fluffychat/lib/utils/sqflite_database_builder.dart

import 'dart:convert';
import 'dart:io';
import 'dart:math';

import 'package:flutter/foundation.dart';
import 'package:flutter/services.dart';

import 'package:flutter_secure_storage/flutter_secure_storage.dart';
import 'package:matrix/matrix.dart';
import 'package:path_provider/path_provider.dart';
import 'package:sqflite_common_ffi_web/sqflite_ffi_web.dart';
import 'package:sqflite_sqlcipher/sqflite.dart';
import 'package:universal_html/html.dart' as html;

Future<SqfliteDatabase> sqfliteDatabaseBuilder(Client client) async {
  if (kIsWeb) {
    html.window.navigator.storage?.persist();
    return SqfliteDatabase(
      await databaseFactoryFfiWeb.openDatabase(
        client.clientName,
        options: OpenDatabaseOptions(
          version: 1,
          onCreate: DbTablesExtension.create,
        ),
      ),
      fileStoragePath: null,
      maxFileSize: 0,
    );
  }
  final path = await getDatabasesPath();
  const passwordStorageKey = 'database_password';
  String? password;

  try {
    // Workaround for secure storage is calling Platform.operatingSystem on web
    if (kIsWeb) throw MissingPluginException();

    const secureStorage = FlutterSecureStorage();
    final containsEncryptionKey =
        await secureStorage.read(key: passwordStorageKey) != null;
    if (!containsEncryptionKey) {
      // do not try to create a buggy secure storage for new Linux users
      if (Platform.isLinux) throw MissingPluginException();
      final rng = Random.secure();
      final list = Uint8List(32);
      list.setAll(0, Iterable.generate(list.length, (i) => rng.nextInt(256)));
      final newPassword = base64UrlEncode(list);
      await secureStorage.write(
        key: passwordStorageKey,
        value: newPassword,
      );
    }
    // workaround for if we just wrote to the key and it still doesn't exist
    password = await secureStorage.read(key: passwordStorageKey);
    if (password == null) throw MissingPluginException();
  } on MissingPluginException catch (_) {
    const FlutterSecureStorage()
        .delete(key: passwordStorageKey)
        .catchError((_) {});
    Logs().i('Hive encryption is not supported on this platform');
  } catch (e, s) {
    const FlutterSecureStorage()
        .delete(key: passwordStorageKey)
        .catchError((_) {});
    Logs().w('Unable to init Hive encryption', e, s);
  }

  return SqfliteDatabase(
    await openDatabase(
      '$path/${client.clientName}',
      version: 1,
      onCreate: DbTablesExtension.create,
      password: password,
    ),
    fileStoragePath: await getTemporaryDirectory(),
    maxFileSize: 10 * 1024 * 1024,
  );
}