// scanner/scanPhoto.js
const path = require('path');
const fs = require('fs');
const fsp = require('fs/promises');

const { loadPreviousIndex, saveIndex } = require('./indexStore');
const scanCartella = require('./scanCartella');
const postWithAuth = require('./postWithAuth');

const {
  WEB_ROOT,
  SEND_PHOTOS,
  BASE_URL,
  WRITE_INDEX
} = require('../config');

const createCleanupFunctions = require('./orphanCleanup');

async function scanPhoto(dir, userName, db) {
  console.log(`[SCAN] Avvio scanPhoto per user=${userName}`);

  // Log di configurazione (utile per diagnosi)
  console.log('[SCAN] Config:', {
    WEB_ROOT,
    SEND_PHOTOS,
    BASE_URL,
    WRITE_INDEX
  });

  // 1) Carico l’indice precedente (fonte unica durante la run)
  const previousIndexTree = await loadPreviousIndex(); // <— RAM source
  // 2) Clono l’indice per costruire il nuovo
  const nextIndexTree = JSON.parse(JSON.stringify(previousIndexTree || {}));

  // Funzioni di cleanup (solo thumbs + DB)
  // NOTA: con Opzione A NON leggiamo più l'indice da file e NON aggiorniamo index.json "in itinere"
  const {
    // buildIdsListForFolder,  // <— NON usato in Opzione A
    removeIdFromList,
    deleteThumbsById,
    deleteFromDB
    // deleteFromIndexById     // <— NON usato in Opzione A
  } = createCleanupFunctions(db); // [1](https://electrolux-my.sharepoint.com/personal/fabio_micheluz_electrolux_com/Documents/File%20di%20Microsoft%20Copilot%20Chat/orphanCleanup.js.txt)

  const photosRoot = path.resolve(__dirname, '..', '..', WEB_ROOT, 'photos');
  const userDir = path.join(photosRoot, userName, 'original');

  let changes = [];

  // ---------------------------------------------------------
  // SCAN DI UNA SINGOLA CARTELLA
  // ---------------------------------------------------------
  async function scanSingleFolder(user, cartella, absCartella) {
    console.log(`\n==============================================`);
    console.log(`[SCAN] CARTELLA → ${user}/${cartella}`);
    console.log("==============================================");

    // Costruisci idsIndex dall'indice in RAM (previousIndexTree)
    // Fonte unica di verità per questa run → evita drift con il file su disco.
    let idsIndex = Object.keys(previousIndexTree?.[user]?.[cartella] || {})
      .filter(k => k !== '_folderHash'); // <— niente metadati
    console.log(`[ORPHAN] ID iniziali in RAM (${idsIndex.length}):`);
    idsIndex.forEach(id => console.log(" -", id));

    // File reali trovati nella cartella
    const folderFiles = await scanCartella(
      user,
      cartella,
      absCartella,
      previousIndexTree
    ); // [2](https://electrolux-my.sharepoint.com/personal/fabio_micheluz_electrolux_com/Documents/File%20di%20Microsoft%20Copilot%20Chat/scanCartella.js.txt)

    for (const m of folderFiles) {
      const prev = previousIndexTree?.[m.user]?.[m.cartella]?.[m.id];

      // 🔥 FILE INVARIATO
      if (prev && prev.hash === m._indexHash) {
        console.log(`[SCAN] SKIP (unchanged) → ${m.path}`);
        // Rimuovo SOLO dalla lista orfani (dalla RAM)
        idsIndex = removeIdFromList(idsIndex, m.id); // [1](https://electrolux-my.sharepoint.com/personal/fabio_micheluz_electrolux_com/Documents/File%20di%20Microsoft%20Copilot%20Chat/orphanCleanup.js.txt)
        continue;
      }

      // 🔥 FILE NUOVO O MODIFICATO → aggiorno nextIndexTree
      nextIndexTree[m.user] ??= {};
      nextIndexTree[m.user][m.cartella] ??= {};
      nextIndexTree[m.user][m.cartella][m.id] = {
        id: m.id,
        user: m.user,
        cartella: m.cartella,
        path: m.path,
        hash: m._indexHash
      };

      // Rimuovo dalla lista orfani (in RAM)
      idsIndex = removeIdFromList(idsIndex, m.id); // [1](https://electrolux-my.sharepoint.com/personal/fabio_micheluz_electrolux_com/Documents/File%20di%20Microsoft%20Copilot%20Chat/orphanCleanup.js.txt)
      changes.push(m);
    }

    // ---------------------------------------------------------
    // ORFANI → rimuovo SOLO da nextIndexTree + thumbs + DB
    // ---------------------------------------------------------
    if (idsIndex.length > 0) {
      console.log(`[ORPHAN] ID orfani trovati nella cartella ${cartella}:`);
      idsIndex.forEach(id => console.log(" -", id));
    } else {
      console.log(`[ORPHAN] Nessun ID orfano nella cartella ${cartella}`);
    }

    for (const orphanId of idsIndex) {
      console.log(`\n[ORPHAN] Eliminazione ID → ${orphanId}`);

      // 1) Cancello thumbs
      const thumbsDeleted = await deleteThumbsById(orphanId); // [1](https://electrolux-my.sharepoint.com/personal/fabio_micheluz_electrolux_com/Documents/File%20di%20Microsoft%20Copilot%20Chat/orphanCleanup.js.txt)
      console.log(` → thumbsDeleted = ${thumbsDeleted}`);

      // 2) Cancello dal DB
      const dbDeleted = deleteFromDB(orphanId); // [1](https://electrolux-my.sharepoint.com/personal/fabio_micheluz_electrolux_com/Documents/File%20di%20Microsoft%20Copilot%20Chat/orphanCleanup.js.txt)
      console.log(` → dbDeleted = ${dbDeleted}`);

      // 3) Cancello SOLO da nextIndexTree (in RAM)
      const userTree = nextIndexTree[user];
      if (userTree && userTree[cartella] && userTree[cartella][orphanId]) {
        delete userTree[cartella][orphanId];
        console.log(` → nextIndexTree updated (removed ${orphanId})`);
      }

      console.log(`[ORPHAN] COMPLETATO → ${orphanId}`);
    }

    console.log(`==============================================\n`);
  }

  // ---------------------------------------------------------
  // SCAN SOLO SOTTOCARTELLE — niente _root
  // ---------------------------------------------------------
  let entries = [];
  try {
    entries = await fsp.readdir(userDir, { withFileTypes: true });
  } catch {
    console.log(`[SCAN] Nessuna directory per utente ${userName}`);
    return [];
  }

  for (const e of entries) {
    if (!e.isDirectory()) continue;
    const cartella = e.name;
    const absCartella = path.join(userDir, cartella);
    await scanSingleFolder(userName, cartella, absCartella);
  }

  // ---------------------------------------------------------
  // SALVO SOLO nextIndexTree (scrittura unica a fine run)
  // ---------------------------------------------------------
  if (WRITE_INDEX) {
    await saveIndex(nextIndexTree); // [1](https://electrolux-my.sharepoint.com/personal/fabio_micheluz_electrolux_com/Documents/File%20di%20Microsoft%20Copilot%20Chat/orphanCleanup.js.txt)
  }

  // ---------------------------------------------------------
  // INVIO AL SERVER
  // ---------------------------------------------------------
  if (SEND_PHOTOS && BASE_URL && changes.length) {
    for (const p of changes) {
      try {
        await postWithAuth(`${BASE_URL}/photos`, p);
      } catch (err) {
        console.error('Errore invio:', err.message);
      }
    }
  }

  console.log(`SCAN COMPLETATA: ${changes.length} file aggiornati`);
  return changes;
}

module.exports = scanPhoto;