const test = require('node:test');
const assert = require('node:assert/strict');
const http = require('node:http');
const express = require('express');
const rateLimit = require('express-rate-limit');
const { setup, teardown, cleanup } = require('../helpers');

/* ------------------------------------------------------------------ */
/* Helpers                                                             */
/* ------------------------------------------------------------------ */

function createJar() {
  return { cookies: [] };
}

function jarSet(jar, res) {
  const cookies = res.headers['set-cookie'];
  if (cookies && cookies.length) {
    jar.cookies = cookies.map((c) => c.split(';')[0]);
  }
}

function jarGet(jar) {
  return jar.cookies.join('; ');
}

function fetchJson(base, path, options = {}) {
  return new Promise((resolve, reject) => {
    const url = new URL(path, base);
    const opts = {
      method: options.method || 'GET',
      headers: {
        'Content-Type': 'application/json',
        ...(options.cookie ? { Cookie: options.cookie } : {}),
      },
    };
    const req = http.request(url, opts, (res) => {
      let data = '';
      res.on('data', (c) => { data += c; });
      res.on('end', () => {
        resolve({
          status: res.statusCode,
          headers: res.headers,
          body: data ? JSON.parse(data) : null,
        });
      });
    });
    req.on('error', reject);
    if (options.body) req.write(JSON.stringify(options.body));
    req.end();
  });
}

/* ------------------------------------------------------------------ */
/* Test: real login limiter is active (not a no-op)                    */
/* ------------------------------------------------------------------ */

test('rate limiter: login limiter is active and adds headers', async () => {
  const baseUrl = await setup();
  try {
    // Send 10 bad logins — all should return 401 (max=1000 in test env)
    for (let i = 0; i < 10; i++) {
      const res = await fetchJson(baseUrl, '/api/auth/login', {
        method: 'POST',
        body: { username: 'nonexistent', password: 'wrong' },
      });
      assert.equal(res.status, 401, `Login attempt ${i + 1} should return 401`);
      assert.equal(res.body.ok, false);
      assert.equal(res.body.error.code, 'INVALID_CREDENTIALS');
    }

    // Verify rate-limit headers are present (proves real limiter, not no-op stub)
    const res = await fetchJson(baseUrl, '/api/auth/login', {
      method: 'POST',
      body: { username: 'nonexistent', password: 'wrong' },
    });
    assert.equal(res.status, 401);
    assert.ok(
      res.headers['x-ratelimit-limit'] || res.headers['x-ratelimit-remaining'] !== undefined,
      'Response should include rate-limit headers from real limiter'
    );
  } finally {
    await teardown();
    cleanup();
  }
});

/* ------------------------------------------------------------------ */
/* Test: real register limiter is active                               */
/* ------------------------------------------------------------------ */

test('rate limiter: register limiter is active and adds headers', async () => {
  const baseUrl = await setup();
  try {
    const res = await fetchJson(baseUrl, '/api/auth/register', {
      method: 'POST',
      body: { username: 'ratelimituser', password: 'password123' },
    });
    assert.equal(res.status, 201);
    assert.equal(res.body.ok, true);
    assert.ok(
      res.headers['x-ratelimit-limit'] || res.headers['x-ratelimit-remaining'] !== undefined,
      'Register should include rate-limit headers'
    );
  } finally {
    await teardown();
    cleanup();
  }
});

/* ------------------------------------------------------------------ */
/* Test: 429 response shape is correct JSON envelope                   */
/* ------------------------------------------------------------------ */

test('rate limiter: 429 returns correct error envelope', async () => {
  // Create a minimal Express app with a low-limit rate limiter to verify
  // the 429 response shape matches the standard error envelope.
  const testApp = express();
  testApp.use(express.json());
  testApp.set('trust proxy', 1);

  const limiter = rateLimit({
    windowMs: 60 * 1000,
    max: 10,
    message: { ok: false, error: { code: 'RATE_LIMITED', message: 'Too many login attempts. Try again later.' } },
  });

  testApp.post('/api/test-login', limiter, (_req, res) => {
    res.json({ ok: true, data: { user: { id: 1, username: 'test' } } });
  });

  const server = await new Promise((resolve) => {
    const s = testApp.listen(0, () => resolve(s));
  });
  const port = server.address().port;
  const testUrl = `http://localhost:${port}`;

  try {
    // Send 10 requests (all succeed) + 1 (should be 429)
    for (let i = 0; i < 10; i++) {
      const res = await fetchJson(testUrl, '/api/test-login', {
        method: 'POST',
        body: { username: 'x', password: 'y' },
      });
      assert.equal(res.status, 200);
    }

    // 11th request → 429
    const res = await fetchJson(testUrl, '/api/test-login', {
      method: 'POST',
      body: { username: 'x', password: 'y' },
    });
    assert.equal(res.status, 429);
    assert.equal(res.body.ok, false);
    assert.equal(res.body.error.code, 'RATE_LIMITED');
    assert.equal(res.body.error.message, 'Too many login attempts. Try again later.');
  } finally {
    server.close();
  }
});

/* ------------------------------------------------------------------ */
/* Test: global /api limiter covers auth routes                        */
/* ------------------------------------------------------------------ */

test('rate limiter: global /api limiter covers auth routes', async () => {
  const baseUrl = await setup();
  try {
    const res = await fetchJson(baseUrl, '/api/auth/login', {
      method: 'POST',
      body: { username: 'ratetest2', password: 'wrongpass' },
    });
    assert.equal(res.status, 401);
    assert.ok(
      res.headers['x-ratelimit-limit'] || res.headers['x-ratelimit-remaining'] !== undefined,
      'Global /api limiter should add rate-limit headers to auth responses'
    );
  } finally {
    await teardown();
    cleanup();
  }
});