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

const CONFIG_KEYS = [
  'paycheck1_day',
  'paycheck2_day',
  'paycheck1_gross',
  'paycheck1_net',
  'paycheck2_gross',
  'paycheck2_net',
];

const DEFAULTS = {
  paycheck1_day: 1,
  paycheck2_day: 15,
};

async function getAllConfig() {
  const result = await pool.query(
    'SELECT key, value FROM config WHERE key = ANY($1)',
    [CONFIG_KEYS]
  );

  const map = {};
  for (const row of result.rows) {
    map[row.key] = row.value;
  }

  const config = {};
  for (const key of CONFIG_KEYS) {
    const raw = map[key] !== undefined ? map[key] : (DEFAULTS[key] !== undefined ? String(DEFAULTS[key]) : null);
    config[key] = raw !== null ? Number(raw) : null;
  }

  return config;
}

router.get('/config', async (req, res) => {
  try {
    const config = await getAllConfig();
    res.json(config);
  } catch (err) {
    console.error('GET /api/config error:', err);
    res.status(500).json({ error: 'Failed to fetch config' });
  }
});

router.put('/config', async (req, res) => {
  try {
    const updates = req.body;
    const validKeys = Object.keys(updates).filter((k) => CONFIG_KEYS.includes(k));

    if (validKeys.length > 0) {
      const client = await pool.connect();
      try {
        await client.query('BEGIN');
        for (const key of validKeys) {
          await client.query(
            `INSERT INTO config (key, value) VALUES ($1, $2)
             ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value`,
            [key, String(updates[key])]
          );
        }
        await client.query('COMMIT');
      } catch (err) {
        await client.query('ROLLBACK');
        throw err;
      } finally {
        client.release();
      }
    }

    const config = await getAllConfig();
    res.json(config);
  } catch (err) {
    console.error('PUT /api/config error:', err);
    res.status(500).json({ error: 'Failed to update config' });
  }
});

module.exports = router;