// api_v1/scanner/scanNewCartella.js
const path = require('path');
const fsp = require('fs/promises');
const { WEB_ROOT, SUPPORTED_EXTS } = require('../config');
const scanPhoto = require('./scanPhoto');

// ---------------------------------------------------------
// Conta ricorsivamente i file in /photos/<user>/original/<folder>/
// ---------------------------------------------------------
async function countFilesInUserFolder(userName, folderName) {
  const rootDir = path.join(WEB_ROOT, userName, "original", folderName);
  let count = 0;

  async function walk(dir) {
    let entries = [];
    try {
      entries = await fsp.readdir(dir, { withFileTypes: true });
    } catch {
      return;
    }

    for (const e of entries) {
      const abs = path.join(dir, e.name);

      if (e.isDirectory()) {
        await walk(abs);
      } else {
        const ext = path.extname(e.name).toLowerCase();
        if (SUPPORTED_EXTS.has(ext)) {
          count++;
        }
      }
    }
  }

  await walk(rootDir);
  return count;
}

// ---------------------------------------------------------
// Crea thumbs/<folder> e scansiona la cartella come fa /scan
// ---------------------------------------------------------
async function scanNewCartella(userName, folderName, db) {
  // 1) crea la cartella root in thumbs
  const thumbsDir = path.join(WEB_ROOT, userName, "thumbs", folderName);
  await fsp.mkdir(thumbsDir, { recursive: true });

  // 2) conta i file ricorsivamente
  const TOTAL_FILES = await countFilesInUserFolder(userName, folderName);

  // 3) esegui lo scan della cartella
  const CURRENT = { value: 0 };
  const start = Date.now();

  const newFiles = await scanPhoto(
    folderName,
    userName,
    db,
    CURRENT,
    TOTAL_FILES,
    start
  );

  return {
    ok: true,
    folder: folderName,
    totalFiles: TOTAL_FILES,
    newFiles
  };
}

module.exports = {
  scanNewCartella,
  countFilesInUserFolder
};