import 'package:flutter/material.dart';
import 'package:mobile_scanner/mobile_scanner.dart';

import '../api/oa_client.dart';
import '../theme.dart';

class ScanLoginPage extends StatefulWidget {
  const ScanLoginPage({super.key, required this.api, this.ticket = ''});
  final OaClient api;
  final String ticket;

  @override
  State<ScanLoginPage> createState() => _ScanLoginPageState();
}

class _ScanLoginPageState extends State<ScanLoginPage> {
  late final TextEditingController _ticket;
  final MobileScannerController _scanner = MobileScannerController();
  bool _loading = false;
  bool _scanned = false;
  String _err = '';
  String _code = '';

  @override
  void initState() {
    super.initState();
    _ticket = TextEditingController(text: widget.ticket);
  }

  @override
  void dispose() {
    _ticket.dispose();
    _scanner.dispose();
    super.dispose();
  }

  String _ticketFrom(String raw) {
    final value = raw.trim();
    final uri = Uri.tryParse(value);
    if (uri?.scheme == 'fengyingoa' && uri?.host == 'qr') {
      return uri?.queryParameters['ticket']?.trim() ?? '';
    }
    return value;
  }

  Future<void> _ok([String? scanned]) async {
    final t = _ticketFrom(scanned ?? _ticket.text);
    if (t.isEmpty) {
      setState(() => _err = '请扫描电脑端二维码');
      return;
    }
    setState(() {
      _loading = true;
      _err = '';
    });
    try {
      final raw = await widget.api.post('/auth/qr/confirm', {'ticket': t});
      final map =
          raw is Map ? Map<String, dynamic>.from(raw) : <String, dynamic>{};
      if (!mounted) return;
      setState(() {
        _ticket.text = t;
        _code = '${map['code'] ?? ''}';
        _scanned = true;
      });
      await _scanner.stop();
    } catch (e) {
      if (mounted) setState(() => _err = '$e');
    } finally {
      if (mounted) setState(() => _loading = false);
    }
  }

  Future<void> _onDetect(BarcodeCapture capture) async {
    if (_loading || _scanned) return;
    final raw = capture.barcodes
        .map((b) => b.rawValue?.trim() ?? '')
        .firstWhere((v) => v.isNotEmpty, orElse: () => '');
    if (raw.isEmpty) return;
    await _ok(raw);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      appBar: AppBar(title: const Text('扫一扫登录电脑')),
      body: Padding(
        padding: const EdgeInsets.all(20),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            if (_code.isEmpty) ...[
              const Text('扫描电脑端二维码后，手机会生成一次性六位登录码。请把该六码填写到电脑端，电脑才会完成登录。',
                  style: TextStyle(color: kMute, height: 1.5)),
              const SizedBox(height: 16),
              ClipRRect(
                borderRadius: BorderRadius.circular(12),
                child: AspectRatio(
                  aspectRatio: 1,
                  child:
                      MobileScanner(controller: _scanner, onDetect: _onDetect),
                ),
              ),
            ] else ...[
              const Text('请在电脑端输入以下一次性六位登录码：',
                  style: TextStyle(color: kMute, height: 1.5)),
              const SizedBox(height: 24),
              Center(
                child: SelectableText(
                  _code,
                  style: const TextStyle(
                      fontSize: 42,
                      fontWeight: FontWeight.w700,
                      letterSpacing: 12,
                      color: kInk),
                ),
              ),
              const SizedBox(height: 12),
              const Center(
                  child: Text('两分钟内有效；不要把此码发给他人。',
                      style: TextStyle(color: kMute))),
              const SizedBox(height: 24),
              FilledButton(
                onPressed: () => Navigator.pop(context, true),
                child: const Text('我已在电脑端输入'),
              ),
            ],
            const SizedBox(height: 16),
            if (_code.isEmpty)
              TextField(
                controller: _ticket,
                decoration: const InputDecoration(hintText: '扫码异常时，可粘贴二维码内容'),
                textCapitalization: TextCapitalization.characters,
              ),
            if (_err.isNotEmpty) ...[
              const SizedBox(height: 12),
              Text(_err, style: const TextStyle(color: kDanger)),
            ],
            if (_code.isEmpty) ...[
              const SizedBox(height: 20),
              FilledButton(
                onPressed: _loading ? null : _ok,
                child: Text(_loading ? '确认中…' : '确认扫码'),
              ),
            ],
          ],
        ),
      ),
    );
  }
}