AppFlowy/frontend/app_flowy/lib/plugins/board/application/board_data_controller.dart

// import 'dart:collection';

// import 'package:flowy_sdk/log.dart';
// import 'package:flowy_sdk/protobuf/flowy-error/errors.pb.dart';
// import 'package:flowy_sdk/protobuf/flowy-folder/view.pb.dart';
// import 'package:flowy_sdk/protobuf/flowy-grid/block_entities.pb.dart';
// import 'package:flowy_sdk/protobuf/flowy-grid/field_entities.pb.dart';
// import 'package:flowy_sdk/protobuf/flowy-grid/grid_entities.pb.dart';
// import 'dart:async';
// import 'package:dartz/dartz.dart';

// typedef OnFieldsChanged = void Function(UnmodifiableListView<FieldPB>);
// typedef OnGridChanged = void Function(GridPB);

// typedef OnRowsChanged = void Function(
//   List<GridRowInfo> rowInfos,
//   GridRowChangeReason,
// );
// typedef ListenONRowChangedCondition = bool Function();

// class GridDataController {
//   final String gridId;
//   final GridService _gridFFIService;
//   final GridFieldCache fieldCache;

//   // key: the block id
//   final LinkedHashMap<String, GridBlockCache> _blocks;
//   UnmodifiableMapView<String, GridBlockCache> get blocks =>
//       UnmodifiableMapView(_blocks);

//   OnRowsChanged? _onRowChanged;
//   OnFieldsChanged? _onFieldsChanged;
//   OnGridChanged? _onGridChanged;

//   List<GridRowInfo> get rowInfos {
//     final List<GridRowInfo> rows = [];
//     for (var block in _blocks.values) {
//       rows.addAll(block.rows);
//     }
//     return rows;
//   }

//   GridDataController({required ViewPB view})
//       : gridId = view.id,
//         _blocks = LinkedHashMap.identity(),
//         _gridFFIService = GridService(gridId: view.id),
//         fieldCache = GridFieldCache(gridId: view.id);

//   void addListener({
//     required OnGridChanged onGridChanged,
//     required OnRowsChanged onRowsChanged,
//     required OnFieldsChanged onFieldsChanged,
//   }) {
//     _onGridChanged = onGridChanged;
//     _onRowChanged = onRowsChanged;
//     _onFieldsChanged = onFieldsChanged;

//     fieldCache.addListener(onFields: (fields) {
//       _onFieldsChanged?.call(UnmodifiableListView(fields));
//     });
//   }

//   Future<Either<Unit, FlowyError>> loadData() async {
//     final result = await _gridFFIService.loadGrid();
//     return Future(
//       () => result.fold(
//         (grid) async {
//           _initialBlocks(grid.blocks);
//           _onGridChanged?.call(grid);
//           return await _loadFields(grid);
//         },
//         (err) => right(err),
//       ),
//     );
//   }

//   void createRow() {
//     _gridFFIService.createRow();
//   }

//   Future<void> dispose() async {
//     await _gridFFIService.closeGrid();
//     await fieldCache.dispose();

//     for (final blockCache in _blocks.values) {
//       blockCache.dispose();
//     }
//   }

//   void _initialBlocks(List<BlockPB> blocks) {
//     for (final block in blocks) {
//       if (_blocks[block.id] != null) {
//         Log.warn("Initial duplicate block's cache: ${block.id}");
//         return;
//       }

//       final cache = GridBlockCache(
//         gridId: gridId,
//         block: block,
//         fieldCache: fieldCache,
//       );

//       cache.addListener(
//         onChangeReason: (reason) {
//           _onRowChanged?.call(rowInfos, reason);
//         },
//       );

//       _blocks[block.id] = cache;
//     }
//   }

//   Future<Either<Unit, FlowyError>> _loadFields(GridPB grid) async {
//     final result = await _gridFFIService.getFields(fieldIds: grid.fields);
//     return Future(
//       () => result.fold(
//         (fields) {
//           fieldCache.fields = fields.items;
//           _onFieldsChanged?.call(UnmodifiableListView(fieldCache.fields));
//           return left(unit);
//         },
//         (err) => right(err),
//       ),
//     );
//   }
// }