import 'package:flutter/material.dart';
import 'package:frontend_splatournament_manager/providers/tournament_provider.dart';
import 'package:provider/provider.dart';
import 'package:intl/intl.dart';

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

  @override
  State<CreateTournamentPage> createState() => _CreateTournamentPageState();
}

class _CreateTournamentPageState extends State<CreateTournamentPage> {
  final _formKey = GlobalKey<FormState>();
  final _nameController = TextEditingController();
  final _descriptionController = TextEditingController();

  int _maxTeamAmount = 2;

  DateTime? _startDate;
  DateTime? _endDate;

  bool _isLoading = false;

  final DateFormat _dateFormat = DateFormat('dd.MM.yyyy', 'de_DE');

  Future<void> _selectDate(BuildContext context, bool isStart) async {
    final initialDate = DateTime.now();
    final picked = await showDatePicker(
      context: context,
      locale: const Locale('de', 'DE'),
      initialDate: initialDate,
      firstDate: initialDate,
      lastDate: DateTime(2101),
    );
    if (picked != null) {
      setState(() {
        if (isStart) {
          _startDate = picked;
        } else {
          _endDate = picked;
        }
      });
    }
  }

  void _submitForm() async {
    if (!_formKey.currentState!.validate()) return;
    if (_startDate == null || _endDate == null) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(
          content: Text(
            'Bitte wähle sowohl ein Start- als auch ein Enddatum aus.',
          ),
        ),
      );
      return;
    }

    if (_endDate!.isBefore(_startDate!)) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(
          content: Text('Das Enddatum darf nicht vor dem Startdatum liegen.'),
        ),
      );
      return;
    }

    setState(() => _isLoading = true);

    try {
      final provider = Provider.of<TournamentProvider>(context, listen: false);
      await provider.createTournament(
        _nameController.text,
        _descriptionController.text,
        _maxTeamAmount,
        _startDate!,
        _endDate!,
      );
      if (!mounted) return;
      Navigator.pop(context);
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text(
            'Fehler: ${e.toString().replaceFirst('Exception: ', '')}',
          ),
        ),
      );
    } finally {
      if (mounted) setState(() => _isLoading = false);
    }
  }

  @override
  void dispose() {
    _nameController.dispose();
    _descriptionController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Turnier erstellen')),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(16.0),
        child: Form(
          key: _formKey,
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              TextFormField(
                controller: _nameController,
                decoration: const InputDecoration(labelText: 'Name'),
                validator: (value) =>
                    value == null || value.isEmpty ? 'Pflichtfeld' : null,
              ),
              const SizedBox(height: 16),
              TextFormField(
                controller: _descriptionController,
                decoration: const InputDecoration(labelText: 'Beschreibung'),
                maxLines: 3,
                validator: (value) =>
                    value == null || value.isEmpty ? 'Pflichtfeld' : null,
              ),
              const SizedBox(height: 16),
              DropdownButtonFormField<int>(
                initialValue: _maxTeamAmount,
                decoration: const InputDecoration(labelText: 'Maximale Teams'),
                items: [2, 4, 8].map((int value) {
                  return DropdownMenuItem<int>(
                    value: value,
                    child: Text(value.toString()),
                  );
                }).toList(),
                onChanged: (int? newValue) {
                  if (newValue != null) {
                    setState(() {
                      _maxTeamAmount = newValue;
                    });
                  }
                },
              ),
              const SizedBox(height: 24),
              Row(
                children: [
                  Expanded(
                    child: OutlinedButton(
                      onPressed: () => _selectDate(context, true),
                      child: Text(
                        _startDate == null
                            ? 'Startdatum wählen'
                            : 'Start: ${_dateFormat.format(_startDate!)}',
                      ),
                    ),
                  ),
                  const SizedBox(width: 16),
                  Expanded(
                    child: OutlinedButton(
                      onPressed: () => _selectDate(context, false),
                      child: Text(
                        _endDate == null
                            ? 'Enddatum wählen'
                            : 'Ende: ${_dateFormat.format(_endDate!)}',
                      ),
                    ),
                  ),
                ],
              ),
              const SizedBox(height: 32),
              ElevatedButton(
                onPressed: _isLoading ? null : _submitForm,
                child: _isLoading
                    ? const CircularProgressIndicator()
                    : const Text('Turnier erstellen'),
              ),
            ],
          ),
        ),
      ),
    );
  }
}