const express = require('express');
const { Pool } = require('pg');
const path = require('path');

const app = express();
app.use(express.json());
app.use(express.static(path.join(__dirname, 'public')));

const pool = new Pool({
  connectionString: process.env.DATABASE_URL,
});

async function initDB() {
  const client = await pool.connect();
  try {
    await client.query(`
      CREATE TABLE IF NOT EXISTS todos (
        id SERIAL PRIMARY KEY,
        text TEXT NOT NULL,
        done BOOLEAN NOT NULL DEFAULT false,
        created_at TIMESTAMP NOT NULL DEFAULT NOW()
      )
    `);
    console.log('Database table ready');
  } finally {
    client.release();
  }
}

// GET /api/todos
app.get('/api/todos', async (req, res) => {
  try {
    const { rows } = await pool.query('SELECT * FROM todos ORDER BY created_at DESC');
    res.json(rows);
  } catch (err) {
    console.error(err);
    res.status(500).json({ error: 'Failed to fetch todos' });
  }
});

// POST /api/todos
app.post('/api/todos', async (req, res) => {
  const { text } = req.body;
  if (!text || typeof text !== 'string' || !text.trim()) {
    return res.status(400).json({ error: '"text" is required' });
  }
  try {
    const { rows } = await pool.query(
      'INSERT INTO todos (text) VALUES ($1) RETURNING *',
      [text.trim()]
    );
    res.status(201).json(rows[0]);
  } catch (err) {
    console.error(err);
    res.status(500).json({ error: 'Failed to create todo' });
  }
});

// PUT /api/todos/:id/toggle
app.put('/api/todos/:id/toggle', async (req, res) => {
  try {
    const { rows } = await pool.query(
      'UPDATE todos SET done = NOT done WHERE id = $1 RETURNING *',
      [req.params.id]
    );
    if (rows.length === 0) return res.status(404).json({ error: 'Todo not found' });
    res.json(rows[0]);
  } catch (err) {
    console.error(err);
    res.status(500).json({ error: 'Failed to toggle todo' });
  }
});

// DELETE /api/todos/:id
app.delete('/api/todos/:id', async (req, res) => {
  try {
    const { rowCount } = await pool.query('DELETE FROM todos WHERE id = $1', [req.params.id]);
    if (rowCount === 0) return res.status(404).json({ error: 'Todo not found' });
    res.json({ message: 'Todo deleted' });
  } catch (err) {
    console.error(err);
    res.status(500).json({ error: 'Failed to delete todo' });
  }
});

initDB().then(() => {
  const PORT = process.env.PORT || 3000;
  app.listen(PORT, () => console.log(`Server running on port ${PORT}`));
});