import 'dart:async';

import 'package:sysfarma_mobile/src/app/widgets/app_loader.dart';
import 'package:sysfarma_mobile/src/app/widgets/app_panel.dart';
import 'package:sysfarma_mobile/src/app/widgets/empty_state_panel.dart';
import 'package:sysfarma_mobile/src/core/network/api_client.dart';
import 'package:sysfarma_mobile/src/core/network/connectivity_service.dart';
import 'package:sysfarma_mobile/src/core/network/mobile_api_response.dart';
import 'package:sysfarma_mobile/src/core/printing/bluetooth_print_service.dart';
import 'package:sysfarma_mobile/src/core/state/unsaved_work_provider.dart';
import 'package:sysfarma_mobile/src/core/storage/offline_pos_store.dart';
import 'package:sysfarma_mobile/src/core/storage/tenant_session_store.dart';
import 'package:sysfarma_mobile/src/core/theme/app_tokens.dart';
import 'package:sysfarma_mobile/src/features/settings/presentation/printer_settings_screen.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:url_launcher/url_launcher_string.dart';

class SalesScreen extends ConsumerStatefulWidget {
  const SalesScreen({super.key});

  @override
  ConsumerState<SalesScreen> createState() => _SalesScreenState();
}

class _SalesScreenState extends ConsumerState<SalesScreen> {
  static const String _printerMacKey = 'printer_mac';
  static const String _printerNameKey = 'printer_name';

  late Future<_SalesBundle> _future;
  final TextEditingController _searchController = TextEditingController();

  bool _handleAuthFailure(MobileApiResponse response) {
    if (response.errors['auth'] == true && mounted) {
      context.go('/login');
      return true;
    }
    return false;
  }

  final TextEditingController _notesController = TextEditingController();
  final ScrollController _scrollController = ScrollController();
  final GlobalKey _catalogKey = GlobalKey();
  final List<_CartLine> _cart = <_CartLine>[];
  // Lineas en proceso de fade+collapse antes de sacarlas de _cart de verdad
  // (ver _openCartSheet) - asi el ListView tiene tiempo de animar la salida
  // en vez de que el item desaparezca de golpe en el siguiente build.
  final Set<_CartLine> _removingCartLines = {};
  Map<String, dynamic>? _selectedCustomer;
  String? _documentTypeId;
  int? _seriesId;
  String? _paymentConditionId;
  // Estado de pagos estilo POS web: cada método es un tile con su propio monto.
  final Map<String, TextEditingController> _methodAmountControllers = {};
  final Map<String, String> _methodReferences = {};
  String? _activeMethodId;
  bool _paymentsTouched = false;
  bool _isSubmitting = false;
  bool _suppressCartSheet = false;
  bool _isSyncingPending = false;
  int _pendingSalesCount = 0;
  Timer? _searchDebounce;
  StreamSubscription<bool>? _connectivitySub;

  // Customers pagination state
  List<Map<String, dynamic>> _allCustomers = [];
  int _customersPage = 1;
  bool _customersHasMore = true;
  bool _isLoadingMoreCustomers = false;

  // Items search state
  List<Map<String, dynamic>> _allItems = [];
  int _itemsPage = 1;
  bool _itemsHasMore = true;
  bool _isLoadingItems = false;
  String _itemsQuery = '';

  @override
  void initState() {
    super.initState();
    _searchController.addListener(_onSearchChanged);
    _future = _load();
    _connectivitySub = ref
        .read(connectivityServiceProvider)
        .onConnectivityChanged
        .listen((connected) {
      if (connected) {
        _syncPendingSales();
      }
    });
  }

  @override
  void dispose() {
    _connectivitySub?.cancel();
    _searchDebounce?.cancel();
    _searchController.dispose();
    _notesController.dispose();
    _scrollController.dispose();
    // El carrito local muere con la pantalla; que el shell deje de creer
    // que hay una venta en curso.
    ref.read(hasUnsavedSaleCartProvider.notifier).state = false;
    super.dispose();
  }

  Future<_SalesBundle> _load() async {
    final session = await ref.read(tenantSessionStoreProvider).readSession();
    final establishmentId = session?.activeEstablishmentId;
    final offline = ref.read(offlinePosStoreProvider);
    try {
      final api = ref.read(apiClientProvider);
      final results = await Future.wait([
        api.documentsTablesByEstablishment(establishmentId: establishmentId),
        api.items(
            perPage: 10,
            page: 1,
            context: 'sale',
            establishmentId: establishmentId),
        api.customers(perPage: 10, page: 1, establishmentId: establishmentId),
      ]);
      final tables = results[0] as MobileApiResponse<Map<String, dynamic>>;
      final items = results[1] as MobileApiResponse<List<Map<String, dynamic>>>;
      final customers =
          results[2] as MobileApiResponse<List<Map<String, dynamic>>>;
      // ignore: avoid_print
      print(
          '[EnterFarma] sales _load tables.success=${tables.success} items.success=${items.success} customers.success=${customers.success}');
      // ignore: avoid_print
      print(
          '[EnterFarma] sales _load tables.msg=${tables.message} items.msg=${items.message} customers.msg=${customers.message}');

      var itemsList = items.data ?? const <Map<String, dynamic>>[];
      var customersList = customers.data ?? const <Map<String, dynamic>>[];
      var tablesData = tables.data ?? const <String, dynamic>{};

      final hasNetworkFailure = _looksLikeNetworkError(tables.message) ||
          _looksLikeNetworkError(items.message) ||
          _looksLikeNetworkError(customers.message);

      if (hasNetworkFailure) {
        final cachedTables = await offline.readTables();
        final cachedItems = await offline.readItems();
        final cachedCustomers = await offline.readCustomers();

        if (!tables.success && cachedTables.isNotEmpty) {
          tablesData = cachedTables;
        }
        if (!items.success && cachedItems.isNotEmpty) {
          itemsList = cachedItems;
        }
        if (!customers.success && cachedCustomers.isNotEmpty) {
          customersList = cachedCustomers;
        }
      }

      if (tables.success) {
        await offline.saveTables(tablesData);
      }
      if (items.success) {
        await offline.saveItems(itemsList);
      }
      if (customers.success) {
        await offline.saveCustomers(customersList);
      }
      final pending = await offline.readPendingSales();
      _pendingSalesCount = pending.length;

      // Initialize customers pagination
      _allCustomers = List<Map<String, dynamic>>.from(customersList);
      _customersPage = 1;
      _customersHasMore =
          customers.meta['has_more'] == true && customersList.isNotEmpty;
      _isLoadingMoreCustomers = false;

      _allItems = List<Map<String, dynamic>>.from(itemsList);
      _itemsPage = 1;
      _itemsHasMore = items.meta['has_more'] == true && itemsList.isNotEmpty;
      _isLoadingItems = false;

      if (_selectedCustomer == null) {
        final defaultCustomer =
            customersList.cast<Map<String, dynamic>?>().firstWhere(
                  (row) => row?['number']?.toString() == '99999999',
                  orElse: () => null,
                );
        if (defaultCustomer != null) {
          _selectedCustomer = Map<String, dynamic>.from(defaultCustomer);
        }
      }

      return _SalesBundle(
        tables: tablesData,
        tablesSuccess: tables.success || tablesData.isNotEmpty,
        tablesMessage: tables.success
            ? tables.message
            : (tablesData.isNotEmpty
                ? 'Cargando datos locales.'
                : tables.message),
        items: itemsList,
        itemsSuccess: items.success || itemsList.isNotEmpty,
        itemsMessage: items.success
            ? items.message
            : (itemsList.isNotEmpty ? 'Catalogo local.' : items.message),
        customers: customersList,
        customersSuccess: customers.success || customersList.isNotEmpty,
        customersMessage: customers.success
            ? customers.message
            : (customersList.isNotEmpty
                ? 'Clientes locales.'
                : customers.message),
      );
    } catch (e) {
      final rawError = e.toString();
      final isNetworkError = _looksLikeNetworkError(rawError);
      final cachedTables = await offline.readTables();
      final cachedItems = await offline.readItems();
      final cachedCustomers = await offline.readCustomers();
      final pending = await offline.readPendingSales();
      _pendingSalesCount = pending.length;
      final offlineFallbackMessage = isNetworkError
          ? 'Sin internet. Para vender offline primero carga Ventas una vez con conexion para guardar catalogo y clientes.'
          : rawError;
      return _SalesBundle(
        tables: cachedTables,
        tablesSuccess: cachedTables.isNotEmpty,
        tablesMessage: cachedTables.isNotEmpty
            ? 'Cargando datos locales.'
            : offlineFallbackMessage,
        items: cachedItems,
        itemsSuccess: cachedItems.isNotEmpty,
        itemsMessage: cachedItems.isNotEmpty ? 'Catalogo local.' : null,
        customers: cachedCustomers,
        customersSuccess: cachedCustomers.isNotEmpty,
        customersMessage:
            cachedCustomers.isNotEmpty ? 'Clientes locales.' : null,
      );
    }
  }

  Future<void> _refresh() async {
    final future = _load();
    setState(() {
      _future = future;
    });
    await future;
  }

  void _showMessage(String message) {
    if (!mounted) {
      return;
    }

    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text(message),
        behavior: SnackBarBehavior.fixed,
      ),
    );
  }

  String _shortDocTypeLabel(Map<String, dynamic> docType) {
    final id = docType['id']?.toString() ?? '';
    const shortNames = {
      '01': 'Factura',
      '03': 'Boleta',
      '07': 'Nota crédito',
      '08': 'Nota débito',
      '80': 'Nota venta',
    };
    return shortNames[id] ?? (docType['description']?.toString() ?? 'Doc');
  }

  Future<void> _openOptionsSheet(_SalesBundle bundle) async {
    _initPaymentTilesIfNeeded(bundle);
    await showModalBottomSheet<void>(
      context: context,
      isScrollControlled: true,
      builder: (sheetCtx) {
        return StatefulBuilder(
          builder: (sheetCtx, setSheetState) {
            final documentTypeId = _resolvedDocumentTypeId(bundle);
            final seriesId = _resolvedSeriesId(bundle, documentTypeId);
            final paymentConditionId = _resolvedPaymentConditionId(bundle);
            final activeSeries = bundle.seriesFor(documentTypeId);
            final totals = _calculateTotals();
            final covered = _paymentsCovered;
            final pending = totals.total - covered;

            return SafeArea(
              child: SingleChildScrollView(
                padding: EdgeInsets.fromLTRB(
                  20,
                  16,
                  20,
                  24 + MediaQuery.of(sheetCtx).viewInsets.bottom,
                ),
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Row(
                      children: [
                        const Icon(Icons.tune_rounded,
                            color: AppTokens.primary),
                        const SizedBox(width: 10),
                        Text(
                          'Opciones del comprobante',
                          style: Theme.of(context).textTheme.titleMedium,
                        ),
                      ],
                    ),
                    const SizedBox(height: 18),
                    Wrap(
                      spacing: 8,
                      runSpacing: 8,
                      children: [
                        for (final docType in bundle.documentTypes)
                          ChoiceChip(
                            label: Text(_shortDocTypeLabel(docType)),
                            selected:
                                documentTypeId == docType['id']?.toString(),
                            onSelected: (_) {
                              _setDocumentType(
                                  docType['id']?.toString(), bundle);
                              setSheetState(() {});
                            },
                          ),
                      ],
                    ),
                    const SizedBox(height: 14),
                    DropdownButtonFormField<int>(
                      initialValue: seriesId,
                      isExpanded: true,
                      decoration: const InputDecoration(
                        labelText: 'Serie',
                        prefixIcon: Icon(Icons.confirmation_number_rounded),
                      ),
                      items: [
                        for (final series in activeSeries)
                          DropdownMenuItem<int>(
                            value: _asInt(series['id']),
                            child:
                                Text(series['number']?.toString() ?? 'Serie'),
                          ),
                      ],
                      onChanged: (value) {
                        setState(() => _seriesId = value);
                        setSheetState(() {});
                      },
                    ),
                    const SizedBox(height: 14),
                    DropdownButtonFormField<String>(
                      initialValue: paymentConditionId,
                      isExpanded: true,
                      decoration: const InputDecoration(
                        labelText: 'Condición de pago',
                        prefixIcon: Icon(Icons.account_balance_wallet_rounded),
                      ),
                      items: [
                        for (final condition in bundle.paymentConditions)
                          DropdownMenuItem<String>(
                            value: condition['id']?.toString(),
                            child: Text(condition['name']?.toString() ??
                                condition['description']?.toString() ??
                                'Condicion'),
                          ),
                      ],
                      onChanged: (value) {
                        setState(() => _paymentConditionId = value);
                        setSheetState(() {});
                      },
                    ),
                    if (paymentConditionId == '01') ...[
                      const SizedBox(height: 18),
                      Row(
                        children: [
                          const Icon(Icons.payments_rounded,
                              size: 18, color: AppTokens.secondary),
                          const SizedBox(width: 6),
                          Text(
                            'Métodos de pago',
                            style: Theme.of(context).textTheme.titleSmall,
                          ),
                          const Spacer(),
                          TextButton.icon(
                            onPressed: () {
                              setState(() {
                                _paymentsTouched = false;
                                _methodReferences.clear();
                                _initPaymentTilesIfNeeded(bundle);
                              });
                              setSheetState(() {});
                            },
                            icon: const Icon(Icons.refresh_rounded, size: 16),
                            label: const Text('Resetear'),
                          ),
                        ],
                      ),
                      const SizedBox(height: 8),
                      for (final method in bundle.paymentMethodTypes.where((m) {
                        final isCredit = m['is_credit'];
                        final isCreditFlag = isCredit == true ||
                            isCredit == 1 ||
                            isCredit?.toString() == '1' ||
                            isCredit?.toString() == 'true';
                        return !isCreditFlag;
                      }))
                        Padding(
                          padding: const EdgeInsets.only(bottom: 8),
                          child: _PaymentMethodTile(
                            method: method,
                            controller:
                                _ctrlForMethod(method['id']?.toString() ?? ''),
                            isActive: _amountForMethod(
                                    method['id']?.toString() ?? '') >
                                0,
                            isSelected:
                                _activeMethodId == method['id']?.toString(),
                            reference: _methodReferences[
                                method['id']?.toString() ?? ''],
                            isCash: (method['id']?.toString() ?? '') ==
                                _defaultPaymentMethodTypeId(bundle),
                            onTap: () {
                              final id = method['id']?.toString() ?? '';
                              setState(() {
                                _paymentsTouched = true;
                                _onPaymentTileTapped(id, totals.total);
                              });
                              setSheetState(() {});
                            },
                            onAmountChanged: (_) {
                              final id = method['id']?.toString() ?? '';
                              setState(() {
                                _paymentsTouched = true;
                                _activeMethodId = id;
                              });
                              setSheetState(() {});
                            },
                            onReferenceTap: () async {
                              final id = method['id']?.toString() ?? '';
                              final value = await _askReference(
                                method['description']?.toString() ?? 'Pago',
                                _methodReferences[id] ?? '',
                              );
                              if (value != null) {
                                setState(() {
                                  _methodReferences[id] = value;
                                  _paymentsTouched = true;
                                });
                                setSheetState(() {});
                              }
                            },
                          ),
                        ),
                      Container(
                        padding: const EdgeInsets.symmetric(
                            horizontal: 12, vertical: 12),
                        decoration: BoxDecoration(
                          color: pending.abs() < 0.01
                              ? AppTokens.success.withValues(alpha: 0.10)
                              : pending > 0
                                  ? AppTokens.warning.withValues(alpha: 0.10)
                                  : AppTokens.primary.withValues(alpha: 0.10),
                          borderRadius:
                              BorderRadius.circular(AppTokens.radiusSmall),
                        ),
                        child: Row(
                          children: [
                            Icon(
                              pending.abs() < 0.01
                                  ? Icons.check_circle_rounded
                                  : pending > 0
                                      ? Icons.info_outline_rounded
                                      : Icons.attach_money_rounded,
                              size: 18,
                              color: pending.abs() < 0.01
                                  ? AppTokens.success
                                  : pending > 0
                                      ? AppTokens.warning
                                      : AppTokens.primary,
                            ),
                            const SizedBox(width: 8),
                            Expanded(
                              child: Text(
                                pending.abs() < 0.01
                                    ? 'Total: S/ ${totals.total.toStringAsFixed(2)}'
                                    : pending > 0
                                        ? 'Faltante: S/ ${pending.toStringAsFixed(2)}'
                                        : 'Vuelto: S/ ${(-pending).toStringAsFixed(2)}',
                                style: Theme.of(context)
                                    .textTheme
                                    .bodyMedium
                                    ?.copyWith(fontWeight: FontWeight.w600),
                              ),
                            ),
                            Text(
                              'Pagado: S/ ${covered.toStringAsFixed(2)}',
                              style: Theme.of(context).textTheme.bodySmall,
                            ),
                          ],
                        ),
                      ),
                    ],
                    const SizedBox(height: 14),
                    TextField(
                      controller: _notesController,
                      minLines: 2,
                      maxLines: 4,
                      decoration: const InputDecoration(
                        labelText: 'Observaciones',
                        prefixIcon: Icon(Icons.sticky_note_2_rounded),
                      ),
                    ),
                    const SizedBox(height: 18),
                    SizedBox(
                      width: double.infinity,
                      child: FilledButton.icon(
                        onPressed: () => Navigator.of(sheetCtx).pop(),
                        icon: const Icon(Icons.check_rounded),
                        label: const Text('Cerrar opciones'),
                      ),
                    ),
                  ],
                ),
              ),
            );
          },
        );
      },
    );
    if (mounted) setState(() {});
  }

  Future<String?> _askReference(String methodName, String current) async {
    final controller = TextEditingController(text: current);
    return showDialog<String>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: Text('Referencia · $methodName'),
        content: TextField(
          controller: controller,
          autofocus: true,
          decoration: const InputDecoration(
            hintText: 'Ej. operación, voucher, últimos 4',
          ),
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            child: const Text('Cancelar'),
          ),
          FilledButton(
            onPressed: () => Navigator.pop(ctx, controller.text.trim()),
            child: const Text('Guardar'),
          ),
        ],
      ),
    );
  }

  Future<void> _scanSalesBarcode() async {
    final value = await context.push<String>('/scanner');
    if (value == null || value.isEmpty || !mounted) return;
    _searchController.text = value;
    setState(() {});
  }

  Future<bool> _ensureCashOpen() async {
    final api = ref.read(apiClientProvider);
    final response = await api.cashStatus();
    if (!mounted) {
      return false;
    }

    if (!response.success) {
      if (_looksLikeNetworkError(response.message)) {
        _showMessage(
          'Sin internet. Se continuara en modo offline y la venta se guardara en cola.',
        );
        return true;
      }
      _showMessage(
          response.message ?? 'No se pudo validar el estado de la caja.');
      return false;
    }

    final data = response.data ?? const <String, dynamic>{};
    final hasOpenCash = data['has_open_cash'] == true || data['cash'] != null;
    if (hasOpenCash) {
      return true;
    }

    await _openCashSheetForSales();
    return false;
  }

  Future<void> _openCashSheetForSales() async {
    final beginningBalanceController = TextEditingController(text: '0');
    final formKey = GlobalKey<FormState>();
    String? errorText;
    var isSubmitting = false;

    await showModalBottomSheet<void>(
      context: context,
      isScrollControlled: true,
      builder: (context) {
        return StatefulBuilder(
          builder: (context, setSheetState) {
            Future<void> submit() async {
              if (!(formKey.currentState?.validate() ?? false) ||
                  isSubmitting) {
                return;
              }

              setSheetState(() {
                isSubmitting = true;
                errorText = null;
              });

              final api = ref.read(apiClientProvider);
              final response = await api.openCash(
                beginningBalance:
                    double.tryParse(beginningBalanceController.text.trim()) ??
                        0,
              );

              if (!response.success) {
                setSheetState(() {
                  isSubmitting = false;
                  errorText =
                      response.message ?? 'No se pudo aperturar la caja.';
                });
                return;
              }

              if (!context.mounted) return;
              if (Navigator.of(context).canPop()) {
                Navigator.of(context).pop();
              }
              _showMessage(response.message ?? 'Caja aperturada.');
            }

            return SafeArea(
              child: SingleChildScrollView(
                padding: EdgeInsets.fromLTRB(
                  20,
                  8,
                  20,
                  24 + MediaQuery.of(context).viewInsets.bottom,
                ),
                child: Form(
                  key: formKey,
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Row(
                        children: [
                          CircleAvatar(
                            backgroundColor:
                                AppTokens.success.withValues(alpha: 0.12),
                            foregroundColor: AppTokens.success,
                            child: const Icon(Icons.lock_open_rounded),
                          ),
                          const SizedBox(width: 12),
                          Expanded(
                            child: Column(
                              crossAxisAlignment: CrossAxisAlignment.start,
                              children: [
                                Text(
                                  'Aperturar caja',
                                  style:
                                      Theme.of(context).textTheme.headlineSmall,
                                ),
                                const SizedBox(height: 4),
                                Text(
                                  'Abre la caja con un saldo inicial para empezar a emitir.',
                                  style: Theme.of(context)
                                      .textTheme
                                      .bodyMedium
                                      ?.copyWith(
                                        color: AppTokens.secondary,
                                      ),
                                ),
                              ],
                            ),
                          ),
                        ],
                      ),
                      const SizedBox(height: 18),
                      TextFormField(
                        controller: beginningBalanceController,
                        keyboardType: const TextInputType.numberWithOptions(
                            decimal: true),
                        decoration: const InputDecoration(
                          labelText: 'Saldo inicial',
                          prefixIcon: Icon(Icons.payments_rounded),
                        ),
                        validator: (value) {
                          if (value == null || value.trim().isEmpty) {
                            return 'Ingresa el saldo inicial.';
                          }
                          if (double.tryParse(value.trim()) == null) {
                            return 'Ingresa un monto valido.';
                          }
                          return null;
                        },
                      ),
                      if (errorText != null) ...[
                        const SizedBox(height: 12),
                        Text(
                          errorText!,
                          style:
                              Theme.of(context).textTheme.bodyMedium?.copyWith(
                                    color: AppTokens.danger,
                                  ),
                        ),
                      ],
                      const SizedBox(height: 16),
                      SizedBox(
                        width: double.infinity,
                        child: FilledButton(
                          onPressed: isSubmitting ? null : submit,
                          child: Text(isSubmitting
                              ? 'Procesando...'
                              : 'Aperturar caja'),
                        ),
                      ),
                    ],
                  ),
                ),
              ),
            );
          },
        );
      },
    );
  }

  String? _resolvedDocumentTypeId(_SalesBundle bundle) {
    if (_documentTypeId != null) {
      return _documentTypeId;
    }

    if (bundle.documentTypes.isEmpty) {
      return null;
    }

    final defaultType =
        bundle.documentTypes.cast<Map<String, dynamic>?>().firstWhere(
              (row) => row?['id']?.toString() == '03',
              orElse: () => null,
            );

    return defaultType?['id']?.toString() ??
        bundle.documentTypes.first['id']?.toString();
  }

  int? _resolvedSeriesId(_SalesBundle bundle, String? documentTypeId) {
    if (_seriesId != null) {
      final exists = bundle
          .seriesFor(documentTypeId)
          .any((row) => _asInt(row['id']) == _seriesId);
      if (exists) {
        return _seriesId;
      }
    }

    final currentSeries = bundle.seriesFor(documentTypeId);
    if (currentSeries.isEmpty) {
      return null;
    }

    final defaultSeries =
        currentSeries.cast<Map<String, dynamic>?>().firstWhere(
              (row) => row?['is_default'] == true,
              orElse: () => null,
            );

    return _asInt(defaultSeries?['id']) ?? _asInt(currentSeries.first['id']);
  }

  String _resolvedPaymentConditionId(_SalesBundle bundle) {
    if (_paymentConditionId != null) {
      return _paymentConditionId!;
    }

    final defaultRow =
        bundle.paymentConditions.cast<Map<String, dynamic>?>().firstWhere(
              (row) => row?['id']?.toString() == '01',
              orElse: () => null,
            );

    return defaultRow?['id']?.toString() ?? '01';
  }

  String _defaultPaymentMethodTypeId(_SalesBundle bundle) {
    return bundle.paymentMethodTypes.isNotEmpty
        ? bundle.paymentMethodTypes.first['id']?.toString() ?? '01'
        : '01';
  }

  String? _defaultPaymentDestinationId(_SalesBundle bundle) {
    if (bundle.paymentDestinations.isEmpty) return null;
    final cash =
        bundle.paymentDestinations.cast<Map<String, dynamic>?>().firstWhere(
              (row) => row?['id']?.toString() == 'cash',
              orElse: () => null,
            );
    return cash?['id']?.toString() ??
        bundle.paymentDestinations.first['id']?.toString();
  }

  TextEditingController _ctrlForMethod(String id) {
    return _methodAmountControllers.putIfAbsent(
      id,
      () => TextEditingController(text: '0.00'),
    );
  }

  double _amountForMethod(String id) {
    final txt = _methodAmountControllers[id]?.text.trim() ?? '';
    return double.tryParse(txt) ?? 0;
  }

  void _setAmountForMethod(String id, double amount) {
    final ctrl = _ctrlForMethod(id);
    ctrl.text = amount > 0 ? amount.toStringAsFixed(2) : '0.00';
    ctrl.selection = TextSelection.fromPosition(
      TextPosition(offset: ctrl.text.length),
    );
  }

  void _initPaymentTilesIfNeeded(_SalesBundle bundle) {
    final cashMethods = bundle.paymentMethodTypes.where((m) {
      // Excluye crédito (factura a 30 días, etc.) en condición contado.
      final isCredit = m['is_credit'];
      final isCreditFlag = isCredit == true ||
          isCredit == 1 ||
          isCredit?.toString() == '1' ||
          isCredit?.toString() == 'true';
      if (isCreditFlag) return false;

      // Respeta el active_pos del POS web.
      final activePos = m['active_pos'];
      if (activePos == null) return true;
      if (activePos is bool) return activePos;
      return activePos.toString() == '1' || activePos.toString() == 'true';
    }).toList();
    if (cashMethods.isEmpty) return;
    for (final m in cashMethods) {
      final id = m['id']?.toString() ?? '';
      if (id.isEmpty) continue;
      _ctrlForMethod(id);
    }
    if (!_paymentsTouched) {
      final totals = _calculateTotals();
      final cashId = cashMethods.first['id']?.toString() ?? '01';
      for (final m in cashMethods) {
        final id = m['id']?.toString() ?? '';
        if (id.isNotEmpty) _setAmountForMethod(id, 0);
      }
      _setAmountForMethod(cashId, totals.total);
      _activeMethodId = cashId;
      _methodReferences.clear();
    }
  }

  double get _paymentsCovered {
    var sum = 0.0;
    for (final entry in _methodAmountControllers.entries) {
      sum += _amountForMethod(entry.key);
    }
    return sum;
  }

  void _onPaymentTileTapped(String id, double totalDocument) {
    final tappedAmount = _amountForMethod(id);
    final activeBefore = _activePayments();

    // Tap en un tile activo → toggle off (quita su monto).
    if (tappedAmount > 0 && _activeMethodId == id) {
      _setAmountForMethod(id, 0);
      // Si quedó sin métodos activos, vuelve a marcar éste como seleccionado vacío.
      final remaining = _activePayments();
      _activeMethodId = remaining.isNotEmpty ? remaining.first.key : id;
      return;
    }

    // Caso 1: hay un método activo que ya cubre el total → transferir todo al tapeado.
    if (activeBefore.length == 1 &&
        (activeBefore.first.value - totalDocument).abs() < 0.01 &&
        totalDocument > 0) {
      _setAmountForMethod(activeBefore.first.key, 0);
      _setAmountForMethod(id, totalDocument);
      _activeMethodId = id;
      return;
    }

    // Caso 2: pago mixto en construcción → asigna lo que falta al nuevo método.
    final covered = _paymentsCovered;
    final remaining = totalDocument - covered;
    if (remaining > 0) {
      _setAmountForMethod(id, _amountForMethod(id) + remaining);
    } else if (tappedAmount <= 0) {
      // Nada falta; activa el método con el total para reemplazo manual.
      _setAmountForMethod(id, totalDocument);
    }
    _activeMethodId = id;
  }

  List<MapEntry<String, double>> _activePayments() {
    final list = <MapEntry<String, double>>[];
    for (final entry in _methodAmountControllers.entries) {
      final amount = _amountForMethod(entry.key);
      if (amount > 0) list.add(MapEntry(entry.key, amount));
    }
    return list;
  }

  void _onSearchChanged() {
    _searchDebounce?.cancel();
    _searchDebounce = Timer(const Duration(milliseconds: 350), () {
      _searchItems(query: _searchController.text.trim());
    });
  }

  Future<void> _searchItems({required String query}) async {
    final normalized = query.trim();
    if (_itemsQuery == normalized && _allItems.isNotEmpty) {
      return;
    }

    setState(() {
      _itemsQuery = normalized;
      _isLoadingItems = true;
    });

    final response = await ref.read(apiClientProvider).items(
          perPage: 40,
          page: 1,
          context: 'sale',
          search: normalized.isEmpty ? null : normalized,
        );

    if (!mounted) {
      return;
    }

    setState(() {
      _allItems = response.data ?? const <Map<String, dynamic>>[];
      _itemsPage = 1;
      _itemsHasMore = response.meta['has_more'] == true && _allItems.isNotEmpty;
      _isLoadingItems = false;
    });
  }

  Future<void> _loadMoreItems() async {
    if (_isLoadingItems || !_itemsHasMore) {
      return;
    }

    setState(() => _isLoadingItems = true);

    final response = await ref.read(apiClientProvider).items(
          perPage: 40,
          page: _itemsPage + 1,
          context: 'sale',
          search: _itemsQuery.isEmpty ? null : _itemsQuery,
        );

    if (!mounted) {
      return;
    }

    final newItems = response.data ?? const <Map<String, dynamic>>[];
    setState(() {
      _allItems.addAll(newItems);
      _itemsPage += 1;
      _itemsHasMore = response.meta['has_more'] == true && newItems.isNotEmpty;
      _isLoadingItems = false;
    });
  }

  List<Map<String, dynamic>> _filteredItems(_SalesBundle bundle) {
    if (_allItems.isNotEmpty || _itemsQuery.isNotEmpty || _isLoadingItems) {
      return _allItems;
    }

    return bundle.items;
  }

  void _setDocumentType(String? value, _SalesBundle bundle) {
    setState(() {
      _documentTypeId = value;
      _seriesId = _resolvedSeriesId(bundle, value);
    });
  }

  Future<void> _addItem(Map<String, dynamic> item) async {
    final itemId = _asInt(item['id']);
    if (itemId == null) {
      return;
    }

    final isService = _isService(item);
    final stock = _itemStock(item);
    final unitTypes = _itemUnitTypes(item);
    final presentation = await _pickPresentation(item);
    if (unitTypes.length > 1 && presentation == null) {
      return;
    }
    final selectedUnitTypeId =
        presentation?.unitTypeId ?? item['unit_type_id']?.toString();
    final quantityFactor = presentation?.quantityUnit ?? 1;
    final unitPrice = presentation?.unitPrice ?? _saleUnitPriceForCart(item);

    if (!isService && stock <= 0) {
      _showMessage('El producto no tiene stock disponible.');
      return;
    }
    if (!isService && quantityFactor > stock) {
      _showMessage('La cantidad supera el stock disponible.');
      return;
    }

    final existingIndex = _cart.indexWhere(
      (line) =>
          line.itemId == itemId &&
          line.presentationUnitTypeId == selectedUnitTypeId,
    );
    setState(() {
      if (existingIndex >= 0) {
        final nextQuantity = _cart[existingIndex].quantity + 1;
        if (!isService && nextQuantity * quantityFactor > stock) {
          _showMessage('La cantidad supera el stock disponible.');
          return;
        }
        _cart[existingIndex].quantity += 1;
      } else {
        _cart.add(_CartLine(
          item: Map<String, dynamic>.from(item),
          quantity: 1,
          unitPrice: unitPrice,
          presentationUnitTypeId: selectedUnitTypeId,
          presentationDescription: presentation?.description,
          quantityFactor: quantityFactor,
        ));
      }
    });
  }

  void _changeQuantity(_CartLine line, double delta) {
    final nextQuantity = line.quantity + delta;
    if (nextQuantity <= 0) {
      setState(() => _cart.remove(line));
      return;
    }

    final isService = _isService(line.item);
    final stock = _itemStock(line.item);
    if (!isService && delta > 0 && nextQuantity * line.quantityFactor > stock) {
      _showMessage('La cantidad supera el stock disponible.');
      return;
    }

    setState(() => line.quantity = nextQuantity);
  }

  double _itemStock(Map<String, dynamic> item) {
    if (_isService(item)) {
      return double.infinity;
    }
    return _asDouble(item['stock']);
  }

  bool _isService(Map<String, dynamic> item) {
    final unitType = item['unit_type_id']?.toString().toUpperCase();
    if (unitType == 'ZZ') {
      return true;
    }
    final itemType = item['item_type_id']?.toString();
    return itemType == '02';
  }

  Future<void> _loadMoreCustomers(
      void Function(void Function()) setSheetState) async {
    if (_isLoadingMoreCustomers || !_customersHasMore) {
      return;
    }

    setSheetState(() => _isLoadingMoreCustomers = true);

    try {
      final response = await ref.read(apiClientProvider).customers(
            perPage: 60,
            page: _customersPage + 1,
          );

      if (response.success) {
        final newItems = response.data ?? const [];
        final moreAvailable = response.meta['has_more'] == true;

        setSheetState(() {
          _allCustomers.addAll(newItems);
          _customersPage += 1;
          _customersHasMore = moreAvailable && newItems.isNotEmpty;
          _isLoadingMoreCustomers = false;
        });
      } else {
        setSheetState(() => _isLoadingMoreCustomers = false);
      }
    } catch (_) {
      setSheetState(() => _isLoadingMoreCustomers = false);
    }
  }

  Future<void> _selectCustomer(_SalesBundle bundle) async {
    final customerScrollController = ScrollController();

    final picked = await showModalBottomSheet<Map<String, dynamic>>(
      context: context,
      isScrollControlled: true,
      builder: (context) {
        var query = '';

        return StatefulBuilder(
          builder: (context, setSheetState) {
            // Attach scroll listener for customer pagination
            customerScrollController.removeListener(() {});
            void onCustomerScroll() {
              if (customerScrollController.hasClients &&
                  customerScrollController.position.pixels >=
                      customerScrollController.position.maxScrollExtent - 200) {
                _loadMoreCustomers(setSheetState);
              }
            }

            customerScrollController.addListener(onCustomerScroll);

            final source =
                _allCustomers.isNotEmpty ? _allCustomers : bundle.customers;
            final filtered = query.trim().isEmpty
                ? source
                : source.where((customer) {
                    final text = [
                      customer['description'],
                      customer['name'],
                      customer['number'],
                    ].whereType<String>().join(' ').toLowerCase();

                    return text.contains(query.trim().toLowerCase());
                  }).toList();

            return SafeArea(
              child: Padding(
                padding: EdgeInsets.fromLTRB(
                  20,
                  8,
                  20,
                  24 + MediaQuery.of(context).viewInsets.bottom,
                ),
                child: SizedBox(
                  height: MediaQuery.of(context).size.height * 0.72,
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text('Seleccionar cliente',
                          style: Theme.of(context).textTheme.headlineSmall),
                      const SizedBox(height: 8),
                      Text(
                        'Elige el receptor antes de emitir el comprobante o la nota.',
                        style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                              color: AppTokens.secondary,
                            ),
                      ),
                      const SizedBox(height: 16),
                      TextField(
                        decoration: const InputDecoration(
                          labelText: 'Buscar cliente',
                          prefixIcon: Icon(Icons.search_rounded),
                        ),
                        onChanged: (value) =>
                            setSheetState(() => query = value),
                      ),
                      const SizedBox(height: 16),
                      Expanded(
                        child: filtered.isEmpty
                            ? const EmptyStatePanel(
                                icon: Icons.person_off_rounded,
                                title: 'No hay coincidencias',
                                subtitle:
                                    'Prueba con documento, nombre o razon social.',
                              )
                            : ListView.separated(
                                controller: customerScrollController,
                                itemCount: filtered.length +
                                    (_isLoadingMoreCustomers ? 1 : 0),
                                separatorBuilder: (_, __) =>
                                    const SizedBox(height: 10),
                                itemBuilder: (context, index) {
                                  if (index >= filtered.length) {
                                    return const Padding(
                                      padding:
                                          EdgeInsets.symmetric(vertical: 16),
                                      child: Center(
                                        child: SizedBox(
                                          width: 24,
                                          height: 24,
                                          child: CircularProgressIndicator(
                                              strokeWidth: 2),
                                        ),
                                      ),
                                    );
                                  }

                                  final customer = filtered[index];
                                  final selected = _asInt(customer['id']) ==
                                      _asInt(_selectedCustomer?['id']);

                                  return InkWell(
                                    borderRadius: BorderRadius.circular(
                                        AppTokens.radiusMedium),
                                    onTap: () =>
                                        Navigator.of(context).pop(customer),
                                    child: Ink(
                                      padding: const EdgeInsets.all(16),
                                      decoration: BoxDecoration(
                                        color: selected
                                            ? AppTokens.primary
                                                .withValues(alpha: 0.08)
                                            : AppTokens.surface,
                                        borderRadius: BorderRadius.circular(
                                            AppTokens.radiusMedium),
                                        border: Border.all(
                                          color: selected
                                              ? AppTokens.primary
                                              : AppTokens.border,
                                        ),
                                      ),
                                      child: Row(
                                        children: [
                                          CircleAvatar(
                                            backgroundColor: AppTokens.primary
                                                .withValues(alpha: 0.12),
                                            foregroundColor: AppTokens.primary,
                                            child: const Icon(
                                                Icons.person_rounded),
                                          ),
                                          const SizedBox(width: 14),
                                          Expanded(
                                            child: Column(
                                              crossAxisAlignment:
                                                  CrossAxisAlignment.start,
                                              children: [
                                                Text(
                                                  customer['name']
                                                          ?.toString() ??
                                                      'Cliente',
                                                  style: Theme.of(context)
                                                      .textTheme
                                                      .titleMedium,
                                                ),
                                                const SizedBox(height: 4),
                                                Text(
                                                  customer['description']
                                                          ?.toString() ??
                                                      customer['number']
                                                          ?.toString() ??
                                                      'Sin documento',
                                                  style: Theme.of(context)
                                                      .textTheme
                                                      .bodyMedium
                                                      ?.copyWith(
                                                        color:
                                                            AppTokens.secondary,
                                                      ),
                                                ),
                                              ],
                                            ),
                                          ),
                                          if (selected)
                                            const Icon(
                                              Icons.check_circle_rounded,
                                              color: AppTokens.primary,
                                            ),
                                        ],
                                      ),
                                    ),
                                  );
                                },
                              ),
                      ),
                    ],
                  ),
                ),
              ),
            );
          },
        );
      },
    );

    customerScrollController.dispose();

    if (picked == null) {
      return;
    }

    setState(() => _selectedCustomer = Map<String, dynamic>.from(picked));
  }

  Future<void> _showDocumentDetail(
    Map<String, dynamic> record,
    _SalesBundle bundle,
  ) async {
    Map<String, dynamic> detail = Map<String, dynamic>.from(record);
    final id = _asInt(record['id']);
    final model = record['model']?.toString() ?? 'document';

    if (id != null) {
      final response = await ref
          .read(apiClientProvider)
          .documentDetail(id: id, model: model);
      if (response.success && response.data != null) {
        detail = Map<String, dynamic>.from(response.data!);
      }
    }

    final pdfUrl = detail['pdf_url']?.toString();
    final ticketUrl = detail['ticket_url']?.toString();
    final normalizedPdfUrl = (pdfUrl ?? '').trim();
    final normalizedTicketUrl = (ticketUrl ?? '').trim();
    final compactPdfUrl =
        normalizedTicketUrl.isNotEmpty ? normalizedTicketUrl : normalizedPdfUrl;
    final hasCompactPdf = compactPdfUrl.isNotEmpty;
    final hasShareableLink =
        normalizedTicketUrl.isNotEmpty || normalizedPdfUrl.isNotEmpty;
    final numberFull = detail['number_full']?.toString() ?? 'Comprobante';
    final customer = detail['customer']?['description']?.toString() ?? '';
    final currency = detail['currency_type_id']?.toString() ?? 'PEN';
    final total = _formatNumber(_asDouble(detail['total']));
    final dateOfIssue = detail['date_of_issue']?.toString() ?? '-';

    if (!mounted) {
      return;
    }

    await showModalBottomSheet<void>(
      context: context,
      isScrollControlled: true,
      builder: (context) {
        void closeSheet() {
          Navigator.of(context).pop();
        }

        void suppressCartSheet() {
          _suppressCartSheet = true;
          Future<void>.delayed(const Duration(milliseconds: 500), () {
            if (!mounted) {
              return;
            }
            setState(() => _suppressCartSheet = false);
          });
        }

        void scrollToCatalog() {
          final target = _catalogKey.currentContext;
          if (target == null) {
            return;
          }
          Scrollable.ensureVisible(
            target,
            duration: const Duration(milliseconds: 300),
            curve: Curves.easeOut,
          );
        }

        return SafeArea(
          child: SingleChildScrollView(
            padding: const EdgeInsets.fromLTRB(20, 12, 20, 24),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Container(
                  width: double.infinity,
                  padding: const EdgeInsets.all(14),
                  decoration: BoxDecoration(
                    color: AppTokens.success.withValues(alpha: 0.10),
                    borderRadius: BorderRadius.circular(AppTokens.radiusMedium),
                    border: Border.all(
                      color: AppTokens.success.withValues(alpha: 0.28),
                    ),
                  ),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Row(
                        children: [
                          TweenAnimationBuilder<double>(
                            tween: Tween(begin: 0, end: 1),
                            duration: const Duration(milliseconds: 500),
                            curve: Curves.elasticOut,
                            builder: (context, value, child) => Transform.scale(
                              scale: value,
                              child: child,
                            ),
                            child: const Icon(Icons.check_circle_rounded,
                                color: AppTokens.success, size: 28),
                          ),
                          const SizedBox(width: 8),
                          Text(
                            'Venta exitosa',
                            style: Theme.of(context).textTheme.titleLarge,
                          ),
                        ],
                      ),
                      const SizedBox(height: 8),
                      Text(
                        numberFull,
                        style:
                            Theme.of(context).textTheme.titleMedium?.copyWith(
                                  fontWeight: FontWeight.w800,
                                ),
                      ),
                      if (customer.isNotEmpty) ...[
                        const SizedBox(height: 4),
                        Text(
                          customer,
                          style:
                              Theme.of(context).textTheme.bodyMedium?.copyWith(
                                    color: AppTokens.secondary,
                                  ),
                        ),
                      ],
                    ],
                  ),
                ),
                const SizedBox(height: 16),
                AppPanel(
                  title: 'Resumen',
                  subtitle: detail['document_type_description']?.toString() ??
                      'Comprobante',
                  child: Column(
                    children: [
                      _InfoRow(label: 'Fecha', value: dateOfIssue),
                      const SizedBox(height: 10),
                      _InfoRow(
                        label: 'Total',
                        value: '$currency $total',
                        emphasize: true,
                      ),
                    ],
                  ),
                ),
                const SizedBox(height: 16),
                AppPanel(
                  title: 'Acciones',
                  subtitle: null,
                  child: Row(
                    children: [
                      Expanded(
                        child: Tooltip(
                          message: 'Imprimir',
                          child: FilledButton.tonal(
                            onPressed: id == null
                                ? null
                                : () => _printTicketDirect(id, model),
                            child: const Icon(Icons.print_rounded),
                          ),
                        ),
                      ),
                      const SizedBox(width: 8),
                      Expanded(
                        child: Tooltip(
                          message: 'PDF',
                          child: FilledButton.tonal(
                            onPressed: hasCompactPdf
                                ? () => _openExternal(compactPdfUrl)
                                : null,
                            child: const Icon(Icons.picture_as_pdf_rounded),
                          ),
                        ),
                      ),
                      const SizedBox(width: 8),
                      Expanded(
                        child: FilledButton.tonal(
                          onPressed: hasShareableLink
                              ? () => _shareWhatsApp(
                                    detail: detail,
                                    pdfUrl: pdfUrl,
                                    ticketUrl: ticketUrl,
                                  )
                              : null,
                          style: FilledButton.styleFrom(
                            padding: const EdgeInsets.symmetric(vertical: 10),
                            backgroundColor:
                                const Color(0xFF25D366).withValues(alpha: 0.14),
                          ),
                          child: Row(
                            mainAxisAlignment: MainAxisAlignment.center,
                            children: [
                              Image.asset(
                                'assets/icon/whatsapp_logo.png',
                                width: 18,
                                height: 18,
                                errorBuilder: (_, __, ___) => const Icon(
                                  Icons.chat_rounded,
                                  size: 18,
                                  color: Color(0xFF25D366),
                                ),
                              ),
                            ],
                          ),
                        ),
                      ),
                    ],
                  ),
                ),
                const SizedBox(height: 16),
                Row(
                  children: [
                    Expanded(
                      child: OutlinedButton(
                        onPressed: () {
                          suppressCartSheet();
                          closeSheet();
                          if (!mounted) {
                            return;
                          }
                          context.go('/home');
                        },
                        child: const Text('Volver'),
                      ),
                    ),
                    const SizedBox(width: 12),
                    Expanded(
                      child: FilledButton(
                        onPressed: () {
                          suppressCartSheet();
                          closeSheet();
                          if (!mounted) {
                            return;
                          }
                          Future<void>.delayed(
                            const Duration(milliseconds: 50),
                            () {
                              if (!mounted) {
                                return;
                              }
                              scrollToCatalog();
                            },
                          );
                        },
                        child: const Text('Nueva venta'),
                      ),
                    ),
                  ],
                ),
              ],
            ),
          ),
        );
      },
    );
  }

  Future<void> _openExternal(String? url) async {
    final value = url?.trim() ?? '';
    if (value.isEmpty) {
      _showMessage('No hay enlace disponible para este documento.');
      return;
    }
    final ok = await launchUrlString(
      value,
      mode: LaunchMode.externalApplication,
    );
    if (!ok && mounted) {
      _showMessage('No se pudo abrir el enlace.');
    }
  }

  Future<void> _printTicketDirect(int documentId, String model) async {
    final messenger = ScaffoldMessenger.of(context);
    final printerReady = await _ensurePrinterConfiguredAndConnected();
    if (!printerReady) {
      return;
    }

    messenger.showSnackBar(
      const SnackBar(
        content: Text('Preparando impresion...'),
        duration: Duration(seconds: 1),
      ),
    );

    final api = ref.read(apiClientProvider);
    final response = await api
        .documentPrintPayload(id: documentId, model: model)
        .timeout(const Duration(seconds: 10));
    if (!response.success || response.data == null) {
      if (!mounted) return;
      messenger.showSnackBar(
        SnackBar(
          content:
              Text(response.message ?? 'No se pudo preparar la impresion.'),
          backgroundColor: AppTokens.danger,
        ),
      );
      return;
    }

    try {
      await BluetoothPrintService()
          .printTicket(response.data!)
          .timeout(const Duration(seconds: 15));
      if (!mounted) return;
      messenger.showSnackBar(
        const SnackBar(content: Text('Ticket enviado a la impresora.')),
      );
    } on StateError {
      if (!mounted) return;
      final goSetup = await showDialog<bool>(
        context: context,
        builder: (ctx) => AlertDialog(
          title: const Text('Impresora no conectada'),
          content: const Text(
            'No hay una impresora Bluetooth conectada. Deseas configurarla ahora?',
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.pop(ctx, false),
              child: const Text('Cancelar'),
            ),
            FilledButton(
              onPressed: () => Navigator.pop(ctx, true),
              child: const Text('Configurar'),
            ),
          ],
        ),
      );
      if (!mounted) return;
      if (goSetup == true) {
        await showPrinterSettings(context, ref);
      }
    } on TimeoutException {
      if (!mounted) return;
      messenger.showSnackBar(
        const SnackBar(
          content: Text('Tiempo de espera agotado al imprimir.'),
          backgroundColor: AppTokens.danger,
        ),
      );
    } catch (e) {
      if (!mounted) return;
      messenger.showSnackBar(
        SnackBar(
          content: Text('Error al imprimir: $e'),
          backgroundColor: AppTokens.danger,
        ),
      );
    }
  }

  Future<bool> _ensurePrinterConfiguredAndConnected() async {
    final storage = ref.read(secureStorageProvider);
    final savedMac = await storage.read(key: _printerMacKey);
    final savedName = await storage.read(key: _printerNameKey);

    if (!mounted) {
      return false;
    }

    if (savedMac == null || savedMac.trim().isEmpty) {
      final goSetup = await showDialog<bool>(
            context: context,
            builder: (ctx) => AlertDialog(
              title: const Text('Impresora no configurada'),
              content: const Text(
                'No tienes una impresora configurada. Conecta y configura una impresora Bluetooth para imprimir.',
              ),
              actions: [
                TextButton(
                  onPressed: () => Navigator.pop(ctx, false),
                  child: const Text('Cancelar'),
                ),
                FilledButton(
                  onPressed: () => Navigator.pop(ctx, true),
                  child: const Text('Configurar'),
                ),
              ],
            ),
          ) ??
          false;

      if (goSetup) {
        if (!mounted) return false;
        await showPrinterSettings(context, ref);
      }
      return false;
    }

    final printService = ref.read(bluetoothPrintServiceProvider);
    final connected = await printService.refreshConnectionStatus();
    if (connected) {
      return true;
    }

    if (!mounted) {
      return false;
    }

    final displayName =
        (savedName == null || savedName.trim().isEmpty) ? savedMac : savedName;
    final goSetup = await showDialog<bool>(
          context: context,
          builder: (ctx) => AlertDialog(
            title: const Text('Impresora desconectada'),
            content: Text(
              'La impresora guardada ($displayName) no esta conectada. Enciendela y vuelve a vincular si es necesario.',
            ),
            actions: [
              TextButton(
                onPressed: () => Navigator.pop(ctx, false),
                child: const Text('Cancelar'),
              ),
              FilledButton(
                onPressed: () => Navigator.pop(ctx, true),
                child: const Text('Configurar'),
              ),
            ],
          ),
        ) ??
        false;

    if (goSetup) {
      if (!mounted) return false;
      await showPrinterSettings(context, ref);
    }
    return false;
  }

  Future<void> _shareWhatsApp({
    required Map<String, dynamic> detail,
    String? pdfUrl,
    String? ticketUrl,
  }) async {
    final link = (ticketUrl ?? pdfUrl ?? '').trim();
    if (link.isEmpty) {
      _showMessage('No hay enlace disponible para compartir.');
      return;
    }

    final number = detail['number_full']?.toString() ?? 'Documento';
    final customer = detail['customer']?['description']?.toString() ?? '';
    final total = _formatNumber(_asDouble(detail['total']));
    final currency = detail['currency_type_id']?.toString() ?? 'PEN';
    final text = [
      number,
      if (customer.isNotEmpty) customer,
      'Total $currency $total',
      link,
    ].join('\n');

    final url = 'https://wa.me/?text=${Uri.encodeComponent(text)}';
    final ok = await launchUrlString(
      url,
      mode: LaunchMode.externalApplication,
    );
    if (!ok && mounted) {
      _showMessage('No se pudo abrir WhatsApp.');
    }
  }

  Future<void> _submitSale(
    _SalesBundle bundle, {
    VoidCallback? onSubmittingChanged,
  }) async {
    final documentTypeId = _resolvedDocumentTypeId(bundle);
    final seriesId = _resolvedSeriesId(bundle, documentTypeId);

    if (_selectedCustomer == null) {
      _showMessage('Selecciona un cliente antes de emitir.');
      return;
    }

    if (documentTypeId == null || seriesId == null) {
      _showMessage('Selecciona un tipo de documento y una serie valida.');
      return;
    }

    if (_cart.isEmpty) {
      _showMessage('Agrega al menos un producto al carrito.');
      return;
    }

    final customerDocumentType =
        _selectedCustomer?['identity_document_type_id']?.toString();
    final totals = _calculateTotals();

    if (documentTypeId == '01' && customerDocumentType != '6') {
      _showMessage('La factura requiere un cliente con RUC.');
      return;
    }

    if (documentTypeId == '03' &&
        totals.total > 700 &&
        !const ['1', '4', '6', '7'].contains(customerDocumentType)) {
      _showMessage(
          'La boleta mayor a 700 requiere un documento valido en el cliente.');
      return;
    }

    // _isSubmitting arranca ANTES de _ensureCashOpen() (que tambien llama a
    // la red) para que el boton muestre "Emitiendo..." durante toda la
    // espera, no solo durante createDocument. onSubmittingChanged fuerza el
    // refresco del bottom sheet (sheetSetState), que vive fuera del arbol de
    // _SalesScreenState y no se entera del setState de aca solo.
    setState(() => _isSubmitting = true);
    onSubmittingChanged?.call();

    final cashReady = await _ensureCashOpen();
    if (!cashReady) {
      if (mounted) setState(() => _isSubmitting = false);
      onSubmittingChanged?.call();
      return;
    }

    final idempotencyKey = _nextIdempotencyKey();
    final payload = _buildPayload(bundle,
        documentTypeId: documentTypeId, seriesId: seriesId);
    final response = await ref.read(apiClientProvider).createDocument(
          payload: payload,
          idempotencyKey: idempotencyKey,
        );

    if (!mounted) {
      return;
    }

    setState(() => _isSubmitting = false);
    onSubmittingChanged?.call();

    if (_handleAuthFailure(response)) {
      return;
    }

    if (!response.success) {
      final isNetworkError = _looksLikeNetworkError(response.message);
      if (isNetworkError) {
        await ref.read(offlinePosStoreProvider).enqueuePendingSale({
          'idempotency_key': idempotencyKey,
          'payload': payload,
          'created_at': DateTime.now().toIso8601String(),
          'attempts': 0,
          'last_error': null,
          'status': 'pending',
        });
        final pending =
            await ref.read(offlinePosStoreProvider).readPendingSales();
        setState(() {
          _pendingSalesCount = pending.length;
          _cart.clear();
          _notesController.clear();
          _paymentsTouched = false;
          _methodReferences.clear();
        });
        _showMessage(
          'Sin internet: venta en cola (${pending.length}). El comprobante fiscal se emitira al sincronizar.',
        );
        return;
      }

      _showMessage(response.message ?? 'No se pudo emitir el documento.');
      return;
    }

    final record = Map<String, dynamic>.from(
      (response.data ?? const <String, dynamic>{})['record'] as Map? ??
          const {},
    );

    setState(() {
      _cart.clear();
      _notesController.clear();
      _paymentsTouched = false;
      _methodReferences.clear();
    });

    _showMessage(response.message ?? 'Documento emitido.');
    await _showDocumentDetail(record, bundle);
  }

  Future<void> _syncPendingSales() async {
    if (_isSyncingPending) return;
    final online = await ref.read(connectivityServiceProvider).isConnected;
    if (!online) return;

    setState(() => _isSyncingPending = true);
    final store = ref.read(offlinePosStoreProvider);
    final api = ref.read(apiClientProvider);
    final pending = await store.readPendingSales();
    final remaining = <Map<String, dynamic>>[];

    for (final row in pending) {
      final payload = Map<String, dynamic>.from(
        row['payload'] as Map? ?? const <String, dynamic>{},
      );
      final key = row['idempotency_key']?.toString() ?? _nextIdempotencyKey();
      final attempts = (row['attempts'] as num?)?.toInt() ?? 0;
      final response = await api.createDocument(
        payload: payload,
        idempotencyKey: key,
      );

      if (!response.success) {
        remaining.add({
          ...row,
          'attempts': attempts + 1,
          'status': 'failed',
          'last_error': response.message,
        });
      }
    }

    await store.replacePendingSales(remaining);
    if (!mounted) return;
    setState(() {
      _pendingSalesCount = remaining.length;
      _isSyncingPending = false;
    });
    if (pending.isNotEmpty) {
      _showMessage(
        remaining.isEmpty
            ? 'Sincronizacion completada.'
            : 'Sincronizacion parcial. Pendientes: ${remaining.length}',
      );
    }
  }

  bool _looksLikeNetworkError(String? message) {
    final value = (message ?? '').toLowerCase();
    return value.contains('socket') ||
        value.contains('timeout') ||
        value.contains('network') ||
        value.contains('connection') ||
        value.contains('conect');
  }

  String _nextIdempotencyKey() {
    final now = DateTime.now().microsecondsSinceEpoch;
    final rand = (now % 1000000).toString().padLeft(6, '0');
    return 'mob-$now-$rand';
  }

  Map<String, dynamic> _buildPayload(
    _SalesBundle bundle, {
    required String documentTypeId,
    required int seriesId,
  }) {
    final now = DateTime.now();
    final dateOfIssue = _formatDate(now);
    final timeOfIssue = _formatTime(now);
    final paymentConditionId = _resolvedPaymentConditionId(bundle);
    final totals = _calculateTotals();
    final currencyTypeId = _cart.isEmpty
        ? 'PEN'
        : (_cart.first.item['currency_type_id']?.toString() ?? 'PEN');

    final defaultDestination = _defaultPaymentDestinationId(bundle);
    final active = _activePayments();
    final payments = paymentConditionId == '01'
        ? active
            .map((entry) => {
                  'id': null,
                  'date_of_payment': dateOfIssue,
                  'payment_method_type_id': entry.key,
                  'payment_destination_id': defaultDestination,
                  'reference': (_methodReferences[entry.key] ?? '').isEmpty
                      ? null
                      : _methodReferences[entry.key],
                  'payment': entry.value,
                })
            .toList()
        : const <Map<String, dynamic>>[];

    final firstMethodId = active.isNotEmpty
        ? active.first.key
        : _defaultPaymentMethodTypeId(bundle);

    final fees = paymentConditionId == '02'
        ? [
            {
              'id': null,
              'date': dateOfIssue,
              'currency_type_id': currencyTypeId,
              'amount': totals.total,
            },
          ]
        : const <Map<String, dynamic>>[];

    return {
      'mobile_compose': true,
      'model': documentTypeId == '80' ? 'sale_note' : 'document',
      'document_type_id': documentTypeId,
      'series_id': seriesId,
      'customer_id': _selectedCustomer?['id'],
      'currency_type_id': currencyTypeId,
      'exchange_rate_sale': 1,
      'date_of_issue': dateOfIssue,
      'time_of_issue': timeOfIssue,
      'date_of_due': dateOfIssue,
      'payment_condition_id': paymentConditionId,
      'payment_method_type_id': firstMethodId,
      'operation_type_id': '0101',
      'additional_information': _notesController.text.trim().isEmpty
          ? null
          : _notesController.text.trim(),
      'total_prepayment': 0,
      'total_discount': 0,
      'total_charge': 0,
      'total_exportation': 0,
      'total_free': 0,
      'total_taxed': totals.taxed,
      'total_unaffected': totals.unaffected,
      'total_exonerated': totals.exonerated,
      'total_igv': totals.igv,
      'total_igv_free': 0,
      'total_base_isc': 0,
      'total_isc': 0,
      'total_base_other_taxes': 0,
      'total_other_taxes': 0,
      'total_plastic_bag_taxes': 0,
      'total_taxes': totals.igv,
      'total_value': totals.value,
      'subtotal': totals.total,
      'total': totals.total,
      'items': _cart.map(_buildLinePayload).toList(),
      'payments': payments,
      'fee': fees,
      'charges': const <Map<String, dynamic>>[],
      'discounts': const <Map<String, dynamic>>[],
      'guides': const <Map<String, dynamic>>[],
      'total_pending_payment': paymentConditionId == '02' ? totals.total : 0,
    };
  }

  Map<String, dynamic> _buildLinePayload(_CartLine line) {
    final row = _calculateLine(line);
    final item = line.item;
    final unitTypeId = line.presentationUnitTypeId ?? item['unit_type_id'];

    return {
      'item_id': line.itemId,
      'item': {
        'id': line.itemId,
        'description': item['description'],
        'internal_id': item['internal_id'],
        'unit_type_id': unitTypeId,
        'sale_unit_price': line.unitPrice,
        'unit_price': line.unitPrice,
        'has_igv': item['has_igv'] == true,
        'purchase_unit_price': 0,
        'is_set': item['is_set'] == true,
        'lots': const <Map<String, dynamic>>[],
      },
      'quantity': line.quantity,
      'unit_value': row.unitValue,
      'price_type_id': '01',
      'unit_price': line.unitPrice,
      'affectation_igv_type_id': row.affectationIgvTypeId,
      'total_base_igv': row.totalBaseIgv,
      'percentage_igv': row.percentageIgv,
      'total_igv': row.totalIgv,
      'system_isc_type_id': null,
      'total_base_isc': 0,
      'percentage_isc': 0,
      'total_isc': 0,
      'total_base_other_taxes': 0,
      'percentage_other_taxes': 0,
      'total_other_taxes': 0,
      'total_plastic_bag_taxes': 0,
      'total_taxes': row.totalTaxes,
      'total_value': row.totalValue,
      'total_charge': 0,
      'total_discount': 0,
      'total': row.total,
      'attributes': const <Map<String, dynamic>>[],
      'charges': const <Map<String, dynamic>>[],
      'discounts': const <Map<String, dynamic>>[],
      'warehouse_id': null,
      'additional_information': null,
      'quantity_factor': line.quantityFactor,
      'presentation_description': line.presentationDescription,
      'presentation_unit_type_id': unitTypeId,
    };
  }

  _CartTotals _calculateTotals() {
    var taxed = 0.0;
    var unaffected = 0.0;
    var exonerated = 0.0;
    var value = 0.0;
    var igv = 0.0;
    var total = 0.0;

    for (final line in _cart) {
      final row = _calculateLine(line);
      value += row.totalValue;
      igv += row.totalIgv;
      total += row.total;

      if (_isTaxed(row.affectationIgvTypeId)) {
        taxed += row.totalValue;
      } else if (_isExonerated(row.affectationIgvTypeId)) {
        exonerated += row.totalValue;
      } else {
        unaffected += row.totalValue;
      }
    }

    return _CartTotals(
      taxed: _round2(taxed),
      unaffected: _round2(unaffected),
      exonerated: _round2(exonerated),
      value: _round2(value),
      igv: _round2(igv),
      total: _round2(total),
    );
  }

  _CalculatedLine _calculateLine(_CartLine line) {
    final affectationIgvTypeId =
        line.item['sale_affectation_igv_type_id']?.toString() ?? '10';
    final quantity = line.quantity;
    final unitPrice = line.unitPrice;
    const percentageIgv = 18.0;
    final taxed = _isTaxed(affectationIgvTypeId);
    final unitValue = taxed ? unitPrice / 1.18 : unitPrice;
    final totalValue = unitValue * quantity;
    final totalIgv = taxed ? totalValue * 0.18 : 0.0;
    final totalTaxes = totalIgv;
    final total = totalValue + totalTaxes;

    return _CalculatedLine(
      affectationIgvTypeId: affectationIgvTypeId,
      percentageIgv: percentageIgv,
      unitValue: _round4(unitValue),
      totalBaseIgv: taxed ? _round2(totalValue) : 0,
      totalValue: _round2(totalValue),
      totalIgv: _round2(totalIgv),
      totalTaxes: _round2(totalTaxes),
      total: _round2(total),
    );
  }

  double _saleUnitPriceForCart(Map<String, dynamic> item) {
    final unitTypes = _itemUnitTypes(item);
    final selected = _defaultPresentationForItem(item, unitTypes);
    final basePrice = selected == null
        ? _asDouble(item['sale_unit_price'])
        : _presentationUnitPrice(item, selected);
    return _normalizeSalePrice(item, basePrice);
  }

  List<Map<String, dynamic>> _itemUnitTypes(Map<String, dynamic> item) {
    return List<Map<String, dynamic>>.from(
        item['item_unit_types'] as List? ?? const []);
  }

  Map<String, dynamic>? _defaultPresentationForItem(
    Map<String, dynamic> item,
    List<Map<String, dynamic>> unitTypes,
  ) {
    if (unitTypes.isEmpty) {
      return null;
    }

    final defaultIndex = unitTypes.indexWhere((row) {
      final priceDefault = int.tryParse(row['price_default']?.toString() ?? '');
      return priceDefault == 1 || priceDefault == 2 || priceDefault == 3;
    });
    if (defaultIndex >= 0) {
      return unitTypes[defaultIndex];
    }

    final baseUnitTypeId = item['unit_type_id']?.toString();
    final baseIndex = unitTypes.indexWhere(
      (row) => row['unit_type_id']?.toString() == baseUnitTypeId,
    );
    if (baseIndex >= 0) {
      return unitTypes[baseIndex];
    }

    return unitTypes.first;
  }

  double _presentationUnitPrice(
    Map<String, dynamic> item,
    Map<String, dynamic> unitType,
  ) {
    final priceDefault =
        int.tryParse(unitType['price_default']?.toString() ?? '');
    final price1 = _asDouble(unitType['price1']);
    final price2 = _asDouble(unitType['price2']);
    final price3 = _asDouble(unitType['price3']);

    final selected = switch (priceDefault) {
      2 => price2,
      3 => price3,
      _ => price1,
    };

    if (selected > 0) {
      return selected;
    }
    if (price1 > 0) return price1;
    if (price2 > 0) return price2;
    if (price3 > 0) return price3;
    return _asDouble(item['sale_unit_price']);
  }

  double _normalizeSalePrice(Map<String, dynamic> item, double basePrice) {
    final hasIgv = item['has_igv'] == true;
    final affectation =
        item['sale_affectation_igv_type_id']?.toString() ?? '10';

    if (_isTaxed(affectation) && !hasIgv) {
      return _round4(basePrice * 1.18);
    }

    return _round4(basePrice);
  }

  Future<_PresentationSelection?> _pickPresentation(
    Map<String, dynamic> item,
  ) async {
    final unitTypes = _itemUnitTypes(item);
    if (unitTypes.isEmpty) {
      return null;
    }

    if (unitTypes.length == 1) {
      final row = unitTypes.first;
      return _PresentationSelection(
        unitTypeId: row['unit_type_id']?.toString(),
        description: row['description']?.toString() ?? 'Presentacion',
        quantityUnit:
            _asDouble(row['quantity_unit']).clamp(1, 999999).toDouble(),
        unitPrice: _normalizeSalePrice(
          item,
          _presentationUnitPrice(item, row),
        ),
      );
    }

    return showModalBottomSheet<_PresentationSelection>(
      context: context,
      isScrollControlled: true,
      builder: (context) {
        return SafeArea(
          child: ListView.separated(
            padding: const EdgeInsets.fromLTRB(20, 20, 20, 24),
            shrinkWrap: true,
            itemCount: unitTypes.length,
            separatorBuilder: (_, __) => const SizedBox(height: 10),
            itemBuilder: (context, index) {
              final row = unitTypes[index];
              final description =
                  row['description']?.toString() ?? 'Presentacion';
              final quantityUnit =
                  _asDouble(row['quantity_unit']).clamp(1, 999999).toDouble();
              final unitPrice = _normalizeSalePrice(
                item,
                _presentationUnitPrice(item, row),
              );
              final unitTypeId = row['unit_type_id']?.toString();

              return ListTile(
                contentPadding: const EdgeInsets.symmetric(horizontal: 8),
                shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(AppTokens.radiusMedium),
                  side: const BorderSide(color: AppTokens.border),
                ),
                title: Text(description),
                subtitle: Text('x${_formatNumber(quantityUnit)}'),
                trailing: Text('PEN ${unitPrice.toStringAsFixed(2)}'),
                onTap: () {
                  Navigator.of(context).pop(
                    _PresentationSelection(
                      unitTypeId: unitTypeId,
                      description: description,
                      quantityUnit: quantityUnit,
                      unitPrice: unitPrice,
                    ),
                  );
                },
              );
            },
          ),
        );
      },
    );
  }

  bool _isTaxed(String affectationIgvTypeId) {
    return affectationIgvTypeId == '10';
  }

  bool _isExonerated(String affectationIgvTypeId) {
    return affectationIgvTypeId.startsWith('2');
  }

  double _asDouble(dynamic value) {
    if (value is num) {
      return value.toDouble();
    }

    return double.tryParse(value?.toString() ?? '') ?? 0;
  }

  int? _asInt(dynamic value) {
    if (value is int) {
      return value;
    }

    return int.tryParse(value?.toString() ?? '');
  }

  double _round2(double value) {
    return double.parse(value.toStringAsFixed(2));
  }

  double _round4(double value) {
    return double.parse(value.toStringAsFixed(4));
  }

  String _formatNumber(double value) {
    if (value == value.roundToDouble()) {
      return value.toStringAsFixed(0);
    }

    return value.toStringAsFixed(2);
  }

  String _formatDate(DateTime value) {
    final month = value.month.toString().padLeft(2, '0');
    final day = value.day.toString().padLeft(2, '0');
    return '${value.year}-$month-$day';
  }

  String _formatTime(DateTime value) {
    final hour = value.hour.toString().padLeft(2, '0');
    final minute = value.minute.toString().padLeft(2, '0');
    final second = value.second.toString().padLeft(2, '0');
    return '$hour:$minute:$second';
  }

  Future<void> _openCartSheet(_SalesBundle bundle) async {
    await showModalBottomSheet<void>(
      context: context,
      isScrollControlled: true,
      useSafeArea: true,
      backgroundColor: Colors.transparent,
      builder: (context) {
        return StatefulBuilder(
          builder: (context, sheetSetState) {
            final totals = _calculateTotals();

            return FractionallySizedBox(
              heightFactor: 0.9,
              child: Container(
                decoration: const BoxDecoration(
                  color: Colors.white,
                  borderRadius: BorderRadius.vertical(top: Radius.circular(28)),
                ),
                child: Column(
                  children: [
                    Padding(
                      padding: const EdgeInsets.fromLTRB(20, 14, 20, 12),
                      child: Row(
                        children: [
                          Container(
                            width: 44,
                            height: 5,
                            decoration: BoxDecoration(
                              color: AppTokens.border,
                              borderRadius: BorderRadius.circular(999),
                            ),
                          ),
                          const Spacer(),
                          Text(
                            'Carrito',
                            style: Theme.of(context).textTheme.titleLarge,
                          ),
                          const Spacer(),
                          IconButton(
                            onPressed: () => Navigator.of(context).pop(),
                            icon: const Icon(Icons.close_rounded),
                          ),
                        ],
                      ),
                    ),
                    Expanded(
                      child: ListView(
                        padding: const EdgeInsets.fromLTRB(20, 0, 20, 20),
                        children: [
                          if (_cart.isEmpty)
                            const EmptyStatePanel(
                              icon: Icons.shopping_cart_outlined,
                              title: 'Sin productos en carrito',
                              subtitle:
                                  'Agrega productos desde el catalogo para calcular la venta.',
                            )
                          else ...[
                            for (final line in _cart) ...[
                              AnimatedOpacity(
                                duration: const Duration(milliseconds: 200),
                                opacity: _removingCartLines.contains(line)
                                    ? 0
                                    : 1,
                                child: AnimatedSize(
                                  duration:
                                      const Duration(milliseconds: 200),
                                  curve: Curves.easeOut,
                                  alignment: Alignment.topCenter,
                                  child: _removingCartLines.contains(line)
                                      ? const SizedBox.shrink()
                                      : _CartItemRow(
                                          line: line,
                                          total: _calculateLine(line).total,
                                          onIncrease: () {
                                            setState(
                                                () => _changeQuantity(line, 1));
                                            sheetSetState(() {});
                                          },
                                          onDecrease: () {
                                            setState(() =>
                                                _changeQuantity(line, -1));
                                            sheetSetState(() {});
                                          },
                                          onRemove: () {
                                            sheetSetState(() =>
                                                _removingCartLines.add(line));
                                            Future.delayed(
                                                const Duration(
                                                    milliseconds: 200), () {
                                              if (!mounted) return;
                                              setState(() {
                                                _cart.remove(line);
                                                _removingCartLines
                                                    .remove(line);
                                              });
                                              try {
                                                sheetSetState(() {});
                                              } catch (_) {
                                                // el modal ya se cerro antes
                                                // de que termine el fade.
                                              }
                                            });
                                          },
                                        ),
                                ),
                              ),
                              if (line != _cart.last)
                                const SizedBox(height: 12),
                            ],
                            const SizedBox(height: 18),
                            Container(
                              width: double.infinity,
                              padding: const EdgeInsets.all(16),
                              decoration: BoxDecoration(
                                color: AppTokens.background,
                                borderRadius: BorderRadius.circular(
                                    AppTokens.radiusMedium),
                                border: Border.all(color: AppTokens.border),
                              ),
                              child: Column(
                                children: [
                                  _InfoRow(
                                      label: 'Operaciones gravadas',
                                      value: _formatNumber(totals.taxed)),
                                  const SizedBox(height: 10),
                                  _InfoRow(
                                      label: 'Operaciones exoneradas',
                                      value: _formatNumber(totals.exonerated)),
                                  const SizedBox(height: 10),
                                  _InfoRow(
                                      label: 'Operaciones inafectas',
                                      value: _formatNumber(totals.unaffected)),
                                  const SizedBox(height: 10),
                                  _InfoRow(
                                      label: 'IGV',
                                      value: _formatNumber(totals.igv)),
                                  const Divider(height: 24),
                                  _InfoRow(
                                    label: 'Total a cobrar',
                                    value: 'PEN ${_formatNumber(totals.total)}',
                                    emphasize: true,
                                  ),
                                ],
                              ),
                            ),
                          ],
                        ],
                      ),
                    ),
                    if (_cart.isNotEmpty)
                      SafeArea(
                        child: Padding(
                          padding: const EdgeInsets.fromLTRB(20, 8, 20, 16),
                          child: FilledButton.icon(
                            style: FilledButton.styleFrom(
                              minimumSize: const Size.fromHeight(52),
                              backgroundColor: AppTokens.cta,
                              foregroundColor: Colors.white,
                            ),
                            onPressed: _isSubmitting
                                ? null
                                : () async {
                                    await _submitSale(
                                      bundle,
                                      onSubmittingChanged: () =>
                                          sheetSetState(() {}),
                                    );
                                    sheetSetState(() {});
                                  },
                            icon: _isSubmitting
                                ? const SizedBox(
                                    width: 18,
                                    height: 18,
                                    child: CircularProgressIndicator(
                                      strokeWidth: 2,
                                      color: Colors.white,
                                    ),
                                  )
                                : const Icon(Icons.point_of_sale_rounded),
                            label: Text(_isSubmitting
                                ? 'Emitiendo...'
                                : 'Emitir documento'),
                          ),
                        ),
                      ),
                  ],
                ),
              ),
            );
          },
        );
      },
    );
  }

  @override
  Widget build(BuildContext context) {
    // Sincroniza si hay una venta en curso para que el shell raíz sepa si
    // debe confirmar antes de navegar/salir con el botón físico atrás.
    final hasCart = _cart.isNotEmpty;
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (!mounted) return;
      final notifier = ref.read(hasUnsavedSaleCartProvider.notifier);
      if (notifier.state != hasCart) notifier.state = hasCart;
    });
    return SafeArea(
      child: RefreshIndicator(
        onRefresh: _refresh,
        child: FutureBuilder<_SalesBundle>(
          future: _future,
          builder: (context, snapshot) {
            if (snapshot.connectionState == ConnectionState.waiting) {
              return const AppLoader();
            }

            if (snapshot.hasError) {
              return ListView(
                padding: AppTokens.pagePadding,
                children: [
                  AppPanel(
                    title: 'Error al cargar ventas',
                    subtitle: snapshot.error.toString(),
                    child: FilledButton.icon(
                      onPressed: _refresh,
                      icon: const Icon(Icons.refresh_rounded),
                      label: const Text('Reintentar'),
                    ),
                  ),
                ],
              );
            }

            final bundle = snapshot.data;
            if (bundle == null || !bundle.isReady) {
              return ListView(
                padding: AppTokens.pagePadding,
                children: [
                  AppPanel(
                    title: 'Ventas',
                    subtitle: bundle?.firstError ??
                        'No se pudo cargar la configuracion comercial.',
                    child: const Text(
                        'Revisa autenticacion, conectividad y datos base del tenant.'),
                  ),
                ],
              );
            }

            final filteredItems = _filteredItems(bundle);

            final navBarBottom = MediaQuery.of(context).padding.bottom;
            final totals = _calculateTotals();
            return Stack(
              children: [
                ListView(
                  controller: _scrollController,
                  padding: AppTokens.pagePadding
                      .copyWith(bottom: navBarBottom + 110),
                  children: [
                    // Cliente compacto en una sola línea
                    InkWell(
                      borderRadius:
                          BorderRadius.circular(AppTokens.radiusMedium),
                      onTap: () => _selectCustomer(bundle),
                      child: Container(
                        padding: const EdgeInsets.symmetric(
                            horizontal: 12, vertical: 10),
                        decoration: BoxDecoration(
                          color: AppTokens.surface,
                          borderRadius:
                              BorderRadius.circular(AppTokens.radiusMedium),
                          border: Border.all(color: AppTokens.border),
                        ),
                        child: Row(
                          children: [
                            CircleAvatar(
                              radius: 16,
                              backgroundColor:
                                  AppTokens.primary.withValues(alpha: 0.12),
                              foregroundColor: AppTokens.primary,
                              child: const Icon(Icons.person_rounded, size: 18),
                            ),
                            const SizedBox(width: 10),
                            Expanded(
                              child: Text(
                                _selectedCustomer?['name']?.toString() ??
                                    'Seleccionar cliente',
                                maxLines: 1,
                                overflow: TextOverflow.ellipsis,
                                style: Theme.of(context).textTheme.titleSmall,
                              ),
                            ),
                            const Icon(Icons.edit_rounded,
                                size: 18, color: AppTokens.secondary),
                          ],
                        ),
                      ),
                    ),
                    const SizedBox(height: 12),
                    // Buscador con scanner
                    Row(
                      children: [
                        Expanded(
                          child: TextField(
                            controller: _searchController,
                            decoration: const InputDecoration(
                              labelText: 'Buscar producto',
                              prefixIcon: Icon(Icons.search_rounded),
                            ),
                          ),
                        ),
                        const SizedBox(width: 8),
                        IconButton.filledTonal(
                          onPressed: _scanSalesBarcode,
                          icon: const Icon(Icons.qr_code_scanner_rounded),
                          tooltip: 'Escanear código',
                        ),
                        const SizedBox(width: 8),
                        IconButton.filledTonal(
                          onPressed: () => _openOptionsSheet(bundle),
                          icon: const Icon(Icons.tune_rounded),
                          tooltip: 'Opciones del comprobante',
                        ),
                      ],
                    ),
                    const SizedBox(height: 12),
                    if (_pendingSalesCount > 0 || _isSyncingPending) ...[
                      Container(
                        padding: const EdgeInsets.symmetric(
                            horizontal: 12, vertical: 10),
                        decoration: BoxDecoration(
                          color: AppTokens.warning.withValues(alpha: 0.10),
                          borderRadius:
                              BorderRadius.circular(AppTokens.radiusSmall),
                          border: Border.all(
                            color: AppTokens.warning.withValues(alpha: 0.40),
                          ),
                        ),
                        child: Row(
                          children: [
                            const Icon(Icons.cloud_sync_rounded,
                                color: AppTokens.warning, size: 18),
                            const SizedBox(width: 8),
                            Expanded(
                              child: Text(
                                _isSyncingPending
                                    ? 'Sincronizando ventas pendientes...'
                                    : 'Ventas pendientes: $_pendingSalesCount',
                                style: Theme.of(context).textTheme.bodyMedium,
                              ),
                            ),
                            TextButton(
                              onPressed:
                                  _isSyncingPending ? null : _syncPendingSales,
                              child: const Text('Sincronizar ahora'),
                            ),
                            IconButton(
                              onPressed: () => context.go('/pending-sync'),
                              icon: const Icon(Icons.chevron_right_rounded),
                              tooltip: 'Ver detalle',
                            ),
                          ],
                        ),
                      ),
                      const SizedBox(height: 12),
                    ],
                    // Catálogo
                    if (_isLoadingItems)
                      const Padding(
                        padding: EdgeInsets.symmetric(vertical: 24),
                        child: Center(
                          child: SizedBox(
                            width: 22,
                            height: 22,
                            child: CircularProgressIndicator(strokeWidth: 2),
                          ),
                        ),
                      )
                    else if (filteredItems.isEmpty)
                      const EmptyStatePanel(
                        icon: Icons.inventory_2_outlined,
                        title: 'Sin productos visibles',
                        subtitle:
                            'Ajusta la búsqueda o revisa el catálogo cargado en el tenant.',
                      )
                    else
                      Column(
                        key: _catalogKey,
                        crossAxisAlignment: CrossAxisAlignment.stretch,
                        children: [
                          for (final item in filteredItems) ...[
                            _CatalogRow(
                              item: item,
                              price: _saleUnitPriceForCart(item),
                              onAdd: () => _addItem(item),
                            ),
                            if (item != filteredItems.last)
                              const SizedBox(height: 8),
                          ],
                          if (_itemsHasMore) ...[
                            const SizedBox(height: 14),
                            OutlinedButton.icon(
                              onPressed:
                                  _isLoadingItems ? null : _loadMoreItems,
                              icon: _isLoadingItems
                                  ? const SizedBox(
                                      width: 16,
                                      height: 16,
                                      child: CircularProgressIndicator(
                                          strokeWidth: 2),
                                    )
                                  : const Icon(Icons.expand_more_rounded),
                              label: Text(
                                _isLoadingItems
                                    ? 'Cargando...'
                                    : 'Cargar más productos',
                              ),
                            ),
                          ],
                        ],
                      ),
                  ],
                ),
                // Barra inferior fija con total + cobrar
                Positioned(
                  left: 0,
                  right: 0,
                  bottom: 0,
                  child: Container(
                    padding: EdgeInsets.fromLTRB(16, 12, 16, navBarBottom + 12),
                    decoration: BoxDecoration(
                      color: AppTokens.surface,
                      border: const Border(
                        top: BorderSide(color: AppTokens.border),
                      ),
                      boxShadow: [
                        BoxShadow(
                          color: AppTokens.textPrimary.withValues(alpha: 0.06),
                          blurRadius: 12,
                          offset: const Offset(0, -2),
                        ),
                      ],
                    ),
                    child: Row(
                      children: [
                        Expanded(
                          child: InkWell(
                            onTap: _cart.isEmpty || _suppressCartSheet
                                ? null
                                : () => _openCartSheet(bundle),
                            borderRadius: BorderRadius.circular(8),
                            child: Padding(
                              padding: const EdgeInsets.all(4),
                              child: Column(
                                crossAxisAlignment: CrossAxisAlignment.start,
                                mainAxisSize: MainAxisSize.min,
                                children: [
                                  AnimatedSwitcher(
                                    duration:
                                        const Duration(milliseconds: 200),
                                    child: Text(
                                      _cart.isEmpty
                                          ? 'Sin items'
                                          : '${_cart.length} item(s)',
                                      key: ValueKey(_cart.length),
                                      style: Theme.of(context)
                                          .textTheme
                                          .bodySmall
                                          ?.copyWith(
                                              color: AppTokens.secondary),
                                    ),
                                  ),
                                  const SizedBox(height: 2),
                                  TweenAnimationBuilder<double>(
                                    tween: Tween<double>(
                                        begin: 0, end: totals.total),
                                    duration:
                                        const Duration(milliseconds: 300),
                                    curve: Curves.easeOut,
                                    builder: (context, value, child) => Text(
                                      'S/ ${value.toStringAsFixed(2)}',
                                      style: Theme.of(context)
                                          .textTheme
                                          .titleLarge
                                          ?.copyWith(
                                            color: AppTokens.primary,
                                            fontWeight: FontWeight.w800,
                                          ),
                                    ),
                                  ),
                                ],
                              ),
                            ),
                          ),
                        ),
                        FilledButton.icon(
                          onPressed: (_cart.isEmpty || _isSubmitting)
                              ? null
                              : () => _submitSale(bundle),
                          icon: _isSubmitting
                              ? const SizedBox(
                                  width: 18,
                                  height: 18,
                                  child: CircularProgressIndicator(
                                    strokeWidth: 2,
                                    color: Colors.white,
                                  ),
                                )
                              : const Icon(Icons.point_of_sale_rounded),
                          label:
                              Text(_isSubmitting ? 'Procesando...' : 'Cobrar'),
                          style: FilledButton.styleFrom(
                            backgroundColor: AppTokens.cta,
                            padding: const EdgeInsets.symmetric(
                                horizontal: 24, vertical: 14),
                          ),
                        ),
                      ],
                    ),
                  ),
                ),
              ],
            );
          },
        ),
      ),
    );
  }
}

class _PaymentMethodTile extends StatelessWidget {
  const _PaymentMethodTile({
    required this.method,
    required this.controller,
    required this.isActive,
    required this.isSelected,
    required this.isCash,
    required this.reference,
    required this.onTap,
    required this.onAmountChanged,
    required this.onReferenceTap,
  });

  final Map<String, dynamic> method;
  final TextEditingController controller;
  final bool isActive;
  final bool isSelected;
  final bool isCash;
  final String? reference;
  final VoidCallback onTap;
  final ValueChanged<String> onAmountChanged;
  final VoidCallback onReferenceTap;

  IconData _iconFor(String? id, String? description) {
    final desc = (description ?? '').toLowerCase();
    if (desc.contains('efectivo') || id == '01') {
      return Icons.payments_rounded;
    }
    if (desc.contains('yape')) return Icons.qr_code_rounded;
    if (desc.contains('plin')) return Icons.qr_code_2_rounded;
    if (desc.contains('visa') ||
        desc.contains('tarjeta') ||
        desc.contains('mastercard')) {
      return Icons.credit_card_rounded;
    }
    if (desc.contains('transfer') || desc.contains('deposito')) {
      return Icons.account_balance_rounded;
    }
    return Icons.payments_outlined;
  }

  @override
  Widget build(BuildContext context) {
    final id = method['id']?.toString();
    final desc = method['description']?.toString() ?? 'Método';
    final borderColor = isSelected
        ? AppTokens.primary
        : isActive
            ? AppTokens.primary.withValues(alpha: 0.40)
            : AppTokens.border;
    final bg = isActive
        ? AppTokens.primary.withValues(alpha: 0.06)
        : AppTokens.surface;

    return Material(
      color: Colors.transparent,
      child: InkWell(
        onTap: onTap,
        borderRadius: BorderRadius.circular(AppTokens.radiusSmall),
        child: Container(
          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
          decoration: BoxDecoration(
            color: bg,
            borderRadius: BorderRadius.circular(AppTokens.radiusSmall),
            border: Border.all(
              color: borderColor,
              width: isSelected ? 2 : 1,
            ),
          ),
          child: Row(
            children: [
              Icon(
                _iconFor(id, desc),
                color: isActive ? AppTokens.primary : AppTokens.secondary,
                size: 22,
              ),
              const SizedBox(width: 12),
              Expanded(
                child: Text(
                  desc,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: Theme.of(context).textTheme.titleSmall?.copyWith(
                        fontWeight:
                            isActive ? FontWeight.w700 : FontWeight.w500,
                        color: isActive
                            ? AppTokens.textPrimary
                            : AppTokens.secondary,
                      ),
                ),
              ),
              const SizedBox(width: 8),
              Text(
                'S/',
                style: Theme.of(context).textTheme.bodySmall?.copyWith(
                      color: AppTokens.secondary,
                    ),
              ),
              const SizedBox(width: 4),
              SizedBox(
                width: 90,
                child: TextField(
                  controller: controller,
                  textAlign: TextAlign.right,
                  keyboardType:
                      const TextInputType.numberWithOptions(decimal: true),
                  style: Theme.of(context).textTheme.titleSmall?.copyWith(
                        fontWeight: FontWeight.w700,
                        color: AppTokens.primary,
                      ),
                  decoration: const InputDecoration(
                    isDense: true,
                    contentPadding:
                        EdgeInsets.symmetric(horizontal: 8, vertical: 6),
                    border: OutlineInputBorder(),
                  ),
                  onTap: () {
                    onTap();
                    // Selecciona todo el texto para que el siguiente dígito reemplace,
                    // no se concatene a "0.00".
                    controller.selection = TextSelection(
                      baseOffset: 0,
                      extentOffset: controller.text.length,
                    );
                  },
                  onChanged: onAmountChanged,
                ),
              ),
              if (isActive && !isCash) ...[
                const SizedBox(width: 4),
                IconButton(
                  onPressed: onReferenceTap,
                  icon: Icon(
                    (reference ?? '').isNotEmpty
                        ? Icons.receipt_long_rounded
                        : Icons.receipt_outlined,
                    color: (reference ?? '').isNotEmpty
                        ? AppTokens.primary
                        : AppTokens.secondary,
                    size: 20,
                  ),
                  tooltip: 'Referencia',
                  padding: EdgeInsets.zero,
                  visualDensity: VisualDensity.compact,
                  constraints:
                      const BoxConstraints(minWidth: 28, minHeight: 28),
                ),
              ],
            ],
          ),
        ),
      ),
    );
  }
}

class _SalesBundle {
  const _SalesBundle({
    required this.tables,
    required this.tablesSuccess,
    required this.tablesMessage,
    required this.items,
    required this.itemsSuccess,
    required this.itemsMessage,
    required this.customers,
    required this.customersSuccess,
    required this.customersMessage,
  });

  final Map<String, dynamic> tables;
  final bool tablesSuccess;
  final String? tablesMessage;
  final List<Map<String, dynamic>> items;
  final bool itemsSuccess;
  final String? itemsMessage;
  final List<Map<String, dynamic>> customers;
  final bool customersSuccess;
  final String? customersMessage;

  bool get isReady => tablesSuccess && itemsSuccess && customersSuccess;

  String? get firstError {
    if (!tablesSuccess) return tablesMessage ?? 'Error al cargar tablas.';
    if (!itemsSuccess) return itemsMessage ?? 'Error al cargar productos.';
    if (!customersSuccess) {
      return customersMessage ?? 'Error al cargar clientes.';
    }
    return null;
  }

  List<Map<String, dynamic>> get documentTypes {
    final saleDetail =
        Map<String, dynamic>.from(tables['sale_detail'] as Map? ?? const {});
    final types = List<Map<String, dynamic>>.from(
        saleDetail['document_types'] as List? ?? const []);
    final hasSaleNote = types.any(
      (row) => row['id']?.toString() == '80',
    );
    if (!hasSaleNote) {
      types.add({
        'id': '80',
        'description': 'Nota de venta',
      });
    }
    return types;
  }

  List<Map<String, dynamic>> get series {
    final salePayment =
        Map<String, dynamic>.from(tables['sale_payment'] as Map? ?? const {});
    return List<Map<String, dynamic>>.from(
        salePayment['series'] as List? ?? const []);
  }

  List<Map<String, dynamic>> get paymentConditions {
    final salePayment =
        Map<String, dynamic>.from(tables['sale_payment'] as Map? ?? const {});
    return List<Map<String, dynamic>>.from(
        salePayment['payment_conditions'] as List? ?? const []);
  }

  List<Map<String, dynamic>> get paymentMethodTypes {
    final salePayment =
        Map<String, dynamic>.from(tables['sale_payment'] as Map? ?? const {});
    return List<Map<String, dynamic>>.from(
        salePayment['payment_method_types'] as List? ?? const []);
  }

  String paymentMethodLabel(String? id) {
    if (id == null || id.trim().isEmpty) {
      return 'Pago';
    }
    for (final method in paymentMethodTypes) {
      if (method['id']?.toString() == id) {
        return method['description']?.toString() ?? id;
      }
    }
    return id;
  }

  List<Map<String, dynamic>> get paymentDestinations {
    final salePayment =
        Map<String, dynamic>.from(tables['sale_payment'] as Map? ?? const {});
    return List<Map<String, dynamic>>.from(
        salePayment['payment_destinations'] as List? ?? const []);
  }

  List<Map<String, dynamic>> seriesFor(String? documentTypeId) {
    if (documentTypeId == null) {
      return series;
    }

    final filtered = series
        .where((row) => row['document_type_id']?.toString() == documentTypeId)
        .toList();
    return filtered;
  }

  Map<String, dynamic>? findDocumentType(String? id) {
    if (id == null) {
      return null;
    }

    try {
      return documentTypes.firstWhere((row) => row['id']?.toString() == id);
    } on StateError {
      return null;
    }
  }
}

class _CartLine {
  _CartLine({
    required this.item,
    required this.quantity,
    required this.unitPrice,
    required this.quantityFactor,
    this.presentationUnitTypeId,
    this.presentationDescription,
  });

  final Map<String, dynamic> item;
  double quantity;
  double unitPrice;
  double quantityFactor;
  String? presentationUnitTypeId;
  String? presentationDescription;

  int get itemId => int.tryParse(item['id']?.toString() ?? '') ?? 0;
}

class _PresentationSelection {
  const _PresentationSelection({
    required this.unitTypeId,
    required this.description,
    required this.quantityUnit,
    required this.unitPrice,
  });

  final String? unitTypeId;
  final String description;
  final double quantityUnit;
  final double unitPrice;
}

class _CalculatedLine {
  const _CalculatedLine({
    required this.affectationIgvTypeId,
    required this.percentageIgv,
    required this.unitValue,
    required this.totalBaseIgv,
    required this.totalValue,
    required this.totalIgv,
    required this.totalTaxes,
    required this.total,
  });

  final String affectationIgvTypeId;
  final double percentageIgv;
  final double unitValue;
  final double totalBaseIgv;
  final double totalValue;
  final double totalIgv;
  final double totalTaxes;
  final double total;
}

class _CartTotals {
  const _CartTotals({
    required this.taxed,
    required this.unaffected,
    required this.exonerated,
    required this.value,
    required this.igv,
    required this.total,
  });

  final double taxed;
  final double unaffected;
  final double exonerated;
  final double value;
  final double igv;
  final double total;
}

class _CatalogRow extends StatelessWidget {
  const _CatalogRow({
    required this.item,
    required this.price,
    required this.onAdd,
  });

  final Map<String, dynamic> item;
  final double price;
  final VoidCallback onAdd;

  @override
  Widget build(BuildContext context) {
    final stockValue = item['stock'];
    final hasStock =
        stockValue != null && stockValue.toString().trim().isNotEmpty;
    final stock = double.tryParse(stockValue?.toString() ?? '') ?? 0;
    final unitType = item['unit_type_id']?.toString().toUpperCase();
    final itemType = item['item_type_id']?.toString();
    final isService = unitType == 'ZZ' || itemType == '02';
    final canAdd = isService || stock > 0;
    final lotsEnabled = item['lots_enabled'] == true;
    final unitTypes = List<Map<String, dynamic>>.from(
        item['item_unit_types'] as List? ?? const []);

    return Material(
      color: AppTokens.surface,
      borderRadius: BorderRadius.circular(AppTokens.radiusSmall),
      child: InkWell(
        onTap: canAdd ? onAdd : null,
        borderRadius: BorderRadius.circular(AppTokens.radiusSmall),
        child: Container(
          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(AppTokens.radiusSmall),
            border: Border.all(color: AppTokens.border),
          ),
          child: Row(
            children: [
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Text(
                      item['description']?.toString() ?? 'Producto',
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                      style: Theme.of(context)
                          .textTheme
                          .titleSmall
                          ?.copyWith(fontWeight: FontWeight.w600),
                    ),
                    const SizedBox(height: 2),
                    Row(
                      children: [
                        if (hasStock) ...[
                          Text(
                            'Stock ${stockValue.toString()}',
                            style: Theme.of(context)
                                .textTheme
                                .labelSmall
                                ?.copyWith(
                                  color: stock > 0
                                      ? AppTokens.secondary
                                      : AppTokens.danger,
                                ),
                          ),
                          const SizedBox(width: 8),
                        ],
                        if (unitTypes.length > 1)
                          Text(
                            '${unitTypes.length} pres.',
                            style: Theme.of(context)
                                .textTheme
                                .labelSmall
                                ?.copyWith(color: AppTokens.secondary),
                          ),
                        if (lotsEnabled) ...[
                          if (unitTypes.length > 1) const SizedBox(width: 8),
                          Text(
                            'Lotes',
                            style: Theme.of(context)
                                .textTheme
                                .labelSmall
                                ?.copyWith(color: AppTokens.secondary),
                          ),
                        ],
                      ],
                    ),
                  ],
                ),
              ),
              const SizedBox(width: 10),
              Column(
                crossAxisAlignment: CrossAxisAlignment.end,
                mainAxisSize: MainAxisSize.min,
                children: [
                  Text(
                    'S/ ${price.toStringAsFixed(2)}',
                    style: Theme.of(context).textTheme.titleSmall?.copyWith(
                          color: AppTokens.primary,
                          fontWeight: FontWeight.w700,
                        ),
                  ),
                  const SizedBox(height: 4),
                  SizedBox(
                    width: 36,
                    height: 36,
                    child: IconButton.filledTonal(
                      padding: EdgeInsets.zero,
                      onPressed: canAdd ? onAdd : null,
                      icon: Icon(
                        canAdd ? Icons.add_rounded : Icons.block_rounded,
                        size: 20,
                      ),
                      tooltip: canAdd ? 'Agregar' : 'Sin stock',
                    ),
                  ),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}

class _CartItemRow extends StatelessWidget {
  const _CartItemRow({
    required this.line,
    required this.total,
    required this.onIncrease,
    required this.onDecrease,
    required this.onRemove,
  });

  final _CartLine line;
  final double total;
  final VoidCallback onIncrease;
  final VoidCallback onDecrease;
  final VoidCallback onRemove;

  String _formatNumber(double value) {
    if (value == value.roundToDouble()) {
      return value.toStringAsFixed(0);
    }
    return value.toStringAsFixed(2);
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: AppTokens.surface,
        borderRadius: BorderRadius.circular(AppTokens.radiusMedium),
        border: Border.all(color: AppTokens.border),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      line.item['description']?.toString() ?? 'Producto',
                      maxLines: 2,
                      overflow: TextOverflow.ellipsis,
                      style: Theme.of(context).textTheme.titleMedium,
                    ),
                    const SizedBox(height: 4),
                    Text(
                      line.item['internal_id']?.toString() ?? 'Sin codigo',
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                      style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                            color: AppTokens.secondary,
                          ),
                    ),
                    if (line.presentationDescription != null) ...[
                      const SizedBox(height: 4),
                      Text(
                        'Presentacion: ${line.presentationDescription} x${_formatNumber(line.quantityFactor)}',
                        maxLines: 1,
                        overflow: TextOverflow.ellipsis,
                        style: Theme.of(context).textTheme.bodySmall?.copyWith(
                              color: AppTokens.secondary,
                            ),
                      ),
                    ],
                  ],
                ),
              ),
              IconButton(
                onPressed: onRemove,
                icon: const Icon(Icons.delete_outline_rounded),
                tooltip: 'Quitar',
              ),
            ],
          ),
          const SizedBox(height: 12),
          Row(
            children: [
              _StepperButton(icon: Icons.remove_rounded, onTap: onDecrease),
              Container(
                width: 54,
                alignment: Alignment.center,
                child: AnimatedSwitcher(
                  duration: const Duration(milliseconds: 180),
                  transitionBuilder: (child, animation) => ScaleTransition(
                    scale: animation,
                    child: FadeTransition(opacity: animation, child: child),
                  ),
                  child: Text(
                    line.quantity == line.quantity.roundToDouble()
                        ? line.quantity.toStringAsFixed(0)
                        : line.quantity.toStringAsFixed(2),
                    key: ValueKey(line.quantity),
                    style: Theme.of(context).textTheme.titleMedium,
                  ),
                ),
              ),
              _StepperButton(icon: Icons.add_rounded, onTap: onIncrease),
              const Spacer(),
              Column(
                crossAxisAlignment: CrossAxisAlignment.end,
                children: [
                  Text(
                    'PEN ${line.unitPrice.toStringAsFixed(2)} c/u',
                    style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                          color: AppTokens.secondary,
                        ),
                  ),
                  const SizedBox(height: 4),
                  AnimatedSwitcher(
                    duration: const Duration(milliseconds: 180),
                    child: Text(
                      'PEN ${total.toStringAsFixed(2)}',
                      key: ValueKey(total),
                      style: Theme.of(context).textTheme.titleMedium,
                    ),
                  ),
                ],
              ),
            ],
          ),
        ],
      ),
    );
  }
}

class _StepperButton extends StatefulWidget {
  const _StepperButton({
    required this.icon,
    required this.onTap,
  });

  final IconData icon;
  final VoidCallback onTap;

  @override
  State<_StepperButton> createState() => _StepperButtonState();
}

class _StepperButtonState extends State<_StepperButton> {
  bool _pressed = false;

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: widget.onTap,
      onTapDown: (_) => setState(() => _pressed = true),
      onTapUp: (_) => setState(() => _pressed = false),
      onTapCancel: () => setState(() => _pressed = false),
      child: AnimatedScale(
        scale: _pressed ? 0.85 : 1,
        duration: const Duration(milliseconds: 100),
        curve: Curves.easeOut,
        child: Container(
          width: 36,
          height: 36,
          decoration: BoxDecoration(
            color: AppTokens.surface,
            shape: BoxShape.circle,
            border: Border.all(color: AppTokens.border),
          ),
          child: Icon(widget.icon, size: 18, color: AppTokens.textPrimary),
        ),
      ),
    );
  }
}

class _InfoRow extends StatelessWidget {
  const _InfoRow({
    required this.label,
    required this.value,
    this.emphasize = false,
  });

  final String label;
  final String value;
  final bool emphasize;

  @override
  Widget build(BuildContext context) {
    final valueStyle = emphasize
        ? Theme.of(context).textTheme.titleLarge
        : Theme.of(context).textTheme.titleMedium;

    return Row(
      children: [
        Expanded(
          child: Text(
            label,
            style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                  color: AppTokens.secondary,
                ),
          ),
        ),
        const SizedBox(width: 12),
        Expanded(
          child: Text(
            value,
            textAlign: TextAlign.end,
            overflow: TextOverflow.ellipsis,
            style: valueStyle,
          ),
        ),
      ],
    );
  }
}