import { afterEach, beforeEach, describe, expect, test, vi } from 'vitest';
import { accessCodeRateLimiter } from '@/lib/server/access-code-rate-limit';
import { ACCESS_CODE_COOKIE_NAME } from '@/lib/server/access-token-policy';

const cookieSet = vi.fn();

vi.mock('next/headers', () => ({
  cookies: vi.fn(async () => ({ set: cookieSet })),
}));

function loginRequest(code: string) {
  return new Request('https://ops.example/api/access-code/verify', {
    method: 'POST',
    headers: { 'content-type': 'application/json', origin: 'https://ops.example' },
    body: JSON.stringify({ code }),
  });
}

function chunkedLoginRequest(chunks: string[]) {
  const encoder = new TextEncoder();
  const body = new ReadableStream<Uint8Array>({
    start(controller) {
      for (const chunk of chunks) {
        controller.enqueue(encoder.encode(chunk));
      }
      controller.close();
    },
  });

  return new Request('https://ops.example/api/access-code/verify', {
    method: 'POST',
    headers: {
      'content-type': 'application/json',
      origin: 'https://ops.example',
      'transfer-encoding': 'chunked',
    },
    body,
    duplex: 'half',
  } as RequestInit & { duplex: 'half' });
}

describe('POST /api/access-code/verify', () => {
  beforeEach(() => {
    vi.useFakeTimers();
    vi.setSystemTime(new Date('2026-08-15T00:00:00Z'));
    accessCodeRateLimiter.clear();
    cookieSet.mockClear();
    vi.stubEnv('ACCESS_CODE', 'correct-code');
    vi.stubEnv('ACCESS_CODE_SESSION_TTL_SECONDS', '3600');
    vi.stubEnv('ACCESS_CODE_RATE_LIMIT_MAX_ATTEMPTS', '2');
    vi.stubEnv('ACCESS_CODE_RATE_LIMIT_WINDOW_SECONDS', '900');
    vi.stubEnv('ACCESS_CODE_TRUST_PROXY_HEADERS', 'false');
  });

  afterEach(() => {
    accessCodeRateLimiter.clear();
    vi.unstubAllEnvs();
    vi.useRealTimers();
  });

  test('issues a session whose cookie lifetime matches the token TTL', async () => {
    const { POST } = await import('@/app/api/access-code/verify/route');
    const response = await POST(loginRequest('correct-code'));

    expect(response.status).toBe(200);
    expect(cookieSet).toHaveBeenCalledWith(
      ACCESS_CODE_COOKIE_NAME,
      expect.any(String),
      expect.objectContaining({ httpOnly: true, sameSite: 'lax', maxAge: 3600 }),
    );
  });

  test('rate-limits repeated failed login attempts', async () => {
    const { POST } = await import('@/app/api/access-code/verify/route');

    expect((await POST(loginRequest('wrong-1'))).status).toBe(401);
    expect((await POST(loginRequest('wrong-2'))).status).toBe(401);
    const blocked = await POST(loginRequest('wrong-3'));

    expect(blocked.status).toBe(429);
    expect(blocked.headers.get('retry-after')).toBe('900');
    await expect(blocked.json()).resolves.toMatchObject({ errorCode: 'RATE_LIMITED' });
  });

  test('cross-origin simple requests cannot consume the shared login bucket', async () => {
    const { POST } = await import('@/app/api/access-code/verify/route');
    for (let attempt = 0; attempt < 5; attempt += 1) {
      const response = await POST(
        new Request('https://ops.example/api/access-code/verify', {
          method: 'POST',
          headers: { 'content-type': 'text/plain', origin: 'https://attacker.example' },
          body: JSON.stringify({ code: 'wrong' }),
        }),
      );
      expect(response.status).toBe(403);
    }

    expect((await POST(loginRequest('correct-code'))).status).toBe(200);
  });

  test('wrong content types cannot consume the shared login bucket', async () => {
    const { POST } = await import('@/app/api/access-code/verify/route');
    for (let attempt = 0; attempt < 5; attempt += 1) {
      const response = await POST(
        new Request('https://ops.example/api/access-code/verify', {
          method: 'POST',
          headers: { 'content-type': 'text/plain', origin: 'https://ops.example' },
          body: JSON.stringify({ code: 'wrong' }),
        }),
      );
      expect(response.status).toBe(415);
    }

    expect((await POST(loginRequest('correct-code'))).status).toBe(200);
  });

  test('rejects an oversized declared content length without consuming the login bucket', async () => {
    const { POST } = await import('@/app/api/access-code/verify/route');
    for (let attempt = 0; attempt < 5; attempt += 1) {
      const response = await POST(
        new Request('https://ops.example/api/access-code/verify', {
          method: 'POST',
          headers: {
            'content-type': 'application/json',
            'content-length': '8193',
            origin: 'https://ops.example',
          },
          body: '{}',
        }),
      );
      expect(response.status).toBe(413);
      await expect(response.json()).resolves.toMatchObject({
        errorCode: 'INVALID_REQUEST',
      });
    }

    expect((await POST(loginRequest('correct-code'))).status).toBe(200);
  });

  test('caps the actual bytes of a chunked request before parsing or rate limiting', async () => {
    const { POST } = await import('@/app/api/access-code/verify/route');
    for (let attempt = 0; attempt < 5; attempt += 1) {
      const response = await POST(chunkedLoginRequest(['{"code":"', 'x'.repeat(8 * 1024), '"}']));
      expect(response.status).toBe(413);
      await expect(response.json()).resolves.toMatchObject({
        errorCode: 'INVALID_REQUEST',
      });
    }

    expect((await POST(loginRequest('correct-code'))).status).toBe(200);
  });

  test('malformed JSON is rejected before consuming a login attempt', async () => {
    const { POST } = await import('@/app/api/access-code/verify/route');
    const malformed = () =>
      new Request('https://ops.example/api/access-code/verify', {
        method: 'POST',
        headers: { 'content-type': 'application/json', origin: 'https://ops.example' },
        body: '{',
      });

    expect((await POST(malformed())).status).toBe(400);
    expect((await POST(malformed())).status).toBe(400);
    expect((await POST(loginRequest('wrong-1'))).status).toBe(401);
    expect((await POST(loginRequest('wrong-2'))).status).toBe(401);
    expect((await POST(loginRequest('wrong-3'))).status).toBe(429);
  });
});