import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:shared_preferences/shared_preferences.dart';
import '../../core/theme/app_theme.dart';

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

  @override
  State<AuthScreen> createState() => _AuthScreenState();
}

class _AuthScreenState extends State<AuthScreen> {
  final _phoneController = TextEditingController();
  final _otpController = TextEditingController();
  bool _otpSent = false;
  bool _loading = false;

  Future<void> _sendOtp() async {
    if (_phoneController.text.length < 10) return;
    setState(() => _loading = true);
    // TODO: call PickerQueries.requestOtp via GraphQL
    await Future.delayed(const Duration(seconds: 1));
    setState(() {
      _loading = false;
      _otpSent = true;
    });
  }

  Future<void> _verifyOtp() async {
    if (_otpController.text.length < 4) return;
    setState(() => _loading = true);
    // TODO: call PickerQueries.verifyOtp via GraphQL
    await Future.delayed(const Duration(seconds: 1));
    final prefs = await SharedPreferences.getInstance();
    await prefs.setString('auth_token', 'mock_token_123');
    if (mounted) context.go('/orders');
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: AppColors.primary,
      body: SafeArea(
        child: Padding(
          padding: const EdgeInsets.all(24),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              const SizedBox(height: 40),
              const Text(
                'Велмарт',
                style: TextStyle(fontSize: 32, fontWeight: FontWeight.bold, color: Colors.white),
              ),
              const Text(
                'Комплектовщик',
                style: TextStyle(fontSize: 18, color: Colors.white70),
              ),
              const SizedBox(height: 48),
              Container(
                padding: const EdgeInsets.all(24),
                decoration: BoxDecoration(
                  color: Colors.white,
                  borderRadius: BorderRadius.circular(16),
                ),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    const Text('Авторизація', style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold)),
                    const SizedBox(height: 24),
                    TextField(
                      controller: _phoneController,
                      keyboardType: TextInputType.phone,
                      enabled: !_otpSent,
                      decoration: const InputDecoration(
                        labelText: 'Номер телефону',
                        prefixText: '+380 ',
                        hintText: '67 123 4567',
                      ),
                    ),
                    if (_otpSent) ...[
                      const SizedBox(height: 16),
                      TextField(
                        controller: _otpController,
                        keyboardType: TextInputType.number,
                        maxLength: 6,
                        decoration: const InputDecoration(
                          labelText: 'Код підтвердження',
                          hintText: '000000',
                          counterText: '',
                        ),
                      ),
                      const SizedBox(height: 8),
                      TextButton(
                        onPressed: () => setState(() => _otpSent = false),
                        child: const Text('Змінити номер'),
                      ),
                    ],
                    const SizedBox(height: 24),
                    ElevatedButton(
                      onPressed: _loading ? null : (_otpSent ? _verifyOtp : _sendOtp),
                      child: _loading
                          ? const SizedBox(
                              height: 20,
                              width: 20,
                              child: CircularProgressIndicator(color: Colors.white, strokeWidth: 2),
                            )
                          : Text(_otpSent ? 'Підтвердити' : 'Отримати код'),
                    ),
                  ],
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}