const fs = require('fs');
const express = require('express');
const http = require('http');
const { Server } = require('socket.io');
const ioclient = require('socket.io-client');
const compression = require('compression');

const events = {};
for (let file of fs.readdirSync('./src/events')) {
	file = require('./src/events/' + file);
	for (const event in file)
		events[event] = file[event];
}

function rand32() {
	let str = '';
	const lookups = 'bcdefghjklmnpqrstvwxyz0123456789'.split('');
	while (str.length < 16) {
		const n = Math.random() * lookups.length;
		str += lookups[Math.floor(n)];
	}
	return str;
}

let instance;

function saveSettings() {
	fs.writeFileSync('instance.json', JSON.stringify(instance, null, 2));
}

if (fs.existsSync('instance.json'))
	instance = JSON.parse(fs.readFileSync('instance.json'));
else {
	instance = {
		id: rand32(),
		port: process.env.PORT || 1312,
		url: process.env.URL || null
	};
	saveSettings();
}

if (!instance.url)
	console.log(
		`!! no instance url !
	it will be auto-set by the first user authentication !
	it can be set in instance.json .`);

global.vybe = {
	instance,
	saveSettings,
	instances: {},
	users: {},
	threads: {},
	streams: {},
	connectInstance: async url => {
		let instance = vybe.instances[url];
		function connecting(resolve, reject) {
			instance.socket.on('connect', resolve);
			instance.socket.on('connect_error', error => {
				instance.socket.disconnect();
				reject(error.message);
			});
		}
		if (instance) {
			if (!instance.socket.connected) {
				instance.socket.connect();
				await new Promise(connecting);
			}
		}
		else {
			instance = vybe.instances[url] = {
				socket: ioclient('https://' + url)
			};
			await new Promise(connecting);
		}
		return instance;
	}
};

const app = express();
app.use(compression());
const server = http.createServer(app);
const io = new Server(server, {
	cors: {
		origin: true
	}
});

app.use(express.static('client'));

io.on('connection', (socket) => {
	for (let event in events) {
		socket.on(event, (msg, callback) => {
			if (!events[event]) {
				callback('no such event ' + event);
				return;
			}
			try {
				events[event](msg, callback, socket);
			}
			catch (e) {
				console.log(`${event} threw exception: `, e);
			}
		});
	}
	socket.on('disconnect', reason => {
		let user = vybe.users[socket.__userid];
		if (user)
			user.sockets.splice(user.sockets.indexOf(socket), 1);
		for (let id in vybe.streams) {
			const stream = vybe.streams[id];
			delete stream.listeners[socket.id];
			if (stream.socket === socket.id)
				stream.stop();
		}
	});
});

server.listen(instance.port, () => {
	console.log('server running on port ' + instance.port);
});