const express = require('express');
const router = express.Router();
const { Users } = require('../models');

router.get('/login', (req, res) => {
  res.render('auth/login', { title: 'Login', error: null });
});

router.post('/login', (req, res) => {
  const { username, password } = req.body;

  if (!username || !password) {
    return res.render('auth/login', { title: 'Login', error: 'Username and password are required.' });
  }

  const user = Users.findByUsername(username);
  if (!user || !Users.verifyPassword(user, password)) {
    return res.render('auth/login', { title: 'Login', error: 'Invalid username or password.' });
  }

  req.session.userId = user.id;
  req.session.username = user.username;
  req.session.displayName = user.display_name || user.username;
  req.session.isAdmin = !!user.is_admin;
  req.session.isOrganizer = !!user.is_organizer;

  const returnTo = req.session.returnTo || '/';
  delete req.session.returnTo;
  res.redirect(returnTo);
});

router.get('/register', (req, res) => {
  res.render('auth/register', { title: 'Register', error: null });
});

router.post('/register', (req, res) => {
  const { username, password, password_confirm } = req.body;

  if (!username || !password) {
    return res.render('auth/register', { title: 'Register', error: 'Username and password are required.' });
  }

  if (username.length < 3 || username.length > 24) {
    return res.render('auth/register', { title: 'Register', error: 'Username must be 3-24 characters.' });
  }

  if (!/^[a-zA-Z0-9_-]+$/.test(username)) {
    return res.render('auth/register', { title: 'Register', error: 'Username can only contain letters, numbers, hyphens and underscores.' });
  }

  if (password.length < 6) {
    return res.render('auth/register', { title: 'Register', error: 'Password must be at least 6 characters.' });
  }

  if (password !== password_confirm) {
    return res.render('auth/register', { title: 'Register', error: 'Passwords do not match.' });
  }

  if (Users.findByUsername(username)) {
    return res.render('auth/register', { title: 'Register', error: 'Username is already taken.' });
  }

  try {
    const userId = Users.create(username, password);
    req.session.userId = userId;
    req.session.username = username;
    req.session.displayName = username;
    req.session.isAdmin = false;
    req.session.isOrganizer = false;
    req.session.flash = { type: 'success', message: 'Account created! Welcome to Loot Hunt.' };

    const returnTo = req.session.returnTo || '/';
    delete req.session.returnTo;
    res.redirect(returnTo);
  } catch (err) {
    console.error('Registration error:', err);
    res.render('auth/register', { title: 'Register', error: 'Registration failed. Try a different username.' });
  }
});

router.get('/logout', (req, res) => {
  req.session.destroy(() => {
    res.redirect('/');
  });
});

// ─── Password reset (via admin-generated URL) ────────────
router.get('/reset/:token', (req, res) => {
  const tokenRecord = Users.findByResetToken(req.params.token);
  if (!tokenRecord) {
    return res.render('error', { title: 'Invalid Link', message: 'This password reset link is invalid or has expired.' });
  }
  res.render('auth/reset', { title: 'Reset Password', token: req.params.token, username: tokenRecord.username, error: null });
});

router.post('/reset/:token', (req, res) => {
  const tokenRecord = Users.findByResetToken(req.params.token);
  if (!tokenRecord) {
    return res.render('error', { title: 'Invalid Link', message: 'This password reset link is invalid or has expired.' });
  }

  const { password, password_confirm } = req.body;

  if (!password || password.length < 6) {
    return res.render('auth/reset', { title: 'Reset Password', token: req.params.token, username: tokenRecord.username, error: 'Password must be at least 6 characters.' });
  }

  if (password !== password_confirm) {
    return res.render('auth/reset', { title: 'Reset Password', token: req.params.token, username: tokenRecord.username, error: 'Passwords do not match.' });
  }

  Users.setPassword(tokenRecord.user_id, password);
  Users.consumeResetToken(req.params.token);

  // Log the user in
  req.session.userId = tokenRecord.user_id;
  req.session.username = tokenRecord.username;
  req.session.displayName = tokenRecord.username;
  req.session.isAdmin = false; // they can re-check on next load
  res.redirect('/');
});

module.exports = router;