket events
 *
 */
var ioEvents = function(io) {

    // Rooms namespace
    io.of('/rooms').on('connection', function(socket) {

        // Create a new room
        socket.on('createRoom', function(title) {
            Room.findOne({'title': new RegExp('^' + title + '$', 'i')}, function(err, room){
                if(err) throw err;
                if(room){
                    socket.emit('updateRoomsList', { error: 'Room title already exists.' });
                } else {
                    Room.create({ 
                        title: title
                    }, function(err, newRoom){
                        if(err) throw err;
                        socket.emit('updateRoomsList', newRoom);
                        socket.broadcast.emit('updateRoomsList', newRoom);
                    });
                }
            });
        });
    });

    // Chatroom namespace
    io.of('/chatroom').on('connection', function(socket) {

        // Join a chatroom
        socket.on('join', function(roomId) {
            Room.findById(roomId, function(err, room){
                if(err) throw err;
                if(!room){
                    // Assuming that you already checked in router that chatroom exists
                    // Then, if a room doesn't exist here, return an error to inform the client-side.
                    socket.emit('updateUsersList', { error: 'Room doesnt exist.' });
                } else {
                    // Check if user exists in the session
                    if(socket.request.session.passport == null){
                        return;
                    }

                    Room.addUser(room, socket, function(err, newRoom){

                        // Join the room channel
                        socket.join(newRoom.id);

                        Room.getUsers(newRoom, socket, function(err, users, cuntUserInRoom){
                            if(err) throw err;
                            
                            // Return list of all user connected to the room to the current user
                            socket.emit('updateUsersList', users, true);

                            // Return the current user to other connecting sockets in the room 
                            // ONLY if the user wasn't connected already to the current room
                            if(cuntUserInRoom === 1){
                                socket.broadcast.to(newRoom.id).emit('updateUsersList', users[users.length - 1]);
                            }
                        });
                    });
                }
            });
        });

        // When a socket exits
        socket.on('disconnect', function() {

            // Check if user exists in the session
            if(socket.request.session.passport == null){
                return;
            }

            // Find the room to which the socket is connected to, 
            // and remove the current user + socket from this room
            Room.removeUser(socket, function(err, room, userId, cuntUserInRoom){
                if(err) throw err;

                // Leave the room channel
                socket.leave(room.id);

                // Return the user id ONLY if the user was connected to the current room using one socket
                // The user id will be then used to remove the user from users list on chatroom page
                if(cuntUserInRoom === 1){
                    socket.broadcast.to(room.id).emit('removeUser', userId);
                }
            });
        });

        // When a new message arrives
        socket.on('newMessage', function(roomId, message) {

            // No need to emit 'addMessage' to the current socket
            // As the new message will be added manually in 'main.js' file
            // socket.emit('addMessage', message);
            
            socket.broadcast.to(roomId).emit('addMessage', message);
        });

    });
}

/**
 * Initialize Socket.io
 * Uses Redis as Adapter for Socket.io
 *
 */
var init = function(app){

    var server     = require('http').Server(app);
    var io         = require('socket.io')(server);

    // Force Socket.io to ONLY use "websockets"; No Long Polling.
    io.set('transports', ['websocket']);

    // Using Redis
    let port = config.redis.port;
    let host = config.redis.host;
    let password = config.redis.password;
    let pubClient = redis(port, host, { auth_pass: password });
    let subClient = redis(port, host, { auth_pass: password, return_buffers: true, });
    io.adapter(adapter({ pubClient, subClient }));

    // Allow sockets to access session data
    io.use((socket, next) => {
        require('../session')(socket.request, {}, next);
    });

    // Define all Events
    ioEvents(io);

    // The server object will be then used to list to a port number
    return server;
}

module.exports = init;