/**
 * Prove the anti-wipe guard: a stale empty in-memory DB must not overwrite
 * a richer on-disk materials catalog.
 */
import fs from 'fs';
import path from 'path';
import { fileURLToPath } from 'url';
import initSqlJs from 'sql.js';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const dbPath = path.join(__dirname, '..', 'data', 'configurateur.db');

const SQL = await initSqlJs({
  locateFile: (f) => path.join(__dirname, '..', 'node_modules', 'sql.js', 'dist', f)
});

function count(file) {
  const db = new SQL.Database(fs.readFileSync(file));
  const n = Number(db.exec('SELECT COUNT(*) FROM formex_materials')[0].values[0][0]);
  db.close();
  return n;
}

const before = count(dbPath);
console.log('disk before:', before);
if (before < 1) {
  console.error('FAIL: expected materials on disk before guard test');
  process.exit(1);
}

// Simulate a stale empty process writing the whole file (old wipe mode).
const empty = new SQL.Database();
empty.exec(`
  CREATE TABLE formex_materials (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    formex_code TEXT UNIQUE NOT NULL,
    name TEXT NOT NULL,
    collection TEXT NOT NULL
  );
`);

// Mimic the NEW guarded save from db/index.js
function guardedSave(database) {
  const memCount = Number(database.exec('SELECT COUNT(*) FROM formex_materials')[0]?.values?.[0]?.[0] ?? 0);
  const diskCount = count(dbPath);
  if (diskCount > 0 && memCount < diskCount) {
    console.log(`GUARD OK: refused overwrite (mem=${memCount}, disk=${diskCount})`);
    return false;
  }
  fs.writeFileSync(dbPath, Buffer.from(database.export()));
  return true;
}

const wrote = guardedSave(empty);
empty.close();
const after = count(dbPath);
console.log('disk after:', after);
if (wrote || after !== before) {
  console.error('FAIL: guard did not protect materials');
  process.exit(1);
}
console.log('PASS: scrapes on disk are protected from empty overwrites');