// routes/scanStatus.js
const express = require('express');
const router = express.Router();

const path = require('path');
const fsp = require('fs/promises');

const photosStatusPath = path.resolve(__dirname, '..', 'public/photos/scan_status.json');
const activitiesStatusPath = path.resolve(__dirname, '..', 'public/activities/scan_status.json');

async function readJsonWithRetry(filePath) {
  for (let i = 0; i < 3; i++) {
    try {
      const raw = await fsp.readFile(filePath, 'utf8');
      return JSON.parse(raw);
    } catch (err) {
      if (i === 2) throw err;
      await new Promise(resolve => setTimeout(resolve, 30));
    }
  }
}

router.get('/photos', async (req, res) => {
  try {
    res.setHeader('Cache-Control', 'no-store, no-cache, must-revalidate, proxy-revalidate');
    res.setHeader('Pragma', 'no-cache');
    res.setHeader('Expires', '0');

    const data = await readJsonWithRetry(photosStatusPath);
    res.json(data);
  } catch (err) {
    res.status(200).json({
      current: 0,
      total: 0,
      percent: 0,
      eta: 'calcolo...',
      error: err.message
    });
  }
});

router.get('/activities', async (req, res) => {
  try {
    res.setHeader('Cache-Control', 'no-store, no-cache, must-revalidate, proxy-revalidate');
    res.setHeader('Pragma', 'no-cache');
    res.setHeader('Expires', '0');

    const data = await readJsonWithRetry(activitiesStatusPath);
    res.json(data);
  } catch (err) {
    res.status(200).json({
      current: 0,
      total: 0,
      percent: 0,
      eta: 'calcolo...',
      error: err.message
    });
  }
});

module.exports = router;