import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:shadcn_ui/shadcn_ui.dart';
import '../../core/app_theme.dart';
import '../../core/navigation_provider.dart';
import '../../providers/auth_provider.dart';

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; }
    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; }
    goRoute(ref, 'home');
  }

  @override Widget build(BuildContext context) {
    final authState = ref.watch(authProvider);
    final theme = ShadTheme.of(context);
    if (authState.isLoggedIn && !authState.isLoading) {
      WidgetsBinding.instance.addPostFrameCallback((_) => goRoute(ref, 'home'));
    }

    return Scaffold(
      body: Container(
        decoration: const BoxDecoration(
          gradient: LinearGradient(
            begin: Alignment.topLeft,
            end: Alignment.bottomRight,
            colors: [AppTheme.bg, AppTheme.bg, AppTheme.primaryLight],
          ),
        ),
        child: SafeArea(child: Center(child: SingleChildScrollView(
          padding: const EdgeInsets.symmetric(horizontal: 32),
          child: Column(mainAxisSize: MainAxisSize.min, children: [
            const SizedBox(height: 24),
            // Logo
            Container(
              width: 100, height: 100,
              decoration: BoxDecoration(
                color: AppTheme.primary.withAlpha(25),
                borderRadius: BorderRadius.circular(50),
              ),
              child: Stack(alignment: Alignment.center, children: [
                Container(
                  width: 72, height: 72,
                  decoration: BoxDecoration(
                    color: Colors.white.withAlpha(200),
                    borderRadius: BorderRadius.circular(36),
                  ),
                  child: const Icon(LucideIcons.heart, size: 36, color: AppTheme.primary),
                ),
              ]),
            ),
            const SizedBox(height: 20),
            Text('健康管家', style: TextStyle(fontSize: 32, fontWeight: FontWeight.bold, color: theme.colorScheme.foreground)),
            const SizedBox(height: 8),
            Text('你的 AI 心脏健康管家', style: TextStyle(fontSize: 18, color: theme.colorScheme.mutedForeground)),
            const SizedBox(height: 36),

            // 手机号输入
            _buildPhoneInput(theme),
            const SizedBox(height: AppTheme.sLg),

            // 验证码输入
            _buildCodeRow(theme),
            const SizedBox(height: AppTheme.sSm),

            // 协议勾选
            _buildAgreement(theme),

            // 错误提示
            if (_error != null)
              Padding(padding: const EdgeInsets.only(top: AppTheme.sMd), child: Text(_error!, style: TextStyle(color: theme.colorScheme.destructive, fontSize: 16))),

            const SizedBox(height: AppTheme.rXl),

            // 登录按钮
            _buildLoginButton(theme),

            const SizedBox(height: AppTheme.sXl),
          ]),
        ))),
      ),
    );
  }

  Widget _buildPhoneInput(ShadThemeData theme) {
    return Container(
      decoration: BoxDecoration(
        color: theme.colorScheme.card,
        borderRadius: BorderRadius.circular(AppTheme.rSm),
        boxShadow: [AppTheme.shadowLight],
      ),
      child: Row(children: [
        const Padding(padding: EdgeInsets.only(left: AppTheme.sLg), child: Text('+86', style: TextStyle(fontSize: 19, fontWeight: FontWeight.w500, color: AppTheme.text))),
        Container(width: 1, height: 24, color: theme.colorScheme.border, margin: const EdgeInsets.symmetric(horizontal: AppTheme.sMd)),
        Expanded(
          child: TextField(
            controller: _phoneCtrl,
            keyboardType: TextInputType.phone,
            maxLength: 11,
            style: TextStyle(fontSize: 19, color: theme.colorScheme.foreground),
            decoration: InputDecoration(
              hintText: '请输入手机号',
              hintStyle: TextStyle(color: theme.colorScheme.mutedForeground),
              border: InputBorder.none,
              counterText: '',
              contentPadding: const EdgeInsets.symmetric(vertical: AppTheme.sLg),
            ),
          ),
        ),
      ]),
    );
  }

  Widget _buildCodeRow(ShadThemeData theme) {
    final codeDisabled = _countdown > 0 || _sending;
    return Row(children: [
      Expanded(
        child: Container(
          decoration: BoxDecoration(
            color: theme.colorScheme.card,
            borderRadius: BorderRadius.circular(AppTheme.rSm),
            boxShadow: [AppTheme.shadowLight],
          ),
          child: TextField(
            controller: _codeCtrl,
            keyboardType: TextInputType.number,
            maxLength: 6,
            style: TextStyle(fontSize: 19, color: theme.colorScheme.foreground),
            decoration: InputDecoration(
              hintText: '验证码',
              hintStyle: TextStyle(color: theme.colorScheme.mutedForeground),
              border: InputBorder.none,
              counterText: '',
              contentPadding: const EdgeInsets.symmetric(horizontal: AppTheme.sLg, vertical: AppTheme.sLg),
            ),
          ),
        ),
      ),
      const SizedBox(width: AppTheme.sMd),
      GestureDetector(
        onTap: codeDisabled ? null : _sendSms,
        child: AnimatedContainer(
          duration: const Duration(milliseconds: 200),
          width: 110, height: 52,
          alignment: Alignment.center,
          decoration: BoxDecoration(
            color: codeDisabled ? theme.colorScheme.muted : AppTheme.primary,
            borderRadius: BorderRadius.circular(AppTheme.rSm),
          ),
          child: Text(
            _sending ? '发送中' : _countdown > 0 ? '${_countdown}s' : '获取验证码',
            style: TextStyle(
              fontSize: 17,
              color: codeDisabled ? theme.colorScheme.mutedForeground : Colors.white,
              fontWeight: FontWeight.w500,
            ),
          ),
        ),
      ),
    ]);
  }

  Widget _buildAgreement(ShadThemeData theme) {
    return Align(
      alignment: Alignment.centerLeft,
      child: GestureDetector(
        onTap: () => setState(() => _agreed = !_agreed),
        child: Row(mainAxisSize: MainAxisSize.min, children: [
          Container(
            width: 18, height: 18,
            margin: const EdgeInsets.only(right: 6),
            decoration: BoxDecoration(
              color: _agreed ? AppTheme.primary : Colors.transparent,
              borderRadius: BorderRadius.circular(4),
              border: Border.all(
                color: _agreed ? AppTheme.primary : theme.colorScheme.border,
                width: 1.5,
              ),
            ),
            child: _agreed ? Icon(LucideIcons.check, size: 15, color: theme.colorScheme.primaryForeground) : null,
          ),
          RichText(text: TextSpan(children: [
            TextSpan(text: '已阅读并同意', style: TextStyle(fontSize: 16, color: theme.colorScheme.mutedForeground)),
            TextSpan(text: '《服务协议》', style: const TextStyle(fontSize: 16, color: AppTheme.primary)),
            TextSpan(text: '和', style: TextStyle(fontSize: 16, color: theme.colorScheme.mutedForeground)),
            TextSpan(text: '《隐私政策》', style: const TextStyle(fontSize: 16, color: AppTheme.primary)),
          ])),
        ]),
      ),
    );
  }

  Widget _buildLoginButton(ShadThemeData theme) {
    return GestureDetector(
      onTap: _loading ? null : _login,
      child: Container(
        width: double.infinity,
        height: 52,
        alignment: Alignment.center,
        decoration: BoxDecoration(
          gradient: const LinearGradient(colors: [Color(0xFF9B8FEF), AppTheme.primary]),
          borderRadius: BorderRadius.circular(AppTheme.rPill),
          boxShadow: [BoxShadow(color: AppTheme.primary.withAlpha(80), blurRadius: 16, offset: const Offset(0, 8))],
        ),
        child: _loading
            ? const SizedBox(width: 24, height: 24, child: CircularProgressIndicator(strokeWidth: 2.5, color: Colors.white))
            : const Text('登 录', style: TextStyle(fontSize: 20, color: Colors.white, fontWeight: FontWeight.w600, letterSpacing: 2)),
      ),
    );
  }
}