import { expect, tap } from '@git.zone/tstest/tapbundle';
import { SmartProxy } from '../ts/index.js';
import * as http from 'http';
import * as net from 'net';
import * as tls from 'tls';
import * as fs from 'fs';
import * as path from 'path';
import { fileURLToPath } from 'url';
import { assertPortsFree, findFreePorts } from './helpers/port-allocator.js';

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

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');

let httpBackendPort: number;
let tlsBackendPort: number;
let httpProxyPort: number;
let tlsProxyPort: number;

let httpBackend: http.Server;
let tlsBackend: tls.Server;
let proxy: SmartProxy;

async function pollMetrics(proxyToPoll: SmartProxy): Promise<void> {
  await (proxyToPoll as any).metricsAdapter.poll();
}

async function waitForCondition(
  callback: () => Promise<boolean>,
  timeoutMs: number = 5000,
  stepMs: number = 100,
): Promise<void> {
  const deadline = Date.now() + timeoutMs;
  while (Date.now() < deadline) {
    if (await callback()) {
      return;
    }
    await new Promise((resolve) => setTimeout(resolve, stepMs));
  }
  throw new Error(`Condition not met within ${timeoutMs}ms`);
}

function hasIpDomainRequest(domain: string): boolean {
  const byIp = proxy.getMetrics().connections.domainRequestsByIP();
  for (const domainMap of byIp.values()) {
    if (domainMap.has(domain)) {
      return true;
    }
  }
  return false;
}

tap.test('setup - backend servers for HTTP domain rate metrics', async () => {
  [httpBackendPort, tlsBackendPort, httpProxyPort, tlsProxyPort] = await findFreePorts(4);

  httpBackend = http.createServer((req, res) => {
    let body = '';
    req.on('data', (chunk) => {
      body += chunk;
    });
    req.on('end', () => {
      res.writeHead(200, { 'Content-Type': 'text/plain' });
      res.end(`ok:${body}`);
    });
  });
  await new Promise<void>((resolve) => {
    httpBackend.listen(httpBackendPort, () => resolve());
  });

  tlsBackend = tls.createServer({ cert: CERT_PEM, key: KEY_PEM }, (socket) => {
    socket.on('data', (data) => {
      socket.write(data);
    });
    socket.on('error', () => {});
  });
  await new Promise<void>((resolve) => {
    tlsBackend.listen(tlsBackendPort, () => resolve());
  });
});

tap.test('setup - start proxy with HTTP and TLS passthrough routes', async () => {
  proxy = new SmartProxy({
    routes: [
      {
        id: 'http-domain-rates',
        name: 'http-domain-rates',
        match: { ports: httpProxyPort, domains: 'example.com' },
        action: {
          type: 'forward',
          targets: [{ host: 'localhost', port: httpBackendPort }],
        },
      },
      {
        id: 'tls-passthrough-domain-rates',
        name: 'tls-passthrough-domain-rates',
        match: { ports: tlsProxyPort, domains: 'passthrough.example.com' },
        action: {
          type: 'forward',
          tls: { mode: 'passthrough' },
          targets: [{ host: 'localhost', port: tlsBackendPort }],
        },
      },
    ],
    metrics: { enabled: true, sampleIntervalMs: 100, retentionSeconds: 60 },
  });

  await proxy.start();
  await new Promise((resolve) => setTimeout(resolve, 300));
});

tap.test('HTTP requests populate per-domain HTTP request rates', async () => {
  for (let i = 0; i < 3; i++) {
    await new Promise<void>((resolve, reject) => {
      const body = `payload-${i}`;
      const req = http.request(
        {
          hostname: 'localhost',
          port: httpProxyPort,
          path: '/echo',
          method: 'POST',
          headers: {
            Host: 'Example.COM',
            'Content-Type': 'text/plain',
            'Content-Length': String(body.length),
          },
        },
        (res) => {
          res.resume();
          res.on('end', () => resolve());
        },
      );
      req.on('error', reject);
      req.end(body);
    });
  }

  await waitForCondition(async () => {
    await pollMetrics(proxy);
    const domainMetrics = proxy.getMetrics().requests.byDomain().get('example.com');
    return (domainMetrics?.lastMinute ?? 0) >= 3 && (domainMetrics?.perSecond ?? 0) > 0;
  });

  const exampleMetrics = proxy.getMetrics().requests.byDomain().get('example.com');
  expect(exampleMetrics).toBeTruthy();
  expect(exampleMetrics?.lastMinute).toEqual(3);
  expect(exampleMetrics?.perSecond).toBeGreaterThan(0);
});

tap.test('TLS passthrough SNI does not inflate HTTP domain request rates', async () => {
  const tlsClient = tls.connect({
    host: 'localhost',
    port: tlsProxyPort,
    servername: 'passthrough.example.com',
    rejectUnauthorized: false,
  });

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

  const echoPromise = new Promise<void>((resolve, reject) => {
    tlsClient.once('data', () => resolve());
    tlsClient.once('error', reject);
  });
  tlsClient.write(Buffer.from('hello over tls passthrough'));
  await echoPromise;

  await waitForCondition(async () => {
    await pollMetrics(proxy);
    return hasIpDomainRequest('passthrough.example.com');
  });

  const requestRates = proxy.getMetrics().requests.byDomain();
  expect(requestRates.has('passthrough.example.com')).toBeFalse();
  expect(requestRates.get('example.com')?.lastMinute).toEqual(3);
  expect(hasIpDomainRequest('passthrough.example.com')).toBeTrue();

  tlsClient.destroy();
});

tap.test('cleanup - stop proxy and close backend servers', async () => {
  await proxy.stop();
  await new Promise<void>((resolve) => httpBackend.close(() => resolve()));
  await new Promise<void>((resolve) => tlsBackend.close(() => resolve()));
  await assertPortsFree([httpBackendPort, tlsBackendPort, httpProxyPort, tlsProxyPort]);
});

export default tap.start()