import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:miaoji_zhang/shared/api/api_client.dart';
import 'package:miaoji_zhang/shared/api/auth_api.dart';
import 'package:miaoji_zhang/shared/api/config_api.dart';
import 'package:miaoji_zhang/features/auth/local_data_recovery.dart';
import 'package:miaoji_zhang/shared/services/current_ledger_store.dart';
import 'package:miaoji_zhang/shared/services/local_database.dart';
import 'package:miaoji_zhang/shared/services/session_store.dart';
import 'package:miaoji_zhang/shared/services/push_service.dart';
import 'package:miaoji_zhang/shared/theme/app_theme.dart';
import 'package:miaoji_zhang/shared/version.dart';
import 'package:miaoji_zhang/shared/widgets/app_controls.dart';
import 'package:miaoji_zhang/shared/widgets/brand_logo.dart';

class LoginPage extends StatefulWidget {
  final String? notice;

  const LoginPage({super.key, this.notice});

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

class _LoginPageState extends State<LoginPage> {
  final _user = TextEditingController();
  final _pass = TextEditingController();
  bool _loading = false;

  @override
  void initState() {
    super.initState();
    PublicConfigApi.init().ignore();
    if (widget.notice case final notice? when notice.isNotEmpty) {
      WidgetsBinding.instance.addPostFrameCallback((_) {
        if (mounted) {
          ScaffoldMessenger.of(
            context,
          ).showSnackBar(SnackBar(content: Text(notice)));
        }
      });
    }
  }

  @override
  void dispose() {
    _user.dispose();
    _pass.dispose();
    super.dispose();
  }

  Future<void> _login() async {
    if (_user.text.trim().isEmpty || _pass.text.isEmpty) {
      _showMessage('请输入用户名和密码');
      return;
    }
    final guestSnapshot = SessionStore.instance.isGuest
        ? LocalDatabase.instance.guestSnapshot()
        : null;
    setState(() => _loading = true);
    try {
      final result = await AuthApi.login(_user.text.trim(), _pass.text);
      final profile = result.profile;
      await PushService.instance.refresh();
      await CurrentLedgerStore.instance.ensureLoaded(force: true);
      if (!mounted) return;
      await offerLocalDataRecovery(context, guestSnapshot: guestSnapshot);
      if (!mounted) return;
      if (result.accountClosureCancelled) _showMessage('已取消账号注销，欢迎回来');
      final destination = !profile.onboardingDone
          ? '/onboarding'
          : profile.appMode == 'ai'
          ? '/ai-mode'
          : '/home';
      context.go(destination);
    } catch (error) {
      if (mounted) _showMessage(apiErrorMessage(error));
    } finally {
      if (mounted) setState(() => _loading = false);
    }
  }

  Future<void> _startGuest() async {
    setState(() => _loading = true);
    try {
      await SessionStore.instance.startGuest();
      await CurrentLedgerStore.instance.ensureLoaded(force: true);
      if (mounted) context.go('/home');
    } catch (error) {
      if (mounted) _showMessage(apiErrorMessage(error));
    } finally {
      if (mounted) setState(() => _loading = false);
    }
  }

  void _showMessage(String message) {
    ScaffoldMessenger.of(
      context,
    ).showSnackBar(SnackBar(content: Text(message)));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: ListView(
          padding: const EdgeInsets.symmetric(horizontal: 28),
          children: [
            SizedBox(height: 48),
            Center(
              child: Column(
                children: [
                  const BrandLogo(size: 82),
                  SizedBox(height: 16),
                  Text(
                    PublicConfigApi.appName,
                    style: TextStyle(
                      fontSize: 26,
                      fontWeight: FontWeight.w800,
                      letterSpacing: 1,
                    ),
                  ),
                  SizedBox(height: 8),
                  Text(
                    PublicConfigApi.slogan,
                    style: TextStyle(fontSize: 13, color: context.jz.text2),
                  ),
                  SizedBox(height: 48),
                ],
              ),
            ),
            TextField(
              controller: _user,
              textInputAction: TextInputAction.next,
              decoration: InputDecoration(labelText: '用户名', hintText: '请输入用户名'),
            ),
            SizedBox(height: 12),
            TextField(
              controller: _pass,
              obscureText: true,
              decoration: InputDecoration(labelText: '密码', hintText: '请输入密码'),
              onSubmitted: (_) => _loading ? null : _login(),
            ),
            SizedBox(height: 22),
            JzActionButton(
              label: '登录',
              loading: _loading,
              onPressed: _loading ? null : _login,
            ),
            SizedBox(height: 10),
            JzActionButton(
              label: '游客模式',
              secondary: true,
              onPressed: _loading ? null : _startGuest,
            ),
            SizedBox(height: 7),
            Text(
              '游客数据仅保存在本机；AI、语音解析和图片识别需登录联网',
              textAlign: TextAlign.center,
              style: TextStyle(
                fontSize: 10.5,
                color: context.jz.text3,
                height: 1.45,
              ),
            ),
            SizedBox(height: 8),
            Center(
              child: TextButton(
                onPressed: _loading ? null : () => context.go('/register'),
                child: Text('没有账号？去注册'),
              ),
            ),
            const LoginLegalLinks(),
            SizedBox(height: 20),
            Center(
              child: Text(
                AppVersion.display,
                style: TextStyle(fontSize: 10, color: context.jz.text3),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class LoginLegalLinks extends StatelessWidget {
  const LoginLegalLinks({super.key});

  @override
  Widget build(BuildContext context) {
    return Wrap(
      alignment: WrapAlignment.center,
      spacing: 2,
      runSpacing: 0,
      children: [
        _link(context, '用户协议', 'terms'),
        _link(context, '隐私政策', 'privacy'),
      ],
    );
  }

  Widget _link(BuildContext context, String label, String kind) => TextButton(
    onPressed: () => context.push('/legal/$kind'),
    child: Text(label, style: TextStyle(fontSize: 11.5)),
  );
}