import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:qr_flutter/qr_flutter.dart';

import '../api/oa_client.dart';
import '../session/session.dart';
import '../desktop/desk_theme.dart';
import '../desktop/widgets/desk_widgets.dart';
import '../widgets/beian_footer.dart';

class DesktopLoginPage extends StatefulWidget {
  const DesktopLoginPage({super.key, required this.session, required this.api});
  final SessionStore session;
  final OaClient api;

  @override
  State<DesktopLoginPage> createState() => _DesktopLoginPageState();
}

class _DesktopLoginPageState extends State<DesktopLoginPage> {
  final _codeCtrl = TextEditingController();
  String _ticket = '';
  String _payload = '';
  String _hint = '打开手机端「消息」右上角 + → 扫一扫，扫描此二维码';
  String _error = '';
  bool _submitting = false;
  bool _starting = true;
  Timer? _poll;

  @override
  void initState() {
    super.initState();
    unawaited(_start());
  }

  @override
  void dispose() {
    _poll?.cancel();
    _codeCtrl.dispose();
    super.dispose();
  }

  Future<void> _start() async {
    setState(() {
      _starting = true;
      _error = '';
      _codeCtrl.clear();
      _hint = '打开手机端「消息」右上角 + → 扫一扫，扫描此二维码';
    });
    _poll?.cancel();
    try {
      final raw = await widget.api.post('/auth/qr/start', {});
      final data = raw is Map ? Map<String, dynamic>.from(raw) : <String, dynamic>{};
      final ticket = '${data['ticket'] ?? ''}'.trim();
      if (ticket.isEmpty) throw Exception('无法生成登录码');
      if (!mounted) return;
      setState(() {
        _ticket = ticket;
        _payload = '${data['payload'] ?? 'fengyingoa://qr?ticket=$ticket'}';
        _starting = false;
      });
      _poll = Timer.periodic(const Duration(milliseconds: 1600), (_) => _pollStatus());
    } catch (e) {
      if (!mounted) return;
      setState(() {
        _starting = false;
        _error = '$e';
      });
    }
  }

  Future<void> _pollStatus() async {
    if (_ticket.isEmpty || _submitting) return;
    try {
      final raw = await widget.api.get('/auth/qr/status', query: {'ticket': _ticket});
      final data = raw is Map ? Map<String, dynamic>.from(raw) : <String, dynamic>{};
      final status = '${data['status'] ?? ''}';
      if (!mounted) return;
      if (status == 'code_required') {
        setState(() => _hint = '手机已确认，请输入手机屏幕显示的六位登录码');
        return;
      }
      if (status == 'expired' || status == 'consumed') {
        _poll?.cancel();
        setState(() => _hint = '登录码已过期，正在刷新…');
        await _start();
      }
    } catch (e) {
      if (!mounted) return;
      setState(() => _error = '$e');
    }
  }

  Future<void> _complete() async {
    final code = _codeCtrl.text.trim();
    if (!RegExp(r'^\d{6}$').hasMatch(code)) {
      setState(() => _error = '请输入手机端显示的六位登录码');
      return;
    }
    setState(() {
      _submitting = true;
      _error = '';
    });
    try {
      final raw = await widget.api.post('/auth/qr/complete', {'ticket': _ticket, 'code': code});
      final data = raw is Map ? Map<String, dynamic>.from(raw) : <String, dynamic>{};
      if ('${data['accessToken'] ?? ''}'.isEmpty) throw Exception('电脑登录未完成');
      await widget.session.applyLogin(data);
      try {
        final menus = await widget.api.get('/system/menus');
        await widget.session.setMenus(asMaps(menus).map(MenuNode.fromJson).toList());
      } catch (_) {}
    } catch (e) {
      if (mounted) setState(() => _error = '$e');
    } finally {
      if (mounted) setState(() => _submitting = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: kDeskBg,
      body: Center(
        child: ConstrainedBox(
          constraints: const BoxConstraints(maxWidth: 420),
          child: Material(
            color: kDeskPane,
            borderRadius: BorderRadius.circular(12),
            elevation: 0,
            child: Container(
              decoration: BoxDecoration(
                borderRadius: BorderRadius.circular(12),
                border: Border.all(color: kDeskLine),
              ),
              padding: const EdgeInsets.fromLTRB(36, 40, 36, 32),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  DeskAvatar(label: '风', api: widget.api, size: 64, color: kDeskBind, icon: Icons.apartment),
                  const SizedBox(height: 14),
                  const Text('风影办公', style: TextStyle(fontSize: 22, fontWeight: FontWeight.w700, color: kDeskInk)),
                  const SizedBox(height: 6),
                  const Text(
                    '请使用手机 App 扫码，并输入六位登录码',
                    textAlign: TextAlign.center,
                    style: TextStyle(color: kDeskMute, fontSize: 13, height: 1.5),
                  ),
                  const SizedBox(height: 20),
                  if (_error.isNotEmpty)
                    Padding(
                      padding: const EdgeInsets.only(bottom: 12),
                      child: Text(_error, textAlign: TextAlign.center, style: const TextStyle(color: Color(0xFFFA5151))),
                    ),
                  if (_starting)
                    const Padding(
                      padding: EdgeInsets.symmetric(vertical: 48),
                      child: CircularProgressIndicator(color: kDeskBind),
                    )
                  else if (_payload.isNotEmpty) ...[
                    Container(
                      padding: const EdgeInsets.all(12),
                      decoration: BoxDecoration(
                        color: Colors.white,
                        borderRadius: BorderRadius.circular(8),
                        border: Border.all(color: kDeskLine),
                      ),
                      child: QrImageView(data: _payload, size: 200, backgroundColor: Colors.white),
                    ),
                    const SizedBox(height: 10),
                    Text(_hint, textAlign: TextAlign.center, style: const TextStyle(color: kDeskMute, fontSize: 12)),
                    const SizedBox(height: 18),
                    TextField(
                      controller: _codeCtrl,
                      onChanged: (v) {
                        final next = v.replaceAll(RegExp(r'\D'), '');
                        final clipped = next.length > 6 ? next.substring(0, 6) : next;
                        if (clipped != v) {
                          _codeCtrl.value = TextEditingValue(
                            text: clipped,
                            selection: TextSelection.collapsed(offset: clipped.length),
                          );
                        }
                      },
                      keyboardType: TextInputType.number,
                      textAlign: TextAlign.center,
                      maxLength: 6,
                      inputFormatters: [FilteringTextInputFormatter.digitsOnly, LengthLimitingTextInputFormatter(6)],
                      decoration: const InputDecoration(hintText: '六位登录码', counterText: ''),
                      style: const TextStyle(fontSize: 26, fontWeight: FontWeight.w700, letterSpacing: 8),
                    ),
                    const SizedBox(height: 16),
                    Row(
                      children: [
                        Expanded(
                          child: FilledButton(
                            style: FilledButton.styleFrom(backgroundColor: kDeskBind, minimumSize: const Size.fromHeight(40)),
                            onPressed: _submitting || _ticket.isEmpty ? null : _complete,
                            child: Text(_submitting ? '登录中…' : '确认登录'),
                          ),
                        ),
                        const SizedBox(width: 8),
                        OutlinedButton(onPressed: _starting ? null : _start, child: const Text('刷新')),
                      ],
                    ),
                  ],
                ],
              ),
            ),
          ),
        ),
      ),
      bottomNavigationBar: const BeianFooter(),
    );
  }
}