import cors from 'cors';
import { safeListeningHttpServer } from 'create-listening-server';
import express from 'express';
import * as io from 'socket.io';

const noContentHandler: express.RequestHandler = (_req, res) => {
    res.status(204); // No Content
    res.end();
};

export interface RouteMiddleware {
    path: string;
    handlers: express.RequestHandler | express.RequestHandler[];
}

export interface LaunchOptions {
    httpServerPort?: number;
    socketServerOptions?: Partial<io.ServerOptions>;
    middlewares?: Array<RouteMiddleware>;
}

export async function launchServer({
    httpServerPort = 3000,
    socketServerOptions,
    middlewares = [],
}: LaunchOptions = {}): Promise<{
    close: () => Promise<void>;
    port: number;
    app: express.Express;
    httpServer: import('http').Server;
    socketServer: io.Server;
}> {
    const app = express();
    app.use(cors());

    for (const { path, handlers } of middlewares) {
        app.use(path, handlers);
    }

    app.use('/favicon.ico', noContentHandler);

    const { port, httpServer } = await safeListeningHttpServer(httpServerPort, app as import('http').RequestListener);

    const socketServer = new io.Server(httpServer, {
        cors: {},
        pingTimeout: 30 * 1000 * 60, // 30 minutes. our sockets does not run over network.
        pingInterval: 10 * 1000 * 60, // 10 minutes. our sockets does not run over network.
        httpCompression: false,
        serveClient: false,
        maxHttpBufferSize: 1e8, // 100 MB
        ...socketServerOptions,
        transports: ['websocket'],
    });

    const close = () => {
        httpServer.closeAllConnections();
        return socketServer.close();
    };

    return {
        close,
        port,
        app,
        httpServer,
        socketServer,
    };
}