'use strict';

// Set env BEFORE requiring the middleware (ALLOWED array is built at load time)
process.env.ORIGIN_GUARD_DISABLED = 'false';
process.env.NODE_ENV = 'development';
process.env.ALLOWED_ORIGINS = 'http://localhost:5173,http://localhost:3024';

const originGuard = require('../../middleware/originGuard.middleware');

// ── Mock helpers ──────────────────────────────────────────────────────────────

function makeReq({ method = 'GET', headers = {} } = {}) {
  return { method, headers };
}

function makeRes() {
  const res = {
    _status: null,
    _body: null,
    status(code) { this._status = code; return this; },
    json(body)   { this._body  = body;  return this; },
  };
  return res;
}

// Minimal headers that represent a real browser fetch() call (SPA → API).
// localhost:5173 → localhost:3024 is same-site (same eTLD+1, different port).
const BROWSER_HEADERS = {
  'sec-fetch-site':  'same-site',
  'sec-fetch-mode':  'cors',
  'sec-fetch-dest':  'empty',
  'accept-language': 'en-US,en;q=0.9',
};

// ── Tests ─────────────────────────────────────────────────────────────────────

describe('originGuard middleware', () => {

  // ── Layer 1a: Sec-Fetch-Site presence + value ─────────────────────────────

  test('1. GET with no Sec-Fetch-Site → 403 (Layer 1a: header absent)', () => {
    const req  = makeReq({ method: 'GET', headers: {} });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).not.toHaveBeenCalled();
    expect(res._status).toBe(403);
    expect(res._body).toMatchObject({ status: 'error', message: 'Forbidden.' });
  });

  test('2. GET with Sec-Fetch-Site: cross-site → 403 (Layer 1a: cross-site rejected)', () => {
    const req  = makeReq({ method: 'GET', headers: { 'sec-fetch-site': 'cross-site' } });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).not.toHaveBeenCalled();
    expect(res._status).toBe(403);
    expect(res._body).toMatchObject({ status: 'error', message: 'Forbidden.' });
  });

  // ── Layer 1b: Fetch Metadata family completeness + valid combo ────────────

  test('3. GET with Sec-Fetch-Site but missing Mode and Dest → 403 (Layer 1b: incomplete family)', () => {
    const req  = makeReq({ method: 'GET', headers: { 'sec-fetch-site': 'same-site' } });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).not.toHaveBeenCalled();
    expect(res._status).toBe(403);
    expect(res._body).toMatchObject({ status: 'error', message: 'Forbidden.' });
  });

  test('4. GET with Sec-Fetch-Site + Mode but missing Dest → 403 (Layer 1b: partial family)', () => {
    const req  = makeReq({
      method: 'GET',
      headers: { 'sec-fetch-site': 'same-site', 'sec-fetch-mode': 'cors' },
    });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).not.toHaveBeenCalled();
    expect(res._status).toBe(403);
  });

  test('5. GET with impossible combo (cors + document) → 403 (Layer 1b: invalid combination)', () => {
    const req  = makeReq({
      method: 'GET',
      headers: {
        'sec-fetch-site': 'same-site',
        'sec-fetch-mode': 'cors',
        'sec-fetch-dest': 'document',
        'accept-language': 'en-US',
      },
    });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).not.toHaveBeenCalled();
    expect(res._status).toBe(403);
  });

  test('6. GET with no-cors mode → 403 (Layer 1b: no-cors not expected on API server)', () => {
    const req  = makeReq({
      method: 'GET',
      headers: {
        'sec-fetch-site': 'same-site',
        'sec-fetch-mode': 'no-cors',
        'sec-fetch-dest': 'empty',
        'accept-language': 'en-US',
      },
    });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).not.toHaveBeenCalled();
    expect(res._status).toBe(403);
  });

  // ── Layer 2: Browser presence signals ────────────────────────────────────

  test('7. GET with valid Fetch Metadata but no Sec-CH-UA and no Accept-Language → 403 (Layer 2: no browser fingerprint)', () => {
    const req  = makeReq({
      method: 'GET',
      headers: {
        'sec-fetch-site': 'same-site',
        'sec-fetch-mode': 'cors',
        'sec-fetch-dest': 'empty',
      },
    });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).not.toHaveBeenCalled();
    expect(res._status).toBe(403);
    expect(res._body).toMatchObject({ status: 'error', message: 'Forbidden.' });
  });

  // ── Layer 3: Origin allowlist ─────────────────────────────────────────────

  test('8. POST with full browser headers but foreign Origin → 403 (Layer 3: unlisted origin)', () => {
    const req  = makeReq({
      method: 'POST',
      headers: { ...BROWSER_HEADERS, 'origin': 'http://attacker.com' },
    });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).not.toHaveBeenCalled();
    expect(res._status).toBe(403);
    expect(res._body).toMatchObject({ status: 'error', message: 'Forbidden.' });
  });

  test('9. POST with full browser headers but missing Origin → 403 (Layer 3: no origin header)', () => {
    const req  = makeReq({ method: 'POST', headers: { ...BROWSER_HEADERS } });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).not.toHaveBeenCalled();
    expect(res._status).toBe(403);
  });

  // ── Happy paths ───────────────────────────────────────────────────────────

  test('10. GET with full browser headers (Accept-Language path) → passes', () => {
    const req  = makeReq({ method: 'GET', headers: { ...BROWSER_HEADERS } });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).toHaveBeenCalledTimes(1);
    expect(res._status).toBeNull();
  });

  test('11. GET with Sec-CH-UA instead of Accept-Language (Chromium path) → passes', () => {
    const req  = makeReq({
      method: 'GET',
      headers: {
        'sec-fetch-site': 'same-site',
        'sec-fetch-mode': 'cors',
        'sec-fetch-dest': 'empty',
        'sec-ch-ua': '"Chromium";v="137", "Not/A)Brand";v="24"',
      },
    });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).toHaveBeenCalledTimes(1);
    expect(res._status).toBeNull();
  });

  test('12. POST with full browser headers and allowed Origin → passes', () => {
    const req  = makeReq({
      method: 'POST',
      headers: { ...BROWSER_HEADERS, 'origin': 'http://localhost:5173' },
    });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).toHaveBeenCalledTimes(1);
    expect(res._status).toBeNull();
  });

  test('13. Direct browser navigation (navigate + document, site: none) → passes', () => {
    const req  = makeReq({
      method: 'GET',
      headers: {
        'sec-fetch-site': 'none',
        'sec-fetch-mode': 'navigate',
        'sec-fetch-dest': 'document',
        'sec-fetch-user': '?1',
        'accept-language': 'en-US,en;q=0.9',
        'accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
      },
    });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).toHaveBeenCalledTimes(1);
    expect(res._status).toBeNull();
  });

  test('14. OPTIONS preflight → passes immediately (handled by cors())', () => {
    const req  = makeReq({ method: 'OPTIONS', headers: {} });
    const res  = makeRes();
    const next = jest.fn();

    originGuard(req, res, next);

    expect(next).toHaveBeenCalledTimes(1);
    expect(res._status).toBeNull();
  });

});