AppFlowy/frontend/app_flowy/lib/workspace/application/grid/grid_service.dart

import 'package:dartz/dartz.dart';
import 'package:flowy_sdk/dispatch/dispatch.dart';
import 'package:flowy_sdk/protobuf/flowy-error/errors.pb.dart';
import 'package:flowy_sdk/protobuf/flowy-folder-data-model/view.pb.dart';
import 'package:flowy_sdk/protobuf/flowy-grid-data-model/grid.pb.dart';
import 'package:flutter/foundation.dart';
import 'package:freezed_annotation/freezed_annotation.dart';
import 'package:app_flowy/workspace/application/grid/row/row_service.dart';

part 'grid_service.freezed.dart';

class GridService {
  final String gridId;
  GridService({
    required this.gridId,
  });

  Future<Either<Grid, FlowyError>> loadGrid() async {
    await FolderEventSetLatestView(ViewId(value: gridId)).send();

    final payload = GridId(value: gridId);
    return GridEventGetGridData(payload).send();
  }

  Future<Either<Row, FlowyError>> createRow({Option<String>? startRowId}) {
    CreateRowPayload payload = CreateRowPayload.create()..gridId = gridId;
    startRowId?.fold(() => null, (id) => payload.startRowId = id);
    return GridEventCreateRow(payload).send();
  }

  Future<Either<RepeatedField, FlowyError>> getFields({required List<FieldOrder> fieldOrders}) {
    final payload = QueryFieldPayload.create()
      ..gridId = gridId
      ..fieldOrders = RepeatedFieldOrder(items: fieldOrders);
    return GridEventGetFields(payload).send();
  }

  Future<Either<Unit, FlowyError>> closeGrid() {
    final request = ViewId(value: gridId);
    return FolderEventCloseView(request).send();
  }
}

class FieldsNotifier extends ChangeNotifier {
  List<Field> _fields = [];

  set fields(List<Field> fields) {
    _fields = fields;
    notifyListeners();
  }

  List<Field> get fields => _fields;
}

class GridFieldCache {
  final FieldsNotifier _fieldNotifier = FieldsNotifier();
  GridFieldCache();

  void applyChangeset(GridFieldChangeset changeset) {
    _removeFields(changeset.deletedFields);
    _insertFields(changeset.insertedFields);
    _updateFields(changeset.updatedFields);
  }

  UnmodifiableListView<Field> get unmodifiableFields => UnmodifiableListView(_fieldNotifier.fields);

  List<Field> get clonedFields => [..._fieldNotifier.fields];

  set clonedFields(List<Field> fields) {
    _fieldNotifier.fields = [...fields];
  }

  void listenOnFieldChanged(void Function(List<Field>) onFieldChanged) {
    _fieldNotifier.addListener(() => onFieldChanged(clonedFields));
  }

  void addListener(VoidCallback listener, {void Function(List<Field>)? onChanged}) {
    _fieldNotifier.addListener(() {
      if (onChanged != null) {
        onChanged(clonedFields);
      }
      listener();
    });
  }

  void _removeFields(List<FieldOrder> deletedFields) {
    if (deletedFields.isEmpty) {
      return;
    }
    final List<Field> fields = _fieldNotifier.fields;
    final Map<String, FieldOrder> deletedFieldMap = {
      for (var fieldOrder in deletedFields) fieldOrder.fieldId: fieldOrder
    };

    fields.retainWhere((field) => (deletedFieldMap[field.id] == null));
    _fieldNotifier.fields = fields;
  }

  void _insertFields(List<IndexField> insertedFields) {
    if (insertedFields.isEmpty) {
      return;
    }
    final List<Field> fields = _fieldNotifier.fields;
    for (final indexField in insertedFields) {
      if (fields.length > indexField.index) {
        fields.removeAt(indexField.index);
        fields.insert(indexField.index, indexField.field_1);
      } else {
        fields.add(indexField.field_1);
      }
    }
    _fieldNotifier.fields = fields;
  }

  void _updateFields(List<Field> updatedFields) {
    if (updatedFields.isEmpty) {
      return;
    }
    final List<Field> fields = _fieldNotifier.fields;
    for (final updatedField in updatedFields) {
      final index = fields.indexWhere((field) => field.id == updatedField.id);
      if (index != -1) {
        fields.removeAt(index);
        fields.insert(index, updatedField);
      }
    }
    _fieldNotifier.fields = fields;
  }

  void dispose() {
    _fieldNotifier.dispose();
  }
}

class GridRowCache {
  final String gridId;
  UnmodifiableListView<Field> _fields = UnmodifiableListView([]);
  List<RowData> _rows = [];

  GridRowCache({required this.gridId});

  List<RowData> get rows => [..._rows];

  void updateWithBlock(List<GridBlockOrder> blocks, UnmodifiableListView<Field> fields) {
    _fields = fields;
    _rows = blocks.expand((block) => block.rowOrders).map((rowOrder) {
      return RowData.fromBlockRow(gridId, rowOrder, _fields);
    }).toList();
  }

  void updateFields(UnmodifiableListView<Field> fields) {
    if (fields.isEmpty) {
      return;
    }

    _fields = fields;
    _rows = _rows.map((row) => row.copyWith(fields: fields)).toList();
  }

  Option<GridListState> deleteRows(List<RowOrder> deletedRows) {
    if (deletedRows.isEmpty) {
      return none();
    }

    final List<RowData> newRows = [];
    final List<Tuple2<int, RowData>> deletedIndex = [];
    final Map<String, RowOrder> deletedRowMap = {for (var rowOrder in deletedRows) rowOrder.rowId: rowOrder};
    _rows.asMap().forEach((index, value) {
      if (deletedRowMap[value.rowId] == null) {
        newRows.add(value);
      } else {
        deletedIndex.add(Tuple2(index, value));
      }
    });
    _rows = newRows;

    return Some(GridListState.delete(deletedIndex));
  }

  Option<GridListState> insertRows(List<IndexRowOrder> createdRows) {
    if (createdRows.isEmpty) {
      return none();
    }

    List<int> insertIndexs = [];
    for (final newRow in createdRows) {
      if (newRow.hasIndex()) {
        insertIndexs.add(newRow.index);
        _rows.insert(newRow.index, _toRowData(newRow.rowOrder));
      } else {
        insertIndexs.add(_rows.length);
        _rows.add(_toRowData(newRow.rowOrder));
      }
    }

    return Some(GridListState.insert(insertIndexs));
  }

  void updateRows(List<RowOrder> updatedRows) {
    if (updatedRows.isEmpty) {
      return;
    }

    final List<int> updatedIndexs = [];
    for (final updatedRow in updatedRows) {
      final index = _rows.indexWhere((row) => row.rowId == updatedRow.rowId);
      if (index != -1) {
        _rows.removeAt(index);
        _rows.insert(index, _toRowData(updatedRow));
        updatedIndexs.add(index);
      }
    }
  }

  RowData _toRowData(RowOrder rowOrder) {
    return RowData.fromBlockRow(gridId, rowOrder, _fields);
  }
}

@freezed
class GridListState with _$GridListState {
  const factory GridListState.insert(List<int> indexs) = _Insert;
  const factory GridListState.delete(List<Tuple2<int, RowData>> indexs) = _Delete;
  const factory GridListState.initial() = InitialListState;
}