import 'package:flutter/foundation.dart';

import 'package:collection/collection.dart';

import 'package:pshared/models/payment/wallet.dart';
import 'package:pshared/provider/payment/wallets.dart';


class WalletsController with ChangeNotifier {
  late WalletsProvider _wallets;

  String? _orgRef;

  /// UI-only: which wallets are allowed to be visible
  final Set<String> _visibleWalletIds = <String>{};

  String? _selectedWalletId;

  bool get isLoading => _wallets.isLoading;
  Exception? get error => _wallets.error;

  void update(WalletsProvider wallets) {
    _wallets = wallets;

    final nextOrgRef = wallets.organizationId;
    final orgChanged = nextOrgRef != _orgRef;

    if (orgChanged) {
      _orgRef = nextOrgRef;
      _visibleWalletIds.clear(); // All wallets hidden on org change
      _selectedWalletId = null;
    }

    // Remove ids that no longer exist
    final ids = wallets.wallets.map((w) => w.id).toSet();
    _visibleWalletIds.removeWhere((id) => !ids.contains(id));

    final beforeSelected = _selectedWalletId;

    _selectedWalletId = _resolveSelectedId(
      currentId: _selectedWalletId,
      wallets: wallets.wallets,
      visibleIds: _visibleWalletIds,
    );

    if (beforeSelected != _selectedWalletId || orgChanged) {
      notifyListeners();
    }
  }

  List<Wallet> get wallets => _wallets.wallets;

  bool isVisible(String walletId) => _visibleWalletIds.contains(walletId);
  bool isHidden(String walletId) => !isVisible(walletId);

  List<Wallet> get visibleWallets =>
    wallets.where((w) => _visibleWalletIds.contains(w.id)).toList(growable: false);

  Wallet? get selectedWallet {
    final id = _selectedWalletId;
    if (id == null) return null;
    return wallets.firstWhereOrNull((w) => w.id == id);
  }

  String? get selectedWalletId => _selectedWalletId;

  void selectWallet(Wallet wallet) => selectWalletId(wallet.id);

  void selectWalletId(String walletId) {
    if (_selectedWalletId == walletId) return;

    // Prevent selecting a hidden wallet
    if (!_visibleWalletIds.contains(walletId)) return;

    _selectedWalletId = walletId;
    notifyListeners();
  }

  /// Toggle wallet visibility
  void toggleVisibility(String walletId) {
    final existed = _visibleWalletIds.remove(walletId);
    if (!existed) _visibleWalletIds.add(walletId);

    _selectedWalletId = _resolveSelectedId(
      currentId: _selectedWalletId,
      wallets: wallets,
      visibleIds: _visibleWalletIds,
    );

    notifyListeners();
  }

  /// Show all wallets (bulk action)
  void showAll() {
    final allIds = wallets.map((w) => w.id);
    _visibleWalletIds
      ..clear()
      ..addAll(allIds);

    _selectedWalletId = _resolveSelectedId(
      currentId: _selectedWalletId,
      wallets: wallets,
      visibleIds: _visibleWalletIds,
    );

    notifyListeners();
  }

  String? _resolveSelectedId({
    required String? currentId,
    required List<Wallet> wallets,
    required Set<String> visibleIds,
  }) {
    if (wallets.isEmpty) return null;

    // Keep current selection if it still exists and is visible
    if (currentId != null &&
        visibleIds.contains(currentId) &&
        wallets.any((w) => w.id == currentId)) {
      return currentId;
    }

    // Select the first visible wallet
    final firstVisible = wallets.firstWhereOrNull((w) => visibleIds.contains(w.id));
    return firstVisible?.id;
  }
}