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/boxing_context.dart';
import 'package:pad_scanner/services/feedback_service.dart';
import 'package:pad_scanner/pages/boxing_detail_page.dart';
import 'package:pad_scanner/widgets/status_bar.dart';

// === 装箱模式 ===

enum BoxingMode {
  singleCode, // 单码装箱
  multiCode, // 多码凑箱
}

class BoxingPageArguments {
  final BoxingMode initialMode;
  final List<String> autoScanCodes;

  const BoxingPageArguments({
    required this.initialMode,
    required this.autoScanCodes,
  });
}

// === 页面阶段 ===

enum _Phase {
  waiting, // 等待扫码
  scanned, // 已扫码，显示信息
  submitted, // 已提交成功
}

class _ManyToOnePackedItem {
  final int boxItemId;
  final String zongpaiNo;
  final String? paichanNo;
  final String? workOrderNo;
  final int boxNo;
  final int quantity;
  final int? totalQuantity;

  const _ManyToOnePackedItem({
    required this.boxItemId,
    required this.zongpaiNo,
    this.paichanNo,
    required this.workOrderNo,
    required this.boxNo,
    required this.quantity,
    this.totalQuantity,
  });

  _ManyToOnePackedItem copyWith({
    int? boxNo,
    int? quantity,
    int? totalQuantity,
  }) {
    return _ManyToOnePackedItem(
      boxItemId: boxItemId,
      zongpaiNo: zongpaiNo,
      paichanNo: paichanNo,
      workOrderNo: workOrderNo,
      boxNo: boxNo ?? this.boxNo,
      quantity: quantity ?? this.quantity,
      totalQuantity: totalQuantity ?? this.totalQuantity,
    );
  }
}

// === 主页面 ===

class BoxingPage extends StatefulWidget {
  final BoxingPageArguments? arguments;

  const BoxingPage({super.key, this.arguments});

  @override
  State<BoxingPage> createState() => _BoxingPageState();
}

class _BoxingPageState extends State<BoxingPage> {
  static const _androidKeyCodeButtonR1 = 103;

  final _scannerService = ScannerService();
  final _apiService = ApiService();
  final _feedbackService = FeedbackService();
  final _focusNode = FocusNode();
  StreamSubscription<ScanResult>? _scanSubscription;

  // 模式
  BoxingMode _mode = BoxingMode.singleCode;

  // 阶段
  _Phase _phase = _Phase.waiting;

  // 当前总排号
  String? _zongpaiNo;

  // 排产号信息（来自后端查询）
  String? _paichanNo;
  String? _workOrderNo;
  int? _erpQuantity;
  List<CurrentZongpaiBoxData> _currentZongpaiBoxes = [];
  List<BoxDetailData> _existingBoxes = [];
  int _maxBoxNo = 0;

  // 输入
  final _boxNoController = TextEditingController();
  final _quantityController = TextEditingController();
  final _boxNoFocusNode = FocusNode();
  final _quantityFocusNode = FocusNode();

  // 多码凑箱：本次操作已确认装入当前箱的明细
  final _manyToOnePackedItems = <_ManyToOnePackedItem>[];
  int? _editingPackedItemId;
  String _editingPackedQuantity = '';
  int? _deletingPackedItemId;
  int? _editingAssignedItemId;
  String _editingAssignedQuantity = '';
  int? _deletingAssignedItemId;
  String? _lastScannedPaichanNo;
  String? _paichanSwitchNotice;

  // 提交中
  bool _isSubmitting = false;

  // 单码装箱：上次提交的箱号（用于继续添加预填）
  int? _lastBoxNo;
  CurrentZongpaiBoxData? _editingBox;

  // 重复箱号
  bool _isDuplicateBoxNo = false;

  // Status bar state
  StatusDotColor _statusDot = StatusDotColor.blue;
  String _statusText = '等待扫码';
  String? _statusOverrideText;
  StatusDotColor? _statusOverrideDot;
  bool _isAutoProcessing = false;
  final _autoWarnings = <String>[];

  @override
  void initState() {
    super.initState();
    final arguments = widget.arguments;
    if (arguments != null) {
      _mode = arguments.initialMode;
    }
    _boxNoController.addListener(_onBoxNoTextChanged);
    _scanSubscription = _scannerService.scanResults.listen(_onScan);
    if (arguments != null && arguments.autoScanCodes.isNotEmpty) {
      WidgetsBinding.instance.addPostFrameCallback((_) {
        _processAutoScanCodes(arguments.autoScanCodes);
      });
    }
    WidgetsBinding.instance.addPostFrameCallback((_) => _requestFocus());
  }

  @override
  void dispose() {
    _boxNoController.removeListener(_onBoxNoTextChanged);
    _scanSubscription?.cancel();
    _focusNode.dispose();
    _boxNoController.dispose();
    _quantityController.dispose();
    _boxNoFocusNode.dispose();
    _quantityFocusNode.dispose();
    _feedbackService.dispose();
    super.dispose();
  }

  void _requestFocus() {
    if (mounted) {
      _focusNode.requestFocus();
    }
  }

  void _onKeyEvent(KeyEvent event) {
    if (event is! KeyDownEvent || _isAutoProcessing) return;
    if (_isModeSwitchKey(event)) {
      _cycleMode();
    }
  }

  bool _isModeSwitchKey(KeyEvent event) {
    final key = event.logicalKey;
    return key == LogicalKeyboardKey.select ||
        key == LogicalKeyboardKey.gameButtonRight1 ||
        _androidKeyCodeFromLogicalKey(key) == _androidKeyCodeButtonR1;
  }

  int? _androidKeyCodeFromLogicalKey(LogicalKeyboardKey key) {
    final keyId = key.keyId;
    const androidPlane = LogicalKeyboardKey.androidPlane;
    if (keyId >= androidPlane && keyId < androidPlane + 0x100000000) {
      return keyId - androidPlane;
    }
    return null;
  }

  void _onBoxNoTextChanged() {
    if (!mounted || _mode != BoxingMode.multiCode) return;
    setState(() {
      _editingPackedItemId = null;
      _editingPackedQuantity = '';
      _deletingPackedItemId = null;
    });
  }

  // === 模式切换 ===

  String get _modeLabel {
    switch (_mode) {
      case BoxingMode.singleCode:
        return '单码装箱';
      case BoxingMode.multiCode:
        return '多码凑箱';
    }
  }

  void _cycleMode() {
    _feedbackService.trigger(FeedbackEvent.modeSwitch);
    setState(() {
      switch (_mode) {
        case BoxingMode.singleCode:
          _mode = BoxingMode.multiCode;
        case BoxingMode.multiCode:
          _mode = BoxingMode.singleCode;
      }
      _resetState();
    });
  }

  void _resetState() {
    _phase = _Phase.waiting;
    _zongpaiNo = null;
    _paichanNo = null;
    _workOrderNo = null;
    _erpQuantity = null;
    _currentZongpaiBoxes = [];
    _existingBoxes = [];
    _maxBoxNo = 0;
    _boxNoController.clear();
    _quantityController.clear();
    _manyToOnePackedItems.clear();
    _editingPackedItemId = null;
    _editingPackedQuantity = '';
    _deletingPackedItemId = null;
    _editingAssignedItemId = null;
    _editingAssignedQuantity = '';
    _deletingAssignedItemId = null;
    _lastScannedPaichanNo = null;
    _paichanSwitchNotice = null;
    _isSubmitting = false;
    _lastBoxNo = null;
    _editingBox = null;
    _isDuplicateBoxNo = false;
    _statusOverrideText = null;
    _statusOverrideDot = null;
  }

  // === 扫码处理 ===

  void _onScan(ScanResult result) {
    if (_isAutoProcessing) {
      return;
    }

    final parsed = CodeParser.parse(result.barcode);

    if (parsed.type != CodeType.zongpaiNo) {
      _feedbackService.trigger(FeedbackEvent.scanInvalid);
      _showStatusOverride(
        '无效码，请重新扫描',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
      return;
    }

    final zongpai = parsed.value;

    // 三种模式都允许后扫入的总排号覆盖当前扫码区；未确认数据不会入库。
    _queryBoxInfo(zongpai);
  }

  Future<bool> _queryBoxInfo(String zongpai) async {
    final configService = AppConfigService();
    final baseUrl = await configService.getString('api_url') ?? '';
    if (baseUrl.isEmpty) {
      _feedbackService.trigger(FeedbackEvent.submitFailure);
      _showStatusOverride(
        '未配置 API 地址，请前往设置',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
      return false;
    }

    final result = await _apiService.fetchBoxInfo(
      baseUrl: baseUrl,
      zongpaiNo: zongpai,
    );

    if (!mounted) return false;

    if (!result.success) {
      final isNetwork = result.errorMessage == '网络异常，请检查网络连接';
      _feedbackService.trigger(
        isNetwork ? FeedbackEvent.networkError : FeedbackEvent.scanInvalid,
      );
      _showStatusOverride(
        result.errorMessage ?? '查询失败',
        isNetwork ? StatusDotColor.yellow : StatusDotColor.red,
        const Duration(seconds: 2),
      );
      return false;
    }

    _feedbackService.trigger(FeedbackEvent.scanValid);

    setState(() {
      _zongpaiNo = zongpai;
      _paichanNo = result.paichanNo;
      _workOrderNo = result.workOrderNo;
      _erpQuantity = result.quantity;
      _currentZongpaiBoxes = result.currentZongpaiBoxes;
      _existingBoxes = result.existingBoxes;
      _maxBoxNo = result.maxBoxNo;
      _phase = _Phase.scanned;
      _isDuplicateBoxNo = false;
      _editingBox = null;
      _editingAssignedItemId = null;
      _editingAssignedQuantity = '';
      _deletingAssignedItemId = null;
      _statusOverrideText = null;
      if (_mode == BoxingMode.singleCode) {
        _paichanSwitchNotice = null;
      }

      // 根据模式自动填充
      _applyAutoFill();
    });
    return true;
  }

  Future<void> _processAutoScanCodes(List<String> codes) async {
    if (!mounted) return;
    setState(() {
      _isAutoProcessing = true;
      _autoWarnings.clear();
      _statusOverrideText = '正在同步转运数据...';
      _statusOverrideDot = StatusDotColor.orange;
    });

    if (_mode == BoxingMode.singleCode) {
      final code = codes.first;
      final ok = await _queryBoxInfo(code);
      if (!ok && mounted) {
        setState(() => _autoWarnings.add('总排号 $code 未找到排产号信息，已忽略'));
      }
    } else {
      for (final code in codes) {
        if (!mounted) return;
        final queried = await _queryBoxInfo(code);
        if (!queried) {
          if (mounted) {
            setState(() => _autoWarnings.add('总排号 $code 未找到排产号信息，已忽略'));
          }
          continue;
        }
        if (!_canSubmit) {
          if (mounted) {
            setState(() => _autoWarnings.add('总排号 $code 暂不能装箱，已忽略'));
          }
          continue;
        }
        final saved = await _submit();
        if (!saved && mounted) {
          setState(() => _autoWarnings.add('总排号 $code 自动装箱失败，请手动处理'));
        }
      }
    }

    if (!mounted) return;
    setState(() {
      _isAutoProcessing = false;
      _statusOverrideText = null;
      _statusOverrideDot = null;
    });
    _focusQuantityInput();
    _requestFocus();
  }

  void _applyAutoFill() {
    switch (_mode) {
      case BoxingMode.singleCode:
        final remaining = _remainingQuantity;
        if (remaining <= 0) {
          _boxNoController.clear();
          _quantityController.clear();
          _statusOverrideText = '该总排号已全部装箱完毕';
          _statusOverrideDot = StatusDotColor.red;
          return;
        }
        if (_lastBoxNo != null) {
          _boxNoController.text = (_lastBoxNo! + 1).toString();
        } else {
          _boxNoController.text = (_maxBoxNo + 1).toString();
        }
        _quantityController.text = remaining.toString();
        _quantityController.selection = TextSelection(
          baseOffset: 0,
          extentOffset: _quantityController.text.length,
        );
        WidgetsBinding.instance.addPostFrameCallback((_) {
          if (mounted && _mode == BoxingMode.singleCode) {
            _quantityFocusNode.requestFocus();
          }
        });
      case BoxingMode.multiCode:
        final decision = decideMultiCodePaichanContext(
          lastPaichanNo: _lastScannedPaichanNo,
          currentPaichanNo: _paichanNo,
          currentBoxNoText: _boxNoController.text,
          maxBoxNo: _maxBoxNo,
        );
        if (decision.isSwitched) {
          _manyToOnePackedItems.clear();
          _editingPackedItemId = null;
          _editingPackedQuantity = '';
          _deletingPackedItemId = null;
          _paichanSwitchNotice = '排产号已切换：${_paichanNo ?? "--"}';
          _feedbackService.trigger(FeedbackEvent.paichanSwitch);
        } else {
          _paichanSwitchNotice = null;
        }
        final boxNoToApply = decision.boxNoToApply;
        if (boxNoToApply != null) {
          _boxNoController.text = boxNoToApply.toString();
        }
        _lastScannedPaichanNo = _paichanNo;
        final remaining = _remainingQuantity;
        if (remaining <= 0) {
          _quantityController.clear();
          _statusOverrideText = '该总排号已全部装箱完毕';
          _statusOverrideDot = StatusDotColor.red;
          return;
        }
        _quantityController.text = remaining.toString();
        _quantityController.selection = TextSelection(
          baseOffset: 0,
          extentOffset: _quantityController.text.length,
        );
        WidgetsBinding.instance.addPostFrameCallback((_) {
          if (mounted && _mode == BoxingMode.multiCode) {
            _quantityFocusNode.requestFocus();
          }
        });
    }
    _isDuplicateBoxNo = _boxNoIsDuplicate();
  }

  // === 重复箱号检测 ===

  bool _boxNoIsDuplicate() {
    final boxNo = int.tryParse(_boxNoController.text);
    if (boxNo == null) {
      return false;
    }
    return switch (_mode) {
      BoxingMode.multiCode => false,
      BoxingMode.singleCode => _currentZongpaiBoxes.any((b) {
        if (b.boxNo != boxNo) return false;
        return _editingBox == null || b.boxItemId != _editingBox!.boxItemId;
      }),
    };
  }

  void _checkDuplicateBoxNo() {
    setState(() => _isDuplicateBoxNo = _boxNoIsDuplicate());
  }

  // === 提交 ===

  int get _packedQuantity {
    return _currentZongpaiBoxes.fold<int>(
      0,
      (sum, item) => sum + item.quantity,
    );
  }

  int get _remainingQuantity {
    final total = _erpQuantity ?? 0;
    return total - _packedQuantity;
  }

  bool get _quantityTooHigh {
    final qty = int.tryParse(_quantityController.text);
    return qty != null && qty > _remainingQuantity;
  }

  bool get _canSubmit {
    if (_isSubmitting || _phase != _Phase.scanned) return false;
    if (_zongpaiNo == null) return false;
    final boxNo = int.tryParse(_boxNoController.text);
    final qty = int.tryParse(_quantityController.text);
    if (boxNo == null || boxNo <= 0 || qty == null || qty <= 0) return false;
    if (_quantityTooHigh) return false;
    if (_isDuplicateBoxNo) return false;
    return true;
  }

  void _submitFromKeyboard() {
    if (_canSubmit) {
      _submit();
    }
  }

  void _focusQuantityInput() {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (!mounted) return;
      _quantityFocusNode.requestFocus();
      _quantityController.selection = TextSelection(
        baseOffset: 0,
        extentOffset: _quantityController.text.length,
      );
    });
  }

  int? get _currentManyToOneBoxNo {
    final boxNo = int.tryParse(_boxNoController.text.trim());
    if (boxNo == null || boxNo <= 0) return null;
    return boxNo;
  }

  List<_ManyToOnePackedItem> get _visibleManyToOnePackedItems {
    final boxNo = _currentManyToOneBoxNo;
    if (boxNo == null) return const [];
    final byItemId = <int, _ManyToOnePackedItem>{};
    for (final box in _existingBoxes.where((box) => box.boxNo == boxNo)) {
      for (final item in box.items) {
        final boxItemId = item.boxItemId;
        if (boxItemId == null) continue;
        byItemId[boxItemId] = _ManyToOnePackedItem(
          boxItemId: boxItemId,
          zongpaiNo: item.zongpaiNo,
          paichanNo: _paichanNo,
          workOrderNo: item.workOrderNo,
          boxNo: boxNo,
          quantity: item.quantity,
          totalQuantity: item.totalQuantity,
        );
      }
    }
    for (final item in _manyToOnePackedItems.where(
      (item) => item.boxNo == boxNo,
    )) {
      byItemId[item.boxItemId] = item;
    }
    return byItemId.values.toList(growable: false);
  }

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

    final configService = AppConfigService();
    final baseUrl = await configService.getString('api_url') ?? '';
    if (baseUrl.isEmpty) {
      _feedbackService.trigger(FeedbackEvent.submitFailure);
      _showStatusOverride(
        '未配置 API 地址，请前往设置',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
      return false;
    }

    final boxNo = int.parse(_boxNoController.text);
    final quantity = int.parse(_quantityController.text);

    setState(() => _isSubmitting = true);

    final editing = _editingBox;
    final result = editing == null
        ? await _apiService.saveBoxRecord(
            baseUrl: baseUrl,
            zongpaiNo: _zongpaiNo!,
            boxNo: boxNo,
            quantity: quantity,
          )
        : await _apiService.updateBoxRecord(
            baseUrl: baseUrl,
            boxItemId: editing.boxItemId,
            boxNo: boxNo,
            quantity: quantity,
          );

    if (!mounted) return false;

    setState(() => _isSubmitting = false);

    if (result.success) {
      if (editing == null) {
        _onSubmitSuccess(boxNo, quantity, result.boxItemId);
      } else {
        _onUpdateSuccess(editing, boxNo, quantity);
      }
      return true;
    } else if (result.isDuplicate) {
      _feedbackService.trigger(FeedbackEvent.duplicateBoxNo);
      _showStatusOverride(
        '该总排号在箱号 ${result.boxNo ?? ""} 已存在，请重新输入',
        StatusDotColor.amber,
        const Duration(seconds: 2),
      );
      return false;
    } 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),
      );
      return false;
    }
  }

  void _onSubmitSuccess(int boxNo, int quantity, int? boxItemId) {
    _feedbackService.trigger(FeedbackEvent.submitSuccess);

    setState(() {
      _lastBoxNo = boxNo;
      if (_mode == BoxingMode.singleCode && boxItemId != null) {
        _currentZongpaiBoxes = List.from(_currentZongpaiBoxes)
          ..add(
            CurrentZongpaiBoxData(
              boxItemId: boxItemId,
              boxNo: boxNo,
              quantity: quantity,
            ),
          );
      }
      _addExistingBoxItem(boxNo, quantity, boxItemId);
      _maxBoxNo = _maxBoxNo > boxNo ? _maxBoxNo : boxNo;
    });

    switch (_mode) {
      case BoxingMode.singleCode:
        final remaining = _remainingQuantity;
        if (remaining <= 0) {
          _showStatusOverride(
            '装箱成功',
            StatusDotColor.green,
            const Duration(milliseconds: 1500),
          );
          Future.delayed(const Duration(milliseconds: 1500), () {
            if (mounted) setState(() => _resetState());
          });
        } else {
          setState(() {
            _phase = _Phase.scanned;
            _boxNoController.text = (boxNo + 1).toString();
            _quantityController.text = remaining.toString();
            _quantityController.selection = TextSelection(
              baseOffset: 0,
              extentOffset: _quantityController.text.length,
            );
            _isDuplicateBoxNo = false;
          });
          _focusQuantityInput();
          _showStatusOverride(
            '请继续完成剩余数量装箱',
            StatusDotColor.green,
            const Duration(milliseconds: 1500),
          );
        }

      case BoxingMode.multiCode:
        _lastScannedPaichanNo = _paichanNo;
        setState(() {
          if (boxItemId != null) {
            _manyToOnePackedItems.add(
              _ManyToOnePackedItem(
                boxItemId: boxItemId,
                zongpaiNo: _zongpaiNo!,
                paichanNo: _paichanNo,
                workOrderNo: _workOrderNo,
                boxNo: boxNo,
                quantity: quantity,
                totalQuantity: _erpQuantity,
              ),
            );
          }
          _phase = _Phase.waiting;
          _zongpaiNo = null;
          _editingPackedItemId = null;
          _editingPackedQuantity = '';
          _deletingPackedItemId = null;
        });
        _showStatusOverride(
          '装箱成功，请继续扫码',
          StatusDotColor.green,
          const Duration(milliseconds: 1500),
        );
    }
  }

  void _onUpdateSuccess(
    CurrentZongpaiBoxData editing,
    int boxNo,
    int quantity,
  ) {
    _feedbackService.trigger(FeedbackEvent.submitSuccess);

    setState(() {
      _currentZongpaiBoxes = _currentZongpaiBoxes.map((item) {
        if (item.boxItemId != editing.boxItemId) return item;
        return CurrentZongpaiBoxData(
          boxItemId: item.boxItemId,
          boxNo: boxNo,
          quantity: quantity,
        );
      }).toList();
      _replaceExistingBoxItem(editing, boxNo, quantity);
      _editingBox = null;
      _lastBoxNo = _maxBoxNo;
      _boxNoController.text = (_maxBoxNo + 1).toString();
      final remaining = _remainingQuantity;
      if (remaining > 0) {
        _quantityController.text = remaining.toString();
      } else {
        _quantityController.clear();
      }
      _isDuplicateBoxNo = false;
    });
    _showStatusOverride(
      '修改成功',
      StatusDotColor.green,
      const Duration(milliseconds: 1500),
    );
  }

  void _replaceExistingBoxItem(
    CurrentZongpaiBoxData editing,
    int boxNo,
    int quantity,
  ) {
    final nextBoxes = <BoxDetailData>[];
    for (final box in _existingBoxes) {
      final items = box.items.where((item) {
        return item.boxItemId != editing.boxItemId;
      }).toList();
      if (items.isNotEmpty) {
        nextBoxes.add(BoxDetailData(boxNo: box.boxNo, items: items));
      }
    }

    final targetIndex = nextBoxes.indexWhere((box) => box.boxNo == boxNo);
    final updatedItem = BoxItemData(
      boxItemId: editing.boxItemId,
      zongpaiNo: _zongpaiNo!,
      workOrderNo: _workOrderNo,
      quantity: quantity,
      totalQuantity: _erpQuantity,
    );
    if (targetIndex >= 0) {
      final target = nextBoxes[targetIndex];
      nextBoxes[targetIndex] = BoxDetailData(
        boxNo: target.boxNo,
        items: [...target.items, updatedItem],
      );
    } else {
      nextBoxes.add(BoxDetailData(boxNo: boxNo, items: [updatedItem]));
    }
    nextBoxes.sort((a, b) => a.boxNo.compareTo(b.boxNo));
    _existingBoxes = nextBoxes;
    _maxBoxNo = nextBoxes.fold<int>(
      0,
      (max, box) => box.boxNo > max ? box.boxNo : max,
    );
  }

  void _addExistingBoxItem(int boxNo, int quantity, int? boxItemId) {
    final item = BoxItemData(
      boxItemId: boxItemId,
      zongpaiNo: _zongpaiNo!,
      workOrderNo: _workOrderNo,
      quantity: quantity,
      totalQuantity: _erpQuantity,
    );
    final index = _existingBoxes.indexWhere((box) => box.boxNo == boxNo);
    if (index < 0) {
      _existingBoxes = [
        ..._existingBoxes,
        BoxDetailData(boxNo: boxNo, items: [item]),
      ]..sort((a, b) => a.boxNo.compareTo(b.boxNo));
      return;
    }

    final next = List<BoxDetailData>.from(_existingBoxes);
    final box = next[index];
    next[index] = BoxDetailData(boxNo: box.boxNo, items: [...box.items, item]);
    _existingBoxes = next;
  }

  // === 操作按钮 ===

  void _onGoBack() {
    setState(() => _resetState());
  }

  void _finishManyToOneBox() {
    final currentBoxNo = int.tryParse(_boxNoController.text.trim());
    setState(() {
      _manyToOnePackedItems.clear();
      _editingPackedItemId = null;
      _editingPackedQuantity = '';
      _deletingPackedItemId = null;
      _zongpaiNo = null;
      _phase = _Phase.waiting;
      _quantityController.clear();
      if (currentBoxNo != null && currentBoxNo > 0) {
        _boxNoController.text = (currentBoxNo + 1).toString();
      }
      _statusOverrideText = null;
      _statusOverrideDot = null;
    });
  }

  void _startEditAssigned(CurrentZongpaiBoxData item) {
    setState(() {
      _editingAssignedItemId = item.boxItemId;
      _editingAssignedQuantity = item.quantity.toString();
      _deletingAssignedItemId = null;
      _statusOverrideText = null;
      _statusOverrideDot = null;
    });
  }

  void _cancelEditAssigned() {
    setState(() {
      _editingAssignedItemId = null;
      _editingAssignedQuantity = '';
    });
  }

  int _maxAssignedQuantity(CurrentZongpaiBoxData item) {
    final total = _erpQuantity ?? 0;
    final packedWithoutItem = _packedQuantity - item.quantity;
    return total - packedWithoutItem;
  }

  void _refreshSingleCodeNewInput({bool focusQuantity = true}) {
    _lastBoxNo = _maxBoxNo;
    _boxNoController.text = (_maxBoxNo + 1).toString();
    final remaining = _remainingQuantity;
    if (remaining > 0) {
      _quantityController.text = remaining.toString();
      _quantityController.selection = TextSelection(
        baseOffset: 0,
        extentOffset: _quantityController.text.length,
      );
      if (focusQuantity) {
        _focusQuantityInput();
      }
    } else {
      _quantityController.clear();
    }
    _isDuplicateBoxNo = false;
  }

  Future<void> _saveAssignedItem(CurrentZongpaiBoxData item) async {
    final quantity = int.tryParse(_editingAssignedQuantity);
    if (quantity == null || quantity <= 0) {
      _showStatusOverride(
        '请输入有效数量',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
      return;
    }
    if (quantity > _maxAssignedQuantity(item)) {
      _showStatusOverride(
        '超出可装数量上限',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
      return;
    }

    final configService = AppConfigService();
    final baseUrl = await configService.getString('api_url') ?? '';
    if (baseUrl.isEmpty) {
      _showStatusOverride(
        '未配置 API 地址，请前往设置',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
      return;
    }

    setState(() => _isSubmitting = true);
    final result = await _apiService.updateBoxRecord(
      baseUrl: baseUrl,
      boxItemId: item.boxItemId,
      boxNo: item.boxNo,
      quantity: quantity,
    );
    if (!mounted) return;

    setState(() => _isSubmitting = false);
    if (result.success) {
      setState(() {
        _currentZongpaiBoxes = _currentZongpaiBoxes.map((box) {
          if (box.boxItemId != item.boxItemId) return box;
          return CurrentZongpaiBoxData(
            boxItemId: box.boxItemId,
            boxNo: box.boxNo,
            quantity: quantity,
          );
        }).toList();
        _replaceExistingBoxItem(item, item.boxNo, quantity);
        _editingAssignedItemId = null;
        _editingAssignedQuantity = '';
        _refreshSingleCodeNewInput();
      });
      _showStatusOverride(
        '修改成功',
        StatusDotColor.green,
        const Duration(milliseconds: 1500),
      );
    } else {
      final dot = result.isDuplicate
          ? StatusDotColor.amber
          : StatusDotColor.red;
      _showStatusOverride(
        result.errorMessage ?? '修改失败',
        dot,
        const Duration(seconds: 2),
      );
    }
  }

  Future<void> _deleteAssignedItem(CurrentZongpaiBoxData item) async {
    final configService = AppConfigService();
    final baseUrl = await configService.getString('api_url') ?? '';
    if (baseUrl.isEmpty) {
      _showStatusOverride(
        '未配置 API 地址，请前往设置',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
      return;
    }

    setState(() => _isSubmitting = true);
    final result = await _apiService.deleteBoxRecord(
      baseUrl: baseUrl,
      boxItemId: item.boxItemId,
    );
    if (!mounted) return;

    setState(() {
      _isSubmitting = false;
      if (result.success) {
        _currentZongpaiBoxes = _currentZongpaiBoxes
            .where((box) => box.boxItemId != item.boxItemId)
            .toList();
        _removeExistingBoxItem(item.boxItemId);
        if (_editingAssignedItemId == item.boxItemId) {
          _editingAssignedItemId = null;
          _editingAssignedQuantity = '';
        }
        _deletingAssignedItemId = null;
        _refreshSingleCodeNewInput();
      }
    });

    if (result.success) {
      _showStatusOverride(
        '删除成功',
        StatusDotColor.green,
        const Duration(milliseconds: 1500),
      );
    } else {
      _showStatusOverride(
        result.errorMessage ?? '删除失败',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
    }
  }

  void _startEditPackedItem(_ManyToOnePackedItem item) {
    setState(() {
      _editingPackedItemId = item.boxItemId;
      _editingPackedQuantity = item.quantity.toString();
      _deletingPackedItemId = null;
    });
  }

  void _cancelEditPackedItem() {
    setState(() {
      _editingPackedItemId = null;
      _editingPackedQuantity = '';
    });
  }

  Future<void> _savePackedItem(_ManyToOnePackedItem item) async {
    final quantity = int.tryParse(_editingPackedQuantity);
    final boxNo = int.tryParse(_boxNoController.text.trim());
    if (quantity == null || quantity <= 0 || boxNo == null || boxNo <= 0) {
      _showStatusOverride(
        '请输入有效箱号和数量',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
      return;
    }

    final configService = AppConfigService();
    final baseUrl = await configService.getString('api_url') ?? '';
    if (baseUrl.isEmpty) {
      _showStatusOverride(
        '未配置 API 地址，请前往设置',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
      return;
    }

    setState(() => _isSubmitting = true);
    final result = await _apiService.updateBoxRecord(
      baseUrl: baseUrl,
      boxItemId: item.boxItemId,
      boxNo: boxNo,
      quantity: quantity,
    );
    if (!mounted) return;

    setState(() => _isSubmitting = false);
    if (result.success) {
      setState(() {
        final index = _manyToOnePackedItems.indexWhere(
          (packed) => packed.boxItemId == item.boxItemId,
        );
        if (index >= 0) {
          _manyToOnePackedItems[index] = _manyToOnePackedItems[index].copyWith(
            boxNo: boxNo,
            quantity: quantity,
          );
        }
        _replaceExistingPackedItem(item, boxNo, quantity);
        _editingPackedItemId = null;
        _editingPackedQuantity = '';
      });
      _showStatusOverride(
        '修改成功',
        StatusDotColor.green,
        const Duration(milliseconds: 1500),
      );
    } else {
      final dot = result.isDuplicate
          ? StatusDotColor.amber
          : StatusDotColor.red;
      _showStatusOverride(
        result.errorMessage ?? '修改失败',
        dot,
        const Duration(seconds: 2),
      );
    }
  }

  void _replaceExistingPackedItem(
    _ManyToOnePackedItem item,
    int boxNo,
    int quantity,
  ) {
    final nextBoxes = <BoxDetailData>[];
    for (final box in _existingBoxes) {
      final items = box.items.where((boxItem) {
        return boxItem.boxItemId != item.boxItemId;
      }).toList();
      if (items.isNotEmpty) {
        nextBoxes.add(BoxDetailData(boxNo: box.boxNo, items: items));
      }
    }

    final updatedItem = BoxItemData(
      boxItemId: item.boxItemId,
      zongpaiNo: item.zongpaiNo,
      workOrderNo: item.workOrderNo,
      quantity: quantity,
      totalQuantity: item.totalQuantity,
    );
    final targetIndex = nextBoxes.indexWhere((box) => box.boxNo == boxNo);
    if (targetIndex >= 0) {
      final target = nextBoxes[targetIndex];
      nextBoxes[targetIndex] = BoxDetailData(
        boxNo: target.boxNo,
        items: [...target.items, updatedItem],
      );
    } else {
      nextBoxes.add(BoxDetailData(boxNo: boxNo, items: [updatedItem]));
    }
    nextBoxes.sort((a, b) => a.boxNo.compareTo(b.boxNo));
    _existingBoxes = nextBoxes;
    _maxBoxNo = nextBoxes.fold<int>(
      0,
      (max, box) => box.boxNo > max ? box.boxNo : max,
    );
  }

  Future<void> _deletePackedItem(_ManyToOnePackedItem item) async {
    final configService = AppConfigService();
    final baseUrl = await configService.getString('api_url') ?? '';
    if (baseUrl.isEmpty) {
      _showStatusOverride(
        '未配置 API 地址，请前往设置',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
      return;
    }

    setState(() => _isSubmitting = true);
    final result = await _apiService.deleteBoxRecord(
      baseUrl: baseUrl,
      boxItemId: item.boxItemId,
    );
    if (!mounted) return;

    setState(() {
      _isSubmitting = false;
      if (result.success) {
        _manyToOnePackedItems.removeWhere(
          (packed) => packed.boxItemId == item.boxItemId,
        );
        _removeExistingBoxItem(item.boxItemId);
        if (_editingPackedItemId == item.boxItemId) {
          _editingPackedItemId = null;
          _editingPackedQuantity = '';
        }
        _deletingPackedItemId = null;
      }
    });

    if (result.success) {
      _showStatusOverride(
        '删除成功',
        StatusDotColor.green,
        const Duration(milliseconds: 1500),
      );
    } else {
      _showStatusOverride(
        result.errorMessage ?? '删除失败',
        StatusDotColor.red,
        const Duration(seconds: 2),
      );
    }
  }

  void _removeExistingBoxItem(int boxItemId) {
    final nextBoxes = <BoxDetailData>[];
    for (final box in _existingBoxes) {
      final items = box.items
          .where((item) => item.boxItemId != boxItemId)
          .toList();
      if (items.isNotEmpty) {
        nextBoxes.add(BoxDetailData(boxNo: box.boxNo, items: items));
      }
    }
    _existingBoxes = nextBoxes;
    _maxBoxNo = nextBoxes.fold<int>(
      0,
      (max, box) => box.boxNo > max ? box.boxNo : max,
    );
  }

  // === Status bar management ===

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

  // === 导航到详情页 ===

  void _openDetail() {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (_) => BoxingDetailPage(
          paichanNo: _paichanNo ?? '',
          existingBoxes: _existingBoxes,
        ),
      ),
    );
  }

  // === 状态文字 ===

  void _updateBaseStatus() {
    if (_isAutoProcessing) {
      _statusDot = StatusDotColor.orange;
      _statusText = '正在同步转运数据...';
      return;
    }
    if (_isSubmitting) {
      _statusDot = StatusDotColor.orange;
      _statusText = '正在提交…';
      return;
    }
    if (_isDuplicateBoxNo && _phase == _Phase.scanned) {
      _statusDot = StatusDotColor.amber;
      _statusText = '箱号 ${_boxNoController.text} 已存在，请重新输入';
      return;
    }
    if (_quantityTooHigh && _phase == _Phase.scanned) {
      _statusDot = StatusDotColor.red;
      _statusText = '超出可装数量上限';
      return;
    }
    if (_paichanSwitchNotice != null) {
      _statusDot = StatusDotColor.blue;
      _statusText = '排产号已切换，箱号已重置';
      return;
    }
    switch (_phase) {
      case _Phase.waiting:
        _statusDot = StatusDotColor.blue;
        if (_mode == BoxingMode.multiCode &&
            _visibleManyToOnePackedItems.isNotEmpty) {
          _statusText = '请继续扫码或完成本箱';
        } else {
          _statusText = '等待扫码';
        }
      case _Phase.scanned:
        _statusDot = StatusDotColor.blue;
        if (_remainingQuantity <= 0) {
          _statusDot = StatusDotColor.red;
          _statusText = '该总排号已全部装箱完毕';
          return;
        }
        _statusText = _mode == BoxingMode.multiCode
            ? '数量已填入，请确认或修改'
            : '数量已填入，请确认或修改';
      case _Phase.submitted:
        _statusDot = StatusDotColor.green;
        switch (_mode) {
          case BoxingMode.singleCode:
            _statusText = '装箱成功，可继续添加或返回';
          case BoxingMode.multiCode:
            _statusText = '请扫描下一个总排号';
        }
    }
  }

  // === Build ===

  @override
  Widget build(BuildContext context) {
    final colorScheme = Theme.of(context).colorScheme;
    final isWaiting = _phase == _Phase.waiting && _zongpaiNo == null;
    final showActionButtons =
        _phase == _Phase.scanned && _mode == BoxingMode.singleCode;

    _updateBaseStatus();
    final effectiveDot = _statusOverrideDot ?? _statusDot;
    final effectiveText = _statusOverrideText ?? _statusText;

    return KeyboardListener(
      focusNode: _focusNode,
      onKeyEvent: _onKeyEvent,
      child: Scaffold(
        appBar: AppBar(
          title: const Text('装箱编号'),
          titleSpacing: 12,
          actions: [
            _buildModePill(),
            const SizedBox(width: 8),
          ],
        ),
        body: Column(
          children: [
            if (_isAutoProcessing)
              Container(
                width: double.infinity,
                padding: const EdgeInsets.symmetric(
                  vertical: 6,
                  horizontal: 12,
                ),
                color: Colors.orange.shade50,
                child: Row(
                  children: [
                    SizedBox(
                      width: 12,
                      height: 12,
                      child: CircularProgressIndicator(
                        strokeWidth: 1.5,
                        color: Colors.orange.shade700,
                      ),
                    ),
                    const SizedBox(width: 6),
                    Text(
                      '正在同步转运数据...',
                      style: TextStyle(
                        color: Colors.orange.shade900,
                        fontSize: 12,
                      ),
                    ),
                  ],
                ),
              ),
            if (_autoWarnings.isNotEmpty)
              Container(
                width: double.infinity,
                padding: const EdgeInsets.symmetric(
                  vertical: 6,
                  horizontal: 12,
                ),
                color: Colors.amber.shade100,
                child: Text(
                  _autoWarnings.join('；'),
                  style: TextStyle(color: Colors.amber.shade900, fontSize: 12),
                ),
              ),
            if (_paichanSwitchNotice != null)
              Container(
                width: double.infinity,
                padding: const EdgeInsets.symmetric(
                  vertical: 6,
                  horizontal: 12,
                ),
                color: Colors.blue.shade50,
                child: Text(
                  _paichanSwitchNotice!,
                  style: TextStyle(color: Colors.blue.shade900, fontSize: 12),
                ),
              ),
            if (_isDuplicateBoxNo && _phase == _Phase.scanned)
              Container(
                width: double.infinity,
                padding: const EdgeInsets.symmetric(
                  vertical: 6,
                  horizontal: 12,
                ),
                color: Colors.amber.shade100,
                child: Text(
                  '箱号 ${_boxNoController.text} 已存在，请重新输入',
                  style: TextStyle(color: Colors.amber.shade900, fontSize: 12),
                ),
              ),

            Expanded(
              child: _mode == BoxingMode.multiCode
                  ? _buildManyToOneBody(colorScheme)
                  : SingleChildScrollView(
                      padding: const EdgeInsets.all(12),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          _buildScanArea(isWaiting),
                          const SizedBox(height: 12),
                          _buildInfoArea(isWaiting, colorScheme),
                          const Divider(height: 24),
                          if (_mode == BoxingMode.singleCode &&
                              !isWaiting &&
                              _currentZongpaiBoxes.isNotEmpty) ...[
                            _buildAssignedBoxes(),
                            const Divider(height: 24),
                          ],
                          _buildInputArea(isWaiting),
                        ],
                      ),
                    ),
            ),

            // 操作按钮（单码装箱 / 多码凑箱）
            if (showActionButtons)
              Padding(
                padding: const EdgeInsets.symmetric(
                  horizontal: 12,
                  vertical: 4,
                ),
                child: Row(
                  children: [
                    Expanded(
                      child: OutlinedButton(
                        onPressed: _onGoBack,
                        style: OutlinedButton.styleFrom(
                          minimumSize: const Size.fromHeight(40),
                        ),
                        child: const Text('返回'),
                      ),
                    ),
                    if (_mode == BoxingMode.singleCode &&
                        _editingBox == null) ...[
                      const SizedBox(width: 12),
                      const Expanded(child: SizedBox.shrink()),
                    ],
                    if (_mode == BoxingMode.singleCode &&
                        _editingBox != null) ...[
                      const SizedBox(width: 12),
                      Expanded(
                        child: ElevatedButton(
                          onPressed: _cancelEditAssigned,
                          style: ElevatedButton.styleFrom(
                            minimumSize: const Size.fromHeight(40),
                          ),
                          child: const Text('取消'),
                        ),
                      ),
                    ],
                  ],
                ),
              ),

            // 底部状态栏
            StatusBar(dotColor: effectiveDot, text: effectiveText),
          ],
        ),
      ),
    );
  }

  Widget _buildModePill() {
    final isSingle = _mode == BoxingMode.singleCode;
    final bgColor =
        isSingle ? Colors.blue.shade700 : Colors.orange.shade700;

    return GestureDetector(
      onTap: _isAutoProcessing ? null : _cycleMode,
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 9, vertical: 3),
        decoration: BoxDecoration(
          color: bgColor,
          borderRadius: BorderRadius.circular(12),
        ),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            const Icon(Icons.swap_horiz, color: Colors.white, size: 14),
            const SizedBox(width: 4),
            Text(
              _modeLabel,
              style: const TextStyle(
                color: Colors.white,
                fontSize: 11,
                fontWeight: FontWeight.w700,
              ),
            ),
            const SizedBox(width: 4),
            Container(
              padding: const EdgeInsets.symmetric(horizontal: 4),
              decoration: BoxDecoration(
                color: Colors.white.withValues(alpha: 0.22),
                borderRadius: BorderRadius.circular(4),
              ),
              child: const Text(
                'P2',
                style: TextStyle(
                  color: Colors.white,
                  fontSize: 10,
                  fontWeight: FontWeight.w600,
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildAssignedBoxes() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        const Text(
          '已分配',
          style: TextStyle(fontSize: 13, color: Colors.black54),
        ),
        const SizedBox(height: 6),
        ..._currentZongpaiBoxes.map(_buildAssignedBoxRow),
      ],
    );
  }

  Widget _buildAssignedBoxRow(CurrentZongpaiBoxData item) {
    final editing = _editingAssignedItemId == item.boxItemId;
    final deleting = _deletingAssignedItemId == item.boxItemId;
    return Container(
      margin: const EdgeInsets.only(bottom: 6),
      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 6),
      decoration: BoxDecoration(
        color: editing ? Colors.orange.shade50 : Colors.grey.shade50,
        border: Border.all(
          color: editing ? Colors.orange : Colors.grey.shade300,
        ),
        borderRadius: BorderRadius.circular(6),
      ),
      child: Column(
        children: [
          Row(
            children: [
              Expanded(
                child: Text(
                  '${item.boxNo}号箱',
                  style: const TextStyle(
                    fontSize: 13,
                    fontWeight: FontWeight.w600,
                  ),
                  overflow: TextOverflow.ellipsis,
                ),
              ),
              if (editing)
                SizedBox(
                  width: 56,
                  height: 32,
                  child: TextField(
                    keyboardType: TextInputType.none,
                    inputFormatters: [FilteringTextInputFormatter.digitsOnly],
                    textAlign: TextAlign.center,
                    controller:
                        TextEditingController(text: _editingAssignedQuantity)
                          ..selection = TextSelection.collapsed(
                            offset: _editingAssignedQuantity.length,
                          ),
                    onChanged: (value) => _editingAssignedQuantity = value,
                    onEditingComplete: () {},
                    onSubmitted: (_) => _saveAssignedItem(item),
                    decoration: const InputDecoration(
                      contentPadding: EdgeInsets.symmetric(horizontal: 6),
                      border: OutlineInputBorder(),
                    ),
                  ),
                )
              else
                Text(
                  '数量 ${item.quantity}',
                  style: const TextStyle(fontSize: 13),
                ),
              const SizedBox(width: 4),
              if (editing) ...[
                IconButton(
                  tooltip: '保存',
                  visualDensity: VisualDensity.compact,
                  icon: const Icon(Icons.check, size: 18),
                  onPressed: _isSubmitting
                      ? null
                      : () => _saveAssignedItem(item),
                ),
                IconButton(
                  tooltip: '取消',
                  visualDensity: VisualDensity.compact,
                  icon: const Icon(Icons.close, size: 18),
                  onPressed: _isSubmitting ? null : _cancelEditAssigned,
                ),
              ] else ...[
                IconButton(
                  tooltip: '修改',
                  visualDensity: VisualDensity.compact,
                  icon: const Icon(Icons.edit, size: 18),
                  onPressed: _isSubmitting
                      ? null
                      : () => _startEditAssigned(item),
                ),
                IconButton(
                  tooltip: '删除',
                  visualDensity: VisualDensity.compact,
                  icon: const Icon(Icons.delete_outline, size: 18),
                  onPressed: _isSubmitting
                      ? null
                      : () {
                          setState(() {
                            _deletingAssignedItemId = item.boxItemId;
                            _editingAssignedItemId = null;
                            _editingAssignedQuantity = '';
                          });
                        },
                ),
              ],
            ],
          ),
          if (deleting)
            Padding(
              padding: const EdgeInsets.only(top: 4),
              child: Row(
                children: [
                  const Expanded(
                    child: Text('确认删除此条记录？', style: TextStyle(fontSize: 13)),
                  ),
                  TextButton(
                    onPressed: _isSubmitting
                        ? null
                        : () => _deleteAssignedItem(item),
                    child: const Text('是'),
                  ),
                  TextButton(
                    onPressed: _isSubmitting
                        ? null
                        : () => setState(() => _deletingAssignedItemId = null),
                    child: const Text('否'),
                  ),
                ],
              ),
            ),
        ],
      ),
    );
  }

  Widget _buildManyToOneBody(ColorScheme colorScheme) {
    final hasScan = _zongpaiNo != null && _phase == _Phase.scanned;
    final visibleItems = _visibleManyToOnePackedItems;

    return Column(
      children: [
        // Header bar: box number + paichan info merged
        _buildManyToOneHeaderBar(),
        // List header (sticky above scroll area)
        _buildManyToOneListHeader(visibleItems.length),
        // Scrollable list
        Expanded(
          child: visibleItems.isEmpty
              ? Center(
                  child: Text(
                    '尚未装入任何物料',
                    style: TextStyle(
                      fontSize: 13,
                      color: Colors.grey.shade500,
                      fontStyle: FontStyle.italic,
                    ),
                  ),
                )
              : ListView.builder(
                  itemCount: visibleItems.length,
                  itemBuilder: (context, index) {
                    return _buildManyToOnePackedRow(
                      visibleItems[index],
                      index + 1,
                    );
                  },
                ),
        ),
        // Fixed bottom area: scan bar + submit + finish
        _buildManyToOneBottomArea(hasScan),
      ],
    );
  }

  // ── Header bar: box number + paichan info ──

  Widget _buildManyToOneHeaderBar() {
    final hasDetail = _existingBoxes.isNotEmpty;
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      decoration: BoxDecoration(
        color: Colors.grey.shade50,
        border: Border(
          bottom: BorderSide(color: Colors.grey.shade300),
        ),
      ),
      child: Row(
        children: [
          // Box number
          const Text(
            '箱号',
            style: TextStyle(
              fontSize: 11,
              fontWeight: FontWeight.w600,
              color: Colors.black54,
            ),
          ),
          const SizedBox(width: 6),
          SizedBox(
            width: 52,
            height: 32,
            child: TextField(
              controller: _boxNoController,
              focusNode: _boxNoFocusNode,
              enabled: !_isSubmitting,
              keyboardType: TextInputType.none,
              inputFormatters: [FilteringTextInputFormatter.digitsOnly],
              textAlign: TextAlign.center,
              onEditingComplete: () {},
              onSubmitted: (_) => _submitFromKeyboard(),
              decoration: InputDecoration(
                contentPadding: EdgeInsets.zero,
                border: OutlineInputBorder(
                  borderRadius: BorderRadius.circular(6),
                ),
                enabledBorder: OutlineInputBorder(
                  borderRadius: BorderRadius.circular(6),
                  borderSide: BorderSide(color: Colors.grey.shade400),
                ),
                focusedBorder: OutlineInputBorder(
                  borderRadius: BorderRadius.circular(6),
                  borderSide: const BorderSide(color: Colors.blue, width: 1.5),
                ),
              ),
              style: const TextStyle(fontSize: 18, fontWeight: FontWeight.w800),
            ),
          ),
          // Divider
          Container(
            width: 1,
            height: 28,
            margin: const EdgeInsets.symmetric(horizontal: 10),
            color: Colors.grey.shade300,
          ),
          // Paichan info
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              mainAxisSize: MainAxisSize.min,
              children: [
                Text(
                  _paichanNo ?? '--',
                  style: const TextStyle(
                    fontSize: 13,
                    fontWeight: FontWeight.w700,
                  ),
                  overflow: TextOverflow.ellipsis,
                ),
                Text(
                  '已有 ${_existingBoxes.length} 箱 · 最大箱号 $_maxBoxNo',
                  style: TextStyle(fontSize: 11, color: Colors.grey.shade500),
                  overflow: TextOverflow.ellipsis,
                ),
              ],
            ),
          ),
          // Detail link
          TextButton(
            onPressed: hasDetail ? _openDetail : null,
            style: TextButton.styleFrom(
              padding: const EdgeInsets.symmetric(horizontal: 4),
              minimumSize: Size.zero,
              tapTargetSize: MaterialTapTargetSize.shrinkWrap,
            ),
            child: Text(
              '详情',
              style: TextStyle(
                fontSize: 11,
                color: hasDetail
                    ? Theme.of(context).colorScheme.primary
                    : Colors.grey.shade400,
              ),
            ),
          ),
        ],
      ),
    );
  }

  // ── List header ──

  Widget _buildManyToOneListHeader(int count) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 7),
      decoration: BoxDecoration(
        color: Colors.white,
        border: Border(bottom: BorderSide(color: Colors.grey.shade300)),
      ),
      child: Row(
        children: [
          const Expanded(
            child: Text(
              '已装入本箱',
              style: TextStyle(
                fontSize: 11,
                fontWeight: FontWeight.w700,
                color: Colors.black54,
                letterSpacing: 0.5,
              ),
            ),
          ),
          Text(
            '$count 项',
            style: TextStyle(
              fontSize: 11,
              fontWeight: FontWeight.w700,
              color: Theme.of(context).colorScheme.primary,
            ),
          ),
        ],
      ),
    );
  }

  // ── Packed item row ──

  Widget _buildManyToOnePackedRow(_ManyToOnePackedItem item, int index) {
    final editing = _editingPackedItemId == item.boxItemId;
    final deleting = _deletingPackedItemId == item.boxItemId;
    final totalText = item.totalQuantity?.toString() ?? '--';

    final barColor =
        editing ? Colors.amber : (deleting ? Colors.red : Colors.green);

    return Column(
      children: [
        Container(
          height: 40,
          padding: const EdgeInsets.symmetric(horizontal: 12),
          decoration: BoxDecoration(
            color: editing
                ? Colors.yellow.shade50
                : (deleting ? Colors.red.shade50 : null),
            border: Border(
              bottom: BorderSide(color: Colors.grey.shade200),
            ),
          ),
          child: Row(
            children: [
              // Index
              SizedBox(
                width: 14,
                child: Text(
                  '$index',
                  textAlign: TextAlign.right,
                  style: TextStyle(
                    fontSize: 10,
                    fontWeight: FontWeight.w600,
                    color: Colors.grey.shade500,
                  ),
                ),
              ),
              const SizedBox(width: 6),
              // Color bar
              Container(
                width: 3,
                height: 26,
                decoration: BoxDecoration(
                  color: barColor,
                  borderRadius: BorderRadius.circular(2),
                ),
              ),
              const SizedBox(width: 6),
              // Main info
              Expanded(
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      item.zongpaiNo,
                      style: const TextStyle(
                        fontSize: 12,
                        fontWeight: FontWeight.w700,
                      ),
                      overflow: TextOverflow.ellipsis,
                    ),
                    Text(
                      item.workOrderNo ?? '--',
                      style: TextStyle(
                        fontSize: 11,
                        color: Colors.grey.shade500,
                      ),
                      overflow: TextOverflow.ellipsis,
                    ),
                  ],
                ),
              ),
              // Quantity / edit input
              if (editing)
                SizedBox(
                  width: 52,
                  height: 26,
                  child: TextField(
                    keyboardType: TextInputType.none,
                    inputFormatters: [FilteringTextInputFormatter.digitsOnly],
                    textAlign: TextAlign.center,
                    controller:
                        TextEditingController(text: _editingPackedQuantity)
                          ..selection = TextSelection.collapsed(
                            offset: _editingPackedQuantity.length,
                          ),
                    onChanged: (value) => _editingPackedQuantity = value,
                    decoration: InputDecoration(
                      contentPadding: const EdgeInsets.symmetric(horizontal: 4),
                      border: OutlineInputBorder(
                        borderRadius: BorderRadius.circular(4),
                        borderSide:
                            const BorderSide(color: Colors.amber, width: 1.5),
                      ),
                    ),
                    style: const TextStyle(
                      fontSize: 13,
                      fontWeight: FontWeight.w600,
                    ),
                  ),
                )
              else
                Text(
                  '${item.quantity} / $totalText',
                  style: TextStyle(
                    fontSize: 12,
                    fontWeight: FontWeight.w600,
                    color: deleting ? Colors.red : Colors.green.shade700,
                  ),
                ),
              // Action buttons
              if (editing) ...[
                _iconBtn(
                  Icons.check,
                  color: Colors.green,
                  onTap: _isSubmitting ? null : () => _savePackedItem(item),
                ),
                _iconBtn(
                  Icons.close,
                  color: Colors.grey,
                  onTap:
                      _isSubmitting ? null : _cancelEditPackedItem,
                ),
              ] else ...[
                _iconBtn(
                  Icons.edit,
                  color: Colors.orange.shade700,
                  onTap: _isSubmitting
                      ? null
                      : () => _startEditPackedItem(item),
                ),
                _iconBtn(
                  Icons.delete_outline,
                  color: Colors.red,
                  onTap: _isSubmitting
                      ? null
                      : () {
                          setState(() {
                            _deletingPackedItemId = item.boxItemId;
                            _editingPackedItemId = null;
                            _editingPackedQuantity = '';
                          });
                        },
                ),
              ],
            ],
          ),
        ),
        // Inline delete confirmation
        if (deleting)
          Container(
            padding: const EdgeInsets.only(
              left: 34,
              right: 12,
              top: 2,
              bottom: 5,
            ),
            decoration: BoxDecoration(
              color: Colors.red.shade50,
              border: Border(
                bottom: BorderSide(color: Colors.red.shade200),
              ),
            ),
            child: Row(
              children: [
                const Expanded(
                  child: Text(
                    '确认删除？',
                    style: TextStyle(
                      fontSize: 12,
                      color: Colors.red,
                      fontWeight: FontWeight.w500,
                    ),
                  ),
                ),
                TextButton(
                  onPressed: _isSubmitting
                      ? null
                      : () => _deletePackedItem(item),
                  style: TextButton.styleFrom(
                    padding:
                        const EdgeInsets.symmetric(horizontal: 8, vertical: 3),
                    minimumSize: Size.zero,
                    tapTargetSize: MaterialTapTargetSize.shrinkWrap,
                    backgroundColor: Colors.red.shade100,
                    shape: RoundedRectangleBorder(
                      borderRadius: BorderRadius.circular(4),
                    ),
                  ),
                  child: const Text(
                    '删除',
                    style: TextStyle(
                      fontSize: 12,
                      fontWeight: FontWeight.w700,
                      color: Colors.red,
                    ),
                  ),
                ),
                const SizedBox(width: 4),
                TextButton(
                  onPressed: _isSubmitting
                      ? null
                      : () => setState(() => _deletingPackedItemId = null),
                  style: TextButton.styleFrom(
                    padding:
                        const EdgeInsets.symmetric(horizontal: 8, vertical: 3),
                    minimumSize: Size.zero,
                    tapTargetSize: MaterialTapTargetSize.shrinkWrap,
                  ),
                  child: const Text(
                    '取消',
                    style: TextStyle(
                      fontSize: 12,
                      fontWeight: FontWeight.w700,
                      color: Colors.grey,
                    ),
                  ),
                ),
              ],
            ),
          ),
      ],
    );
  }

  // ── Compact icon button helper ──

  Widget _iconBtn(IconData icon, {Color? color, VoidCallback? onTap}) {
    return SizedBox(
      width: 28,
      height: 28,
      child: IconButton(
        icon: Icon(icon, size: 16),
        color: color,
        onPressed: onTap,
        padding: EdgeInsets.zero,
        constraints: const BoxConstraints(minWidth: 28, minHeight: 28),
      ),
    );
  }

  // ── Fixed bottom area ──

  Widget _buildManyToOneBottomArea(bool hasScan) {
    final hasItems = _visibleManyToOnePackedItems.isNotEmpty;
    return Container(
      decoration: BoxDecoration(
        color: Colors.white,
        border: Border(top: BorderSide(color: Colors.grey.shade300)),
      ),
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          _buildManyToOneScanBar(hasScan),
          _buildManyToOneSubmitRow(hasScan),
          Padding(
            padding: const EdgeInsets.fromLTRB(12, 6, 12, 8),
            child: SizedBox(
              width: double.infinity,
              height: 36,
              child: OutlinedButton(
                onPressed: hasItems ? _finishManyToOneBox : null,
                style: OutlinedButton.styleFrom(
                  shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(8),
                  ),
                  side: BorderSide(
                    color: hasItems
                        ? Colors.grey.shade600
                        : Colors.grey.shade300,
                  ),
                ),
                child: Text(
                  '完成本箱',
                  style: TextStyle(
                    fontSize: 14,
                    fontWeight: FontWeight.w700,
                    color: hasItems
                        ? Colors.black87
                        : Colors.grey.shade400,
                  ),
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildManyToOneScanBar(bool hasScan) {
    if (!hasScan) {
      return Container(
        padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 9),
        color: Colors.grey.shade50,
        child: const Row(
          children: [
            Icon(Icons.qr_code_scanner, color: Colors.grey, size: 16),
            SizedBox(width: 8),
            Text(
              '请扫描执行卡二维码',
              style: TextStyle(
                color: Colors.grey,
                fontSize: 13,
                fontWeight: FontWeight.w400,
              ),
            ),
          ],
        ),
      );
    }

    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 9),
      decoration: BoxDecoration(
        color: Colors.green.shade50,
        border: Border(
          bottom: BorderSide(color: Colors.green.shade200),
        ),
      ),
      child: Row(
        children: [
          const Icon(Icons.check_circle, color: Colors.green, size: 15),
          const SizedBox(width: 6),
          Expanded(
            child: Text(
              '${_zongpaiNo ?? ""}  ·  ${_workOrderNo ?? "--"}  ·  ${_erpQuantity ?? "--"}件',
              style: TextStyle(
                fontSize: 13,
                fontWeight: FontWeight.w600,
                color: Colors.green.shade700,
              ),
              overflow: TextOverflow.ellipsis,
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildManyToOneSubmitRow(bool hasScan) {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 7),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.center,
        children: [
          Text(
            '数量',
            style: TextStyle(
              fontSize: 11,
              fontWeight: FontWeight.w600,
              color: hasScan ? Colors.black54 : Colors.grey.shade400,
            ),
          ),
          const SizedBox(width: 6),
          Expanded(
            child: SizedBox(
              height: 34,
              child: TextField(
                controller: _quantityController,
                focusNode: _quantityFocusNode,
                enabled: hasScan && !_isSubmitting,
                keyboardType: TextInputType.none,
                inputFormatters: [FilteringTextInputFormatter.digitsOnly],
                onChanged: (_) => setState(() {}),
                onEditingComplete: () {},
                onSubmitted: (_) => _submitFromKeyboard(),
                decoration: InputDecoration(
                  contentPadding: const EdgeInsets.symmetric(horizontal: 10),
                  border: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(6),
                  ),
                  enabledBorder: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(6),
                    borderSide: BorderSide(
                      color: _quantityTooHigh
                          ? Colors.red
                          : Colors.grey.shade300,
                    ),
                  ),
                  disabledBorder: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(6),
                    borderSide: BorderSide(color: Colors.grey.shade200),
                  ),
                  filled: !hasScan,
                  fillColor: Colors.grey.shade100,
                ),
                style: const TextStyle(
                  fontSize: 15,
                  fontWeight: FontWeight.w600,
                ),
              ),
            ),
          ),
          const SizedBox(width: 8),
          SizedBox(
            height: 34,
            child: ElevatedButton(
              onPressed: _canSubmit ? _submit : null,
              style: ElevatedButton.styleFrom(
                backgroundColor: _canSubmit
                    ? Theme.of(context).colorScheme.primary
                    : Colors.grey.shade200,
                foregroundColor: _canSubmit
                    ? Colors.white
                    : Colors.grey.shade400,
                padding: const EdgeInsets.symmetric(horizontal: 18),
                shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(6),
                ),
              ),
              child: _isSubmitting
                  ? const SizedBox(
                      width: 18,
                      height: 18,
                      child: CircularProgressIndicator(
                        strokeWidth: 2,
                        color: Colors.white,
                      ),
                    )
                  : const Text(
                      '确认',
                      style: TextStyle(
                        fontSize: 14,
                        fontWeight: FontWeight.w700,
                      ),
                    ),
            ),
          ),
        ],
      ),
    );
  }

  // === 扫码区 Widget ===

  Widget _buildScanArea(bool isWaiting) {
    if (isWaiting) {
      return Container(
        width: double.infinity,
        padding: const EdgeInsets.all(16),
        decoration: BoxDecoration(
          color: Colors.grey.shade100,
          borderRadius: BorderRadius.circular(8),
        ),
        child: const Row(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(Icons.qr_code_scanner, color: Colors.grey, size: 20),
            SizedBox(width: 8),
            Text(
              '请扫描执行卡二维码',
              style: TextStyle(color: Colors.grey, fontSize: 14),
            ),
          ],
        ),
      );
    }

    return Container(
      width: double.infinity,
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 12),
      decoration: BoxDecoration(
        border: Border.all(color: Colors.green, width: 2),
        borderRadius: BorderRadius.circular(8),
      ),
      child: Row(
        children: [
          const Icon(Icons.check_circle, color: Colors.green, size: 18),
          const SizedBox(width: 8),
          Text(
            _zongpaiNo ?? '',
            style: const TextStyle(
              fontSize: 18,
              fontWeight: FontWeight.bold,
              color: Colors.black87,
            ),
          ),
          const Spacer(),
          const Text(
            '已识别',
            style: TextStyle(fontSize: 12, color: Colors.green),
          ),
        ],
      ),
    );
  }

  // === 信息区 Widget ===

  Widget _buildInfoArea(bool isWaiting, ColorScheme colorScheme) {
    final grey = isWaiting;
    final paichanText = grey ? '--' : (_paichanNo ?? '--');
    final workOrderText = grey ? '--' : (_workOrderNo ?? '--');
    final quantityText = grey ? '--' : (_erpQuantity?.toString() ?? '--');

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Row(
          children: [
            Expanded(
              flex: 5,
              child: Text(
                paichanText,
                style: TextStyle(
                  fontSize: 20,
                  fontWeight: FontWeight.w700,
                  color: grey ? Colors.grey : Colors.black87,
                ),
                overflow: TextOverflow.ellipsis,
              ),
            ),
            const SizedBox(width: 8),
            Expanded(
              flex: 4,
              child: Text(
                workOrderText,
                textAlign: TextAlign.center,
                style: TextStyle(
                  fontSize: 18,
                  fontWeight: FontWeight.w700,
                  color: grey ? Colors.grey : Colors.black87,
                ),
                overflow: TextOverflow.ellipsis,
              ),
            ),
            const SizedBox(width: 8),
            Expanded(
              flex: 3,
              child: Text(
                quantityText,
                textAlign: TextAlign.right,
                style: TextStyle(
                  fontSize: 18,
                  fontWeight: FontWeight.w700,
                  color: grey ? Colors.grey : Colors.black87,
                ),
                overflow: TextOverflow.ellipsis,
              ),
            ),
          ],
        ),
        const SizedBox(height: 10),

        Row(
          children: [
            Expanded(
              child: Row(
                children: [
                  Text(
                    '已有箱数：',
                    style: TextStyle(
                      fontSize: 13,
                      color: grey ? Colors.grey : Colors.black54,
                    ),
                  ),
                  Text(
                    grey ? '--' : '${_existingBoxes.length}箱',
                    style: TextStyle(
                      fontSize: 13,
                      fontWeight: FontWeight.w600,
                      color: grey ? Colors.grey : Colors.black87,
                    ),
                  ),
                  const SizedBox(width: 16),
                  Text(
                    '最大箱号：',
                    style: TextStyle(
                      fontSize: 13,
                      color: grey ? Colors.grey : Colors.black54,
                    ),
                  ),
                  Text(
                    grey ? '--' : '$_maxBoxNo',
                    style: TextStyle(
                      fontSize: 13,
                      fontWeight: FontWeight.w600,
                      color: _maxBoxNo > 0
                          ? Colors.amber.shade800
                          : Colors.grey,
                    ),
                  ),
                ],
              ),
            ),
            TextButton(
              onPressed: grey || _existingBoxes.isEmpty ? null : _openDetail,
              style: TextButton.styleFrom(
                padding: const EdgeInsets.symmetric(horizontal: 8),
                minimumSize: Size.zero,
                tapTargetSize: MaterialTapTargetSize.shrinkWrap,
              ),
              child: Text(
                '详情 →',
                style: TextStyle(
                  fontSize: 13,
                  color: grey || _existingBoxes.isEmpty
                      ? Colors.grey.shade400
                      : colorScheme.primary,
                ),
              ),
            ),
          ],
        ),
      ],
    );
  }

  // === 输入区 Widget ===

  Widget _buildInputArea(bool isWaiting) {
    final enabled = !isWaiting && _phase == _Phase.scanned;

    return Row(
      crossAxisAlignment: CrossAxisAlignment.end,
      children: [
        // 箱号输入
        Expanded(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text(
                _editingBox == null ? '箱号' : '修改箱号',
                style: TextStyle(
                  fontSize: 13,
                  color: enabled ? Colors.black54 : Colors.grey,
                ),
              ),
              const SizedBox(height: 4),
              SizedBox(
                height: 40,
                child: TextField(
                  controller: _boxNoController,
                  focusNode: _boxNoFocusNode,
                  enabled: enabled,
                  keyboardType: TextInputType.none,
                  inputFormatters: [FilteringTextInputFormatter.digitsOnly],
                  onChanged: (_) => _checkDuplicateBoxNo(),
                  onEditingComplete: () {},
                  onSubmitted: (_) => _submitFromKeyboard(),
                  decoration: InputDecoration(
                    contentPadding: const EdgeInsets.symmetric(horizontal: 10),
                    border: const OutlineInputBorder(),
                    enabledBorder: OutlineInputBorder(
                      borderSide: BorderSide(
                        color: _isDuplicateBoxNo
                            ? Colors.amber
                            : Colors.grey.shade400,
                      ),
                    ),
                  ),
                  style: const TextStyle(fontSize: 16),
                ),
              ),
            ],
          ),
        ),
        const SizedBox(width: 8),

        // 数量输入
        Expanded(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text(
                _editingBox == null ? '数量' : '修改数量',
                style: TextStyle(
                  fontSize: 13,
                  color: enabled ? Colors.black54 : Colors.grey,
                ),
              ),
              const SizedBox(height: 4),
              SizedBox(
                height: 40,
                child: TextField(
                  controller: _quantityController,
                  focusNode: _quantityFocusNode,
                  enabled: enabled,
                  keyboardType: TextInputType.none,
                  inputFormatters: [FilteringTextInputFormatter.digitsOnly],
                  onChanged: (_) => setState(() {}),
                  onEditingComplete: () {},
                  onSubmitted: (_) => _submitFromKeyboard(),
                  decoration: InputDecoration(
                    contentPadding: const EdgeInsets.symmetric(horizontal: 10),
                    border: const OutlineInputBorder(),
                    enabledBorder: OutlineInputBorder(
                      borderSide: BorderSide(
                        color: _quantityTooHigh
                            ? Colors.red
                            : Colors.grey.shade400,
                      ),
                    ),
                  ),
                  style: const TextStyle(fontSize: 16),
                ),
              ),
            ],
          ),
        ),
        const SizedBox(width: 8),

        // 确认按钮
        SizedBox(
          height: 40,
          child: ElevatedButton(
            onPressed: _canSubmit ? _submit : null,
            style: ElevatedButton.styleFrom(
              backgroundColor: _canSubmit
                  ? Theme.of(context).colorScheme.primary
                  : Colors.grey.shade300,
              foregroundColor: _canSubmit ? Colors.white : Colors.grey.shade600,
            ),
            child: _isSubmitting
                ? const SizedBox(
                    width: 18,
                    height: 18,
                    child: CircularProgressIndicator(
                      strokeWidth: 2,
                      color: Colors.white,
                    ),
                  )
                : Text(
                    _editingBox == null ? '确认' : '保存',
                    style: const TextStyle(fontSize: 15),
                  ),
          ),
        ),
      ],
    );
  }
}