import 'package:flutter/foundation.dart';

import 'package:pweb/models/wallet/wallet_transaction.dart';
import 'package:pweb/services/wallet_transactions.dart';


class WalletTransactionsProvider extends ChangeNotifier {
  final WalletTransactionsService _service;

  WalletTransactionsProvider(this._service);

  List<WalletTransaction> _transactions = const [];
  bool _isLoading = false;
  String? _error;
  String? _walletId;
  int _loadSeq = 0;

  List<WalletTransaction> get transactions => List.unmodifiable(_transactions);
  bool get isLoading => _isLoading;
  String? get error => _error;
  String? get walletId => _walletId;

  Future<void> load({String? walletId}) async {
    final targetWalletId = walletId ?? _walletId;
    final requestSeq = ++_loadSeq;
    _walletId = targetWalletId;
    _isLoading = true;
    _error = null;
    notifyListeners();

    try {
      final fetched = await _service.fetchHistory(walletId: targetWalletId);
      if (requestSeq != _loadSeq) return;

      _transactions = targetWalletId == null
          ? fetched
          : fetched.where((tx) => tx.walletId == targetWalletId).toList();
    } catch (e) {
      if (requestSeq != _loadSeq) return;
      _error = e.toString();
    } finally {
      if (requestSeq == _loadSeq) {
        _isLoading = false;
        notifyListeners();
      }
    }
  }
}