import 'package:flutter/material.dart';

import '../api.dart';
import '../main.dart';

/// Self-registration as a Gemeinde Verantwortliche/r: enter the KC invite
/// code, pick your Gemeinde, send the request. The result is a PENDING
/// membership a Leitungsteam member has to approve.
class VerantwortlicheRegisterScreen extends StatefulWidget {
  const VerantwortlicheRegisterScreen({super.key});

  @override
  State<VerantwortlicheRegisterScreen> createState() =>
      _VerantwortlicheRegisterScreenState();
}

class _VerantwortlicheRegisterScreenState
    extends State<VerantwortlicheRegisterScreen> {
  final _code = TextEditingController();
  String? _kcName;
  List<(String id, String name)> _gemeinden = [];
  String? _selectedGemeinde;
  bool _busy = false;
  String? _error;
  String? _done;

  Api get _api => AppScope.of(context).api;

  Future<void> _resolve() async {
    setState(() {
      _busy = true;
      _error = null;
      _kcName = null;
      _gemeinden = [];
    });
    try {
      final res = await _api.resolveInvite(_code.text.trim());
      setState(() {
        _kcName = res['kcName'] as String?;
        _gemeinden = ((res['gemeinden'] as List<dynamic>?) ?? [])
            .map((g) => (g['id'] as String, g['name'] as String))
            .toList();
      });
    } catch (e) {
      setState(() => _error = '$e');
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  Future<void> _submit() async {
    if (_selectedGemeinde == null) return;
    setState(() {
      _busy = true;
      _error = null;
    });
    try {
      final res =
          await _api.registerVerantwortliche(_code.text.trim(), _selectedGemeinde!);
      setState(() => _done =
          'Anfrage gesendet (Status: ${res['status']}). Ein Leitungsteam-Mitglied '
          'muss dich noch freischalten.');
    } catch (e) {
      setState(() => _error = '$e');
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Als Verantwortliche/r registrieren')),
      body: Center(
        child: ConstrainedBox(
          constraints: const BoxConstraints(maxWidth: 420),
          child: ListView(
            padding: const EdgeInsets.all(24),
            children: [
              if (_done != null) ...[
                const Icon(Icons.check_circle, color: Colors.green, size: 48),
                const SizedBox(height: 12),
                Text(_done!, textAlign: TextAlign.center),
                const SizedBox(height: 20),
                FilledButton(
                  onPressed: () => AppScope.of(context).logout(),
                  child: const Text('Abmelden'),
                ),
              ] else ...[
                TextField(
                  controller: _code,
                  decoration: const InputDecoration(
                    labelText: 'KC-Einladungscode',
                    border: OutlineInputBorder(),
                  ),
                ),
                const SizedBox(height: 12),
                OutlinedButton(
                  onPressed: _busy ? null : _resolve,
                  child: const Text('KC suchen'),
                ),
                if (_kcName != null) ...[
                  const SizedBox(height: 20),
                  Text('KC: $_kcName',
                      style: Theme.of(context).textTheme.titleMedium),
                  const SizedBox(height: 8),
                  DropdownButtonFormField<String>(
                    initialValue: _selectedGemeinde,
                    decoration: const InputDecoration(
                      labelText: 'Deine Gemeinde',
                      border: OutlineInputBorder(),
                    ),
                    items: [
                      for (final g in _gemeinden)
                        DropdownMenuItem(value: g.$1, child: Text(g.$2)),
                    ],
                    onChanged: (v) => setState(() => _selectedGemeinde = v),
                  ),
                  const SizedBox(height: 16),
                  FilledButton(
                    onPressed: (_busy || _selectedGemeinde == null) ? null : _submit,
                    child: const Text('Anfrage senden'),
                  ),
                ],
                if (_error != null) ...[
                  const SizedBox(height: 16),
                  Text(_error!,
                      style: TextStyle(color: Theme.of(context).colorScheme.error)),
                ],
              ],
            ],
          ),
        ),
      ),
    );
  }
}