import 'dart:typed_data';

import 'package:halkyon_learn_flutter/src/core/asset/data/asset_gateway.dart';

/// An [AssetGateway] in memory: ids are `asset-001`, `asset-002`, … in the
/// order of creation.
class FakeAssetGateway() implements AssetGateway {
  final _rows = <String, AssetRow>{};
  var _next = 1;

  /// The rows, in the order they were stored.
  List<AssetRow> get rows => [..._rows.values];

  /// The rows deleted, in order.
  final deleted = <String>[];

  /// Stores [row] as if another device had written it and a sync had
  /// brought it here.
  void receiveRemote(AssetRow row) => _rows[row.id] = row;

  @override
  Future<AssetRow?> byId(String id) async => _rows[id];

  @override
  Future<AssetRow?> bySha256(String sha256) async =>
      _rows.values.where((row) => row.sha256 == sha256).firstOrNull;

  @override
  Future<String> insert({
    required String sha256,
    required String mimeType,
    required int byteSize,
    required ByteData payload,
  }) async {
    final id = 'asset-${'${_next++}'.padLeft(3, '0')}';
    _rows[id] = (
      id: id,
      sha256: sha256,
      mimeType: mimeType,
      byteSize: byteSize,
      payload: payload,
    );
    return id;
  }

  @override
  Future<void> delete(String id) async {
    if (_rows.remove(id) != null) {
      deleted.add(id);
    }
  }
}