import 'dart:collection';

import 'package:app_flowy/plugins/grid/application/block/block_cache.dart';
import 'package:app_flowy/plugins/grid/application/field/field_cache.dart';
import 'package:app_flowy/plugins/grid/application/grid_service.dart';
import 'package:flowy_sdk/protobuf/flowy-error/errors.pb.dart';
import 'package:flowy_sdk/protobuf/flowy-folder/view.pb.dart';
import 'dart:async';
import 'package:dartz/dartz.dart';
import 'package:flowy_sdk/protobuf/flowy-grid/protobuf.dart';

typedef OnFieldsChanged = void Function(UnmodifiableListView<FieldPB>);
typedef OnGridChanged = void Function(GridPB);
typedef OnGroupChanged = void Function(List<GroupPB>);
typedef OnError = void Function(FlowyError);

class BoardDataController {
  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);

  OnFieldsChanged? _onFieldsChanged;
  OnGridChanged? _onGridChanged;
  OnGroupChanged? _onGroupChanged;
  OnError? _onError;

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

  void addListener({
    OnGridChanged? onGridChanged,
    OnFieldsChanged? onFieldsChanged,
    OnGroupChanged? onGroupChanged,
    OnError? onError,
  }) {
    _onGridChanged = onGridChanged;
    _onFieldsChanged = onFieldsChanged;
    _onGroupChanged = onGroupChanged;
    _onError = onError;

    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 {
          _onGridChanged?.call(grid);
          return await _loadFields(grid).then((result) {
            return result.fold(
              (l) {
                _loadGroups();
                return left(l);
              },
              (err) => right(err),
            );
          });
        },
        (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();
    }
  }

  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),
      ),
    );
  }

  Future<void> _loadGroups() async {
    final result = await _gridFFIService.loadGroups();
    return Future(
      () => result.fold(
        (groups) {
          _onGroupChanged?.call(groups.items);
        },
        (err) => _onError?.call(err),
      ),
    );
  }
}