import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import '../../providers/auth_provider.dart';

/// 登录页——手机号 + 验证码
class LoginPage extends ConsumerStatefulWidget {
  const LoginPage({super.key});

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

class _LoginPageState extends ConsumerState<LoginPage> {
  final _phoneCtrl = TextEditingController();
  final _codeCtrl = TextEditingController();
  bool _agreed = false;
  bool _sending = false;
  int _countdown = 0;
  bool _loading = false;
  String? _error;

  @override
  void dispose() {
    _phoneCtrl.dispose();
    _codeCtrl.dispose();
    super.dispose();
  }

  Future<void> _sendSms() async {
    final phone = _phoneCtrl.text.trim();
    if (phone.length != 11 || !phone.startsWith('1')) {
      setState(() => _error = '请输入正确的手机号');
      return;
    }
    setState(() { _sending = true; _error = null; });
    final result = await ref.read(authProvider.notifier).sendSms(phone);
    setState(() { _sending = false; });
    if (result.error != null) {
      setState(() => _error = result.error);
      return;
    }
    // 开发阶段自动填充验证码
    if (result.devCode != null) {
      _codeCtrl.text = result.devCode!;
    }
    setState(() => _countdown = 60);
    _startCountdown();
  }

  void _startCountdown() async {
    for (var i = 60; i > 0; i--) {
      await Future.delayed(const Duration(seconds: 1));
      if (!mounted) return;
      setState(() => _countdown = i - 1);
    }
  }

  Future<void> _login() async {
    if (!_agreed) {
      setState(() => _error = '请阅读并同意服务协议和隐私政策');
      return;
    }
    setState(() { _loading = true; _error = null; });
    final err = await ref.read(authProvider.notifier).login(
      _phoneCtrl.text.trim(),
      _codeCtrl.text.trim(),
    );
    setState(() => _loading = false);
    if (err != null) {
      setState(() => _error = err);
      return;
    }
    if (mounted) context.go('/home');
  }

  @override
  Widget build(BuildContext context) {
    final authState = ref.watch(authProvider);

    // 已登录直接跳转
    if (authState.isLoggedIn && !authState.isLoading) {
      WidgetsBinding.instance.addPostFrameCallback((_) => context.go('/home'));
    }

    return Scaffold(
      body: SafeArea(
        child: SingleChildScrollView(
          padding: const EdgeInsets.symmetric(horizontal: 24),
          child: Column(
            children: [
              const SizedBox(height: 80),
              // Logo
              Icon(Icons.local_hospital, size: 64, color: Theme.of(context).colorScheme.primary),
              const SizedBox(height: 16),
              Text('健康管家', style: Theme.of(context).textTheme.headlineLarge),
              const SizedBox(height: 8),
              Text('您的 AI 健康陪伴助手', style: Theme.of(context).textTheme.bodyMedium),
              const SizedBox(height: 48),

              // 手机号
              TextField(
                controller: _phoneCtrl,
                keyboardType: TextInputType.phone,
                maxLength: 11,
                decoration: const InputDecoration(
                  hintText: '手机号',
                  prefixText: '+86 ',
                  counterText: '',
                ),
              ),
              const SizedBox(height: 16),

              // 验证码
              Row(
                children: [
                  Expanded(
                    child: TextField(
                      controller: _codeCtrl,
                      keyboardType: TextInputType.number,
                      maxLength: 6,
                      decoration: const InputDecoration(hintText: '验证码', counterText: ''),
                    ),
                  ),
                  const SizedBox(width: 12),
                  SizedBox(
                    width: 120,
                    height: 48,
                    child: ElevatedButton(
                      onPressed: (_countdown > 0 || _sending) ? null : _sendSms,
                      style: ElevatedButton.styleFrom(
                        backgroundColor: _countdown > 0 ? Colors.grey[300] : null,
                      ),
                      child: Text(
                        _sending ? '发送中' : _countdown > 0 ? '${_countdown}s' : '获取验证码',
                        style: TextStyle(fontSize: 14, color: _countdown > 0 ? Colors.grey[600] : null),
                      ),
                    ),
                  ),
                ],
              ),
              const SizedBox(height: 16),

              // 协议勾选
              Row(
                children: [
                  Checkbox(value: _agreed, onChanged: (v) => setState(() => _agreed = v ?? false)),
                  GestureDetector(
                    onTap: () => setState(() => _agreed = !_agreed),
                    child: Text('已阅读并同意《服务协议》《隐私政策》', style: Theme.of(context).textTheme.labelMedium),
                  ),
                ],
              ),
              const SizedBox(height: 24),

              // 登录按钮
              if (_error != null)
                Padding(
                  padding: const EdgeInsets.only(bottom: 12),
                  child: Text(_error!, style: const TextStyle(color: AppColors.errorRed, fontSize: 14)),
                ),
              SizedBox(
                width: double.infinity,
                height: 48,
                child: ElevatedButton(
                  onPressed: _loading ? null : _login,
                  child: _loading
                    ? const SizedBox(width: 24, height: 24, child: CircularProgressIndicator(strokeWidth: 2, color: Colors.white))
                    : const Text('登 录'),
                ),
              ),
              const SizedBox(height: 80),
            ],
          ),
        ),
      ),
    );
  }
}

/// 引用 AppTheme 颜色
class AppColors {
  static const Color errorRed = Color(0xFFE53935);
}