import { expect, tap } from '@push.rocks/tapbundle';
import * as net from 'net';
import * as crypto from 'crypto';
import { RemoteIngressHub, RemoteIngressEdge } from '../ts/index.js';

// ---------------------------------------------------------------------------
// Helpers (same patterns as test.flowcontrol.node.ts)
// ---------------------------------------------------------------------------

async function findFreePorts(count: number): Promise<number[]> {
  const servers: net.Server[] = [];
  const ports: number[] = [];
  for (let i = 0; i < count; i++) {
    const server = net.createServer();
    await new Promise<void>((resolve) => server.listen(0, '127.0.0.1', resolve));
    ports.push((server.address() as net.AddressInfo).port);
    servers.push(server);
  }
  await Promise.all(servers.map((s) => new Promise<void>((resolve) => s.close(() => resolve()))));
  return ports;
}

type TrackingServer = net.Server & { destroyAll: () => void };

function startEchoServer(port: number, host: string): Promise<TrackingServer> {
  return new Promise((resolve, reject) => {
    const connections = new Set<net.Socket>();
    const server = net.createServer((socket) => {
      connections.add(socket);
      socket.on('close', () => connections.delete(socket));
      let proxyHeaderParsed = false;
      let pendingBuf = Buffer.alloc(0);
      socket.on('data', (data: Buffer) => {
        if (!proxyHeaderParsed) {
          pendingBuf = Buffer.concat([pendingBuf, data]);
          const idx = pendingBuf.indexOf('\r\n');
          if (idx !== -1) {
            proxyHeaderParsed = true;
            const remainder = pendingBuf.subarray(idx + 2);
            if (remainder.length > 0) socket.write(remainder);
          }
          return;
        }
        socket.write(data);
      });
      socket.on('error', () => {});
    }) as TrackingServer;
    server.destroyAll = () => {
      for (const conn of connections) conn.destroy();
      connections.clear();
    };
    server.on('error', reject);
    server.listen(port, host, () => resolve(server));
  });
}

async function forceCloseServer(server: TrackingServer): Promise<void> {
  server.destroyAll();
  await new Promise<void>((resolve) => server.close(() => resolve()));
}

interface TestTunnel {
  hub: RemoteIngressHub;
  edge: RemoteIngressEdge;
  edgePort: number;
  cleanup: () => Promise<void>;
}

/**
 * Start a full hub + edge tunnel using QUIC transport.
 * Edge binds to 127.0.0.1, upstream server binds to 127.0.0.2.
 */
async function startQuicTunnel(edgePort: number, hubPort: number): Promise<TestTunnel> {
  const hub = new RemoteIngressHub();
  const edge = new RemoteIngressEdge();

  await hub.start({
    tunnelPort: hubPort,
    targetHost: '127.0.0.2',
  });

  await hub.updateAllowedEdges([
    { id: 'test-edge', secret: 'test-secret', listenPorts: [edgePort] },
  ]);

  const connectedPromise = new Promise<void>((resolve, reject) => {
    const timeout = setTimeout(() => reject(new Error('QUIC edge did not connect within 10s')), 10000);
    edge.once('tunnelConnected', () => {
      clearTimeout(timeout);
      resolve();
    });
  });

  await edge.start({
    hubHost: '127.0.0.1',
    hubPort,
    edgeId: 'test-edge',
    secret: 'test-secret',
    bindAddress: '127.0.0.1',
    transportMode: 'quic',
  });

  await connectedPromise;
  await new Promise((resolve) => setTimeout(resolve, 500));

  return {
    hub,
    edge,
    edgePort,
    cleanup: async () => {
      await edge.stop();
      await hub.stop();
    },
  };
}

function sendAndReceive(port: number, data: Buffer, timeoutMs = 30000): Promise<Buffer> {
  return new Promise((resolve, reject) => {
    const chunks: Buffer[] = [];
    let totalReceived = 0;
    const expectedLength = data.length;
    let settled = false;

    const client = net.createConnection({ host: '127.0.0.1', port }, () => {
      client.write(data);
      client.end();
    });

    const timer = setTimeout(() => {
      if (!settled) {
        settled = true;
        client.destroy();
        reject(new Error(`Timeout after ${timeoutMs}ms — received ${totalReceived}/${expectedLength} bytes`));
      }
    }, timeoutMs);

    client.on('data', (chunk: Buffer) => {
      chunks.push(chunk);
      totalReceived += chunk.length;
      if (totalReceived >= expectedLength && !settled) {
        settled = true;
        clearTimeout(timer);
        client.destroy();
        resolve(Buffer.concat(chunks));
      }
    });

    client.on('end', () => {
      if (!settled) {
        settled = true;
        clearTimeout(timer);
        resolve(Buffer.concat(chunks));
      }
    });

    client.on('error', (err) => {
      if (!settled) {
        settled = true;
        clearTimeout(timer);
        reject(err);
      }
    });
  });
}

function sha256(buf: Buffer): string {
  return crypto.createHash('sha256').update(buf).digest('hex');
}

// ---------------------------------------------------------------------------
// QUIC Transport E2E Tests
// ---------------------------------------------------------------------------

let tunnel: TestTunnel;
let echoServer: TrackingServer;
let hubPort: number;
let edgePort: number;

tap.test('QUIC setup: start TCP echo server and QUIC tunnel', async () => {
  [hubPort, edgePort] = await findFreePorts(2);

  echoServer = await startEchoServer(edgePort, '127.0.0.2');
  tunnel = await startQuicTunnel(edgePort, hubPort);

  expect(tunnel.hub.running).toBeTrue();
  const status = await tunnel.edge.getStatus();
  expect(status.connected).toBeTrue();
});

tap.test('QUIC: single TCP stream echo — 1KB', async () => {
  const data = crypto.randomBytes(1024);
  const hash = sha256(data);
  const received = await sendAndReceive(edgePort, data, 10000);
  expect(received.length).toEqual(1024);
  expect(sha256(received)).toEqual(hash);
});

tap.test('QUIC: single TCP stream echo — 1MB', async () => {
  const size = 1024 * 1024;
  const data = crypto.randomBytes(size);
  const hash = sha256(data);
  const received = await sendAndReceive(edgePort, data, 30000);
  expect(received.length).toEqual(size);
  expect(sha256(received)).toEqual(hash);
});

tap.test('QUIC: single TCP stream echo — 16MB', async () => {
  const size = 16 * 1024 * 1024;
  const data = crypto.randomBytes(size);
  const hash = sha256(data);
  const received = await sendAndReceive(edgePort, data, 60000);
  expect(received.length).toEqual(size);
  expect(sha256(received)).toEqual(hash);
});

tap.test('QUIC: 10 concurrent TCP streams x 1MB each', async () => {
  const streamCount = 10;
  const payloadSize = 1024 * 1024;

  const promises = Array.from({ length: streamCount }, () => {
    const data = crypto.randomBytes(payloadSize);
    const hash = sha256(data);
    return sendAndReceive(edgePort, data, 30000).then((received) => ({
      sent: hash,
      received: sha256(received),
      sizeOk: received.length === payloadSize,
    }));
  });

  const results = await Promise.all(promises);
  const failures = results.filter((r) => !r.sizeOk || r.sent !== r.received);
  expect(failures.length).toEqual(0);
});

tap.test('QUIC: 50 concurrent TCP streams x 64KB each', async () => {
  const streamCount = 50;
  const payloadSize = 64 * 1024;

  const promises = Array.from({ length: streamCount }, () => {
    const data = crypto.randomBytes(payloadSize);
    const hash = sha256(data);
    return sendAndReceive(edgePort, data, 30000).then((received) => ({
      sent: hash,
      received: sha256(received),
      sizeOk: received.length === payloadSize,
    }));
  });

  const results = await Promise.all(promises);
  const failures = results.filter((r) => !r.sizeOk || r.sent !== r.received);
  expect(failures.length).toEqual(0);
});

tap.test('QUIC: 200 concurrent TCP streams x 16KB each', async () => {
  const streamCount = 200;
  const payloadSize = 16 * 1024;

  const promises = Array.from({ length: streamCount }, () => {
    const data = crypto.randomBytes(payloadSize);
    const hash = sha256(data);
    return sendAndReceive(edgePort, data, 60000).then((received) => ({
      sent: hash,
      received: sha256(received),
      sizeOk: received.length === payloadSize,
    }));
  });

  const results = await Promise.all(promises);
  const failures = results.filter((r) => !r.sizeOk || r.sent !== r.received);
  expect(failures.length).toEqual(0);
});

tap.test('QUIC: TCP tunnel still connected after all tests', async () => {
  const status = await tunnel.edge.getStatus();
  expect(status.connected).toBeTrue();
});

tap.test('QUIC teardown: stop TCP tunnel and echo server', async () => {
  await tunnel.cleanup();
  await forceCloseServer(echoServer);
});

export default tap.start();