// 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');

async function scanUserRoot(userName, userDir, previousIndexTree) {
  console.log(`[SCAN] scanUserRoot → user=${userName}, dir=${userDir}`);

  const results = [];
  const entries = await fsp.readdir(userDir, { withFileTypes: true });

  // 1) File nella 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 hash = sha256(`${st.size}-${st.mtimeMs}`);
    const prev = previousIndexTree?.[userName]?.[cartella]?.[id];

    console.log(`[SCAN] ROOT CHECK → ${fileRelPath}, hash=${hash}, prevHash=${prev?.hash}`);

    if (prev && prev.hash === hash) {
      console.log(`[SCAN] SKIP ROOT (unchanged) → ${fileRelPath}`);
      continue;
    }

    console.log(`[SCAN] PROCESSING ROOT → ${fileRelPath}`);

    const meta = await processFile(
      userName,
      cartella,
      fileRelPath,
      absPath,
      ext,
      st
    );

    meta.id = id;
    meta.path = `/photos/${userName}/original/${cartella}/${fileRelPath}`;
    meta._indexHash = hash;

    results.push(meta);
  }

  // 2) Sottocartelle
  for (const e of entries) {
    if (!e.isDirectory()) continue;

    const cartella = e.name;
    const absCartella = path.join(userDir, cartella);

    console.log(`[SCAN] → Scansiono cartella: ${cartella}`);

    const files = await scanCartella(userName, cartella, absCartella, previousIndexTree);
    results.push(...files);
  }

  return results;
}

module.exports = scanUserRoot;