dev: add recovery screen when sqlite db doesn't open

cw_core/lib/db/sqlite.dart

@@ -1,9 +1,11 @@
 
 import 'dart:io';
 
+import 'package:cw_core/db/sqlite_debug.dart';
 import 'package:cw_core/root_dir.dart';
 import 'package:cw_core/utils/print_verbose.dart';
 import 'package:sqflite_common_ffi/sqflite_ffi.dart';
+import 'package:path/path.dart' as p;
 
 Database? db;
 
@@ -23,7 +25,25 @@ Future<void> _addColumnIfNotExists(
   }
 }
 
+Future<File> sqliteDebugMarkerFile() async {
+  final appDir = await getAppDir();
+  final dbDebugMarker = p.join(appDir.path, ".sqlite_db_debug");
+  return File(dbDebugMarker);
+}
+
 Future<void> initDb({String? pathOverride}) async {
+  final dbDebugMarker = await sqliteDebugMarkerFile();
+  try {
+    if (dbDebugMarker.existsSync()) {
+      throw Exception("Debug marker is present");
+    }
+    await _initDb(pathOverride: pathOverride);
+  } catch (e, s) {
+    await handleSqliteError(e, s);
+  }
+}
+
+Future<void> _initDb({String? pathOverride}) async {
   if (Platform.isLinux || Platform.isWindows) {
     databaseFactory = databaseFactoryFfi;
   }

cw_core/lib/db/sqlite_debug.dart

@@ -0,0 +1,177 @@
+import 'dart:convert';
+import 'dart:io';
+import 'dart:typed_data';
+
+import 'package:cw_core/db/sqlite.dart';
+import 'package:cw_core/root_dir.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+
+Future<void> handleSqliteError(final dynamic error, final StackTrace stackTrace) async {
+  try {
+    final f = await sqliteDebugMarkerFile();
+    f.createSync();
+  } catch (_) {}
+  runApp(
+    SqliteErrorHandlerApp(
+      error: error,
+      stackTrace: stackTrace,
+    ),
+  );
+  await Future.delayed(Duration(hours: 24));
+}
+
+class SqliteErrorHandlerApp extends StatelessWidget {
+  const SqliteErrorHandlerApp({
+    super.key,
+    required this.error,
+    required this.stackTrace,
+  });
+
+  final dynamic error;
+  final StackTrace? stackTrace;
+  @override
+  Widget build(final BuildContext context) {
+    return MaterialApp(
+      debugShowCheckedModeBanner: false,
+      title: 'Cupcake Crash',
+      themeMode: ThemeMode.light,
+      home: SqliteErrorHandler(
+        error: error,
+        stackTrace: stackTrace,
+      ),
+    );
+  }
+}
+
+class SqliteErrorHandler extends StatefulWidget {
+  SqliteErrorHandler({
+    super.key,
+    required this.error,
+    required this.stackTrace,
+  });
+
+  final dynamic error;
+  final StackTrace? stackTrace;
+
+  @override
+  State<SqliteErrorHandler> createState() => _SqliteErrorHandlerState();
+}
+
+class _SqliteErrorHandlerState extends State<SqliteErrorHandler> {
+  String log = "";
+
+  @override
+  Widget build(final BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text("Sqlite Recovery Screen"),
+      ),
+      body: SingleChildScrollView(
+        child: Padding(
+          padding: const EdgeInsets.all(8.0),
+          child: Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: _buildNotice(),
+          ),
+        ),
+      ),
+    );
+  }
+
+  Widget _text(final dynamic element) {
+    return SelectableText(
+      element.toString(),
+    );
+  }
+
+  void _dbgRemoveDebugMarker() async {
+    final f = await sqliteDebugMarkerFile();
+    f.delete();
+  }
+
+  void _corruptTheDb() async {
+    final dbFile = File("${(await getAppDir()).path}/cake.db");
+    await writeBytesToFile(dbFile);
+  }
+
+  void _dumpDb() async {
+    try {
+      final dbFile = File("${(await getAppDir()).path}/cake.db");
+      final jsonText = JsonEncoder.withIndent("    ").convert(await dumpCustomDb(dbFile.path));
+      setState(() {
+          log = jsonText;
+      });
+    } catch (e, s) {
+      setState(() {
+        log = """
+e: $e
+
+s: $s
+""";
+      });
+    }
+  }
+
+  void _removeDb() async {
+    try {
+      File("${(await getAppDir()).path}/cake.db.old").deleteSync();
+    } catch (_) {}
+    final dbFile = File("${(await getAppDir()).path}/cake.db");
+    dbFile.renameSync("${(await getAppDir()).path}/cake.db.old");
+  }
+
+  List<Widget> _debugOptions() {
+    return [
+      _debugButton("Remove debug marker", _dbgRemoveDebugMarker),
+      if (kDebugMode || kProfileMode) _debugButton("[DO NOT PRESS] Corrupt the DB", _corruptTheDb),
+      _debugButton("Remove DB", _removeDb),
+      _debugButton("Dump DB", _dumpDb),
+    ];
+  }
+
+  Widget _debugButton(String text, VoidCallback callback) {
+    return ElevatedButton(
+      onPressed: callback,
+      child: Text(text),
+    );
+  }
+
+  List<Widget> _buildNotice() {
+    return [
+      _text("""Critical error occured in SQLite
+This is very rare, usually caused by the device killing the app before it finishes writing file.
+Here you can recover the database or recreate it to regain access to your wallets.
+During this process some of the metadata may get lost.
+Please contact support@cakewallet.com if you need any help."""),
+      Divider(),
+      ..._debugOptions(),
+      if (log.isNotEmpty) ...[
+        Divider(),
+        SelectableText(
+          log,
+          style: TextStyle(
+            fontSize: 8,
+          ),
+        ),
+      ],
+      Divider(),
+      _text(widget.error),
+      Divider(),
+      _text(widget.stackTrace),
+    ];
+  }
+}
+
+Future<void> writeBytesToFile(File file) async {
+  const int seek = 5;
+  const int count = 50000;
+  final raf = await file.open(mode: FileMode.writeOnlyAppend);
+  try {
+    await raf.setPosition(seek);
+    final zeros = Uint8List.fromList(List.generate(count, (_) => 0x42));
+    await raf.writeFrom(zeros);
+  } finally {
+    await raf.close();
+  }
+}

lib/src/screens/settings/other_settings_page.dart

@@ -1,3 +1,5 @@
+import 'dart:io';
+
 import 'package:cake_wallet/bitcoin/bitcoin.dart';
 import 'package:cake_wallet/entities/new_ui_entities/list_item/list_item_regular_row.dart';
 import 'package:cake_wallet/entities/new_ui_entities/list_item/list_item_selector.dart';
@@ -14,11 +16,13 @@ import 'package:cake_wallet/utils/feature_flag.dart';
 import 'package:cake_wallet/utils/share_util.dart';
 import 'package:cake_wallet/utils/show_pop_up.dart';
 import 'package:cake_wallet/view_model/settings/other_settings_view_model.dart';
+import 'package:cw_core/root_dir.dart';
 import 'package:cw_core/wallet_info.dart';
 import 'package:cw_core/transaction_priority.dart';
 import 'package:cw_core/wallet_type.dart';
 import 'package:cw_core/db/sqlite.dart';
 import 'package:flutter/material.dart';
+import 'package:path/path.dart' as p;
 
 class OtherSettingsPage extends BasePage {
   OtherSettingsPage(this._otherSettingsViewModel) {
@@ -213,6 +217,14 @@ class OtherSettingsPage extends BasePage {
                   ),
                 );
               }),
+          ListItemRegularRow(
+            keyValue: '[dev] fake corrupt sqlite db',
+            label: '[dev] fake corrupt sqlite db',
+            onTap: () async {
+              final dbDebugMarker = await sqliteDebugMarkerFile();
+              dbDebugMarker.create();
+            }
+          ),
         ]
       }),
     );