socketIoHandler.js

import { Server } from 'socket.io';
// import { parse } from 'cookie';
// import socketioAuth from 'socketio-auth';

export default function injectSocketIO(server) {
	const io = new Server(server, {
		cors: {
			origin: [
				'http://localhost:5173',
				'http://localhost:4173',
				process.env?.ORIGIN ?? 'http://localhost',
				'https://tauri.localhost' // Remote Tauri App (SongTextProjector for example)
			]
		}
	});

	io.use((socket, next) => {
		const token = socket.handshake.auth.token;
		if (token && token == process.env.PUBLIC_LIVEVIEW_TOKEN) next();
		else next(new Error('Not Authorized'));
	});

	/*
	io.engine.on("headers", (headers, request) => {
		if (!request.headers.cookie) return;
		const cookies = parse(request.headers.cookie);
		if (!cookies.auth_session) {
			return false;
		}
	});

	socketioAuth(io, {
		authenticate: function (socket, data, callback) {
			//get credentials sent by the client
			var username = data.username;
			var password = data.password;
			var user = { password: ''}; 

			// db.findUser('User', {username:username}, function(err, user) {
				// inform the callback of auth success/failure
				// if (err || !user) return callback(new Error("User not found"));
				return callback(null, user.password == password);
			// });
		}
	});
	*/

	const current_connections = {};

	io.on('connection', (socket) => {
		let identifier = null;

		socket.on('ready', async (data) => {
			const playlistId = data?.playlistId;
			const joinCode = data?.joinCode;
			if (!playlistId || !joinCode) return;
			identifier = `${playlistId}_${joinCode}`;

			if (!current_connections[identifier]) {
				current_connections[identifier] = {
					playlist: data?.playlist ?? '{}',
					currentSongId: 0,
					currentCoupletId: 0
				};
			} else {
				// if (current_connections[identifier].playlist === "{}") {
				if (data?.playlist && data?.playlist !== '{}') {
					current_connections[identifier].playlist = data?.playlist ?? '{}';
					if (current_connections[identifier].playlist !== '{}')
						io.to(identifier).emit('syncPlaylist', {
							playlist: current_connections[identifier].playlist,
							from: socket.id
						});
				}
			}

			// Leave the other rooms, if it has
			for (const room of socket.rooms) {
				if (room !== socket.id) socket.leave(room);
			}
			await socket.join(identifier);

			const sockets = await io.in(identifier).fetchSockets();
			io.to(identifier).emit('userStatus', {
				message: 'user has joined: ' + socket.id,
				count: sockets.length
			});

			socket.emit('syncAll', {
				playlist: current_connections[identifier].playlist,
				currentSongId: current_connections[identifier].currentSongId,
				currentCoupletId: current_connections[identifier].currentCoupletId,
				from: socket.id
			});
		});

		socket.on('setPlaylist', (playlist) => {
			if (identifier && current_connections[identifier]) {
				current_connections[identifier].playlist = playlist;
				io.to(identifier).emit('syncPlaylist', {
					playlist,
					from: socket.id
				});
			}
		});

		socket.on('setCurrentSongId', (id) => {
			if (identifier && current_connections[identifier]) {
				current_connections[identifier].currentSongId = id;
				io.to(identifier).emit('syncCurrentSongId', {
					currentSongId: id,
					from: socket.id
				});
				current_connections[identifier].currentCoupletId = 0;
				io.to(identifier).emit('syncCurrentCoupletId', {
					currentCoupletId: 0,
					from: socket.id
				});
			}
		});

		socket.on('setCurrentCoupletId', (id) => {
			if (identifier && current_connections[identifier]) {
				current_connections[identifier].currentCoupletId = id;
				io.to(identifier).emit('syncCurrentCoupletId', {
					currentCoupletId: id,
					from: socket.id
				});
			}
		});

		socket.on('disconnecting', async () => {
			for (const room of socket.rooms) {
				if (room !== socket.id) {
					const sockets = await io.in(room).fetchSockets();
					socket.to(room).emit('userStatus', {
						message: 'user has left: ' + socket.id,
						count: sockets.length - 1
					});
					// if (sockets.length === 1) {
					//	delete current_connections[identifier];
					// }
				}
			}
		});
	});

	console.log('SocketIO injected');
}