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

const router = express.Router();

// IRL France entière — série INSEE 001515333
const IRL_SERIES = '001515333';

async function fetchIrlFromInsee(year, quarter) {
  const period = `${year}-Q${quarter}`;
  const url = `https://api.insee.fr/series/BDM/V1/data/SERIES_BDM/${IRL_SERIES}?startPeriod=${period}&endPeriod=${period}`;

  const resp = await fetch(url, {
    headers: { 'Accept': 'application/xml' },
  });

  if (!resp.ok) throw new Error(`INSEE API HTTP ${resp.status}`);

  const xml = await resp.text();

  // SDMX-XML : extraire <generic:ObsValue value="142.06"/>
  const match = xml.match(/ObsValue[^/]*value="([\d.]+)"/);
  if (!match) throw new Error('Valeur IRL introuvable dans la réponse XML');

  return parseFloat(match[1]);
}

// GET /api/irl?year=2024&quarter=2
router.get('/', authMiddleware, async (req, res) => {
  const { year, quarter } = req.query;
  if (!year || !quarter) return res.status(400).json({ error: 'year et quarter requis' });

  try {
    const value = await fetchIrlFromInsee(parseInt(year), parseInt(quarter));
    res.json({ value, year: parseInt(year), quarter: parseInt(quarter) });
  } catch (e) {
    console.error('IRL fetch error:', e.message);
    res.status(502).json({ value: null, error: e.message });
  }
});

module.exports = router;