powerage-ristoris-flutter/lib/database/db_connector_io.dart

import 'dart:io';
import 'dart:developer' as dev;
import 'package:drift/native.dart';
import 'package:drift/drift.dart';
import 'package:path/path.dart' as p;
import 'package:path_provider/path_provider.dart';
import 'package:flutter/services.dart' show rootBundle;
import '../core/constants.dart';

QueryExecutor createDb(String dirPath, String dbName) {
  return NativeDatabase(
    File(p.join(dirPath, dbName)),
    logStatements: true,
  );
}

Future<String> ensureDbReady() async {
  String dirPath;

  if (Platform.isAndroid) {
    final extDir = Directory(AppConstants.kAndroidDbDir);
    if (!await extDir.exists()) {
      await extDir.create(recursive: true);
    }
    dirPath = extDir.path;
  } else {
    final dir = await getApplicationDocumentsDirectory();
    dirPath = dir.path;
  }

  final dbFile = File(p.join(dirPath, AppConstants.kDbName));
  if (!await dbFile.exists()) {
    try {
      final data = await rootBundle.load(AppConstants.kAssetsDbPath);
      await dbFile.create(recursive: true);
      await dbFile.writeAsBytes(data.buffer.asUint8List());
    } catch (e) {
      dev.log('Errore copia seed DB: $e');
    }
  }

  if (!await dbFile.exists()) {
    throw Exception(
      'Impossibile creare il file database in $dirPath',
    );
  }

  return dirPath;
}

Future<bool> isDatabaseEmpty(String dirPath) async {
  final dbFile = File(p.join(dirPath, AppConstants.kDbName));
  if (!await dbFile.exists()) return true;
  final stat = await dbFile.stat();
  return stat.size < 1024;
}