import 'package:expense_tracker/models/expense.dart';
import 'package:expense_tracker/widgets/expenses.dart';

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:intl/intl.dart';

import 'dart:io';

final formatter = DateFormat('dd.MM.yyyy');

class NewExpense extends StatefulWidget {
  const NewExpense({super.key, required this.onAddExpense});

  final void Function(Expense expense) onAddExpense;

  @override
  State<StatefulWidget> createState() {
    return _NewExpenseState();
  }
}

class _NewExpenseState extends State<NewExpense> {
  final _titleController = TextEditingController();
  final _amountController = TextEditingController();
  DateTime? _selectedDate;
  Category _selectedCategory = Category.leisure;

  void _presentDatePicker() async {
    final now = DateTime.now();
    final firstDate = DateTime(now.year - 1, now.month, now.day);
    final pickedDate = await showDatePicker(
      context: context,
      initialDate: now,
      firstDate: firstDate,
      lastDate: now,
    );
    setState(() {
      _selectedDate = pickedDate;
    });
  }

  void _showDialog() {
    if (Platform.isIOS) {
      showCupertinoDialog(
        context: context,
        builder: (ctx) => CupertinoAlertDialog(
          title: const Text('Invalid input'),
          content: const Text(
              'Please make sure a valid title, amount date and category was entered.'),
          actions: [
            TextButton(
              onPressed: () {
                Navigator.pop(ctx);
              },
              child: const Text('Okay'),
            ),
          ],
        ),
      );
    } else {
      showDialog(
        context: context,
        builder: (ctx) => AlertDialog(
          title: const Text('Invalid input'),
          content: const Text(
              'Please make sure a valid title, amount date and category was entered.'),
          actions: [
            TextButton(
              onPressed: () {
                Navigator.pop(ctx);
              },
              child: const Text('Okay'),
            ),
          ],
        ),
      );
    }
  }

  void _submitExpenseData() {
    final enteredAmount = double.tryParse(_amountController.text);
    final amountIsInvalid = enteredAmount == null || enteredAmount <= 0;

    if (_titleController.text.trim().isEmpty ||
        amountIsInvalid ||
        _selectedDate == null) {
      _showDialog();
      return;
    }

    widget.onAddExpense(Expense(
      title: _titleController.text,
      amount: enteredAmount,
      date: _selectedDate!,
      category: _selectedCategory,
    ));
    Navigator.pop(context);
  }

  @override
  void dispose() {
    _titleController.dispose();
    _amountController.dispose();
    super.dispose();
  }

  Widget build(BuildContext context) {
    final keyboardSpace = MediaQuery.of(context).viewInsets.bottom;

    return LayoutBuilder(builder: (ctx, constraints) {
      final width = constraints.maxWidth;

      return SizedBox(
        height: double.infinity,
        child: SingleChildScrollView(
          child: Padding(
            padding: EdgeInsets.fromLTRB(16, 48, 16, keyboardSpace + 16),
            child: Column(
              children: [
                if (width >= 600)
                  Row(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Expanded(
                        child: TextField(
                          controller: _titleController,
                          maxLength: 50,
                          decoration: const InputDecoration(
                            label: Text('Title'),
                          ),
                        ),
                      ),
                      const SizedBox(
                        width: 24,
                      ),
                      Expanded(
                        child: TextField(
                          controller: _amountController,
                          keyboardType: const TextInputType.numberWithOptions(
                            decimal: true,
                          ),
                          decoration: const InputDecoration(
                            prefix: Text('\$ '),
                            label: Text('Amount'),
                          ),
                        ),
                      ),
                    ],
                  )
                else
                  TextField(
                    controller: _titleController,
                    maxLength: 50,
                    decoration: const InputDecoration(
                      label: Text('Title'),
                    ),
                  ),
                if (width >= 600)
                  Row(
                    children: [
                      DropdownButton(
                          value: _selectedCategory,
                          items: Category.values
                              .map(
                                (category) => DropdownMenuItem(
                                  value: category,
                                  child: Text(
                                    category.name.toUpperCase(),
                                  ),
                                ),
                              )
                              .toList(),
                          onChanged: (value) {
                            if (value == null) {
                              return;
                            }
                            setState(() {
                              _selectedCategory = value;
                            });
                          }),
                      const SizedBox(width: 24),
                      Expanded(
                        child: Row(
                          mainAxisAlignment: MainAxisAlignment.end,
                          crossAxisAlignment: CrossAxisAlignment.center,
                          children: [
                            Text(
                              _selectedDate == null
                                  ? 'No date selected'
                                  : formatter.format(_selectedDate!),
                            ),
                            IconButton(
                              onPressed: _presentDatePicker,
                              icon: Icon(Icons.calendar_month),
                            ),
                          ],
                        ),
                      ),
                    ],
                  )
                else
                  Row(
                    children: [
                      Expanded(
                        child: TextField(
                          controller: _amountController,
                          keyboardType: const TextInputType.numberWithOptions(
                            decimal: true,
                          ),
                          decoration: const InputDecoration(
                            prefix: Text('\$ '),
                            label: Text('Amount'),
                          ),
                        ),
                      ),
                      const SizedBox(width: 16),
                      Expanded(
                        child: Row(
                          mainAxisAlignment: MainAxisAlignment.end,
                          crossAxisAlignment: CrossAxisAlignment.center,
                          children: [
                            Text(
                              _selectedDate == null
                                  ? 'No date selected'
                                  : formatter.format(_selectedDate!),
                            ),
                            IconButton(
                              onPressed: _presentDatePicker,
                              icon: Icon(Icons.calendar_month),
                            ),
                          ],
                        ),
                      ),
                    ],
                  ),
                const SizedBox(height: 16),
                if (width >= 600)
                  Row(
                    children: [
                      const Spacer(),
                      TextButton(
                        onPressed: () {
                          Navigator.pop(context);
                        },
                        child: const Text('Cancel'),
                      ),
                      ElevatedButton(
                        onPressed: _submitExpenseData,
                        child: const Text('Save Expense'),
                      ),
                    ],
                  )
                else
                  Row(
                    children: [
                      DropdownButton(
                          value: _selectedCategory,
                          items: Category.values
                              .map(
                                (category) => DropdownMenuItem(
                                  value: category,
                                  child: Text(
                                    category.name.toUpperCase(),
                                  ),
                                ),
                              )
                              .toList(),
                          onChanged: (value) {
                            if (value == null) {
                              return;
                            }
                            setState(() {
                              _selectedCategory = value;
                            });
                          }),
                      const Spacer(),
                      TextButton(
                        onPressed: () {
                          Navigator.pop(context);
                        },
                        child: const Text('Cancel'),
                      ),
                      ElevatedButton(
                        onPressed: _submitExpenseData,
                        child: const Text('Save Expense'),
                      ),
                    ],
                  ),
              ],
            ),
          ),
        ),
      );
    });
  }
}