import { describe, it, expect, vi, beforeAll, beforeEach } from 'vitest';
import { createRequire } from 'module';
import { fileURLToPath } from 'url';
import { dirname, resolve } from 'path';
import http from 'http';

const require = createRequire(import.meta.url);
const __dirname = dirname(fileURLToPath(import.meta.url));

// ── Load real PROVIDER_DATA by stubbing only nodemailer ───────────
// This way the mock never drifts from mailer.js.
const nodemailerPath = require.resolve('nodemailer');
require.cache[nodemailerPath] = {
  id: nodemailerPath, filename: nodemailerPath, loaded: true,
  exports: { createTransport: () => ({ sendMail: async () => ({}) }) },
  children: [], paths: [],
};
const { PROVIDER_DATA } = require('../services/mailer');

// ── Replace mailer in cache with full stub (sendErasureMail mocked) ──
const mockSendErasureMail = vi.fn().mockImplementation(({ provider }) => {
  const info = PROVIDER_DATA[provider];
  if (!info?.email) return Promise.resolve({ skipped: true, reason: 'use_form', formUrl: info?.formUrl });
  return Promise.resolve({ skipped: false });
});

const mailerPath = resolve(__dirname, '../services/mailer.js');
require.cache[mailerPath] = {
  id: mailerPath, filename: mailerPath, loaded: true,
  exports: { PROVIDER_DATA, sendErasureMail: mockSendErasureMail },
  children: [], paths: [],
};

// Load route AFTER cache is patched
const eraseRoute = require('../routes/erase');
const express    = require('express');

function buildApp() {
  const app = express();
  app.use(express.json({ limit: '10kb' }));
  app.post('/api/erase', eraseRoute);
  return app;
}

function request(app, body) {
  return new Promise((resolve, reject) => {
    const server = http.createServer(app);
    server.listen(0, '127.0.0.1', () => {
      const { port } = server.address();
      fetch(`http://127.0.0.1:${port}/api/erase`, {
        method:  'POST',
        headers: { 'Content-Type': 'application/json' },
        body:    JSON.stringify(body),
      })
        .then(res => res.json().then(json => ({ status: res.status, body: json })))
        .then(result => { server.close(); resolve(result); })
        .catch(err   => { server.close(); reject(err); });
    });
  });
}

let app;
beforeAll(() => { app = buildApp(); });
beforeEach(() => { mockSendErasureMail.mockClear(); });

// ── Snapshot: catch drift in provider list ────────────────────────
describe('provider registry', () => {
  it('matches snapshot', () => {
    expect(PROVIDER_DATA).toMatchSnapshot();
  });
});

// ── Validation ────────────────────────────────────────────────────
describe('validation', () => {
  it('rejects missing provider', async () => {
    const { status, body } = await request(app, { email: 'test@example.com' });
    expect(status).toBe(400);
    expect(body.error).toMatch(/provider/i);
    expect(mockSendErasureMail).not.toHaveBeenCalled();
  });

  it('rejects missing email', async () => {
    const { status, body } = await request(app, { provider: 'instagram' });
    expect(status).toBe(400);
    expect(body.error).toMatch(/email/i);
    expect(mockSendErasureMail).not.toHaveBeenCalled();
  });

  it('rejects invalid email format', async () => {
    const { status, body } = await request(app, { provider: 'instagram', email: 'not-an-email' });
    expect(status).toBe(400);
    expect(body.error).toMatch(/email/i);
    expect(mockSendErasureMail).not.toHaveBeenCalled();
  });

  it('rejects unknown provider', async () => {
    const { status, body } = await request(app, { provider: 'myspace', email: 'test@example.com' });
    expect(status).toBe(400);
    expect(body.error).toMatch(/proveedor/i);
    expect(mockSendErasureMail).not.toHaveBeenCalled();
  });
});

// ── Form-only providers ───────────────────────────────────────────
describe('form-only providers', () => {
  it('google returns use_form with formUrl', async () => {
    const { status, body } = await request(app, { provider: 'google', email: 'test@example.com' });
    expect(status).toBe(200);
    expect(body.status).toBe('use_form');
    expect(body.formUrl).toMatch(/^https?:\/\//);
    expect(mockSendErasureMail).toHaveBeenCalledOnce();
    expect(mockSendErasureMail).toHaveBeenCalledWith(expect.objectContaining({ provider: 'google', email: 'test@example.com' }));
  });

  it('amazon returns use_form with formUrl', async () => {
    const { status, body } = await request(app, { provider: 'amazon', email: 'test@example.com' });
    expect(status).toBe(200);
    expect(body.status).toBe('use_form');
    expect(body.formUrl).toMatch(/^https?:\/\//);
    expect(mockSendErasureMail).toHaveBeenCalledOnce();
    expect(mockSendErasureMail).toHaveBeenCalledWith(expect.objectContaining({ provider: 'amazon', email: 'test@example.com' }));
  });
});

// ── Successful sends (mocked transport) ──────────────────────────
describe('email providers', () => {
  const providers = Object.entries(PROVIDER_DATA)
    .filter(([, info]) => info.email !== null)
    .map(([key]) => key);

  for (const provider of providers) {
    it(`sends for ${provider}`, async () => {
      const { status, body } = await request(app, {
        provider,
        email:    'smoke@example.com',
        nickname: 'Test User',
      });
      expect(status).toBe(200);
      expect(body.status).toBe('ok');
      expect(body.reference).toHaveLength(12);
      expect(mockSendErasureMail).toHaveBeenCalledOnce();
      expect(mockSendErasureMail).toHaveBeenCalledWith(expect.objectContaining({ provider, email: 'smoke@example.com', nickname: 'Test User' }));
    });
  }
});

// ── CRLF injection sanitization ───────────────────────────────────
describe('sanitization', () => {
  it('strips CRLF from optional fields without erroring', async () => {
    const { status, body } = await request(app, {
      provider: 'instagram',
      email:    'test@example.com',
      nickname: 'user\r\nX-Injected: evil',
      extra:    'line1\nline2',
    });
    expect(status).toBe(200);
    expect(body.status).toBe('ok');
  });
});