import { Router, Request, Response } from 'express';
import bcrypt from 'bcryptjs';
import crypto from 'node:crypto';
import { pool } from '../db';
import { requireCustomer } from '../middleware/customerAuth';
import { sendMail } from '../mailer';
import { MARKETING_CONSENT_TEXT, isValidEmail } from '../utils';
import { asyncRoute } from '../asyncRoute';
import { passwordResetRequestLimiter } from '../rateLimit';

const router = Router();

const SESSION_DAYS = 30;

function setSessionCookie(res: Response, token: string) {
  res.cookie('rd_session', token, {
    httpOnly: true,
    secure: process.env.NODE_ENV === 'production',
    sameSite: 'lax',
    maxAge: SESSION_DAYS * 24 * 60 * 60 * 1000
  });
}

async function createSession(customerId: number): Promise<string> {
  const token = crypto.randomBytes(32).toString('hex');
  const expiresAt = new Date(Date.now() + SESSION_DAYS * 24 * 60 * 60 * 1000);
  await pool.query(
    `INSERT INTO customer_sessions (token, customer_id, expires_at) VALUES ($1, $2, $3)`,
    [token, customerId, expiresAt]
  );
  return token;
}

function publicCustomer(c: any) {
  return {
    id: c.id,
    email: c.email,
    name: c.name,
    email_verified: c.email_verified,
    marketing_consent: c.marketing_consent,
    created_at: c.created_at
  };
}

router.post('/register', async (req: Request, res: Response) => {
  const { email, password, name, marketingConsent } = req.body;
  if (!email || !isValidEmail(String(email)) || !password || String(password).length < 8) {
    return res.status(400).json({ error: 'valid email and password (min 8 chars) required' });
  }
  const normalizedEmail = String(email).toLowerCase().trim();
  const { rows: existing } = await pool.query(`SELECT id FROM customers WHERE email = $1`, [normalizedEmail]);
  if (existing.length) return res.status(409).json({ error: 'an account with this email already exists' });

  const passwordHash = await bcrypt.hash(password, 12);
  const unsubscribeToken = crypto.randomBytes(16).toString('hex');
  const consent = !!marketingConsent;

  const { rows } = await pool.query(
    `INSERT INTO customers (email, password_hash, name, marketing_consent, marketing_consent_at, marketing_consent_text, unsubscribe_token)
     VALUES ($1, $2, $3, $4, $5, $6, $7) RETURNING *`,
    [
      normalizedEmail, passwordHash, name || null,
      consent, consent ? new Date() : null, consent ? MARKETING_CONSENT_TEXT : null,
      unsubscribeToken
    ]
  );
  const customer = rows[0];

  const verifyToken = crypto.randomBytes(24).toString('hex');
  await pool.query(
    `INSERT INTO customer_tokens (token, customer_id, kind, expires_at) VALUES ($1, $2, 'verify_email', $3)`,
    [verifyToken, customer.id, new Date(Date.now() + 24 * 60 * 60 * 1000)]
  );
  const verifyUrl = `${process.env.PUBLIC_URL}/verify-email?token=${verifyToken}`;
  sendMail(
    customer.email,
    'Verify your Redefined Designs account',
    `<p>Welcome! Please <a href="${verifyUrl}">verify your email</a> to finish setting up your account.</p>`
  ).catch(err => console.error('verify email send failed', err));

  const sessionToken = await createSession(customer.id);
  setSessionCookie(res, sessionToken);
  res.json(publicCustomer(customer));
});

router.post('/verify-email', async (req: Request, res: Response) => {
  const { token } = req.body;
  const { rows } = await pool.query(
    `SELECT * FROM customer_tokens WHERE token = $1 AND kind = 'verify_email' AND expires_at > now()`,
    [token]
  );
  if (!rows.length) return res.status(400).json({ error: 'invalid or expired token' });
  await pool.query(`UPDATE customers SET email_verified = true WHERE id = $1`, [rows[0].customer_id]);
  await pool.query(`DELETE FROM customer_tokens WHERE token = $1`, [token]);
  res.json({ status: 'verified' });
});

const RESET_TOKEN_TTL_MS = 60 * 60 * 1000;

// Always answers 200, whether or not the address has an account. A response
// that differed would let anyone test addresses for membership.
//
// Note /register still reveals existence via its 409 on a duplicate address,
// so this protection is currently partial — closing that is its own change.
router.post('/request-password-reset', passwordResetRequestLimiter, asyncRoute(async (req: Request, res: Response) => {
  const email = String(req.body?.email || '').toLowerCase().trim();
  if (!email || !isValidEmail(email)) {
    return res.status(400).json({ error: 'a valid email is required' });
  }

  const { rows } = await pool.query(`SELECT * FROM customers WHERE email = $1`, [email]);
  const customer = rows[0];

  if (customer) {
    // Supersede any outstanding token, so a link cannot be resurrected later
    // from an older message in the customer's inbox.
    await pool.query(`DELETE FROM customer_tokens WHERE customer_id = $1 AND kind = 'password_reset'`, [customer.id]);

    const token = crypto.randomBytes(32).toString('hex');
    await pool.query(
      `INSERT INTO customer_tokens (token, customer_id, kind, expires_at) VALUES ($1, $2, 'password_reset', $3)`,
      [token, customer.id, new Date(Date.now() + RESET_TOKEN_TTL_MS)]
    );

    const resetUrl = `${process.env.PUBLIC_URL}/reset-password?token=${token}`;
    sendMail(
      customer.email,
      'Reset your Redefined Designs password',
      `<p>Someone asked to reset the password for this account.</p>
       <p><a href="${resetUrl}">Choose a new password</a>. This link expires in one hour.</p>
       <p>If this wasn't you, you can ignore this email — your password has not changed.</p>`
    ).catch(err => console.error('password reset email send failed', err));
  }

  res.json({ status: 'sent' });
}));

// Deliberately not rate limited. The limiter above is keyed on the submitted
// email, which this endpoint does not carry, so reusing it would put every
// customer completing a reset into one shared bucket. Nor is a limit needed
// here: the token is 32 random bytes, single-use, and expires in an hour, and
// the expensive bcrypt hash only runs *after* the token has been matched, so
// invalid guesses cost a single indexed lookup.
router.post('/reset-password', asyncRoute(async (req: Request, res: Response) => {
  const { token, password } = req.body || {};
  if (!password || String(password).length < 8) {
    // Checked before the token is looked at, so a rejected attempt does not
    // consume the customer's only reset link.
    return res.status(400).json({ error: 'password must be at least 8 characters' });
  }

  const { rows } = await pool.query(
    `SELECT * FROM customer_tokens WHERE token = $1 AND kind = 'password_reset' AND expires_at > now()`,
    [token]
  );
  if (!rows.length) return res.status(400).json({ error: 'invalid or expired token' });
  const customerId = rows[0].customer_id;

  const passwordHash = await bcrypt.hash(String(password), 12);

  const client = await pool.connect();
  try {
    await client.query('BEGIN');
    await client.query(
      // The customer has demonstrably received mail at this address, which is
      // exactly what verification proves, so an unverified address becomes
      // verified here.
      `UPDATE customers SET password_hash = $1, email_verified = true WHERE id = $2`,
      [passwordHash, customerId]
    );
    // Every existing session goes, including any an attacker holds. Without
    // this, a reset prompted by a compromise leaves the intruder signed in for
    // up to 30 days.
    await client.query(`DELETE FROM customer_sessions WHERE customer_id = $1`, [customerId]);
    await client.query(`DELETE FROM customer_tokens WHERE customer_id = $1 AND kind = 'password_reset'`, [customerId]);
    await client.query('COMMIT');
  } catch (err) {
    await client.query('ROLLBACK');
    throw err;
  } finally {
    client.release();
  }

  const { rows: fresh } = await pool.query(`SELECT * FROM customers WHERE id = $1`, [customerId]);
  const sessionToken = await createSession(customerId);
  setSessionCookie(res, sessionToken);
  res.json(publicCustomer(fresh[0]));
}));

router.post('/login', async (req: Request, res: Response) => {
  const { email, password } = req.body;
  const { rows } = await pool.query(`SELECT * FROM customers WHERE email = $1`, [String(email || '').toLowerCase().trim()]);
  const customer = rows[0];
  if (!customer || !(await bcrypt.compare(password || '', customer.password_hash))) {
    return res.status(401).json({ error: 'invalid email or password' });
  }
  const sessionToken = await createSession(customer.id);
  setSessionCookie(res, sessionToken);
  res.json(publicCustomer(customer));
});

router.post('/logout', async (req: Request, res: Response) => {
  const token = req.cookies?.rd_session;
  if (token) await pool.query(`DELETE FROM customer_sessions WHERE token = $1`, [token]);
  res.clearCookie('rd_session');
  res.status(204).end();
});

router.get('/me', requireCustomer, async (req: Request, res: Response) => {
  const { rows } = await pool.query(`SELECT * FROM customers WHERE id = $1`, [req.customerId]);
  if (!rows.length) return res.status(404).json({ error: 'not found' });
  res.json(publicCustomer(rows[0]));
});

router.put('/me', requireCustomer, async (req: Request, res: Response) => {
  const { name } = req.body;
  const { rows } = await pool.query(
    `UPDATE customers SET name = $1 WHERE id = $2 RETURNING *`,
    [name || null, req.customerId]
  );
  res.json(publicCustomer(rows[0]));
});

router.post('/change-password', requireCustomer, async (req: Request, res: Response) => {
  const { currentPassword, newPassword } = req.body;
  if (!newPassword || String(newPassword).length < 8) {
    return res.status(400).json({ error: 'new password must be at least 8 characters' });
  }
  const { rows } = await pool.query(`SELECT * FROM customers WHERE id = $1`, [req.customerId]);
  const customer = rows[0];
  if (!(await bcrypt.compare(currentPassword || '', customer.password_hash))) {
    return res.status(401).json({ error: 'current password is incorrect' });
  }
  const newHash = await bcrypt.hash(newPassword, 12);
  await pool.query(`UPDATE customers SET password_hash = $1 WHERE id = $2`, [newHash, req.customerId]);
  res.status(204).end();
});

router.post('/me/consent', requireCustomer, async (req: Request, res: Response) => {
  const consent = !!req.body.marketingConsent;
  await pool.query(
    `UPDATE customers SET marketing_consent = $1, marketing_consent_at = now(), marketing_consent_text = $2 WHERE id = $3`,
    [consent, consent ? MARKETING_CONSENT_TEXT : 'Withdrew consent via account settings', req.customerId]
  );
  res.status(204).end();
});

router.get('/me/orders', requireCustomer, async (req: Request, res: Response) => {
  const { rows } = await pool.query(
    `SELECT o.id, o.processor, o.amount_cents, o.status, o.created_at, i.name AS item_name
     FROM orders o JOIN items i ON i.id = o.item_id
     WHERE o.customer_id = $1 ORDER BY o.created_at DESC`,
    [req.customerId]
  );
  res.json(rows);
});

router.get('/me/export', requireCustomer, async (req: Request, res: Response) => {
  const { rows: customerRows } = await pool.query(`SELECT * FROM customers WHERE id = $1`, [req.customerId]);
  const { rows: orderRows } = await pool.query(`SELECT * FROM orders WHERE customer_id = $1`, [req.customerId]);
  res.setHeader('Content-Disposition', 'attachment; filename="my-data.json"');
  res.json({
    customer: publicCustomer(customerRows[0]),
    orders: orderRows,
    exported_at: new Date().toISOString()
  });
});

router.delete('/me', requireCustomer, async (req: Request, res: Response) => {
  await pool.query(`UPDATE orders SET customer_id = NULL WHERE customer_id = $1`, [req.customerId]);
  await pool.query(`DELETE FROM customers WHERE id = $1`, [req.customerId]);
  res.clearCookie('rd_session');
  res.status(204).end();
});

export default router;