Flutter Android login vault: local DB (id+base64 content), email/Google auth, dashboard search/edit/swipe-delete, dark/system theme, minSdk 29

lib/database_helper.dart

@@ -0,0 +1,97 @@
+import 'package:sqflite/sqflite.dart';
+import 'package:path/path.dart';
+import 'package:login_vault_app/constants.dart';
+import 'package:login_vault_app/encryptor.dart';
+
+/// A single saved login/private entry.
+class VaultEntry {
+  final String id; // unique string
+  final String content; // decrypted plaintext
+
+  VaultEntry({required this.id, required this.content});
+
+  /// Build from a DB row (content is stored encrypted).
+  factory VaultEntry.fromDbRow(Map<String, dynamic> row) => VaultEntry(
+        id: row['id'] as String,
+        content: Encryptor.decrypt(row['content'] as String),
+      );
+
+  /// Build a DB row map (content encrypted).
+  Map<String, dynamic> toDbRow() => {
+        'id': id,
+        'content': Encryptor.encrypt(content),
+      };
+}
+
+class DatabaseHelper {
+  static final DatabaseHelper _instance = DatabaseHelper._internal();
+  factory DatabaseHelper() => _instance;
+  DatabaseHelper._internal();
+
+  Database? _db;
+
+  Future<Database> get db async {
+    _db ??= await _initDb();
+    return _db!;
+  }
+
+  Future<Database> _initDb() async {
+    final path = join(await getDatabasesPath(), AppConstants.dbName);
+    return openDatabase(
+      path,
+      version: 1,
+      onCreate: (db, version) async {
+        await db.execute('''
+          CREATE TABLE vault (
+            id TEXT PRIMARY KEY,
+            content TEXT NOT NULL
+          )
+        ''');
+      },
+    );
+  }
+
+  /// Insert a new entry (throws if [id] already exists -> uniqueness).
+  Future<void> insert(VaultEntry entry) async {
+    final d = await db;
+    await d.insert('vault', entry.toDbRow(),
+        conflictAlgorithm: ConflictAlgorithm.fail);
+  }
+
+  /// Update content for an existing [id].
+  Future<void> update(String id, String newContent) async {
+    final d = await db;
+    await d.update(
+      'vault',
+      {'content': Encryptor.encrypt(newContent)},
+      where: 'id = ?',
+      whereArgs: [id],
+    );
+  }
+
+  /// Delete by [id].
+  Future<void> delete(String id) async {
+    final d = await db;
+    await d.delete('vault', where: 'id = ?', whereArgs: [id]);
+  }
+
+  /// Get all entries (used for full list / search).
+  Future<List<VaultEntry>> getAll() async {
+    final d = await db;
+    final rows = await d.query('vault', orderBy: 'id COLLATE NOCASE ASC');
+    return rows.map(VaultEntry.fromDbRow).toList();
+  }
+
+  /// Search ids containing [query] (case-insensitive). Returns matching entries.
+  Future<List<VaultEntry>> search(String query) async {
+    if (query.trim().isEmpty) return getAll();
+    final d = await db;
+    final rows = await d.query(
+      'vault',
+      where: 'id LIKE ?',
+      whereArgs: ['%${query.trim()}%'],
+      orderBy: 'id COLLATE NOCASE ASC',
+    );
+    return rows.map(VaultEntry.fromDbRow).toList();
+  }
+}