import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import '../models/budget.dart';
import '../models/transaction.dart';
import '../services/hive_service.dart';

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

  @override
  State<CreateBudgetScreen> createState() => _CreateBudgetScreenState();
}

class _CreateBudgetScreenState extends State<CreateBudgetScreen> {
  final _formKey = GlobalKey<FormState>();
  TransactionCategory? _selectedCategory;
  BudgetPeriod? _selectedPeriod;
  final _amountController = TextEditingController();
  DateTime? _selectedStartDate;
  DateTime? _selectedEndDate;
  bool _repeatBudget = false;
  final _noteController = TextEditingController();
  late HiveService _hiveService;

  @override
  void initState() {
    super.initState();
    _hiveService = HiveService();
  }

  Future<void> _selectDate(BuildContext context, bool isStart) async {
    final now = DateTime.now();
    final initialDate = isStart
        ? (_selectedStartDate ?? now)
        : (_selectedEndDate ?? now);
    final picked = await showDatePicker(
      context: context,
      initialDate: initialDate,
      firstDate: DateTime(now.year - 5),
      lastDate: DateTime(now.year + 5),
      builder: (context, child) {
        return Theme(
          data: ThemeData.light().copyWith(
            colorScheme: ColorScheme.light(
              primary: Theme.of(context).colorScheme.primary,
              onPrimary: Theme.of(context).colorScheme.onPrimary,
              onSurface: Theme.of(context).colorScheme.onSurface,
            ),
            dialogBackgroundColor: Theme.of(context).colorScheme.surface,
          ),
          child: child!,
        );
      },
    );
    if (picked != null) {
      setState(() {
        if (isStart) {
          _selectedStartDate = picked;
        } else {
          _selectedEndDate = picked;
        }
      });
    }
  }

  Future<void> _saveBudget() async {
    if (_formKey.currentState!.validate() &&
        _selectedCategory != null &&
        _selectedPeriod != null &&
        _selectedStartDate != null &&
        _selectedEndDate != null) {
      final budget = Budget(
        category: _selectedCategory!,
        amount: double.tryParse(_amountController.text) ?? 0.0,
        period: _selectedPeriod!,
        startDate: _selectedStartDate!,
        endDate: _selectedEndDate!,
        repeatBudget: _repeatBudget,
        note: _noteController.text.isNotEmpty ? _noteController.text : null,
      );
      await _hiveService.insertBudget(budget);
      if (mounted) Navigator.pop(context);
    }
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    return Scaffold(
      appBar: AppBar(
        title: const Text('Criar Orçamento',
            style: TextStyle(fontWeight: FontWeight.bold)),
        centerTitle: true,
        backgroundColor: theme.colorScheme.primary,
        foregroundColor: theme.colorScheme.onPrimary,
      ),
      body: SingleChildScrollView(
        child: Padding(
          padding: const EdgeInsets.all(24.0),
          child: Form(
            key: _formKey,
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                DropdownButtonFormField<TransactionCategory>(
                  value: _selectedCategory,
                  decoration: InputDecoration(
                    labelText: 'Categoria',
                    labelStyle: TextStyle(color: theme.colorScheme.onSurface),
                    border: OutlineInputBorder(
                      borderRadius: BorderRadius.circular(12),
                    ),
                    filled: true,
                    fillColor: theme.colorScheme.surfaceVariant,
                  ),
                  items: TransactionCategory.values
                      .map((cat) => DropdownMenuItem(
                            value: cat,
                            child: Text(
                              _getCategoryName(cat),
                              style:
                                  TextStyle(color: theme.colorScheme.onSurface),
                            ),
                          ))
                      .toList(),
                  onChanged: (val) => setState(() => _selectedCategory = val),
                  validator: (val) =>
                      val == null ? 'Selecione a categoria' : null,
                ),
                const SizedBox(height: 16),
                TextFormField(
                  controller: _amountController,
                  keyboardType: TextInputType.number,
                  decoration: InputDecoration(
                    labelText: 'Valor do orçamento',
                    labelStyle: TextStyle(color: theme.colorScheme.onSurface),
                    border: OutlineInputBorder(
                      borderRadius: BorderRadius.circular(12),
                    ),
                    prefixText: '€ ',
                    filled: true,
                    fillColor: theme.colorScheme.surfaceVariant,
                  ),
                  validator: (val) {
                    if (val == null || val.isEmpty) {
                      return 'Informe o valor';
                    }
                    if (double.tryParse(val) == null) {
                      return 'Insira um número válido';
                    }
                    return null;
                  },
                ),
                const SizedBox(height: 16),
                DropdownButtonFormField<BudgetPeriod>(
                  value: _selectedPeriod,
                  decoration: InputDecoration(
                    labelText: 'Período',
                    labelStyle: TextStyle(color: theme.colorScheme.onSurface),
                    border: OutlineInputBorder(
                      borderRadius: BorderRadius.circular(12),
                    ),
                    filled: true,
                    fillColor: theme.colorScheme.surfaceVariant,
                  ),
                  items: BudgetPeriod.values
                      .map((period) => DropdownMenuItem(
                            value: period,
                            child: Text(
                              _getPeriodName(period),
                              style:
                                  TextStyle(color: theme.colorScheme.onSurface),
                            ),
                          ))
                      .toList(),
                  onChanged: (val) => setState(() => _selectedPeriod = val),
                  validator: (val) =>
                      val == null ? 'Selecione o período' : null,
                ),
                const SizedBox(height: 16),
                _buildDateSelectionTile(
                  context,
                  isStart: true,
                  label: 'Data inicial',
                  date: _selectedStartDate,
                ),
                const SizedBox(height: 16),
                _buildDateSelectionTile(
                  context,
                  isStart: false,
                  label: 'Data final',
                  date: _selectedEndDate,
                ),
                const SizedBox(height: 16),
                SwitchListTile(
                  title: const Text('Repetir orçamento'),
                  value: _repeatBudget,
                  onChanged: (val) => setState(() => _repeatBudget = val),
                  tileColor: theme.colorScheme.surfaceVariant,
                  shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(12),
                  ),
                ),
                const SizedBox(height: 16),
                TextFormField(
                  controller: _noteController,
                  decoration: InputDecoration(
                    labelText: 'Observação (opcional)',
                    labelStyle: TextStyle(color: theme.colorScheme.onSurface),
                    border: OutlineInputBorder(
                      borderRadius: BorderRadius.circular(12),
                    ),
                    filled: true,
                    fillColor: theme.colorScheme.surfaceVariant,
                  ),
                  maxLines: 2,
                ),
                const SizedBox(height: 32),
                ElevatedButton(
                  onPressed: _saveBudget,
                  style: ElevatedButton.styleFrom(
                    backgroundColor: theme.colorScheme.primary,
                    foregroundColor: theme.colorScheme.onPrimary,
                    padding: const EdgeInsets.symmetric(vertical: 16),
                    shape: RoundedRectangleBorder(
                      borderRadius: BorderRadius.circular(12),
                    ),
                  ),
                  child: const Text('Salvar'),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }

  Widget _buildDateSelectionTile(BuildContext context,
      {required bool isStart, required String label, DateTime? date}) {
    final theme = Theme.of(context);
    final isSelected = date != null;

    return InkWell(
      onTap: () => _selectDate(context, isStart),
      borderRadius: BorderRadius.circular(12),
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
        decoration: BoxDecoration(
          color: theme.colorScheme.surfaceVariant,
          borderRadius: BorderRadius.circular(12),
          border: Border.all(
            color: isSelected ? theme.colorScheme.primary : Colors.transparent,
            width: 2,
          ),
        ),
        child: Row(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: [
            Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  label,
                  style: theme.textTheme.labelMedium!.copyWith(
                      color: theme.colorScheme.onSurface.withOpacity(0.6)),
                ),
                const SizedBox(height: 4),
                Text(
                  isSelected
                      ? DateFormat('dd/MM/yyyy').format(date!)
                      : 'Selecione a data',
                  style: theme.textTheme.bodyLarge!.copyWith(
                      color: isSelected
                          ? theme.colorScheme.onSurface
                          : theme.colorScheme.onSurface.withOpacity(0.8)),
                ),
              ],
            ),
            Icon(Icons.calendar_today, color: theme.colorScheme.primary),
          ],
        ),
      ),
    );
  }

  String _getCategoryName(TransactionCategory category) {
    switch (category) {
      case TransactionCategory.food:
        return 'Alimentação';
      case TransactionCategory.utilities:
        return 'Contas';
      case TransactionCategory.shopping:
        return 'Compras';
      case TransactionCategory.education:
        return 'Educação';
      case TransactionCategory.salary:
        return 'Salário';
      case TransactionCategory.freelance:
        return 'Freelance';
      case TransactionCategory.invest:
        return 'Investimentos';
      case TransactionCategory.business:
        return 'Negócios';
      case TransactionCategory.transport:
        return 'Transporte';
      case TransactionCategory.medical:
        return 'Saúde';
      case TransactionCategory.social:
        return 'Social';
      case TransactionCategory.leisure:
        return 'Lazer';
      case TransactionCategory.others:
        return 'Outros';
      case TransactionCategory.house:
        return 'Casa';
      case TransactionCategory.subscriptions:
        return 'Assinaturas';
      default:
        return category.name;
    }
  }

  String _getPeriodName(BudgetPeriod period) {
    switch (period) {
      case BudgetPeriod.week:
        return 'Semanal';
      case BudgetPeriod.month:
        return 'Mensal';
      case BudgetPeriod.quarter:
        return 'Trimestral';
      case BudgetPeriod.year:
        return 'Anual';
      default:
        return period.name;
    }
  }
}