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

// Get all budget items for an event
router.get('/event/:eventId', authMiddleware, async (req, res) => {
  try {
    const result = await pool.query(
      `SELECT b.* FROM budget_items b
       JOIN events e ON b.event_id = e.id
       WHERE b.event_id = $1 AND e.user_id = $2
       ORDER BY b.category, b.created_at ASC`,
      [req.params.eventId, req.userId]
    );
    res.json(result.rows);
  } catch (err) {
    console.error(err);
    res.status(500).json({ error: 'Server error' });
  }
});

// Get budget summary for event
router.get('/event/:eventId/summary', authMiddleware, async (req, res) => {
  try {
    const [itemsRes, eventRes] = await Promise.all([
      pool.query(
        `SELECT category,
                SUM(estimated_cost) as estimated,
                SUM(COALESCE(actual_cost, 0)) as actual,
                COUNT(*) as count
         FROM budget_items b
         JOIN events e ON b.event_id = e.id
         WHERE b.event_id = $1 AND e.user_id = $2
         GROUP BY category`,
        [req.params.eventId, req.userId]
      ),
      pool.query('SELECT budget FROM events WHERE id=$1 AND user_id=$2', [req.params.eventId, req.userId]),
    ]);
    const totalEstimated = itemsRes.rows.reduce((s, r) => s + parseFloat(r.estimated || 0), 0);
    const totalActual = itemsRes.rows.reduce((s, r) => s + parseFloat(r.actual || 0), 0);
    const eventBudget = eventRes.rows[0]?.budget || 0;
    res.json({
      event_budget: parseFloat(eventBudget),
      total_estimated: totalEstimated,
      total_actual: totalActual,
      remaining_budget: parseFloat(eventBudget) - totalEstimated,
      over_budget: totalEstimated > parseFloat(eventBudget),
      categories: itemsRes.rows,
    });
  } catch (err) {
    console.error(err);
    res.status(500).json({ error: 'Server error' });
  }
});

// Create budget item
router.post('/', authMiddleware, async (req, res) => {
  const { event_id, category, description, estimated_cost, actual_cost, status } = req.body;
  if (!event_id || !category) return res.status(400).json({ error: 'event_id and category are required' });
  try {
    const eventCheck = await pool.query('SELECT id FROM events WHERE id=$1 AND user_id=$2', [event_id, req.userId]);
    if (eventCheck.rows.length === 0) return res.status(403).json({ error: 'Forbidden' });

    const result = await pool.query(
      `INSERT INTO budget_items (event_id, category, description, estimated_cost, actual_cost, status)
       VALUES ($1, $2, $3, $4, $5, $6) RETURNING *`,
      [event_id, category, description, estimated_cost || 0, actual_cost, status || 'planned']
    );
    res.status(201).json(result.rows[0]);
  } catch (err) {
    console.error(err);
    res.status(500).json({ error: 'Server error' });
  }
});

// Update budget item
router.put('/:id', authMiddleware, async (req, res) => {
  const { category, description, estimated_cost, actual_cost, status } = req.body;
  try {
    const result = await pool.query(
      `UPDATE budget_items SET category=$1, description=$2, estimated_cost=$3, actual_cost=$4, status=$5
       WHERE id=$6 AND event_id IN (SELECT id FROM events WHERE user_id=$7) RETURNING *`,
      [category, description, estimated_cost, actual_cost, status, req.params.id, req.userId]
    );
    if (result.rows.length === 0) return res.status(404).json({ error: 'Budget item not found' });
    res.json(result.rows[0]);
  } catch (err) {
    console.error(err);
    res.status(500).json({ error: 'Server error' });
  }
});

// Delete budget item
router.delete('/:id', authMiddleware, async (req, res) => {
  try {
    const result = await pool.query(
      `DELETE FROM budget_items WHERE id=$1 AND event_id IN (SELECT id FROM events WHERE user_id=$2) RETURNING id`,
      [req.params.id, req.userId]
    );
    if (result.rows.length === 0) return res.status(404).json({ error: 'Budget item not found' });
    res.json({ message: 'Budget item deleted' });
  } catch (err) {
    console.error(err);
    res.status(500).json({ error: 'Server error' });
  }
});

module.exports = router;