import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../core/auth/switch_server.dart';
import '../../core/config.dart';

/// Asks for a new backend address and applies it. Shared by Настройки and the login screen
/// (a wrong address there means you can never reach Настройки).
Future<void> showApiBaseUrlDialog(BuildContext context) async {
  final container = ProviderScope.containerOf(context);
  final result = await showDialog<_Choice>(
    context: context,
    builder: (_) =>
        _ApiBaseUrlDialog(current: container.read(apiBaseUrlProvider)),
  );
  if (result == null) return;
  await switchApiBaseUrl(container, result.url);
}

class _Choice {
  const _Choice(this.url);

  /// null = back to the default address.
  final String? url;
}

class _ApiBaseUrlDialog extends StatefulWidget {
  const _ApiBaseUrlDialog({required this.current});
  final String current;

  @override
  State<_ApiBaseUrlDialog> createState() => _ApiBaseUrlDialogState();
}

class _ApiBaseUrlDialogState extends State<_ApiBaseUrlDialog> {
  late final _controller = TextEditingController(text: widget.current);
  String? _error;

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  void _save() {
    final url = ApiBaseUrlController.normalize(_controller.text);
    if (url == null) {
      setState(() => _error = 'Нужен адрес вида https://fin.example.com');
      return;
    }
    Navigator.pop(context, _Choice(url));
  }

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: const Text('Адрес API'),
      content: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          TextField(
            controller: _controller,
            autofocus: true,
            keyboardType: TextInputType.url,
            decoration: InputDecoration(errorText: _error),
            onSubmitted: (_) => _save(),
          ),
          const SizedBox(height: 12),
          Text(
            'Смена адреса завершит сеанс и очистит локальный кэш.',
            style: Theme.of(context).textTheme.bodySmall,
          ),
        ],
      ),
      actions: [
        TextButton(
          onPressed: () => Navigator.pop(context),
          child: const Text('Отмена'),
        ),
        TextButton(
          onPressed: () => Navigator.pop(context, const _Choice(null)),
          child: const Text('По умолчанию'),
        ),
        FilledButton(onPressed: _save, child: const Text('Сохранить')),
      ],
    );
  }
}