import express from 'express';
import db from '../config/database.js';
import { authenticateToken, authorize } from '../middleware/auth.js';

const router = express.Router();

// Get contractor rates
router.get('/', authenticateToken, async (req, res) => {
  try {
    const { contractorId, subDepartmentId } = req.query;
    
    let query = `
      SELECT cr.*, 
             u.name as contractor_name, u.username as contractor_username,
             sd.name as sub_department_name,
             d.name as department_name
      FROM contractor_rates cr
      JOIN users u ON cr.contractor_id = u.id
      LEFT JOIN sub_departments sd ON cr.sub_department_id = sd.id
      LEFT JOIN departments d ON sd.department_id = d.id
      WHERE 1=1
    `;
    const params = [];

    if (contractorId) {
      query += ' AND cr.contractor_id = ?';
      params.push(contractorId);
    }

    if (subDepartmentId) {
      query += ' AND cr.sub_department_id = ?';
      params.push(subDepartmentId);
    }

    query += ' ORDER BY cr.effective_date DESC, cr.created_at DESC';

    const [rates] = await db.query(query, params);
    res.json(rates);
  } catch (error) {
    console.error('Get contractor rates error:', error);
    res.status(500).json({ error: 'Internal server error' });
  }
});

// Get current rate for a contractor + sub-department combination
router.get('/contractor/:contractorId/current', authenticateToken, async (req, res) => {
  try {
    const { subDepartmentId } = req.query;
    
    let query = `
      SELECT cr.*, 
             u.name as contractor_name, u.username as contractor_username,
             sd.name as sub_department_name
      FROM contractor_rates cr
      JOIN users u ON cr.contractor_id = u.id
      LEFT JOIN sub_departments sd ON cr.sub_department_id = sd.id
      WHERE cr.contractor_id = ?
    `;
    const params = [req.params.contractorId];

    if (subDepartmentId) {
      query += ' AND cr.sub_department_id = ?';
      params.push(subDepartmentId);
    }

    query += ' ORDER BY cr.effective_date DESC LIMIT 1';

    const [rates] = await db.query(query, params);

    if (rates.length === 0) {
      return res.status(404).json({ error: 'No rate found for contractor' });
    }

    res.json(rates[0]);
  } catch (error) {
    console.error('Get current rate error:', error);
    res.status(500).json({ error: 'Internal server error' });
  }
});

// Set contractor rate (Supervisor or SuperAdmin)
router.post('/', authenticateToken, authorize('Supervisor', 'SuperAdmin'), async (req, res) => {
  try {
    const { contractorId, subDepartmentId, activity, rate, effectiveDate } = req.body;

    if (!contractorId || !rate || !effectiveDate) {
      return res.status(400).json({ error: 'Missing required fields (contractorId, rate, effectiveDate)' });
    }

    // Verify contractor exists
    const [contractors] = await db.query(
      'SELECT * FROM users WHERE id = ? AND role = ?',
      [contractorId, 'Contractor']
    );

    if (contractors.length === 0) {
      return res.status(404).json({ error: 'Contractor not found' });
    }

    // Supervisors can only set rates for contractors in their department
    if (req.user.role === 'Supervisor' && contractors[0].department_id !== req.user.departmentId) {
      return res.status(403).json({ error: 'Contractor not in your department' });
    }

    const [result] = await db.query(
      'INSERT INTO contractor_rates (contractor_id, sub_department_id, activity, rate, effective_date) VALUES (?, ?, ?, ?, ?)',
      [contractorId, subDepartmentId || null, activity || null, rate, effectiveDate]
    );

    const [newRate] = await db.query(
      `SELECT cr.*, 
              u.name as contractor_name, u.username as contractor_username,
              sd.name as sub_department_name
       FROM contractor_rates cr
       JOIN users u ON cr.contractor_id = u.id
       LEFT JOIN sub_departments sd ON cr.sub_department_id = sd.id
       WHERE cr.id = ?`,
      [result.insertId]
    );

    res.status(201).json(newRate[0]);
  } catch (error) {
    console.error('Set contractor rate error:', error);
    res.status(500).json({ error: 'Internal server error' });
  }
});

// Update contractor rate
router.put('/:id', authenticateToken, authorize('Supervisor', 'SuperAdmin'), async (req, res) => {
  try {
    const { rate, activity, effectiveDate } = req.body;

    const [existing] = await db.query('SELECT * FROM contractor_rates WHERE id = ?', [req.params.id]);
    
    if (existing.length === 0) {
      return res.status(404).json({ error: 'Rate not found' });
    }

    const updates = [];
    const params = [];

    if (rate !== undefined) {
      updates.push('rate = ?');
      params.push(rate);
    }
    if (activity !== undefined) {
      updates.push('activity = ?');
      params.push(activity);
    }
    if (effectiveDate !== undefined) {
      updates.push('effective_date = ?');
      params.push(effectiveDate);
    }

    if (updates.length === 0) {
      return res.status(400).json({ error: 'No fields to update' });
    }

    params.push(req.params.id);

    await db.query(`UPDATE contractor_rates SET ${updates.join(', ')} WHERE id = ?`, params);

    const [updatedRate] = await db.query(
      `SELECT cr.*, 
              u.name as contractor_name, u.username as contractor_username,
              sd.name as sub_department_name
       FROM contractor_rates cr
       JOIN users u ON cr.contractor_id = u.id
       LEFT JOIN sub_departments sd ON cr.sub_department_id = sd.id
       WHERE cr.id = ?`,
      [req.params.id]
    );

    res.json(updatedRate[0]);
  } catch (error) {
    console.error('Update contractor rate error:', error);
    res.status(500).json({ error: 'Internal server error' });
  }
});

// Delete contractor rate
router.delete('/:id', authenticateToken, authorize('Supervisor', 'SuperAdmin'), async (req, res) => {
  try {
    const [existing] = await db.query('SELECT * FROM contractor_rates WHERE id = ?', [req.params.id]);
    
    if (existing.length === 0) {
      return res.status(404).json({ error: 'Rate not found' });
    }

    await db.query('DELETE FROM contractor_rates WHERE id = ?', [req.params.id]);
    res.json({ message: 'Rate deleted successfully' });
  } catch (error) {
    console.error('Delete contractor rate error:', error);
    res.status(500).json({ error: 'Internal server error' });
  }
});

export default router;