import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:sales_chat/providers/auth_provider.dart';
import 'package:sales_chat/theme/app_theme.dart';

/// 登录页面 —— 微信风格，简约现代
class LoginPage extends StatefulWidget {
  const LoginPage({super.key});

  @override
  State<LoginPage> createState() => _LoginPageState();
}

class _LoginPageState extends State<LoginPage> {
  final _formKey = GlobalKey<FormState>();
  final _accountController = TextEditingController();
  final _passwordController = TextEditingController();
  bool _obscurePassword = true;

  @override
  void dispose() {
    _accountController.dispose();
    _passwordController.dispose();
    super.dispose();
  }

  /// 处理登录请求
  Future<void> _handleLogin() async {
    if (!_formKey.currentState!.validate()) return;

    final authProvider = context.read<AuthProvider>();
    final account = _accountController.text.trim();

    // 判断输入是邮箱还是用户名
    final isEmail = account.contains('@');

    final success = await authProvider.login(
      email: isEmail ? account : null,
      username: isEmail ? null : account,
      password: _passwordController.text,
    );

    if (success && mounted) {
      Navigator.of(context).pushReplacementNamed('/home');
    }
  }

  /// 访客登录弹窗
  Future<void> _handleGuestLogin() async {
    final nickname = await showDialog<String>(
      context: context,
      builder: (context) {
        final controller = TextEditingController();
        return AlertDialog(
          title: const Text('访客登录'),
          content: TextField(
            controller: controller,
            decoration: const InputDecoration(
              labelText: '昵称',
              hintText: '请输入昵称',
            ),
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.pop(context),
              child: const Text('取消'),
            ),
            ElevatedButton(
              onPressed: () => Navigator.pop(context, controller.text.trim()),
              child: const Text('登录'),
            ),
          ],
        );
      },
    );

    if (nickname != null && nickname.isNotEmpty && mounted) {
      final authProvider = context.read<AuthProvider>();
      final success = await authProvider.loginAsGuest(nickname: nickname);
      if (success && mounted) {
        Navigator.of(context).pushReplacementNamed('/home');
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: AppTheme.scaffoldBackground,
      body: SafeArea(
        child: Center(
          child: SingleChildScrollView(
            padding: const EdgeInsets.symmetric(horizontal: 28, vertical: 24),
            child: ConstrainedBox(
              constraints: const BoxConstraints(maxWidth: 400),
              child: Column(
                children: [
                  // 顶部品牌区域
                  const SizedBox(height: 48),
                  Text(
                    '销售聊天',
                    style: Theme.of(context).textTheme.headlineLarge?.copyWith(
                      fontWeight: FontWeight.bold,
                      color: AppTheme.textPrimary,
                      fontSize: 28,
                    ),
                    textAlign: TextAlign.center,
                  ),
                  const SizedBox(height: 40),

                  // 白色卡片容器 —— 表单区域
                  Container(
                    padding: const EdgeInsets.symmetric(
                      horizontal: 24,
                      vertical: 28,
                    ),
                    decoration: BoxDecoration(
                      color: AppTheme.cardBackground,
                      borderRadius: BorderRadius.circular(12),
                    ),
                    child: Form(
                      key: _formKey,
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.stretch,
                        children: [
                          // 账号输入框（邮箱或用户名）
                          TextFormField(
                            controller: _accountController,
                            keyboardType: TextInputType.emailAddress,
                            decoration: const InputDecoration(
                              labelText: '邮箱 / 用户名',
                              hintText: '请输入邮箱或用户名',
                              prefixIcon: Icon(Icons.person_outline),
                            ),
                            validator: (value) {
                              if (value == null || value.isEmpty) {
                                return '请输入邮箱或用户名';
                              }
                              return null;
                            },
                          ),
                          const SizedBox(height: 14),

                          // 密码输入框
                          TextFormField(
                            controller: _passwordController,
                            obscureText: _obscurePassword,
                            decoration: InputDecoration(
                              labelText: '密码',
                              hintText: '请输入密码',
                              prefixIcon: const Icon(Icons.lock_outlined),
                              suffixIcon: IconButton(
                                icon: Icon(
                                  _obscurePassword
                                      ? Icons.visibility_off
                                      : Icons.visibility,
                                ),
                                onPressed: () {
                                  setState(() {
                                    _obscurePassword = !_obscurePassword;
                                  });
                                },
                              ),
                            ),
                            validator: (value) {
                              if (value == null || value.isEmpty) {
                                return '请输入密码';
                              }
                              if (value.length < 6) {
                                return '密码至少需要6个字符';
                              }
                              return null;
                            },
                            onFieldSubmitted: (_) => _handleLogin(),
                          ),
                          const SizedBox(height: 24),

                          // 登录按钮
                          Consumer<AuthProvider>(
                            builder: (context, auth, _) {
                              return ElevatedButton(
                                onPressed: auth.isLoading ? null : _handleLogin,
                                style: ElevatedButton.styleFrom(
                                  backgroundColor: AppTheme.primaryColor,
                                  padding: const EdgeInsets.symmetric(vertical: 14),
                                  shape: RoundedRectangleBorder(
                                    borderRadius: BorderRadius.circular(8),
                                  ),
                                ),
                                child: auth.isLoading
                                    ? const SizedBox(
                                        height: 20,
                                        width: 20,
                                        child: CircularProgressIndicator(
                                          strokeWidth: 2,
                                          valueColor: AlwaysStoppedAnimation<Color>(
                                              Colors.white),
                                        ),
                                      )
                                    : const Text(
                                        '登录',
                                        style: TextStyle(
                                          fontSize: 16,
                                          fontWeight: FontWeight.w600,
                                        ),
                                      ),
                              );
                            },
                          ),
                        ],
                      ),
                    ),
                  ),

                  // 错误信息 —— 卡片下方，红色提示文字
                  Consumer<AuthProvider>(
                    builder: (context, auth, _) {
                      if (auth.error != null) {
                        return Padding(
                          padding: const EdgeInsets.only(top: 12),
                          child: Text(
                            auth.error!,
                            style: TextStyle(
                              color: AppTheme.errorColor,
                              fontSize: 13,
                            ),
                            textAlign: TextAlign.center,
                          ),
                        );
                      }
                      return const SizedBox.shrink();
                    },
                  ),

                  const SizedBox(height: 20),

                  // 访客登录 —— 文字按钮，低调
                  Consumer<AuthProvider>(
                    builder: (context, auth, _) {
                      return TextButton(
                        onPressed: auth.isLoading ? null : _handleGuestLogin,
                        style: TextButton.styleFrom(
                          foregroundColor: AppTheme.textSecondary,
                        ),
                        child: const Text(
                          '访客登录',
                          style: TextStyle(fontSize: 14),
                        ),
                      );
                    },
                  ),

                  const SizedBox(height: 8),

                  // 注册链接
                  Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      Text(
                        '没有账号？',
                        style: TextStyle(
                          color: AppTheme.textSecondary,
                          fontSize: 14,
                        ),
                      ),
                      TextButton(
                        onPressed: () {
                          Navigator.of(context).pushReplacementNamed('/register');
                        },
                        style: TextButton.styleFrom(
                          padding: const EdgeInsets.symmetric(horizontal: 4),
                          minimumSize: Size.zero,
                          tapTargetSize: MaterialTapTargetSize.shrinkWrap,
                        ),
                        child: const Text(
                          '注册',
                          style: TextStyle(fontSize: 14),
                        ),
                      ),
                    ],
                  ),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}