// api_v1/scanner/scanPhotoCartella.js

const scanCartella = require('./scanCartella');
const scanPhotoSingle = require('./scanPhotoSingle');
const { log } = require('./logger');

async function scanPhotoCartella(
  db,
  user,
  cartella,
  absCartella,
  newFiles,
  updateStatusFile,
  CURRENT,
  TOTAL_FILES,
  start,
  deleteThumbsById,
  deleteFromDB,
  onProgress
) {
  log(`📁 Scan cartella: ${cartella}`);
  let lastProgress = 0;

  // ---------------------------------------------------------
  // CARICA TUTTI I RECORD DELLA CARTELLA UNA SOLA VOLTA
  // ---------------------------------------------------------

  const rows = await db('photos')
    .where({ user, cartella })
    .select(
      'id',
      'size_bytes',
      'mtimeMs',
      'fast_hash',
      'path'
    );

  // Map: id -> record DB
  const photosMap = new Map(
    rows.map(row => [row.id, row])
  );

  // Manteniamo il Set per individuare gli orfani
  const idsSet = new Set(
    rows.map(row => row.id)
  );

  log(
    `📊 DB cartella=${cartella}: ${rows.length} record`
  );

  // ---------------------------------------------------------
  // SCANSIONE FILESYSTEM
  // ---------------------------------------------------------

  for await (
    const f of scanCartella(
      user,
      cartella,
      absCartella,
      db
    )
  ) {
    // Aggiorna contatore
    CURRENT.value++;

    // ---------------------------------------------------------
    // PROGRESS THROTTLED
    //
    // Evita una scrittura su disco per ogni singolo file.
    // Aggiorniamo al massimo ogni 500 ms.
    // ---------------------------------------------------------

    const now = Date.now();

    if (now - lastProgress >= 500) {
      lastProgress = now;

      if (updateStatusFile) {
        await updateStatusFile(
          CURRENT,
          TOTAL_FILES,
          start
        );
      }

      if (onProgress) {
        await onProgress();
      }
    }

    // Recupera il record DB dalla Map
    const prev = photosMap.get(f.id) || null;

    // Processa il file
    await scanPhotoSingle(
      db,
      user,
      cartella,
      f,
      newFiles,
      '',
      prev
    );

    // Il file esiste realmente nel filesystem:
    // quindi non è un orfano.
    idsSet.delete(f.id);
  }


  // ---------------------------------------------------------
  // ULTIMO AGGIORNAMENTO PROGRESS
  // ---------------------------------------------------------

  if (updateStatusFile) {
    await updateStatusFile(
      CURRENT,
      TOTAL_FILES,
      start
    );
  }

  if (onProgress) {
    await onProgress();
  }

  // ---------------------------------------------------------
  // GESTIONE ORFANI
  // ---------------------------------------------------------


  for (const orphanId of idsSet) {
    log(`🔴 Orfano: ${orphanId}`);

    await deleteThumbsById(orphanId);
    await deleteFromDB(orphanId, user);
  }
}

module.exports = scanPhotoCartella;