// scanner/scanUser.js
const path = require('path');
const fsp = require('fs/promises');
const scanCartella = require('./scanCartella');
const processFile = require('./processFile');
const { sha256 } = require('./utils');
const { SUPPORTED_EXTS } = require('../config');

/**
 * Scansiona la root dell'utente (p.es. .../<user>/original) e:
 *  - indicizza i file direttamente al root (cartella virtuale "_root")
 *  - per ogni sottocartella, chiama scanCartella
 */
async function scanUserRoot(userName, userDir, previousIndex) {
  const results = [];
  const entries = await fsp.readdir(userDir, { withFileTypes: true });

  // 1) File direttamente al root (virtual folder "_root")
  for (const e of entries) {
    if (e.isDirectory()) continue;

    const ext = path.extname(e.name).toLowerCase();
    if (!SUPPORTED_EXTS.has(ext)) continue;

    const absPath = path.join(userDir, e.name);
    const st = await fsp.stat(absPath);

    const fileRelPath = e.name;
    const cartella = '_root';
    const id = sha256(`${userName}/${cartella}/${fileRelPath}`);

    const prev = previousIndex[id];
    const unchanged =
      prev &&
      prev.size_bytes === st.size &&
      prev.mtimeMs === st.mtimeMs;

    if (unchanged) continue;

    const meta = await processFile(
      userName,
      cartella,
      fileRelPath,
      absPath,
      ext,
      st
    );
    meta.id = id;
    results.push(meta);
  }

  // 2) Sottocartelle (comportamento classico)
  for (const e of entries) {
    if (!e.isDirectory()) continue;
    const cartella = e.name;
    const absCartella = path.join(userDir, cartella);
    const files = await scanCartella(userName, cartella, absCartella, previousIndex);
    results.push(...files);
  }

  return results;
}

module.exports = scanUserRoot;