import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:pad_scanner/services/app_config_service.dart';
import 'package:pad_scanner/services/scanner_service.dart';
import 'package:pad_scanner/services/code_parser.dart';
import 'package:pad_scanner/services/api_service.dart';
import 'package:pad_scanner/services/feedback_service.dart';
import 'package:pad_scanner/services/registration_linking.dart';
import 'package:pad_scanner/pages/boxing_page.dart';
import 'package:pad_scanner/widgets/status_bar.dart';

class RegistrationPage extends StatefulWidget {
  const RegistrationPage({super.key});

  @override
  State<RegistrationPage> createState() => _RegistrationPageState();
}

class _RegistrationPageState extends State<RegistrationPage> {
  final _scannerService = ScannerService();
  final _apiService = ApiService();
  final _feedbackService = FeedbackService();
  final _focusNode = FocusNode();

  StreamSubscription<ScanResult>? _scanSubscription;
  final _zongpaiNos = <String>[];
  String? _locationCode;
  CodeType? _locationType;
  bool _isLocked = false;
  bool _isSubmitting = false;

  StatusDotColor _statusDot = StatusDotColor.blue;
  String _statusText = '等待扫描总排号或货位号…';
  String? _statusOverrideText;
  StatusDotColor? _statusOverrideDot;

  bool _overviewLoading = false;
  bool _overviewNotFound = false;
  String? _overviewError;
  String? _overviewZongpaiNo;
  PaichaOverviewResult? _overview;
  int _overviewRequestId = 0;

  @override
  void initState() {
    super.initState();
    _startScanListening();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      _focusNode.requestFocus();
    });
  }

  @override
  void dispose() {
    _scanSubscription?.cancel();
    _focusNode.dispose();
    _feedbackService.dispose();
    super.dispose();
  }

  void _startScanListening() {
    _scanSubscription ??= _scannerService.scanResults.listen(_onScan);
  }

  Future<void> _stopScanListening() async {
    final subscription = _scanSubscription;
    _scanSubscription = null;
    await subscription?.cancel();
  }

  void _restartScanListening() {
    _scanSubscription?.cancel();
    _scanSubscription = null;
    _startScanListening();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (mounted) {
        _focusNode.requestFocus();
      }
    });
  }

  void _onKeyEvent(KeyEvent event) {
    if (event is KeyDownEvent && event.logicalKey == LogicalKeyboardKey.enter) {
      _submit();
    }
  }

  void _onScan(ScanResult result) {
    final parsed = CodeParser.parse(result.barcode);
    switch (parsed.type) {
      case CodeType.zongpaiNo:
        _handleZongpaiScan(parsed.value);
      case CodeType.locationNormal:
      case CodeType.locationTransit:
        if (!_isLocked) {
          _feedbackService.trigger(FeedbackEvent.scanValid);
          setState(() {
            _locationCode = parsed.value;
            _locationType = parsed.type;
            _clearStatusOverride();
          });
        } else {}
      case CodeType.invalid:
        _feedbackService.trigger(FeedbackEvent.scanInvalid);
        _showStatusOverride(
          '无效码：${result.barcode}',
          StatusDotColor.red,
          const Duration(seconds: 2),
        );
    }
  }

  void _handleZongpaiScan(String zongpaiNo) {
    final shouldRefresh = _overviewZongpaiNo != zongpaiNo;
    _feedbackService.trigger(FeedbackEvent.scanValid);
    setState(() {
      if (_isLocked) {
        if (!_zongpaiNos.contains(zongpaiNo)) {
          _zongpaiNos.add(zongpaiNo);
        }
      } else {
        if (_zongpaiNos.isEmpty) {
          _zongpaiNos.add(zongpaiNo);
        } else {
          _zongpaiNos[0] = zongpaiNo;
        }
      }
      _clearStatusOverride();
    });
    if (shouldRefresh) {
      _loadOverview(zongpaiNo);
    }
  }

  void _removeZongpai(String zongpaiNo) {
    setState(() {
      _zongpaiNos.remove(zongpaiNo);
    });
  }

  void _clearStatusOverride() {
    _statusOverrideText = null;
    _statusOverrideDot = null;
  }

  void _showStatusOverride(String text, StatusDotColor dot, Duration duration) {
    setState(() {
      _statusOverrideText = text;
      _statusOverrideDot = dot;
    });
    Future.delayed(duration, () {
      if (mounted) setState(() => _clearStatusOverride());
    });
  }

  void _updateBaseStatus() {
    if (_isSubmitting) {
      _statusDot = StatusDotColor.orange;
      _statusText = '正在提交…';
      return;
    }
    if (_isLocked && _locationCode != null && _zongpaiNos.isEmpty) {
      _statusDot = StatusDotColor.blue;
      _statusText = '货位已锁定，请扫描下一张执行卡';
      return;
    }
    final hasZongpai = _zongpaiNos.isNotEmpty;
    final hasLocation = _locationCode != null;
    if (hasZongpai && hasLocation) {
      _statusDot = StatusDotColor.blue;
      _statusText = '请确认信息并提交';
    } else if (hasZongpai) {
      _statusDot = StatusDotColor.blue;
      _statusText = '请扫描目标货位号';
    } else if (hasLocation) {
      _statusDot = StatusDotColor.blue;
      _statusText = '请扫描执行卡';
    } else {
      _statusDot = StatusDotColor.blue;
      _statusText = '等待扫描总排号或货位号…';
    }
  }

  bool get _canSubmit =>
      _zongpaiNos.isNotEmpty && _locationCode != null && !_isSubmitting;

  bool get _isTransitTarget => isTransitTarget(_locationType, _locationCode);

  Future<String?> _baseUrl() async {
    final configService = AppConfigService();
    final baseUrl = await configService.getString('api_url') ?? '';
    if (baseUrl.isEmpty) {
      return null;
    }
    return baseUrl;
  }

  Future<void> _loadOverview(String zongpaiNo, {bool force = false}) async {
    if (!force && _overviewZongpaiNo == zongpaiNo && _overview != null) {
      return;
    }
    final requestId = ++_overviewRequestId;
    setState(() {
      _overviewZongpaiNo = zongpaiNo;
      _overviewLoading = true;
      _overviewNotFound = false;
      _overviewError = null;
    });

    final baseUrl = await _baseUrl();
    if (!mounted || requestId != _overviewRequestId) return;
    if (baseUrl == null) {
      setState(() {
        _overviewLoading = false;
        _overviewError = '未配置 API 地址，请前往设置';
      });
      return;
    }

    final result = await _apiService.fetchPaichaOverview(
      baseUrl: baseUrl,
      zongpaiNo: zongpaiNo,
    );
    if (!mounted || requestId != _overviewRequestId) return;

    setState(() {
      _overviewLoading = false;
      if (result.success) {
        _overview = result;
        _overviewNotFound = false;
        _overviewError = null;
      } else if (result.notFound) {
        _overview = null;
        _overviewNotFound = true;
        _overviewError = null;
      } else {
        _overviewError = result.errorMessage ?? '加载失败，点击重试';
      }
    });
  }

  Future<void> _refreshCurrentOverview() async {
    final zongpaiNo = _overviewZongpaiNo;
    if (zongpaiNo == null) return;
    await _loadOverview(zongpaiNo, force: true);
  }

  Future<void> _submit() async {
    if (!_canSubmit) return;

    final baseUrl = await _baseUrl();
    if (baseUrl == null) {
      _feedbackService.trigger(FeedbackEvent.submitFailure);
      _showStatusOverride(
        '未配置 API 地址，请前往设置',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
      return;
    }

    setState(() => _isSubmitting = true);

    if (_isLocked && _zongpaiNos.length > 1) {
      if (_isTransitTarget && !await _ensureBatchSamePaicha(baseUrl)) {
        if (!mounted) return;
        setState(() => _isSubmitting = false);
        _feedbackService.trigger(FeedbackEvent.submitFailure);
        _showStatusOverride(
          batchPaichaMismatchMessage,
          StatusDotColor.red,
          const Duration(seconds: 2),
        );
        return;
      }
      await _submitBatch(baseUrl);
    } else {
      await _submitOne(baseUrl, _zongpaiNos.first);
    }
  }

  Future<bool> _ensureBatchSamePaicha(String baseUrl) async {
    final paichaByCode = <String, String>{};
    final cachedOverview = _overview;
    if (cachedOverview?.success == true && cachedOverview!.paichaNo != null) {
      for (final item in cachedOverview.items) {
        paichaByCode[item.zongpaiNo] = cachedOverview.paichaNo!;
      }
    }

    for (final zongpaiNo in _zongpaiNos) {
      if (paichaByCode.containsKey(zongpaiNo)) continue;
      final result = await _apiService.fetchPaichaOverview(
        baseUrl: baseUrl,
        zongpaiNo: zongpaiNo,
      );
      if (!result.success || result.paichaNo == null) {
        return false;
      }
      for (final item in result.items) {
        paichaByCode[item.zongpaiNo] = result.paichaNo!;
      }
    }

    return allSamePaicha(_zongpaiNos.map((code) => paichaByCode[code]));
  }

  Future<void> _submitOne(String baseUrl, String zongpaiNo) async {
    final result = await _apiService.registerLocation(
      baseUrl: baseUrl,
      zongpaiNo: zongpaiNo,
      locationCode: _locationCode!,
    );

    if (!mounted) return;

    setState(() => _isSubmitting = false);

    if (result.success) {
      _feedbackService.trigger(FeedbackEvent.submitSuccess);
      if (_isTransitTarget) {
        setState(() => _isSubmitting = false);
        await _navigateToBoxing(
          mode: BoxingMode.singleCode,
          codes: [zongpaiNo],
          codesToClear: [zongpaiNo],
          clearLocation: !_isLocked,
        );
        return;
      }
      setState(() {
        _zongpaiNos.remove(zongpaiNo);
        if (!_isLocked) {
          _locationCode = null;
          _locationType = null;
        }
      });
      final msg = result.isOffShelfSuccess
          ? '下架成功'
          : (_isLocked ? '货位已锁定，请扫描下一张执行卡' : '上架成功');
      _showStatusOverride(
        msg,
        StatusDotColor.green,
        const Duration(milliseconds: 1500),
      );
      await _refreshCurrentOverview();
    } else if (result.isDuplicate) {
      _feedbackService.trigger(FeedbackEvent.duplicateError);
      _showDuplicateDialog(zongpaiNo, result.duplicateInfo);
    } else if (result.isAlreadyOffShelf) {
      _feedbackService.trigger(FeedbackEvent.submitFailure);
      _showStatusOverride(
        result.errorMessage ?? '该总排号已下架至转运区域，不可重新上架',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
    } else {
      final isNetwork = result.errorMessage == '网络异常，请检查网络连接';
      _feedbackService.trigger(
        isNetwork ? FeedbackEvent.networkError : FeedbackEvent.submitFailure,
      );
      _showStatusOverride(
        result.errorMessage ?? '提交失败',
        isNetwork ? StatusDotColor.yellow : StatusDotColor.red,
        const Duration(seconds: 2),
      );
    }
  }

  Future<void> _submitBatch(String baseUrl) async {
    int successCount = 0;
    int offShelfCount = 0;
    final failed = <String>[];
    final toRemove = <String>[];
    final transitCodes = <String>[];

    for (final zongpaiNo in List.of(_zongpaiNos)) {
      final result = await _apiService.registerLocation(
        baseUrl: baseUrl,
        zongpaiNo: zongpaiNo,
        locationCode: _locationCode!,
      );
      if (result.success) {
        successCount++;
        if (result.isOffShelfSuccess) {
          offShelfCount++;
        }
        toRemove.add(zongpaiNo);
        if (_isTransitTarget) {
          transitCodes.add(zongpaiNo);
        }
      } else {
        failed.add(zongpaiNo);
        if (result.isDuplicate) {
          if (_isTransitTarget && transitCodes.isNotEmpty) {
            setState(() {
              _zongpaiNos.removeWhere((item) => toRemove.contains(item));
              _isSubmitting = false;
            });
            await _navigateToBoxing(
              mode: BoxingMode.multiCode,
              codes: transitCodes,
              codesToClear: toRemove,
              clearLocation: false,
              returnMessage: '成功 $successCount 条，失败 ${failed.length} 条',
            );
            return;
          }
          setState(() {
            _zongpaiNos.removeWhere((item) => toRemove.contains(item));
            _isSubmitting = false;
          });
          _feedbackService.trigger(FeedbackEvent.duplicateError);
          _showDuplicateDialog(zongpaiNo, result.duplicateInfo);
          return;
        }
        if (result.isAlreadyOffShelf) {
          if (_isTransitTarget && transitCodes.isNotEmpty) {
            setState(() {
              _zongpaiNos.removeWhere((item) => toRemove.contains(item));
              _isSubmitting = false;
            });
            await _navigateToBoxing(
              mode: BoxingMode.multiCode,
              codes: transitCodes,
              codesToClear: toRemove,
              clearLocation: false,
              returnMessage: '成功 $successCount 条，失败 ${failed.length} 条',
            );
            return;
          }
          setState(() {
            _zongpaiNos.removeWhere((item) => toRemove.contains(item));
            _isSubmitting = false;
          });
          _feedbackService.trigger(FeedbackEvent.submitFailure);
          _showStatusOverride(
            result.errorMessage ?? '该总排号已下架至转运区域，不可重新上架',
            StatusDotColor.red,
            const Duration(seconds: 2),
          );
          return;
        }
      }
    }

    if (!mounted) return;

    setState(() {
      _zongpaiNos.removeWhere((item) => toRemove.contains(item));
      _isSubmitting = false;
    });

    if (_isTransitTarget && transitCodes.isNotEmpty) {
      await _navigateToBoxing(
        mode: BoxingMode.multiCode,
        codes: transitCodes,
        codesToClear: toRemove,
        clearLocation: failed.isEmpty,
        returnMessage: failed.isEmpty
            ? null
            : '成功 $successCount 条，失败 ${failed.length} 条',
      );
      return;
    }

    if (failed.isEmpty) {
      _feedbackService.trigger(FeedbackEvent.submitSuccess);
      final msg = offShelfCount == successCount
          ? '批量下架成功（$successCount 条）'
          : '批量上架成功（$successCount 条）';
      _showStatusOverride(
        msg,
        StatusDotColor.green,
        const Duration(milliseconds: 1500),
      );
      await _refreshCurrentOverview();
    } else {
      _feedbackService.trigger(FeedbackEvent.submitFailure);
      _showStatusOverride(
        '成功 $successCount 条，失败 ${failed.length} 条',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
    }
  }

  Future<void> _navigateToBoxing({
    required BoxingMode mode,
    required List<String> codes,
    required List<String> codesToClear,
    required bool clearLocation,
    String? returnMessage,
  }) async {
    await _refreshCurrentOverview();
    if (!mounted) return;
    final navigator = Navigator.of(context);
    await _stopScanListening();
    await navigator.push(
      MaterialPageRoute(
        builder: (_) => BoxingPage(
          arguments: BoxingPageArguments(
            initialMode: mode,
            autoScanCodes: codes,
          ),
        ),
      ),
    );
    if (!mounted) return;
    await Future<void>.delayed(const Duration(milliseconds: 120));
    if (!mounted) return;
    _restartScanListening();
    setState(() {
      _zongpaiNos.removeWhere((item) => codesToClear.contains(item));
      if (clearLocation) {
        _locationCode = null;
        _locationType = null;
      }
    });
    await _refreshCurrentOverview();
    if (!mounted) return;
    if (returnMessage != null) {
      _showStatusOverride(
        returnMessage,
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
    }
  }

  void _showDuplicateDialog(String zongpaiNo, Map<String, dynamic>? info) {
    showDialog(
      context: context,
      barrierDismissible: false,
      builder: (ctx) => AlertDialog(
        backgroundColor: Colors.red.shade50,
        title: const Row(
          children: [
            Icon(Icons.warning, color: Colors.red),
            SizedBox(width: 8),
            Text('重复上架', style: TextStyle(color: Colors.red)),
          ],
        ),
        content: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text('总排号：$zongpaiNo'),
            const SizedBox(height: 4),
            Text('已登记货位：${info?["location_code"] ?? "未知"}'),
            const SizedBox(height: 4),
            Text('登记时间：${info?["registered_at"] ?? "未知"}'),
            const SizedBox(height: 12),
            const Text(
              '请核查实物，确认是否操作错误。',
              style: TextStyle(fontWeight: FontWeight.bold),
            ),
          ],
        ),
        actions: [
          TextButton(
            onPressed: () {
              _feedbackService.stopAlert();
              Navigator.pop(ctx);
            },
            child: const Text('关闭'),
          ),
        ],
      ),
    );
  }

  void _toggleLock(bool value) {
    if (value && _locationCode == null) {
      _feedbackService.trigger(FeedbackEvent.submitFailure);
      _showStatusOverride(
        '请先扫描货位号',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
      return;
    }
    setState(() {
      _isLocked = value;
      if (!value && _zongpaiNos.length > 1) {
        _zongpaiNos.removeRange(0, _zongpaiNos.length - 1);
      }
    });
  }

  String _locationLabel(CodeType? type) {
    if (type == CodeType.locationTransit) return '转运区域';
    return '普通货架';
  }

  Color _locationLabelColor(CodeType? type) {
    if (type == CodeType.locationTransit) return Colors.orange;
    return Colors.blue;
  }

  Color _overviewRowColor(String status) {
    switch (status) {
      case 'on_shelf':
        return const Color(0xFFE3F2FD);
      case 'transferred':
        return const Color(0xFFFFF3E0);
      default:
        return const Color(0xFFF5F5F5);
    }
  }

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;
    _updateBaseStatus();
    final effectiveDot = _statusOverrideDot ?? _statusDot;
    final effectiveText = _statusOverrideText ?? _statusText;

    return KeyboardListener(
      focusNode: _focusNode,
      onKeyEvent: _onKeyEvent,
      child: Scaffold(
        appBar: AppBar(
          title: const Text('上架登记'),
          actions: [
            Padding(
              padding: const EdgeInsets.only(right: 4),
              child: Row(
                children: [
                  const Text('锁定货位', style: TextStyle(fontSize: 13)),
                  Switch(value: _isLocked, onChanged: _toggleLock),
                ],
              ),
            ),
          ],
        ),
        body: Column(
          children: [
            Padding(
              padding: const EdgeInsets.fromLTRB(12, 10, 12, 8),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  const Text(
                    '登记操作区',
                    style: TextStyle(fontSize: 14, fontWeight: FontWeight.w700),
                  ),
                  const SizedBox(height: 6),
                  _isLocked
                      ? _buildLockedInputPanel()
                      : _buildSingleInputPanel(),
                  const SizedBox(height: 10),
                  SizedBox(
                    width: double.infinity,
                    height: 46,
                    child: ElevatedButton(
                      onPressed: _canSubmit ? _submit : null,
                      style: ElevatedButton.styleFrom(
                        backgroundColor: registrationSubmitColor(
                          canSubmit: _canSubmit,
                          isTransitTarget: _isTransitTarget,
                          primaryColor: colorScheme.primary,
                        ),
                        foregroundColor: _canSubmit
                            ? Colors.white
                            : Colors.grey.shade600,
                        shape: RoundedRectangleBorder(
                          borderRadius: BorderRadius.circular(8),
                        ),
                      ),
                      child: _isSubmitting
                          ? const SizedBox(
                              width: 22,
                              height: 22,
                              child: CircularProgressIndicator(
                                strokeWidth: 2,
                                color: Colors.white,
                              ),
                            )
                          : Text(
                              registrationSubmitLabel(
                                isTransitTarget: _isTransitTarget,
                                isLocked: _isLocked,
                                zongpaiCount: _zongpaiNos.length,
                              ),
                              style: const TextStyle(fontSize: 17),
                            ),
                    ),
                  ),
                ],
              ),
            ),
            Divider(height: 1, color: Colors.grey.shade300),
            Expanded(child: _buildOverviewSection()),
            StatusBar(dotColor: effectiveDot, text: effectiveText),
          ],
        ),
      ),
    );
  }

  Widget _buildSingleInputPanel() {
    final hasLocation = _locationCode != null;
    final hasZongpai = _zongpaiNos.isNotEmpty;
    return Container(
      width: double.infinity,
      constraints: const BoxConstraints(minHeight: 58),
      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 10),
      decoration: BoxDecoration(
        border: Border.all(
          color: hasLocation || hasZongpai
              ? Colors.green
              : Colors.grey.shade400,
          width: hasLocation || hasZongpai ? 2 : 1,
        ),
        borderRadius: BorderRadius.circular(8),
      ),
      child: Row(
        children: [
          Flexible(
            flex: 5,
            child: Row(
              mainAxisSize: MainAxisSize.min,
              children: [
                Flexible(
                  child: Text(
                    _locationCode ?? '',
                    overflow: TextOverflow.ellipsis,
                    style: TextStyle(
                      fontSize: 18,
                      fontWeight: FontWeight.bold,
                      color: hasLocation ? Colors.black87 : Colors.grey,
                    ),
                  ),
                ),
                if (hasLocation) ...[
                  const SizedBox(width: 6),
                  _buildLocationChip(),
                ],
              ],
            ),
          ),
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 8),
            child: Text(
              '|',
              style: TextStyle(fontSize: 20, color: Colors.grey.shade500),
            ),
          ),
          Flexible(
            flex: 3,
            child: Text(
              hasZongpai ? _zongpaiNos.first : '',
              textAlign: TextAlign.right,
              overflow: TextOverflow.ellipsis,
              style: TextStyle(
                fontSize: 18,
                fontWeight: FontWeight.bold,
                color: hasZongpai ? Colors.black87 : Colors.grey,
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildLockedInputPanel() {
    final hasLocation = _locationCode != null;
    return Container(
      width: double.infinity,
      constraints: const BoxConstraints(minHeight: 82),
      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 8),
      decoration: BoxDecoration(
        border: Border.all(
          color: hasLocation || _zongpaiNos.isNotEmpty
              ? Colors.green
              : Colors.grey.shade400,
          width: hasLocation || _zongpaiNos.isNotEmpty ? 2 : 1,
        ),
        borderRadius: BorderRadius.circular(8),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              Expanded(
                child: Text(
                  _locationCode ?? '',
                  overflow: TextOverflow.ellipsis,
                  style: TextStyle(
                    fontSize: 18,
                    fontWeight: FontWeight.bold,
                    color: hasLocation ? Colors.black87 : Colors.grey,
                  ),
                ),
              ),
              const Icon(Icons.lock, color: Colors.orange, size: 18),
              const SizedBox(width: 6),
              if (hasLocation) _buildLocationChip(),
            ],
          ),
          const SizedBox(height: 8),
          if (_zongpaiNos.isEmpty)
            const SizedBox(height: 24)
          else
            Wrap(
              spacing: 6,
              runSpacing: 6,
              children: _zongpaiNos
                  .map(
                    (zongpaiNo) => InputChip(
                      label: Text(zongpaiNo),
                      visualDensity: VisualDensity.compact,
                      onDeleted: () => _removeZongpai(zongpaiNo),
                    ),
                  )
                  .toList(),
            ),
        ],
      ),
    );
  }

  Widget _buildLocationChip() {
    final color = _locationLabelColor(_locationType);
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
      decoration: BoxDecoration(
        color: color.withValues(alpha: 0.15),
        borderRadius: BorderRadius.circular(4),
      ),
      child: Text(
        _locationLabel(_locationType),
        style: TextStyle(
          fontSize: 11,
          color: color,
          fontWeight: FontWeight.bold,
        ),
      ),
    );
  }

  Widget _buildOverviewSection() {
    return Padding(
      padding: const EdgeInsets.fromLTRB(12, 8, 12, 8),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              const Expanded(
                child: Text(
                  '排产号货架总览',
                  style: TextStyle(fontSize: 14, fontWeight: FontWeight.w700),
                ),
              ),
              if (_overviewLoading)
                const SizedBox(
                  width: 16,
                  height: 16,
                  child: CircularProgressIndicator(strokeWidth: 2),
                ),
            ],
          ),
          const SizedBox(height: 6),
          Expanded(child: _buildOverviewBody()),
        ],
      ),
    );
  }

  Widget _buildOverviewBody() {
    if (_overviewZongpaiNo == null) {
      return _buildOverviewMessage('扫描总排号后自动显示排产号上架情况');
    }
    if (_overviewLoading && _overview == null) {
      return _buildOverviewMessage('正在加载排产号上架情况…');
    }
    if (_overviewNotFound) {
      return _buildOverviewMessage('暂无排产信息');
    }
    if (_overviewError != null && _overview == null) {
      return _buildRetryMessage(_overviewError!);
    }
    final overview = _overview;
    if (overview == null) {
      return _buildOverviewMessage('扫描总排号后自动显示排产号上架情况');
    }

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        if (_overviewError != null)
          Padding(
            padding: const EdgeInsets.only(bottom: 6),
            child: Row(
              children: [
                Expanded(
                  child: Text(
                    _overviewError!,
                    style: const TextStyle(fontSize: 12, color: Colors.red),
                  ),
                ),
                TextButton(
                  onPressed: _overviewZongpaiNo == null
                      ? null
                      : () => _loadOverview(_overviewZongpaiNo!, force: true),
                  child: const Text('重试'),
                ),
              ],
            ),
          ),
        Text(
          '${overview.paichaNo ?? "--"}   共 ${overview.totalCount} 个总排号',
          style: const TextStyle(fontSize: 13, fontWeight: FontWeight.w600),
        ),
        const SizedBox(height: 6),
        _buildOverviewHeader(),
        Expanded(
          child: ListView.builder(
            itemCount: overview.items.length,
            itemBuilder: (context, index) {
              return _buildOverviewRow(overview.items[index]);
            },
          ),
        ),
      ],
    );
  }

  Widget _buildOverviewHeader() {
    return Container(
      height: 32,
      padding: const EdgeInsets.symmetric(horizontal: 6),
      decoration: BoxDecoration(
        color: Colors.grey.shade200,
        border: Border.all(color: Colors.grey.shade400),
      ),
      child: const Row(
        children: [
          Expanded(flex: 20, child: Text('总排号', style: _headerStyle)),
          Expanded(flex: 20, child: Text('工令号', style: _headerStyle)),
          Expanded(
            flex: 14,
            child: Text('数量', textAlign: TextAlign.center, style: _headerStyle),
          ),
          Expanded(
            flex: 26,
            child: Text('货位号', textAlign: TextAlign.right, style: _headerStyle),
          ),
        ],
      ),
    );
  }

  Widget _buildOverviewRow(PaichaOverviewItem item) {
    final current = item.zongpaiNo == _overviewZongpaiNo;
    final rowStyle = TextStyle(
      fontSize: 12,
      fontWeight: current ? FontWeight.w700 : FontWeight.w500,
      color: Colors.black87,
    );
    return Container(
      constraints: const BoxConstraints(minHeight: 34),
      padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 6),
      decoration: BoxDecoration(
        color: _overviewRowColor(item.status),
        border: Border(
          left: BorderSide(
            color: current ? Colors.green : Colors.grey.shade300,
            width: current ? 2 : 1,
          ),
          right: BorderSide(
            color: current ? Colors.green : Colors.grey.shade300,
            width: current ? 2 : 1,
          ),
          bottom: BorderSide(
            color: current ? Colors.green : Colors.grey.shade300,
            width: current ? 2 : 1,
          ),
        ),
      ),
      child: Row(
        children: [
          Expanded(
            flex: 20,
            child: Text(
              item.zongpaiNo,
              overflow: TextOverflow.ellipsis,
              style: rowStyle,
            ),
          ),
          Expanded(
            flex: 20,
            child: Text(
              item.workOrderNo ?? '--',
              overflow: TextOverflow.ellipsis,
              style: rowStyle,
            ),
          ),
          Expanded(
            flex: 14,
            child: Text(
              item.quantity.toString(),
              textAlign: TextAlign.center,
              overflow: TextOverflow.ellipsis,
              style: rowStyle,
            ),
          ),
          Expanded(
            flex: 26,
            child: Text(
              item.locationCode ?? '—',
              textAlign: TextAlign.right,
              overflow: TextOverflow.ellipsis,
              style: rowStyle,
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildOverviewMessage(String text) {
    return Center(
      child: Text(
        text,
        textAlign: TextAlign.center,
        style: TextStyle(fontSize: 13, color: Colors.grey.shade600),
      ),
    );
  }

  Widget _buildRetryMessage(String text) {
    return Center(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          Text(
            text,
            textAlign: TextAlign.center,
            style: const TextStyle(fontSize: 13, color: Colors.red),
          ),
          const SizedBox(height: 6),
          TextButton(
            onPressed: _overviewZongpaiNo == null
                ? null
                : () => _loadOverview(_overviewZongpaiNo!, force: true),
            child: const Text('重试'),
          ),
        ],
      ),
    );
  }
}

const _headerStyle = TextStyle(fontSize: 12, fontWeight: FontWeight.w700);