WIP

lib/database/linked_list.dart

@@ -0,0 +1,109 @@
+import 'package:sqflite/sqflite.dart';
+
+class LinkedListSQLExpressionGenerator<T, IDType> {
+  final String tableName;
+  final String currentItemColumnName;
+  final String prevItemColumnName;
+
+  final bool multilist;
+  final String? multilistIdentifierColumnName;
+
+  const LinkedListSQLExpressionGenerator({
+    required this.tableName,
+    required this.currentItemColumnName,
+    required this.prevItemColumnName,
+    required this.multilist,
+    required this.multilistIdentifierColumnName,
+  }) : assert(
+          !multilist || multilistIdentifierColumnName != null,
+          "Multilist expressions need to specify their list identifier column name",
+        );
+
+  Future<void> insertItem(
+    DatabaseExecutor db,
+    T item, {
+    int? position,
+    String? list,
+  }) async {
+    assert(
+      !multilist || list != null,
+      "`list` must be specified for multilist tables",
+    );
+
+    throw UnimplementedError();
+  }
+
+  Future<void> moveItemByPosition(
+    DatabaseExecutor db,
+    int from,
+    int to, {
+    String? list,
+  }) async {
+    assert(
+      !multilist || list != null,
+      "`list` must be specified for multilist tables",
+    );
+
+    throw UnimplementedError();
+  }
+
+  Future<void> moveItemById(
+    DatabaseExecutor db,
+    IDType id,
+    int to, {
+    String? list,
+  }) async {
+    assert(
+      !multilist || list != null,
+      "`list` must be specified for multilist tables",
+    );
+    throw UnimplementedError();
+  }
+
+  Future<bool> deleteItemByPosition(
+    DatabaseExecutor db,
+    int position, {
+    String? list,
+  }) async {
+    assert(
+      !multilist || list != null,
+      "`list` must be specified for multilist tables",
+    );
+    throw UnimplementedError();
+  }
+
+  Future<bool> deleteItemById(
+    DatabaseExecutor db,
+    IDType id, {
+    String? list,
+  }) async {
+    assert(
+      !multilist || list != null,
+      "`list` must be specified for multilist tables",
+    );
+    throw UnimplementedError();
+  }
+
+  /// Verify that the linked list is consistent. i.e.
+  ///   - There are no dangling items.
+  ///   - There are no two items with common parents.
+  Future<bool> verify(
+    DatabaseExecutor db, {
+    String? list,
+  }) async {
+    throw UnimplementedError();
+  }
+
+  /// This function tries to fix an inconsistent linked list by:
+  ///   - Finds dangling items and appends them to the end of the list in the order they were found
+  ///   - Finds items with common parents and straightens them out in the order they were found (as well as their tails)
+  Future<bool> autofix(
+    DatabaseExecutor db,
+  ) async {
+    if (multilist) {
+      throw UnimplementedError("autofix is undefined for multilist tables");
+    }
+
+    throw UnimplementedError();
+  }
+}