import {tinyws} from "tinyws";
import { randomUUID } from 'crypto';

export default class SocketHandler {

    constructor(path, args) {
        this.path = path;
        this.connections = {};
        this.handlers = {
            'join': [],
            'leave': [],
            'message': [],
        };

        this.pingInterval = null;
    }

    start(express) {
        express.use(tinyws());
        express.use(this.path, this._receiveRequest.bind(this));

        this.pingInterval = setInterval(() => {
            Object.values(this.connections).forEach(client => {
                if (++client.failedPings > 3) {
                    this.terminateClient(client.id);
                } else {
                    client.ws.ping();
                }
            });
        }, 30000);

        // this.pingInterval
    }

    stop() {
        clearInterval(this.pingInterval);
    }

    broadcast(msg) {
        Object.values(this.connections).forEach(client => {
            client.ws.send(msg);
        });
    }

    async _receiveRequest(req, res) {
        if (req.ws) {
            const ws = await req.ws()
            return this._receiveWebsocket(req, res, ws);
        } else {
            // not handling HTTP
        }
    }

    async _receiveWebsocket(req, res, ws) {
        ws.id = randomUUID();
        this.connections[ws.id] = {
            ws: ws,
            id: ws.id,
            joined: new Date(),
            failedPings: 0,
        };

        ws.on('close', () => {
            this._fire('leave', ws);
            delete this.connections[ws.id];
        });

        ws.on('message', (data, ...args) => {
            this._fire('message', ws, data, ...args);
        });

        ws.on('pong', () => {
            this.connections[ws.id].failedPings = 0;
        });

        this._fire('join', ws);
    }

    terminateClient(uuid) {
        this.connections[uuid].ws.terminate();
        delete this.connections[uuid];
    }

    on(event, callback) {
        this.handlers[event].push(callback);
    }

    _fire(event, ...args) {
        this.handlers[event].forEach(cb => cb(...args));
    }

}