import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import '../../core/auth/auth_state.dart';
import '../../core/theme/app_theme.dart';
import '../../repositories/auth_repository.dart';

class LoginScreen extends ConsumerStatefulWidget {
  const LoginScreen({super.key});

  @override
  ConsumerState<LoginScreen> createState() => _LoginScreenState();
}

class _LoginScreenState extends ConsumerState<LoginScreen> {
  final _formKey = GlobalKey<FormState>();
  final _hotelCodeCtrl = TextEditingController();
  final _usernameCtrl = TextEditingController();
  final _passwordCtrl = TextEditingController();
  bool _loading = false;
  bool _obscure = true;
  String? _errorMessage;

  @override
  void dispose() {
    _hotelCodeCtrl.dispose();
    _usernameCtrl.dispose();
    _passwordCtrl.dispose();
    super.dispose();
  }

  Future<void> _login() async {
    if (!_formKey.currentState!.validate()) return;
    setState(() {
      _loading = true;
      _errorMessage = null;
    });

    try {
      final user = await AuthRepository.login(
        hotelCode: _hotelCodeCtrl.text.trim(),
        username: _usernameCtrl.text.trim(),
        password: _passwordCtrl.text,
      );
      await ref.read(authStateProvider.notifier).login(user);
      if (mounted) context.go('/stock-in');
    } on AuthException catch (e) {
      setState(() => _errorMessage = e.message);
    } catch (e) {
      setState(() => _errorMessage = '登录失败：$e');
    } finally {
      if (mounted) setState(() => _loading = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: AppTheme.primaryDark,
      body: Stack(
        children: [
          // Background pattern
          Positioned.fill(
            child: CustomPaint(painter: _BackgroundPainter()),
          ),
          Center(
            child: Card(
              elevation: 12,
              shadowColor: Colors.black38,
              shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(8)),
              child: Container(
                width: 400,
                padding: const EdgeInsets.all(40),
                child: Form(
                  key: _formKey,
                  child: Column(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      // Logo
                      Container(
                        width: 80,
                        height: 80,
                        decoration: BoxDecoration(
                          gradient: const LinearGradient(
                            colors: [AppTheme.primaryLight, AppTheme.primaryDark],
                            begin: Alignment.topLeft,
                            end: Alignment.bottomRight,
                          ),
                          borderRadius: BorderRadius.circular(12),
                          boxShadow: [
                            BoxShadow(
                              color: AppTheme.primary.withAlpha(102),
                              blurRadius: 12,
                              offset: const Offset(0, 4),
                            ),
                          ],
                        ),
                        child: const Icon(Icons.wine_bar,
                            color: Colors.white, size: 44),
                      ),
                      const SizedBox(height: 20),
                      const Text(
                        '酒库管理系统',
                        style: TextStyle(
                          fontSize: 24,
                          fontWeight: FontWeight.w700,
                          color: AppTheme.primaryDark,
                          letterSpacing: 1,
                        ),
                      ),
                      const SizedBox(height: 6),
                      const Text(
                        '酒店仓库管理解决方案',
                        style: TextStyle(
                            fontSize: 13, color: AppTheme.textSecondary),
                      ),
                      const SizedBox(height: 32),

                      // Hotel code
                      TextFormField(
                        controller: _hotelCodeCtrl,
                        decoration: const InputDecoration(
                          labelText: '门店编号',
                          hintText: '请输入门店编号',
                          prefixIcon: Icon(Icons.store_outlined, size: 20),
                        ),
                        validator: (v) =>
                            (v == null || v.isEmpty) ? '请输入门店编号' : null,
                        textInputAction: TextInputAction.next,
                      ),
                      const SizedBox(height: 14),

                      // Username
                      TextFormField(
                        controller: _usernameCtrl,
                        decoration: const InputDecoration(
                          labelText: '用户名',
                          hintText: '请输入用户名',
                          prefixIcon: Icon(Icons.person_outline, size: 20),
                        ),
                        validator: (v) =>
                            (v == null || v.isEmpty) ? '请输入用户名' : null,
                        textInputAction: TextInputAction.next,
                      ),
                      const SizedBox(height: 14),

                      // Password
                      TextFormField(
                        controller: _passwordCtrl,
                        obscureText: _obscure,
                        decoration: InputDecoration(
                          labelText: '密码',
                          hintText: '请输入密码',
                          prefixIcon:
                              const Icon(Icons.lock_outline, size: 20),
                          suffixIcon: IconButton(
                            icon: Icon(
                                _obscure
                                    ? Icons.visibility_off
                                    : Icons.visibility,
                                size: 20),
                            onPressed: () =>
                                setState(() => _obscure = !_obscure),
                          ),
                        ),
                        validator: (v) =>
                            (v == null || v.isEmpty) ? '请输入密码' : null,
                        onFieldSubmitted: (_) => _login(),
                      ),

                      // Inline error message
                      if (_errorMessage != null) ...[
                        const SizedBox(height: 12),
                        Container(
                          width: double.infinity,
                          padding: const EdgeInsets.symmetric(
                              horizontal: 12, vertical: 10),
                          decoration: BoxDecoration(
                            color: AppTheme.danger.withAlpha(15),
                            borderRadius: BorderRadius.circular(4),
                            border: Border.all(
                                color: AppTheme.danger.withAlpha(80)),
                          ),
                          child: Row(
                            children: [
                              const Icon(Icons.error_outline,
                                  color: AppTheme.danger, size: 16),
                              const SizedBox(width: 8),
                              Expanded(
                                child: Text(
                                  _errorMessage!,
                                  style: const TextStyle(
                                      color: AppTheme.danger, fontSize: 13),
                                ),
                              ),
                            ],
                          ),
                        ),
                      ],

                      const SizedBox(height: 24),
                      SizedBox(
                        width: double.infinity,
                        height: 46,
                        child: ElevatedButton(
                          onPressed: _loading ? null : _login,
                          style: ElevatedButton.styleFrom(
                            shape: RoundedRectangleBorder(
                                borderRadius: BorderRadius.circular(4)),
                          ),
                          child: _loading
                              ? const SizedBox(
                                  width: 20,
                                  height: 20,
                                  child: CircularProgressIndicator(
                                      strokeWidth: 2, color: Colors.white))
                              : const Text('登  录',
                                  style: TextStyle(
                                      fontSize: 16,
                                      fontWeight: FontWeight.w500,
                                      letterSpacing: 2)),
                        ),
                      ),
                    ],
                  ),
                ),
              ),
            ),
          ),
          Positioned(
            bottom: 16,
            left: 0,
            right: 0,
            child: Center(
              child: Text(
                '© 2026 酒库管理系统 v1.0.0',
                style: TextStyle(
                    color: Colors.white.withAlpha(102), fontSize: 12),
              ),
            ),
          ),
        ],
      ),
    );
  }
}

class _BackgroundPainter extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint()
      ..color = const Color(0xFF1976D2).withAlpha(38)
      ..style = PaintingStyle.fill;
    canvas.drawCircle(
        Offset(size.width * 0.1, size.height * 0.2), 180, paint);
    canvas.drawCircle(
        Offset(size.width * 0.9, size.height * 0.8), 220, paint);
    paint.color = const Color(0xFF0D47A1).withAlpha(26);
    canvas.drawCircle(
        Offset(size.width * 0.8, size.height * 0.1), 140, paint);
  }

  @override
  bool shouldRepaint(covariant CustomPainter oldDelegate) => false;
}