const express = require('express');
const pool = require('../db');
const { authMiddleware } = require('../auth');

const router = express.Router();
router.use(authMiddleware);

const DEFAULT_CATEGORIES = [
  { value: 'eau', label: 'Eau', icon: '💧' },
  { value: 'gaz', label: 'Gaz', icon: '🔥' },
  { value: 'electricite', label: 'Électricité', icon: '⚡' },
  { value: 'entretien', label: 'Entretien / Réparations', icon: '🔧' },
  { value: 'ascenseur', label: 'Ascenseur', icon: '🛗' },
  { value: 'ordures', label: 'Ordures ménagères', icon: '🗑️' },
  { value: 'assurance', label: 'Assurance', icon: '🛡️' },
  { value: 'autre', label: 'Autre', icon: '📦' },
];

// Seed default categories for a user if none exist
async function ensureDefaults(userId) {
  const count = (await pool.query('SELECT COUNT(*) FROM charge_categories WHERE user_id = $1', [userId])).rows[0].count;
  if (parseInt(count) === 0) {
    for (let i = 0; i < DEFAULT_CATEGORIES.length; i++) {
      const c = DEFAULT_CATEGORIES[i];
      await pool.query(
        'INSERT INTO charge_categories (user_id, value, label, icon, sort_order) VALUES ($1, $2, $3, $4, $5)',
        [userId, c.value, c.label, c.icon, i]
      );
    }
  }
}

// GET /api/categories - List all categories for user
router.get('/', async (req, res) => {
  await ensureDefaults(req.userId);
  const rows = (await pool.query(
    'SELECT * FROM charge_categories WHERE user_id = $1 ORDER BY sort_order, id',
    [req.userId]
  )).rows;
  res.json(rows);
});

// POST /api/categories - Create a new category
router.post('/', async (req, res) => {
  const { value, label, icon } = req.body;
  if (!value || !label) return res.status(400).json({ error: 'Valeur et libellé requis' });

  // Check uniqueness
  const existing = (await pool.query(
    'SELECT id FROM charge_categories WHERE user_id = $1 AND value = $2',
    [req.userId, value]
  )).rows[0];
  if (existing) return res.status(400).json({ error: 'Cette valeur existe déjà' });

  const maxOrder = (await pool.query(
    'SELECT COALESCE(MAX(sort_order), 0) + 1 as next FROM charge_categories WHERE user_id = $1',
    [req.userId]
  )).rows[0].next;

  const result = await pool.query(
    'INSERT INTO charge_categories (user_id, value, label, icon, sort_order) VALUES ($1, $2, $3, $4, $5) RETURNING *',
    [req.userId, value, label, icon || '📦', maxOrder]
  );
  res.status(201).json(result.rows[0]);
});

// PUT /api/categories/reorder - Reorder categories (must be before /:id)
router.put('/reorder', async (req, res) => {
  const { order } = req.body;
  if (!Array.isArray(order)) return res.status(400).json({ error: 'Tableau d\'ordre requis' });

  for (let i = 0; i < order.length; i++) {
    await pool.query(
      'UPDATE charge_categories SET sort_order = $1 WHERE id = $2 AND user_id = $3',
      [i, order[i], req.userId]
    );
  }
  res.json({ success: true });
});

// PUT /api/categories/:id - Update a category
router.put('/:id', async (req, res) => {
  const { label, icon } = req.body;
  const cat = (await pool.query(
    'SELECT id FROM charge_categories WHERE id = $1 AND user_id = $2',
    [req.params.id, req.userId]
  )).rows[0];
  if (!cat) return res.status(404).json({ error: 'Catégorie non trouvée' });

  await pool.query(
    'UPDATE charge_categories SET label = $1, icon = $2 WHERE id = $3',
    [label, icon || '📦', req.params.id]
  );
  res.json({ success: true });
});

// DELETE /api/categories/:id - Delete a category
router.delete('/:id', async (req, res) => {
  const cat = (await pool.query(
    'SELECT * FROM charge_categories WHERE id = $1 AND user_id = $2',
    [req.params.id, req.userId]
  )).rows[0];
  if (!cat) return res.status(404).json({ error: 'Catégorie non trouvée' });

  // Check if category is in use
  const inUse = (await pool.query(
    'SELECT COUNT(*) FROM charges WHERE user_id = $1 AND category = $2',
    [req.userId, cat.value]
  )).rows[0].count;
  if (parseInt(inUse) > 0) {
    return res.status(400).json({ error: `Impossible de supprimer : ${inUse} charge(s) utilisent cette catégorie` });
  }

  await pool.query('DELETE FROM charge_categories WHERE id = $1', [req.params.id]);
  res.json({ success: true });
});

module.exports = router;