import 'dart:ui';
import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import 'package:provider/provider.dart';
import 'package:google_fonts/google_fonts.dart';

// Importações originais mantidas
import 'package:kzeduca_app/models/transaction.dart';
import 'package:kzeduca_app/widgets/transaction_calculator.dart';
import 'package:kzeduca_app/services/i18n_service.dart';
import 'package:kzeduca_app/services/user_state_service.dart';
import 'package:kzeduca_app/services/transaction_list_notifier.dart';

// KzEduca Palette
const _kGradientStart = Color(0xFF512DA8); // Roxo vibrante
const _kGradientEnd = Color(0xFF000000); // Preto profundo
const _kAccent = Color(0xFF00BFA5); // Verde água
const _kAction = Color(0xFFFFD600); // Amarelo/dourado
const _kExpenseColor = Color(0xFFFF5252); // Vermelho de erro
const _kIncomeColor = Color(0xFF69F0AE); // Verde de sucesso

class AddTransactionScreen extends StatefulWidget {
  const AddTransactionScreen({super.key});

  @override
  State<AddTransactionScreen> createState() => _AddTransactionScreenState();
}

class _AddTransactionScreenState extends State<AddTransactionScreen> {
  TransactionType _selectedType = TransactionType.expense;
  double _currentAmount = 0.0;
  TransactionCategory _selectedCategory = TransactionCategory.food;
  DateTime _selectedDate = DateTime.now();
  final TextEditingController _noteController = TextEditingController();
  final TextEditingController _titleController = TextEditingController();

  bool _showCalculator = false;

  final Map<TransactionCategory, String> _expenseCategoryNames = {
    TransactionCategory.food: 'food',
    TransactionCategory.transport: 'transport',
    TransactionCategory.social: 'social',
    TransactionCategory.education: 'education',
    TransactionCategory.medical: 'medical',
    TransactionCategory.shopping: 'shopping',
    TransactionCategory.others: 'others',
    TransactionCategory.house: 'house',
    TransactionCategory.utilities: 'utilities',
    TransactionCategory.subscriptions: 'subscriptions',
    TransactionCategory.leisure: 'leisure',
    TransactionCategory.gym: 'gym',
    TransactionCategory.gifts: 'gifts',
    TransactionCategory.pets: 'pets',
    TransactionCategory.tax: 'tax',
  };

  final Map<TransactionCategory, String> _incomeCategoryNames = {
    TransactionCategory.salary: 'salary',
    TransactionCategory.invest: 'invest',
    TransactionCategory.business: 'business',
    TransactionCategory.freelance: 'freelance',
    TransactionCategory.dividends: 'dividends',
    TransactionCategory.loan: 'loan',
    TransactionCategory.refund: 'refund',
    TransactionCategory.others: 'others',
    TransactionCategory.allowance: 'allowance',
    TransactionCategory.bonus: 'bonus',
  };

  final Map<TransactionCategory, IconData> _categoryIcons = {
    TransactionCategory.food: Icons.restaurant_menu_rounded,
    TransactionCategory.transport: Icons.directions_car_rounded,
    TransactionCategory.social: Icons.people_rounded,
    TransactionCategory.education: Icons.school_rounded,
    TransactionCategory.medical: Icons.medical_services_rounded,
    TransactionCategory.shopping: Icons.shopping_bag_rounded,
    TransactionCategory.house: Icons.home_rounded,
    TransactionCategory.utilities: Icons.lightbulb_rounded,
    TransactionCategory.subscriptions: Icons.subscriptions_rounded,
    TransactionCategory.leisure: Icons.sports_esports_rounded,
    TransactionCategory.gym: Icons.fitness_center_rounded,
    TransactionCategory.gifts: Icons.card_giftcard_rounded,
    TransactionCategory.pets: Icons.pets_rounded,
    TransactionCategory.salary: Icons.monetization_on_rounded,
    TransactionCategory.invest: Icons.trending_up_rounded,
    TransactionCategory.business: Icons.work_rounded,
    TransactionCategory.freelance: Icons.laptop_chromebook_rounded,
    TransactionCategory.dividends: Icons.show_chart_rounded,
    TransactionCategory.loan: Icons.account_balance_rounded,
    TransactionCategory.refund: Icons.undo_rounded,
    TransactionCategory.others: Icons.category_rounded,
    TransactionCategory.allowance: Icons.card_giftcard_rounded,
    TransactionCategory.bonus: Icons.stars_rounded,
    TransactionCategory.tax: Icons.account_balance_wallet_rounded,
  };

  void _onAmountChanged(double newAmount) {
    setState(() {
      _currentAmount = newAmount;
      // UX: Garante que a calculadora esteja visível se o valor for alterado.
      if (newAmount > 0.0) {
        _showCalculator = true; 
      }
    });
  }

  Future<void> _selectDate(BuildContext context) async {
    final DateTime? picked = await showDatePicker(
      context: context,
      initialDate: _selectedDate,
      firstDate: DateTime(2000),
      lastDate: DateTime(2101),
      locale: const Locale('pt', 'BR'),
      builder: (context, child) {
        return Theme(
          data: ThemeData.dark().copyWith(
            colorScheme: ColorScheme.dark(
              primary: _kAccent,
              onPrimary: Colors.white,
              surface: Colors.grey.shade900,
              onSurface: Colors.white,
            ),
            textButtonTheme: TextButtonThemeData(
              style: TextButton.styleFrom(
                foregroundColor: _kAccent,
              ),
            ),
          ),
          child: child!,
        );
      },
    );
    if (picked != null && picked != _selectedDate) {
      setState(() {
        _selectedDate = picked;
      });
    }
  }

  void _saveTransaction() async {
    // Usamos 'listen: false' para evitar rebuilds desnecessários no método.
    final i18n = Provider.of<I18nService>(context, listen: false);

    if (_currentAmount <= 0) {
      _showSnackBar(i18n.t('error campo de entrada valor monetario'), isError: true);
      return;
    }

    if (_titleController.text.trim().isEmpty) {
      _showSnackBar(i18n.t('erro campo entrada titulo '), isError: true);
      return;
    }

    // A classe Transaction deve vir do seu arquivo 'models/transaction.dart'
    final newTransaction = Transaction(
      title: _titleController.text.trim(),
      amount: _currentAmount,
      type: _selectedType,
      category: _selectedCategory,
      date: _selectedDate,
      note: _noteController.text.isEmpty ? null : _noteController.text.trim(),
    );

    try {
      final txnList = Provider.of<TransactionListNotifier>(context, listen: false);
      await txnList.addTransaction(newTransaction);
      final userStateService = Provider.of<UserStateService>(context, listen: false);
      await userStateService.recalculateBalanceFromHive();
      _showSnackBar(i18n.t('transaction salva com success'));
      Navigator.pop(context, true);
    } catch (e) {
      _showSnackBar('${i18n.t('erro ao salvar transaction')}: $e', isError: true);
    }
  }

  void _showSnackBar(String message, {bool isError = false}) {
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text(
          message,
          style: GoogleFonts.montserrat(color: Colors.white, fontWeight: FontWeight.w600),
        ),
        // UX: Usar a cor de destaque para sucesso e a cor de erro para falha
        backgroundColor: isError ? _kExpenseColor.withOpacity(0.9) : _kIncomeColor.withOpacity(0.9), 
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
        behavior: SnackBarBehavior.floating,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final i18n = Provider.of<I18nService>(context);

    return Scaffold(
      extendBodyBehindAppBar: true,
      backgroundColor: Colors.transparent,
      appBar: AppBar(
        title: Text(
          i18n.t('add_transaction_title'),
          style: GoogleFonts.montserrat(
            color: Colors.white,
            fontWeight: FontWeight.w600,
          ),
        ),
        backgroundColor: Colors.transparent,
        foregroundColor: Colors.white,
        elevation: 0,
        centerTitle: true,
      ),
      body: Stack(
        children: [
          Container(
            decoration: const BoxDecoration(
              gradient: LinearGradient(
                colors: [_kGradientStart, _kGradientEnd],
                begin: Alignment.topCenter,
                end: Alignment.bottomCenter,
              ),
            ),
          ),
          Center(
            child: ClipRRect(
              borderRadius: BorderRadius.circular(25.0),
              child: BackdropFilter(
                filter: ImageFilter.blur(sigmaX: 15, sigmaY: 15),
                child: Container(
                  width: MediaQuery.of(context).size.width * 0.9,
                  height: MediaQuery.of(context).size.height * 0.85,
                  padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 16),
                  decoration: BoxDecoration(
                    color: Colors.white.withOpacity(0.1),
                    borderRadius: BorderRadius.circular(25.0),
                    border: Border.all(color: Colors.white.withOpacity(0.2)),
                    boxShadow: [
                      BoxShadow(
                        color: Colors.black.withOpacity(0.4),
                        blurRadius: 20,
                        offset: const Offset(0, 10),
                      ),
                    ],
                  ),
                  child: Column(
                    children: [
                      _buildHeader(i18n),
                      const SizedBox(height: 20),
                      Expanded(
                        child: SingleChildScrollView(
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.stretch,
                            children: [
                              _buildFormFields(i18n),
                              const SizedBox(height: 20),
                              _buildCategorySection(i18n),
                              const SizedBox(height: 20),
                            ],
                          ),
                        ),
                      ),
                      // MELHORIA UX: Usar AnimatedSize para transição mais suave da Calculadora
                      AnimatedSize( 
                        duration: const Duration(milliseconds: 300),
                        curve: Curves.easeOut,
                        child: _showCalculator
                            ? Column(
                                children: [
                                  TransactionCalculator(
                                    // A calculadora é responsável por chamar _onAmountChanged
                                    onAmountChanged: _onAmountChanged, 
                                    onSave: _saveTransaction,
                                  ),
                                  const SizedBox(height: 15),
                                ],
                              )
                            : const SizedBox(height: 0), // Oculta a calculadora
                      ),
                      // O botão Salvar aparece sempre, exceto se for integrado na calculadora
                      _buildSaveButton(i18n), 
                    ],
                  ),
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildSaveButton(I18nService i18n) {
    // Se a calculadora estiver visível, ela deve ter seu próprio botão de salvar
    // A implementação do seu código original a colocava fora do bloco da calculadora, mantive assim para consistência
    // No entanto, se o TransactionCalculator tiver um botão "Salvar" interno, este aqui pode ser oculto
    
    // Se você não quiser o botão de salvar duplicado quando a calculadora estiver visível:
    // if (_showCalculator) return const SizedBox.shrink();

    return ElevatedButton(
      onPressed: _saveTransaction,
      style: ElevatedButton.styleFrom(
        backgroundColor: _kAccent,
        foregroundColor: Colors.black87,
        padding: const EdgeInsets.symmetric(horizontal: 30, vertical: 15),
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(15)),
        elevation: 8,
        shadowColor: _kAccent.withOpacity(0.5),
      ),
      child: Text(
        i18n.t('save_transaction'),
        style: GoogleFonts.montserrat(fontSize: 16, fontWeight: FontWeight.bold),
      ),
    );
  }

  Widget _buildHeader(I18nService i18n) {
    return Column(
      children: [
        _buildTypeSelection(i18n),
        const SizedBox(height: 30),
        _buildAmountDisplay(i18n),
      ],
    );
  }

  Widget _buildTypeSelection(I18nService i18n) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        _buildTypeButton(i18n.t('expense'), TransactionType.expense, Icons.arrow_downward_rounded),
        const SizedBox(width: 15),
        _buildTypeButton(i18n.t('income'), TransactionType.income, Icons.arrow_upward_rounded),
      ],
    );
  }

  Widget _buildTypeButton(String label, TransactionType type, IconData icon) {
    final isSelected = _selectedType == type;
    final Color selectedColor = type == TransactionType.expense ? _kExpenseColor : _kIncomeColor;
    final Color textColor = isSelected ? Colors.white : Colors.white.withOpacity(0.7);

    return Expanded(
      child: GestureDetector(
        onTap: () {
          setState(() {
            _selectedType = type;
            // Garante que a categoria inicial do novo tipo seja selecionada
            _selectedCategory = type == TransactionType.expense
                ? _expenseCategoryNames.keys.first
                : _incomeCategoryNames.keys.first;
            // UX: Zera o valor ao mudar o tipo de transação
            _currentAmount = 0.0; 
            _showCalculator = false;
          });
        },
        child: AnimatedContainer(
          duration: const Duration(milliseconds: 300),
          padding: const EdgeInsets.symmetric(vertical: 16, horizontal: 8),
          decoration: BoxDecoration(
            gradient: isSelected
                ? LinearGradient(colors: [selectedColor.withOpacity(0.7), selectedColor.withOpacity(0.5)])
                : null,
            color: isSelected ? null : Colors.white.withOpacity(0.1),
            borderRadius: BorderRadius.circular(15),
            border: Border.all(color: isSelected ? selectedColor : Colors.white.withOpacity(0.2)),
            boxShadow: [
              BoxShadow(
                color: isSelected ? selectedColor.withOpacity(0.4) : Colors.black.withOpacity(0.1),
                blurRadius: 10,
                offset: const Offset(0, 4),
              ),
            ],
          ),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Icon(icon, color: textColor),
              const SizedBox(width: 8),
              Text(
                label,
                style: GoogleFonts.montserrat(
                  fontSize: 16,
                  color: textColor,
                  fontWeight: isSelected ? FontWeight.bold : FontWeight.normal,
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildAmountDisplay(I18nService i18n) {
    return GestureDetector(
      // UX: Clicar no valor alterna a visibilidade da calculadora
      onTap: () {
        setState(() {
          _showCalculator = !_showCalculator;
        });
      },
      child: Center(
        child: Text(
          '${i18n.t('kwanza_symbol')} ${NumberFormat.currency(locale: 'pt_BR', symbol: '').format(_currentAmount)}',
          style: GoogleFonts.montserrat(
            fontSize: 50,
            fontWeight: FontWeight.w900,
            color: _selectedType == TransactionType.expense
                ? _kExpenseColor
                : _kIncomeColor,
          ),
        ),
      ),
    );
  }

  Widget _buildFormFields(I18nService i18n) {
    return Column(
      children: [
        _buildCustomTextField(
          controller: _titleController,
          label: i18n.t('transaction_title'),
          hint: i18n.t('example_title'),
          icon: Icons.description_rounded,
        ),
        const SizedBox(height: 20),
        _buildCustomTextField(
          controller: _noteController,
          label: i18n.t('notes_optional'),
          hint: i18n.t('example_notes'),
          icon: Icons.notes_rounded,
          maxLines: 3,
        ),
        const SizedBox(height: 20),
        _buildDatePickerField(i18n),
      ],
    );
  }

  Widget _buildCustomTextField({
    required TextEditingController controller,
    required String label,
    required String hint,
    required IconData icon,
    int maxLines = 1,
  }) {
    // MELHORIA UX: Cores de texto, ícone e hint ajustadas para o tema escuro.
    const Color lightTextColor = Colors.white;
    final Color iconColor = lightTextColor.withOpacity(0.7);
    final Color hintColor = lightTextColor.withOpacity(0.5);

    return Container(
      decoration: BoxDecoration(
        color: Colors.white.withOpacity(0.1),
        borderRadius: BorderRadius.circular(15),
        // MELHORIA UX: Borda consistente com o restante da interface
        border: Border.all(color: Colors.white.withOpacity(0.2)), 
        boxShadow: [
          BoxShadow(
            color: Colors.black.withOpacity(0.2),
            blurRadius: 10,
            offset: const Offset(0, 4),
          ),
        ],
      ),
      child: TextField(
        controller: controller,
        maxLines: maxLines,
        textCapitalization: TextCapitalization.sentences,
        // MELHORIA UX: Cor do texto digitado ajustada para branco
        style: GoogleFonts.montserrat(color: lightTextColor, fontWeight: FontWeight.w500), 
        decoration: InputDecoration(
          labelText: label,
          hintText: hint,
          // MELHORIA UX: Cor do ícone ajustada para o tema escuro
          prefixIcon: Icon(icon, color: iconColor), 
          // MELHORIA UX: Cor do label e hint ajustada para o tema escuro
          labelStyle: GoogleFonts.montserrat(color: iconColor), 
          hintStyle: GoogleFonts.montserrat(color: hintColor),
          border: InputBorder.none,
          contentPadding: const EdgeInsets.symmetric(horizontal: 20, vertical: 15),
        ),
      ),
    );
  }

  Widget _buildDatePickerField(I18nService i18n) {
    return GestureDetector(
      onTap: () => _selectDate(context),
      child: Container(
        padding: const EdgeInsets.symmetric(vertical: 15, horizontal: 20),
        decoration: BoxDecoration(
          color: Colors.white.withOpacity(0.1),
          borderRadius: BorderRadius.circular(15),
          border: Border.all(color: Colors.white.withOpacity(0.2)),
          boxShadow: [
            BoxShadow(
              color: Colors.black.withOpacity(0.2),
              blurRadius: 10,
              offset: const Offset(0, 4),
            ),
          ],
        ),
        child: Row(
          children: [
            Icon(Icons.calendar_today_rounded, color: Colors.white.withOpacity(0.7)),
            const SizedBox(width: 15),
            Expanded(
              child: Text(
                DateFormat('dd \'de\' MMM \'de\' yyyy', 'pt_BR').format(_selectedDate),
                style: GoogleFonts.montserrat(fontSize: 16, color: Colors.white, fontWeight: FontWeight.w500),
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildCategorySection(I18nService i18n) {
    final categories = _selectedType == TransactionType.expense
        ? _expenseCategoryNames
        : _incomeCategoryNames;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        Text(
          i18n.t('select_category'),
          style: GoogleFonts.montserrat(
            fontSize: 18,
            fontWeight: FontWeight.w600,
            color: Colors.white,
          ),
        ),
        const SizedBox(height: 15),
        Wrap(
          spacing: 12.0,
          runSpacing: 12.0,
          children: categories.entries.map((entry) {
            return _buildCategoryButton(i18n, entry.key, i18n.t(entry.value));
          }).toList(),
        ),
      ],
    );
  }

  Widget _buildCategoryButton(I18nService i18n, TransactionCategory category, String label) {
    final isSelected = _selectedCategory == category;
    final selectedColor = _selectedType == TransactionType.expense ? _kExpenseColor : _kIncomeColor;
    final textColor = isSelected ? Colors.white : Colors.white.withOpacity(0.7);

    return GestureDetector(
      onTap: () {
        setState(() {
          _selectedCategory = category;
        });
      },
      child: AnimatedContainer(
        duration: const Duration(milliseconds: 300),
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
        decoration: BoxDecoration(
          color: isSelected ? selectedColor.withOpacity(0.2) : Colors.white.withOpacity(0.1),
          borderRadius: BorderRadius.circular(20),
          border: Border.all(color: isSelected ? selectedColor : Colors.white.withOpacity(0.2)),
          boxShadow: isSelected
              ? [
                  BoxShadow(
                    color: selectedColor.withOpacity(0.4),
                    blurRadius: 10,
                    offset: const Offset(0, 4),
                  ),
                ]
              : [],
        ),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(
              _categoryIcons[category],
              color: textColor,
            ),
            const SizedBox(width: 8),
            Text(
              label,
              style: GoogleFonts.montserrat(
                color: textColor,
                fontWeight: isSelected ? FontWeight.bold : FontWeight.normal,
              ),
            ),
          ],
        ),
      ),
    );
  }
}