import { expect, tap } from '@git.zone/tstest/tapbundle';
import { SmartProxy } from '../ts/index.js';
import type { IRouteConfig } from '../ts/index.js';
import * as net from 'net';
import * as http from 'http';
import * as tls from 'tls';
import * as https from 'https';
import * as fs from 'fs';
import * as path from 'path';
import { fileURLToPath } from 'url';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

// ────────────────────────────────────────────────────────────────────────────
// Port assignments (unique to avoid conflicts with other tests)
// ────────────────────────────────────────────────────────────────────────────
const TCP_ECHO_PORT = 47500;
const HTTP_ECHO_PORT = 47501;
const TLS_ECHO_PORT = 47502;
const PROXY_TCP_PORT = 47510;
const PROXY_HTTP_PORT = 47511;
const PROXY_TLS_PASS_PORT = 47512;
const PROXY_TLS_TERM_PORT = 47513;
const PROXY_SOCKET_PORT = 47514;
const PROXY_MULTI_A_PORT = 47515;
const PROXY_MULTI_B_PORT = 47516;
const PROXY_TP_HTTP_PORT = 47517;

// ────────────────────────────────────────────────────────────────────────────
// Test certificates
// ────────────────────────────────────────────────────────────────────────────
const CERT_PEM = fs.readFileSync(path.join(__dirname, '..', 'assets', 'certs', 'cert.pem'), 'utf8');
const KEY_PEM = fs.readFileSync(path.join(__dirname, '..', 'assets', 'certs', 'key.pem'), 'utf8');

// ────────────────────────────────────────────────────────────────────────────
// Backend servers
// ────────────────────────────────────────────────────────────────────────────
let tcpEchoServer: net.Server;
let httpEchoServer: http.Server;
let tlsEchoServer: tls.Server;

// Helper: force-poll the metrics adapter
async function pollMetrics(proxy: SmartProxy): Promise<void> {
  await (proxy as any).metricsAdapter.poll();
}

// ════════════════════════════════════════════════════════════════════════════
// Setup: backend servers
// ════════════════════════════════════════════════════════════════════════════
tap.test('setup - TCP echo server', async () => {
  tcpEchoServer = net.createServer((socket) => {
    socket.on('data', (data) => socket.write(data));
    socket.on('error', () => {});
  });
  await new Promise<void>((resolve) => {
    tcpEchoServer.listen(TCP_ECHO_PORT, () => {
      console.log(`TCP echo server on port ${TCP_ECHO_PORT}`);
      resolve();
    });
  });
});

tap.test('setup - HTTP echo server', async () => {
  httpEchoServer = http.createServer((req, res) => {
    let body = '';
    req.on('data', (chunk) => (body += chunk));
    req.on('end', () => {
      res.writeHead(200, { 'Content-Type': 'text/plain' });
      res.end(`echo:${body}`);
    });
  });
  await new Promise<void>((resolve) => {
    httpEchoServer.listen(HTTP_ECHO_PORT, () => {
      console.log(`HTTP echo server on port ${HTTP_ECHO_PORT}`);
      resolve();
    });
  });
});

tap.test('setup - TLS echo server', async () => {
  tlsEchoServer = tls.createServer(
    { cert: CERT_PEM, key: KEY_PEM },
    (socket) => {
      socket.on('data', (data) => socket.write(data));
      socket.on('error', () => {});
    },
  );
  await new Promise<void>((resolve) => {
    tlsEchoServer.listen(TLS_ECHO_PORT, () => {
      console.log(`TLS echo server on port ${TLS_ECHO_PORT}`);
      resolve();
    });
  });
});

// ════════════════════════════════════════════════════════════════════════════
// Group 1: TCP Forward (plain TCP passthrough — no domain, no TLS)
// ════════════════════════════════════════════════════════════════════════════
tap.test('TCP forward - real-time byte tracking', async (tools) => {
  const proxy = new SmartProxy({
    routes: [
      {
        id: 'tcp-forward',
        name: 'tcp-forward',
        match: { ports: PROXY_TCP_PORT },
        action: {
          type: 'forward',
          targets: [{ host: 'localhost', port: TCP_ECHO_PORT }],
        },
      },
    ],
    metrics: { enabled: true, sampleIntervalMs: 100, retentionSeconds: 60 },
  });
  await proxy.start();

  // Connect and send data
  const client = new net.Socket();
  await new Promise<void>((resolve, reject) => {
    client.connect(PROXY_TCP_PORT, 'localhost', () => resolve());
    client.on('error', reject);
  });

  let received = 0;
  client.on('data', (data) => (received += data.length));

  // Send 10 KB in chunks over 1 second
  const chunk = Buffer.alloc(1024, 'A');
  for (let i = 0; i < 10; i++) {
    client.write(chunk);
    await tools.delayFor(100);
  }

  // Wait for echo data and sampling to accumulate
  await tools.delayFor(500);

  // === Key assertion: metrics visible WHILE the connection is still open ===
  // Before this change, TCP bytes were only reported after connection close.
  // Now bytes are reported per-chunk in real-time.
  await pollMetrics(proxy);

  const mDuring = proxy.getMetrics();
  const bytesInDuring = mDuring.totals.bytesIn();
  const bytesOutDuring = mDuring.totals.bytesOut();
  console.log(`TCP forward (during) — bytesIn: ${bytesInDuring}, bytesOut: ${bytesOutDuring}`);
  expect(bytesInDuring).toBeGreaterThan(0);
  expect(bytesOutDuring).toBeGreaterThan(0);

  // Check that throughput is non-zero during active TCP traffic
  const tpDuring = mDuring.throughput.recent();
  console.log(`TCP forward (during) — recent throughput: in=${tpDuring.in}, out=${tpDuring.out}`);
  expect(tpDuring.in + tpDuring.out).toBeGreaterThan(0);

  // Close connection
  client.destroy();
  await tools.delayFor(500);

  // Final check
  await pollMetrics(proxy);
  const m = proxy.getMetrics();
  const bytesIn = m.totals.bytesIn();
  const bytesOut = m.totals.bytesOut();
  console.log(`TCP forward (final) — bytesIn: ${bytesIn}, bytesOut: ${bytesOut}`);
  expect(bytesIn).toBeGreaterThanOrEqual(bytesInDuring);
  expect(bytesOut).toBeGreaterThanOrEqual(bytesOutDuring);

  // Check per-route tracking
  const byRoute = m.throughput.byRoute();
  console.log('TCP forward — throughput byRoute:', Array.from(byRoute.entries()));

  await proxy.stop();
  await tools.delayFor(200);
});

// ════════════════════════════════════════════════════════════════════════════
// Group 2: HTTP Forward (plain HTTP proxy)
// ════════════════════════════════════════════════════════════════════════════
tap.test('HTTP forward - byte totals tracking', async (tools) => {
  const proxy = new SmartProxy({
    routes: [
      {
        id: 'http-forward',
        name: 'http-forward',
        match: { ports: PROXY_HTTP_PORT },
        action: {
          type: 'forward',
          targets: [{ host: 'localhost', port: HTTP_ECHO_PORT }],
        },
      },
    ],
    metrics: { enabled: true, sampleIntervalMs: 100, retentionSeconds: 60 },
  });
  await proxy.start();
  await tools.delayFor(300);

  // Send 10 HTTP requests with 1 KB body each
  for (let i = 0; i < 10; i++) {
    const body = 'X'.repeat(1024);
    await new Promise<void>((resolve, reject) => {
      const req = http.request(
        {
          hostname: 'localhost',
          port: PROXY_HTTP_PORT,
          path: '/echo',
          method: 'POST',
          headers: { 'Content-Type': 'text/plain', 'Content-Length': String(body.length) },
        },
        (res) => {
          let data = '';
          res.on('data', (chunk) => (data += chunk));
          res.on('end', () => resolve());
        },
      );
      req.on('error', reject);
      req.setTimeout(5000, () => {
        req.destroy();
        reject(new Error('HTTP request timeout'));
      });
      req.end(body);
    });
  }

  // Wait for sampling + poll
  await tools.delayFor(500);
  await pollMetrics(proxy);

  const m = proxy.getMetrics();
  const bytesIn = m.totals.bytesIn();
  const bytesOut = m.totals.bytesOut();
  console.log(`HTTP forward — bytesIn: ${bytesIn}, bytesOut: ${bytesOut}`);

  // Both directions should have bytes (CountingBody tracks request + response)
  expect(bytesIn).toBeGreaterThan(0);
  expect(bytesOut).toBeGreaterThan(0);

  await proxy.stop();
  await tools.delayFor(200);
});

// ════════════════════════════════════════════════════════════════════════════
// Group 3: TLS Passthrough (SNI-based, Rust passes encrypted data through)
// ════════════════════════════════════════════════════════════════════════════
tap.test('TLS passthrough - byte totals tracking', async (tools) => {
  const proxy = new SmartProxy({
    routes: [
      {
        id: 'tls-passthrough',
        name: 'tls-passthrough',
        match: { ports: PROXY_TLS_PASS_PORT, domains: 'localhost' },
        action: {
          type: 'forward',
          tls: { mode: 'passthrough' },
          targets: [{ host: 'localhost', port: TLS_ECHO_PORT }],
        },
      },
    ],
    metrics: { enabled: true, sampleIntervalMs: 100, retentionSeconds: 60 },
  });
  await proxy.start();
  await tools.delayFor(300);

  // Connect via TLS through the proxy (SNI: localhost)
  const tlsClient = tls.connect(
    {
      host: 'localhost',
      port: PROXY_TLS_PASS_PORT,
      servername: 'localhost',
      rejectUnauthorized: false,
    },
  );

  await new Promise<void>((resolve, reject) => {
    tlsClient.on('secureConnect', () => resolve());
    tlsClient.on('error', reject);
  });

  // Send some data
  const data = Buffer.alloc(2048, 'B');
  tlsClient.write(data);

  // Wait for echo
  let received = 0;
  tlsClient.on('data', (chunk) => (received += chunk.length));
  await tools.delayFor(1000);

  console.log(`TLS passthrough — received ${received} bytes back`);
  expect(received).toBeGreaterThan(0);

  tlsClient.destroy();
  await tools.delayFor(500);

  await pollMetrics(proxy);

  const m = proxy.getMetrics();
  const bytesIn = m.totals.bytesIn();
  const bytesOut = m.totals.bytesOut();
  console.log(`TLS passthrough — bytesIn: ${bytesIn}, bytesOut: ${bytesOut}`);

  // TLS passthrough tracks encrypted bytes flowing through
  expect(bytesIn).toBeGreaterThan(0);
  expect(bytesOut).toBeGreaterThan(0);

  await proxy.stop();
  await tools.delayFor(200);
});

// ════════════════════════════════════════════════════════════════════════════
// Group 4: TLS Terminate + HTTP (Rust terminates TLS, forwards to HTTP backend)
// ════════════════════════════════════════════════════════════════════════════
tap.test('TLS terminate + HTTP forward - byte totals tracking', async (tools) => {
  const proxy = new SmartProxy({
    routes: [
      {
        id: 'tls-terminate',
        name: 'tls-terminate',
        match: { ports: PROXY_TLS_TERM_PORT, domains: 'localhost' },
        action: {
          type: 'forward',
          tls: {
            mode: 'terminate',
            certificate: {
              cert: CERT_PEM,
              key: KEY_PEM,
            },
          },
          targets: [{ host: 'localhost', port: HTTP_ECHO_PORT }],
        },
      },
    ],
    metrics: { enabled: true, sampleIntervalMs: 100, retentionSeconds: 60 },
    disableDefaultCert: true,
  });
  await proxy.start();
  await tools.delayFor(300);

  // Send HTTPS request through the proxy
  const body = 'Z'.repeat(2048);
  await new Promise<void>((resolve, reject) => {
    const req = https.request(
      {
        hostname: 'localhost',
        port: PROXY_TLS_TERM_PORT,
        path: '/echo',
        method: 'POST',
        headers: { 'Content-Type': 'text/plain', 'Content-Length': String(body.length) },
        rejectUnauthorized: false,
      },
      (res) => {
        let data = '';
        res.on('data', (chunk) => (data += chunk));
        res.on('end', () => {
          console.log(`TLS terminate — response: ${data.slice(0, 50)}...`);
          resolve();
        });
      },
    );
    req.on('error', reject);
    req.setTimeout(5000, () => {
      req.destroy();
      reject(new Error('HTTPS request timeout'));
    });
    req.end(body);
  });

  await tools.delayFor(500);
  await pollMetrics(proxy);

  const m = proxy.getMetrics();
  const bytesIn = m.totals.bytesIn();
  const bytesOut = m.totals.bytesOut();
  console.log(`TLS terminate — bytesIn: ${bytesIn}, bytesOut: ${bytesOut}`);

  // TLS terminate: request body (bytesIn) and response body (bytesOut) via CountingBody
  expect(bytesIn).toBeGreaterThan(0);
  expect(bytesOut).toBeGreaterThan(0);

  await proxy.stop();
  await tools.delayFor(200);
});

// ════════════════════════════════════════════════════════════════════════════
// Group 5: Socket Handler (JS callback handling)
// ════════════════════════════════════════════════════════════════════════════
tap.test('Socket handler - byte totals tracking', async (tools) => {
  const proxy = new SmartProxy({
    routes: [
      {
        id: 'socket-handler',
        name: 'socket-handler',
        match: { ports: PROXY_SOCKET_PORT },
        action: {
          type: 'socket-handler',
          socketHandler: (socket, _context) => {
            socket.on('data', (data) => socket.write(data)); // echo
            socket.on('error', () => {});
          },
        },
      },
    ],
    metrics: { enabled: true, sampleIntervalMs: 100, retentionSeconds: 60 },
  });
  await proxy.start();
  await tools.delayFor(300);

  // Connect and send data
  const client = new net.Socket();
  await new Promise<void>((resolve, reject) => {
    client.connect(PROXY_SOCKET_PORT, 'localhost', () => resolve());
    client.on('error', reject);
  });

  const data = Buffer.alloc(4096, 'C');
  client.write(data);

  let received = 0;
  client.on('data', (chunk) => (received += chunk.length));
  await tools.delayFor(500);

  console.log(`Socket handler — received ${received} bytes back`);

  client.destroy();
  await tools.delayFor(500);

  await pollMetrics(proxy);

  const m = proxy.getMetrics();
  const bytesIn = m.totals.bytesIn();
  const bytesOut = m.totals.bytesOut();
  console.log(`Socket handler — bytesIn: ${bytesIn}, bytesOut: ${bytesOut}`);

  // Socket handler relay now records bytes after copy_bidirectional completes
  expect(bytesIn).toBeGreaterThan(0);
  expect(bytesOut).toBeGreaterThan(0);

  await proxy.stop();
  await tools.delayFor(200);
});

// ════════════════════════════════════════════════════════════════════════════
// Group 6: Multi-route throughput isolation
// ════════════════════════════════════════════════════════════════════════════
tap.test('Multi-route throughput isolation', async (tools) => {
  const proxy = new SmartProxy({
    routes: [
      {
        id: 'route-alpha',
        name: 'route-alpha',
        match: { ports: PROXY_MULTI_A_PORT },
        action: {
          type: 'forward',
          targets: [{ host: 'localhost', port: TCP_ECHO_PORT }],
        },
      },
      {
        id: 'route-beta',
        name: 'route-beta',
        match: { ports: PROXY_MULTI_B_PORT },
        action: {
          type: 'forward',
          targets: [{ host: 'localhost', port: TCP_ECHO_PORT }],
        },
      },
    ],
    metrics: { enabled: true, sampleIntervalMs: 100, retentionSeconds: 60 },
  });
  await proxy.start();
  await tools.delayFor(300);

  // Send different amounts to each route
  // Route alpha: 8 KB
  const clientA = new net.Socket();
  await new Promise<void>((resolve, reject) => {
    clientA.connect(PROXY_MULTI_A_PORT, 'localhost', () => resolve());
    clientA.on('error', reject);
  });
  clientA.on('data', () => {}); // drain
  for (let i = 0; i < 8; i++) {
    clientA.write(Buffer.alloc(1024, 'A'));
    await tools.delayFor(50);
  }

  // Route beta: 2 KB
  const clientB = new net.Socket();
  await new Promise<void>((resolve, reject) => {
    clientB.connect(PROXY_MULTI_B_PORT, 'localhost', () => resolve());
    clientB.on('error', reject);
  });
  clientB.on('data', () => {}); // drain
  for (let i = 0; i < 2; i++) {
    clientB.write(Buffer.alloc(1024, 'B'));
    await tools.delayFor(50);
  }

  await tools.delayFor(500);

  // Close both
  clientA.destroy();
  clientB.destroy();
  await tools.delayFor(500);

  await pollMetrics(proxy);

  const m = proxy.getMetrics();

  // Check per-route throughput exists for both
  const byRoute = m.throughput.byRoute();
  console.log('Multi-route — throughput byRoute:', Array.from(byRoute.entries()));

  // Check per-route connection counts
  const connByRoute = m.connections.byRoute();
  console.log('Multi-route — connections byRoute:', Array.from(connByRoute.entries()));

  // Both routes should have tracked data
  const totalIn = m.totals.bytesIn();
  const totalOut = m.totals.bytesOut();
  console.log(`Multi-route — total bytesIn: ${totalIn}, bytesOut: ${totalOut}`);

  expect(totalIn).toBeGreaterThan(0);
  expect(totalOut).toBeGreaterThan(0);

  await proxy.stop();
  await tools.delayFor(200);
});

// ════════════════════════════════════════════════════════════════════════════
// Group 7: Throughput sampling over time (HTTP-based for real-time tracking)
//
// Uses HTTP proxy path where CountingBody reports bytes incrementally
// as each request/response body completes. This allows the sampling task
// to capture non-zero throughput during active traffic.
// ════════════════════════════════════════════════════════════════════════════
tap.test('Throughput sampling - values appear during active HTTP traffic', async (tools) => {
  const proxy = new SmartProxy({
    routes: [
      {
        id: 'sampling-test',
        name: 'sampling-test',
        match: { ports: PROXY_TP_HTTP_PORT },
        action: {
          type: 'forward',
          targets: [{ host: 'localhost', port: HTTP_ECHO_PORT }],
        },
      },
    ],
    metrics: { enabled: true, sampleIntervalMs: 100, retentionSeconds: 60 },
  });
  await proxy.start();
  await tools.delayFor(300);

  // Send HTTP requests continuously for ~2 seconds
  let sending = true;
  let requestCount = 0;
  const sendLoop = (async () => {
    while (sending) {
      const body = 'D'.repeat(5120); // 5 KB per request
      try {
        await new Promise<void>((resolve, reject) => {
          const req = http.request(
            {
              hostname: 'localhost',
              port: PROXY_TP_HTTP_PORT,
              path: '/echo',
              method: 'POST',
              headers: { 'Content-Type': 'text/plain', 'Content-Length': String(body.length) },
            },
            (res) => {
              res.on('data', () => {});
              res.on('end', () => resolve());
            },
          );
          req.on('error', reject);
          req.setTimeout(3000, () => {
            req.destroy();
            reject(new Error('timeout'));
          });
          req.end(body);
        });
        requestCount++;
      } catch {
        // Ignore errors during shutdown
        break;
      }
    }
  })();

  // After 1.5 seconds of active traffic, check throughput
  await tools.delayFor(1500);

  await pollMetrics(proxy);

  const m = proxy.getMetrics();
  const tp = m.throughput.instant();
  const totalIn = m.totals.bytesIn();
  const totalOut = m.totals.bytesOut();
  console.log(`Sampling test — after 1.5s of traffic: instant in=${tp.in}, out=${tp.out}`);
  console.log(`Sampling test — totals: bytesIn=${totalIn}, bytesOut=${totalOut}, requests=${requestCount}`);

  // Totals should definitely be non-zero after 1.5s of HTTP requests
  expect(totalIn + totalOut).toBeGreaterThan(0);

  // Throughput instant should be non-zero during active traffic.
  // The sampling interval is 100ms, so we've had ~15 samples by now.
  // Each sample captures bytes from completed HTTP request/response bodies.
  // Note: this can occasionally be 0 if sample boundaries don't align, so we
  // also check that at least the throughput was non-zero for *some* recent window.
  const tpRecent = m.throughput.recent();
  console.log(`Sampling test — recent throughput: in=${tpRecent.in}, out=${tpRecent.out}`);
  expect(tpRecent.in + tpRecent.out).toBeGreaterThan(0);

  // Stop sending
  sending = false;
  await sendLoop;

  // After traffic stops, wait for metrics to settle
  await tools.delayFor(500);
  await pollMetrics(proxy);

  const mAfter = proxy.getMetrics();
  const tpAfter = mAfter.throughput.instant();
  console.log(`Sampling test — after traffic stops: instant in=${tpAfter.in}, out=${tpAfter.out}`);

  await proxy.stop();
  await tools.delayFor(200);
});

// ════════════════════════════════════════════════════════════════════════════
// Cleanup
// ════════════════════════════════════════════════════════════════════════════
tap.test('cleanup - close backend servers', async () => {
  await new Promise<void>((resolve) => tcpEchoServer.close(() => resolve()));
  await new Promise<void>((resolve) => httpEchoServer.close(() => resolve()));
  await new Promise<void>((resolve) => tlsEchoServer.close(() => resolve()));
  console.log('All backend servers closed');
});

export default tap.start();