const express = require('express');
const crypto = require('crypto');
const { requireRole } = require('../middleware/auth');
const {
  canReadUser,
  canUpdateUser,
  canManageUserStatus,
  canChangeUserEmail,
  canManageUserRoleOrTeam,
} = require('../policies/accessPolicy');

const USER_PUBLIC_FIELDS = 'id, tenant_id, team_id, name, email, slug, role, status, bio, avatar_url, sound_enabled, created_at';

const createUsersRouter = ({ pool, upload, transporter, getBaseUrl }) => {
  const router = express.Router();

  router.get('/users', async (req, res) => {
    try {
      const { tenantId } = req.query;
      const effectiveTenantId = req.user.role === 'super_admin' ? tenantId : req.user.tenant_id;

      let q = `SELECT ${USER_PUBLIC_FIELDS} FROM users`;
      const params = [];
      if (effectiveTenantId && effectiveTenantId !== 'all') {
        q += ' WHERE tenant_id = ?';
        params.push(effectiveTenantId);
      }

      if (req.user.role === 'manager') {
        if (req.user.team_id) {
          q += (params.length > 0 ? ' AND' : ' WHERE') + ' (team_id = ? OR id = ?)';
          params.push(req.user.team_id, req.user.id);
        } else {
          q += (params.length > 0 ? ' AND' : ' WHERE') + ' id = ?';
          params.push(req.user.id);
        }
      }

      const [rows] = await pool.query(q, params);
      res.json(rows);
    } catch (error) {
      res.status(500).json({ error: error.message });
    }
  });

  router.get('/users/:idOrSlug', async (req, res) => {
    try {
      const [rows] = await pool.query(`SELECT ${USER_PUBLIC_FIELDS} FROM users WHERE id = ? OR slug = ?`, [req.params.idOrSlug, req.params.idOrSlug]);
      if (!rows || rows.length === 0) return res.status(404).json({ error: 'Not found' });
      if (!req.user || !req.user.role) return res.status(401).json({ error: 'Não autenticado' });

      if (!canReadUser(req.user, rows[0])) return res.status(403).json({ error: 'Acesso negado.' });

      res.json(rows[0]);
    } catch (error) {
      console.error('Error in GET /users/:idOrSlug:', error);
      res.status(500).json({ error: error.message });
    }
  });

  router.post('/users', requireRole(['admin', 'manager', 'super_admin']), async (req, res) => {
    const { name, email, role, team_id, tenant_id } = req.body;
    const effectiveTenantId = req.user.role === 'super_admin' ? tenant_id : req.user.tenant_id;

    let finalRole = role || 'agent';
    let finalTeamId = team_id || null;

    if (req.user.role === 'manager') {
      if (!req.user.team_id) return res.status(403).json({ error: 'Gerente sem time não pode criar membros.' });
      finalRole = 'agent';
      finalTeamId = req.user.team_id;
    }
    try {
      const [existing] = await pool.query('SELECT id FROM users WHERE email = ?', [email]);
      if (existing.length > 0) return res.status(400).json({ error: 'E-mail já cadastrado.' });

      const uid = `u_${crypto.randomUUID().split('-')[0]}`;
      const slug = `${name.toLowerCase().replace(/[^a-z0-9]+/g, '-')}-${crypto.randomBytes(4).toString('hex')}`;
      const placeholderHash = 'pending_setup';

      await pool.query(
        'INSERT INTO users (id, tenant_id, team_id, name, email, password_hash, slug, role, status) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)',
        [uid, effectiveTenantId, finalTeamId, name, email, placeholderHash, slug, finalRole, 'active']
      );

      const token = crypto.randomBytes(32).toString('hex');
      await pool.query(
        'INSERT INTO password_resets (email, token, expires_at) VALUES (?, ?, DATE_ADD(NOW(), INTERVAL 15 MINUTE))',
        [email, token]
      );

      const setupLink = `${getBaseUrl(req)}/#/reset-password?token=${token}`;

      await transporter.sendMail({
        from: `"Fasto" <${process.env.MAIL_FROM || 'nao-responda@blyzer.com.br'}>`,
        to: email,
        subject: 'Bem-vindo ao Fasto - Finalize seu cadastro',
        html: `
          <div style="font-family: sans-serif; max-width: 600px; margin: 0 auto; padding: 20px; border: 1px solid #e2e8f0; border-radius: 12px; background: #ffffff; color: #0f172a;">
            <h2 style="color: #0f172a;">Olá, ${name}!</h2>
            <p style="color: #475569;">Você foi convidado para participar da equipe no Fasto.</p>
            <p style="color: #475569;">Clique no botão abaixo para definir sua senha e acessar sua conta:</p>
            <div style="text-align: center; margin: 30px 0;">
              <a href="${setupLink}" style="background-color: #0f172a; color: white; padding: 12px 24px; text-decoration: none; border-radius: 8px; font-weight: bold; display: inline-block;">Finalizar Cadastro</a>
            </div>
            <p style="font-size: 12px; color: #94a3b8;">Este link expira em 15 minutos. Se você não esperava este convite, ignore este e-mail.</p>
            <div style="border-top: 1px solid #f1f5f9; margin-top: 20px; padding-top: 20px; text-align: center;">
              <p style="font-size: 12px; color: #94a3b8;">Desenvolvido por <a href="https://blyzer.com.br" style="color: #3b82f6; text-decoration: none;">Blyzer</a></p>
            </div>
          </div>
        `
      });
      res.status(201).json({ id: uid, message: 'Convite enviado com sucesso.' });
    } catch (error) {
      console.error('Invite error:', error);
      res.status(500).json({ error: error.message });
    }
  });

  router.put('/users/:id', async (req, res) => {
    const { name, bio, role, team_id, status, email, sound_enabled } = req.body;
    try {
      const [existing] = await pool.query('SELECT * FROM users WHERE id = ?', [req.params.id]);
      if (existing.length === 0) return res.status(404).json({ error: 'Not found' });

      if (!canUpdateUser(req.user, existing[0])) return res.status(403).json({ error: 'Acesso negado.' });

      const finalRole = canManageUserRoleOrTeam(req.user) && role !== undefined ? role : existing[0].role;
      const finalTeamId = canManageUserRoleOrTeam(req.user) && team_id !== undefined ? team_id : existing[0].team_id;
      const finalStatus = canManageUserStatus(req.user) && status !== undefined ? status : existing[0].status;
      const finalEmail = canChangeUserEmail(req.user, existing[0]) && email !== undefined ? email : existing[0].email;
      const finalSoundEnabled = req.user.id === req.params.id && sound_enabled !== undefined ? sound_enabled : (existing[0].sound_enabled ?? true);

      if (finalEmail !== existing[0].email) {
        const [emailCheck] = await pool.query('SELECT id FROM users WHERE email = ? AND id != ?', [finalEmail, req.params.id]);
        if (emailCheck.length > 0) return res.status(400).json({ error: 'E-mail já está em uso.' });
      }

      await pool.query(
        'UPDATE users SET name = ?, bio = ?, email = ?, role = ?, team_id = ?, status = ?, sound_enabled = ? WHERE id = ?',
        [name || existing[0].name, bio !== undefined ? bio : existing[0].bio, finalEmail, finalRole, finalTeamId || null, finalStatus, finalSoundEnabled, req.params.id]
      );

      if (finalTeamId && finalTeamId !== existing[0].team_id && existing[0].status === 'active') {
        const [team] = await pool.query('SELECT name FROM teams WHERE id = ?', [finalTeamId]);
        if (team.length > 0) {
          await pool.query(
            'INSERT INTO notifications (id, user_id, type, title, message, link) VALUES (?, ?, ?, ?, ?, ?)',
            [crypto.randomUUID(), req.params.id, 'info', 'Novo Time', `Você foi adicionado ao time ${team[0].name}.`, '/']
          );
        }
      }

      res.json({ message: 'User updated successfully.' });
    } catch (error) {
      console.error('Update user error:', error);
      res.status(500).json({ error: error.message });
    }
  });

  router.delete('/users/:id', requireRole(['admin', 'super_admin']), async (req, res) => {
    try {
      const [existing] = await pool.query('SELECT tenant_id FROM users WHERE id = ?', [req.params.id]);
      if (existing.length === 0) return res.status(404).json({ error: 'Not found' });
      if (req.user.role !== 'super_admin' && existing[0].tenant_id !== req.user.tenant_id) {
        return res.status(403).json({ error: 'Acesso negado.' });
      }

      await pool.query('DELETE FROM users WHERE id = ?', [req.params.id]);
      res.json({ message: 'User deleted successfully.' });
    } catch (error) {
      console.error('Delete user error:', error);
      res.status(500).json({ error: error.message });
    }
  });

  router.post('/users/:id/avatar', upload.single('avatar'), async (req, res) => {
    try {
      if (!req.file) return res.status(400).json({ error: 'Nenhum arquivo enviado.' });

      if (req.user.id !== req.params.id && req.user.role !== 'super_admin') {
        return res.status(403).json({ error: 'Acesso negado.' });
      }

      const avatarUrl = `/uploads/${req.file.filename}`;
      await pool.query('UPDATE users SET avatar_url = ? WHERE id = ?', [avatarUrl, req.params.id]);

      res.json({ avatarUrl });
    } catch (error) {
      console.error('Avatar upload error:', error);
      res.status(500).json({ error: error.message });
    }
  });

  return router;
};

module.exports = { createUsersRouter };