const express = require('express');
const cors = require('cors');
const rateLimit = require('express-rate-limit');
const Database = require('better-sqlite3');
const path = require('path');

const app = express();
const PORT = process.env.PORT || 3001;

app.use(cors());
app.use(express.json());

// Apply rate limiting to all API routes
const apiLimiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 300, // limit each IP to 300 requests per windowMs
  standardHeaders: true,
  legacyHeaders: false,
  message: { error: 'リクエストが多すぎます。しばらくしてから再試行してください。' },
});
app.use('/api', apiLimiter);

const dbPath = path.join(__dirname, 'data.db');
const db = new Database(dbPath);

// Initialize database schema
db.exec(`
  CREATE TABLE IF NOT EXISTS cars (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    name TEXT NOT NULL,
    description TEXT DEFAULT ''
  );

  CREATE TABLE IF NOT EXISTS reservations (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    car_id INTEGER NOT NULL,
    start_date TEXT NOT NULL,
    end_date TEXT NOT NULL,
    customer_name TEXT DEFAULT '',
    notes TEXT DEFAULT '',
    FOREIGN KEY (car_id) REFERENCES cars(id) ON DELETE CASCADE
  );
`);

// Seed some initial cars if none exist
const carCount = db.prepare('SELECT COUNT(*) as cnt FROM cars').get();
if (carCount.cnt === 0) {
  const insertCar = db.prepare('INSERT INTO cars (name, description) VALUES (?, ?)');
  insertCar.run('代車 A', '');
  insertCar.run('代車 B', '');
  insertCar.run('代車 C', '');
}

// --- Cars API ---
app.get('/api/cars', (req, res) => {
  const cars = db.prepare('SELECT * FROM cars ORDER BY id').all();
  res.json(cars);
});

app.post('/api/cars', (req, res) => {
  const { name, description = '' } = req.body;
  if (!name || !name.trim()) {
    return res.status(400).json({ error: '車名は必須です' });
  }
  const result = db.prepare('INSERT INTO cars (name, description) VALUES (?, ?)').run(name.trim(), description);
  const car = db.prepare('SELECT * FROM cars WHERE id = ?').get(result.lastInsertRowid);
  res.status(201).json(car);
});

app.put('/api/cars/:id', (req, res) => {
  const { name, description } = req.body;
  if (!name || !name.trim()) {
    return res.status(400).json({ error: '車名は必須です' });
  }
  const result = db.prepare('UPDATE cars SET name = ?, description = ? WHERE id = ?').run(name.trim(), description ?? '', req.params.id);
  if (result.changes === 0) {
    return res.status(404).json({ error: '車が見つかりません' });
  }
  const car = db.prepare('SELECT * FROM cars WHERE id = ?').get(req.params.id);
  res.json(car);
});

app.delete('/api/cars/:id', (req, res) => {
  const result = db.prepare('DELETE FROM cars WHERE id = ?').run(req.params.id);
  if (result.changes === 0) {
    return res.status(404).json({ error: '車が見つかりません' });
  }
  res.json({ success: true });
});

// --- Reservations API ---
app.get('/api/reservations', (req, res) => {
  const reservations = db.prepare('SELECT * FROM reservations ORDER BY start_date').all();
  res.json(reservations);
});

app.post('/api/reservations', (req, res) => {
  const { car_id, start_date, end_date, customer_name = '', notes = '' } = req.body;
  if (!car_id || !start_date || !end_date) {
    return res.status(400).json({ error: 'car_id, start_date, end_date は必須です' });
  }
  if (start_date > end_date) {
    return res.status(400).json({ error: '開始日は終了日以前である必要があります' });
  }
  const result = db.prepare(
    'INSERT INTO reservations (car_id, start_date, end_date, customer_name, notes) VALUES (?, ?, ?, ?, ?)'
  ).run(car_id, start_date, end_date, customer_name, notes);
  const reservation = db.prepare('SELECT * FROM reservations WHERE id = ?').get(result.lastInsertRowid);
  res.status(201).json(reservation);
});

app.put('/api/reservations/:id', (req, res) => {
  const { car_id, start_date, end_date, customer_name, notes } = req.body;
  if (!car_id || !start_date || !end_date) {
    return res.status(400).json({ error: 'car_id, start_date, end_date は必須です' });
  }
  if (start_date > end_date) {
    return res.status(400).json({ error: '開始日は終了日以前である必要があります' });
  }
  const result = db.prepare(
    'UPDATE reservations SET car_id = ?, start_date = ?, end_date = ?, customer_name = ?, notes = ? WHERE id = ?'
  ).run(car_id, start_date, end_date, customer_name ?? '', notes ?? '', req.params.id);
  if (result.changes === 0) {
    return res.status(404).json({ error: '予約が見つかりません' });
  }
  const reservation = db.prepare('SELECT * FROM reservations WHERE id = ?').get(req.params.id);
  res.json(reservation);
});

app.delete('/api/reservations/:id', (req, res) => {
  const result = db.prepare('DELETE FROM reservations WHERE id = ?').run(req.params.id);
  if (result.changes === 0) {
    return res.status(404).json({ error: '予約が見つかりません' });
  }
  res.json({ success: true });
});

app.listen(PORT, () => {
  console.log(`Server running on http://localhost:${PORT}`);
});