const fs = require('fs');
const http = require('http');
const httpProxy = require('http-proxy');
const HyperDHTServer = require('hyperdht');
const libNet = require('hyper-cmd-lib-net');
const goodbye = require('graceful-goodbye');
const libKeys = require('hyper-cmd-lib-keys');
const b32 = require("hi-base32");
const net = require("net");
const pump = require("pump");
let invalid = false;

let mod = 0;
const tunnels = {};
const agent = new http.Agent({ maxSockets: Number.MAX_VALUE });
const content = fs.readFileSync('404.txt', 'utf8');
const DEBUG = 0; // Set DEBUG to 1 to enable debug mode
// Enabling DEBUG mode will slow down the code, please only enable this if you need
// Information about connections coming in because you need to validate connection hashes.

const startServer = async () => {
    console.log("Creating HyperDHT server...");
    const dhtServer = new HyperDHTServer();
    await dhtServer.ready();
    console.log("HyperDHT server created and ready.");

    const proxy = httpProxy.createProxyServer({
        ws: true,
        agent: agent,
        timeout: 360000
    });

    const server = http.createServer(async function (req, res) {
        try {
            console.log("Incoming HTTP request...");
            const split = req.headers.host.split('.');
            if (DEBUG === 1) console.log("Request Headers Host Split: ", split);
            const publicKey = Buffer.from(b32.decode.asBytes(split[0].toUpperCase()));
            if (DEBUG === 1) {
                console.log("Public Key Buffer: ", publicKey);
                console.log("Length: " + publicKey.length);
            }
            if (!(publicKey.length >= 32)) {
                console.log("Invalid Connection!")
                res.writeHead(404, { 'Content-Type': 'text/html' });
                res.end(content);
                invalid = true
            } else {
                invalid = false
            }
            if (invalid == true) return
            if (!tunnels[publicKey]) {
                console.log("No tunnel found for public key, creating new tunnel...");
                const port = 1337 + ((mod++) % 1000);
                const server = net.createServer(function (servsock) {
                    console.log('Incoming Connection, Connecting to:', publicKey.toString('hex'));
                    if (DEBUG === 1) console.log("Public Key Length: ", publicKey.toString('hex').length);
                    const socket = dhtServer.connect(publicKey);

                    const local = servsock;
                    let open = { local: true, remote: true };
                    local.on('data', (d) => {
                        if (DEBUG === 1) console.log("Local Data: ", d);
                        socket.write(d);
                    });
                    socket.on('data', (d) => {
                        if (DEBUG === 1) console.log("Socket Data: ", d);
                        local.write(d);
                    });

                    const remoteend = (type) => {
                        if (DEBUG === 1) console.log('Local Connection Ended, Ending Remote Connection');
                        if (open.remote) socket.end();
                        open.remote = false;
                    };

                    const localend = (type) => {
                        if (DEBUG === 1) console.log('Remote Connection Ended, Ending Local Connection');
                        if (open.local) local.end();
                        open.local = false;
                    };

                    local.on('error', remoteend);
                    local.on('finish', remoteend);
                    local.on('end', remoteend);
                    socket.on('finish', localend);
                    socket.on('error', localend);
                    socket.on('end', localend);
                });

                server.listen(port, "127.0.0.1");
                tunnels[publicKey] = port;
                console.log("New tunnel created. Public Key:", publicKey, "Port:", port);
                proxy.web(req, res, {
                    target: 'http://127.0.0.1:' + port
                }, function (e) {
                    console.log("Proxy Web Error: ", e);
                    res.writeHead(404, { 'Content-Type': 'text/html' });
                    res.end(content);
                });
                return;
            } else {
                console.log('Tunnel exists for public key:', publicKey);
                proxy.web(req, res, {
                    target: 'http://127.0.0.1:' + tunnels[publicKey]
                }, function (e) {
                    console.log("Proxy Web Error: ", e);
                    res.writeHead(404, { 'Content-Type': 'text/html' });
                    res.end(content);
                });
            }
        } catch (e) {
            console.error("Error Occurred: ", e);
        }
    });

    server.on('upgrade', function (req, socket, head) {
        console.log('Upgrade Request');
        const split = req.headers.host.split('.');
        const publicKey = Buffer.from(b32.decode.asBytes(split[0].toUpperCase()));
        proxy.ws(req, socket, {
            target: 'http://127.0.0.1:' + tunnels[publicKey]
        }, function (e) {
            console.error("Proxy WS Error: ", e);
            socket.end();
        });
    });

    server.listen(8081);
    console.log("HTTP server listening on port 8081");

    process.on('SIGINT', function () {
        console.log("Shutting down...");
        server.close();
        dhtServer.destroy();
        console.log("Shutdown complete.");
        process.exit();
    });
};

startServer().catch(console.error);