lib/search: make JaDBConnection into extension, add verifyTables

lib/models/verifyTables.dart

@@ -0,0 +1,39 @@
+import 'package:jadb/_data_ingestion/jmdict/table_names.dart';
+import 'package:jadb/_data_ingestion/kanjidic/table_names.dart';
+import 'package:jadb/_data_ingestion/radkfile/table_names.dart';
+import 'package:jadb/_data_ingestion/tanos-jlpt/table_names.dart';
+import 'package:sqflite_common/sqlite_api.dart';
+
+Future<void> verifyTablesWithDbConnection(DatabaseExecutor db) async {
+  final Set<String> tables = await db
+      .query(
+    'sqlite_master',
+    columns: ['name'],
+    where: 'type = ?',
+    whereArgs: ['table'],
+  )
+      .then((result) {
+    return result.map((row) => row['name'] as String).toSet();
+  });
+
+  final Set<String> expectedTables = {
+    ...JMdictTableNames.allTables,
+    ...KANJIDICTableNames.allTables,
+    ...RADKFILETableNames.allTables,
+    ...TanosJLPTTableNames.allTables,
+  };
+
+  final missingTables = expectedTables.difference(tables);
+
+  if (missingTables.isNotEmpty) {
+    throw Exception([
+      'Missing tables:',
+      missingTables.map((table) => '  - $table').join('\n'),
+      '',
+      'Found tables:\n',
+      tables.map((table) => '  - $table').join('\n'),
+      '',
+      'Please ensure the database is correctly set up.',
+    ].join('\n'));
+  }
+}