import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:tdesign_flutter/tdesign_flutter.dart';
import '../../core/i18n/app_localizations.dart';
import '../../core/navigation/host_app_channel.dart';
import '../../core/storage/draft_storage.dart';
import '../../shared/widgets/action_bar.dart';
import '../../shared/widgets/submitting_dialog.dart';
import '../../shared/widgets/form_section.dart';
import '../../shared/widgets/form_field_row.dart';
import '../../shared/widgets/nav_bar_config.dart';
import '../../shared/widgets/attachment_picker.dart';
import '../../core/theme/app_colors.dart';
import '../../core/theme/app_colors_extension.dart';
import '../../core/constants/enums.dart';
import '../../core/data/mock_api_data.dart';
import 'expense_apply_api.dart';
import 'widgets/expense_apply_detail_dialog.dart';

class ExpenseApplyCreatePage extends ConsumerStatefulWidget {
  final String? id;
  const ExpenseApplyCreatePage({super.key, this.id});

  @override
  ConsumerState<ExpenseApplyCreatePage> createState() =>
      _ExpenseApplyCreatePageState();
}

class _ExpenseApplyCreatePageState
    extends ConsumerState<ExpenseApplyCreatePage>
    with WidgetsBindingObserver {
  static const _draftKey = 'expense_apply';

  // ── 基本信息 ──
  String _urgency = Urgency.normal.value;
  final _purposeController = TextEditingController();
  final _purposeFocus = FocusNode();
  String _validUntil = '';
  final _referenceNoController = TextEditingController();
  final _remarkController = TextEditingController();
  final _remarkFocus = FocusNode();
  final _scrollCtrl = ScrollController();

  // ── 费用明细 ──
  final List<_DetailItem> _details = [];
  int _detailIdCounter = 1;

  // ── 附件 ──
  late final AttachmentPickerController _attachmentController;

  // ── 草稿 ──
  late Future<bool> _draftFuture;
  bool _draftHandled = false;
  bool _isPoppingToNative = false;

  // ── 参考数据（从 API 加载） ──
  List<CostTypeItem> _costTypes = [];
  List<ProjectCodeItem> _projects = [];
  List<DepartmentItem> _departments = [];
  bool _refDataLoading = true;

  // ── 申请部门 ──
  String _selectedDeptId = '';
  String _selectedDeptName = '';


  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
    SystemChrome.setSystemUIOverlayStyle(
      const SystemUiOverlayStyle(
        statusBarColor: Colors.transparent,
        statusBarIconBrightness: Brightness.dark,
      ),
    );
    _attachmentController = AttachmentPickerController(maxCount: 9)
      ..addListener(() => setState(() {}));
    _purposeFocus.addListener(() => _ensureVisible(_purposeFocus));
    _remarkFocus.addListener(() => _ensureVisible(_remarkFocus));
    _draftFuture = DraftStorage.has(_draftKey);
    _loadRefData();
  }

  Future<void> _loadRefData() async {
    try {
      final api = ref.read(expenseApplyApiProvider);
      final results = await Future.wait([
        api.getCostTypes(),
        api.getProjectCodes(),
        api.getDepartments(),
      ]);
      if (!mounted) return;
      setState(() {
        _costTypes = results[0] as List<CostTypeItem>;
        _projects = results[1] as List<ProjectCodeItem>;
        _departments = results[2] as List<DepartmentItem>;
        _refDataLoading = false;
        // 自动匹配当前用户的部门
        _autoSelectDept();
      });
    } catch (_) {
      if (!mounted) return;
      setState(() => _refDataLoading = false);
    }
  }

  void _autoSelectDept() {
    if (_selectedDeptId.isNotEmpty) return; // 已选中则不覆盖
    final dep = HostAppChannel.dep;
    if (dep.isEmpty) return;
    final match = _departments.where((d) => d.dep == dep);
    if (match.isNotEmpty) {
      _selectedDeptId = match.first.dep;
      _selectedDeptName = match.first.name;
    }
  }

  void _ensureVisible(FocusNode node) {
    if (!node.hasFocus) return;
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (node.hasFocus && _scrollCtrl.hasClients) {
        final ctx = node.context;
        if (ctx != null) {
          Scrollable.ensureVisible(
            ctx,
            alignment: 0.3,
            duration: const Duration(milliseconds: 300),
          );
        }
      }
    });
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    _purposeController.dispose();
    _purposeFocus.dispose();
    _referenceNoController.dispose();
    _remarkController.dispose();
    _remarkFocus.dispose();
    _attachmentController.dispose();
    _scrollCtrl.dispose();
    super.dispose();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    if (state == AppLifecycleState.resumed && _isPoppingToNative) {
      _isPoppingToNative = false;
      HostAppChannel.refresh();
      setState(() {
        _draftHandled = false;
        _draftFuture = DraftStorage.has(_draftKey);
        _refDataLoading = true;
      });
      _loadRefData();
    }
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context);
    ref
        .read(navBarConfigProvider.notifier)
        .update(
          NavBarConfig(
            title: l10n.get('expenseApplyRequest'),
            showBack: true,
            onBack: () => _doPop(),
          ),
        );

    return FutureBuilder<bool>(
      future: _draftFuture,
      builder: (ctx, snapshot) {
        final hasDraft = snapshot.hasData && snapshot.data == true;

        if (hasDraft && !_draftHandled) {
          _draftHandled = true;
          WidgetsBinding.instance.addPostFrameCallback((_) {
            if (mounted) _showDraftDialog();
          });
        }

        return PopScope(
          canPop: false,
          onPopInvokedWithResult: (didPop, _) {
            if (didPop) return;
            _doPop();
          },
          child: Column(
            children: [
              Expanded(
                child: GestureDetector(
                  onTap: () => FocusScope.of(context).unfocus(),
                  child: SingleChildScrollView(
                    controller: _scrollCtrl,
                    padding: const EdgeInsets.all(16),
                    child: Column(
                      children: [
                        _buildBasicInfo(l10n),
                        const SizedBox(height: 16),
                        _buildDetailsSection(l10n),
                        const SizedBox(height: 16),
                        _buildAttachmentSection(l10n),
                        const SizedBox(height: 80),
                      ],
                    ),
                  ),
                ),
              ),
              _buildBottomBar(l10n),
            ],
          ),
        );
      },
    );
  }

  // ═══ 草稿持久化 ═══

  Future<void> _restoreDraft() async {
    final data = await DraftStorage.load(_draftKey);
    if (data == null) return;
    final attData = data['attachments'] as List<dynamic>?;
    if (attData != null) {
      await _attachmentController.restoreFromPaths(attData.cast<String>());
    }
    setState(() {
      _urgency = data['urgency'] as String? ?? Urgency.normal.value;
      _purposeController.text = data['purpose'] as String? ?? '';
      _validUntil = data['validUntil'] as String? ?? '';
      _referenceNoController.text = data['referenceNo'] as String? ?? '';
      _remarkController.text = data['remark'] as String? ?? '';
      _selectedDeptId = data['deptId'] as String? ?? '';
      _selectedDeptName = data['deptName'] as String? ?? '';
      _details.clear();
      final detailList = data['details'] as List<dynamic>?;
      if (detailList != null) {
        for (final d in detailList) {
          final m = d as Map<String, dynamic>;
          _details.add(_DetailItem(
            id: m['id'] as int? ?? _detailIdCounter++,
            category: m['category'] as String? ?? '',
            categoryName: m['categoryName'] as String? ?? '',
            acctSubjectId: m['acctSubjectId'] as String? ?? '',
            acctSubjectName: m['acctSubjectName'] as String? ?? '',
            purpose: m['purpose'] as String? ?? '',
            projectId: m['projectId'] as int? ?? 0,
            projectName: m['projectName'] as String? ?? '',
            costDeptId: m['costDeptId'] as String? ?? '',
            costDeptName: m['costDeptName'] as String? ?? '',
            startDate: m['startDate'] as String? ?? '',
            endDate: m['endDate'] as String? ?? '',
            estimatedAmount: (m['estimatedAmount'] as num?)?.toDouble() ?? 0,
            remark: m['remark'] as String? ?? '',
          ));
        }
      }
      _detailIdCounter = _details.isEmpty ? 1 : _details.map((d) => d.id).reduce((a, b) => a > b ? a : b) + 1;
    });
  }

  Future<void> _saveDraftToStorage() async {
    final detailList = _details.map((d) => {
      'id': d.id,
      'category': d.category,
      'categoryName': d.categoryName,
      'acctSubjectId': d.acctSubjectId,
      'acctSubjectName': d.acctSubjectName,
      'purpose': d.purpose,
      'projectId': d.projectId,
      'projectName': d.projectName,
      'costDeptId': d.costDeptId,
      'costDeptName': d.costDeptName,
      'startDate': d.startDate,
      'endDate': d.endDate,
      'estimatedAmount': d.estimatedAmount,
      'remark': d.remark,
    }).toList();
    await DraftStorage.save(_draftKey, {
      'urgency': _urgency,
      'purpose': _purposeController.text,
      'deptId': _selectedDeptId,
      'deptName': _selectedDeptName,
      'validUntil': _validUntil,
      'referenceNo': _referenceNoController.text,
      'remark': _remarkController.text,
      'attachments': _attachmentController.toPathList(),
      'details': detailList,
    });
  }

  // ═══ 草稿弹窗 ═══
  // 使用 showDialog 而非内联渲染，确保 TDAlertDialog 获取正确的主题上下文
  void _showDraftDialog() {
    final l10n = AppLocalizations.of(context);
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    showDialog(
      context: context,
      barrierDismissible: false,
      builder: (ctx) => TDAlertDialog(
        title: l10n.get('draftFound'),
        content: l10n.get('draftRestorePrompt'),
        leftBtn: TDDialogButtonOptions(
          title: l10n.get('discard'),
          titleColor: colors.textSecondary,
          action: () {
            Navigator.pop(ctx);
            DraftStorage.delete(_draftKey);
          },
        ),
        rightBtn: TDDialogButtonOptions(
          title: l10n.get('restore'),
          titleColor: colors.primary,
          action: () {
            Navigator.pop(ctx);
            _restoreDraft();
          },
        ),
      ),
    );
  }

  // ═══ 1. 基本信息 ═══
  Widget _buildBasicInfo(AppLocalizations l10n) {
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    return FormSection(
      title: l10n.get('basicInfo'),
      leadingIcon: Icons.info_outline,
      children: [
        FormFieldRow(
          label: l10n.get('date'),
          value: _today(),
          readOnly: true,
          showArrow: false,
        ),
        const SizedBox(height: 16),
        FormFieldRow(
          label: l10n.get('applicant'),
          value: HostAppChannel.usr.isNotEmpty && HostAppChannel.usrName.isNotEmpty
              ? '${HostAppChannel.usr}/${HostAppChannel.usrName}'
              : '--',
          readOnly: true,
          showArrow: false,
        ),
        const SizedBox(height: 16),
        FormFieldRow(
          label: l10n.get('applyDept'),
          value: _selectedDeptName,
          hint: l10n.get('pleaseSelect'),
          onTap: _refDataLoading ? null : () => _showDeptPicker(),
        ),
        const SizedBox(height: 16),
        _label(l10n.get('emergencyLevel'), required: true),
        const SizedBox(height: 8),
        _buildUrgencyRadio(l10n),
        const SizedBox(height: 16),
        _label(l10n.get('applyReason'), required: true),
        const SizedBox(height: 8),
        TDTextarea(
          controller: _purposeController,
          focusNode: _purposeFocus,
          hintText: l10n.get('enterApplyReason'),
          maxLines: 4,
          minLines: 1,
          maxLength: 500,
          indicator: true,
          padding: EdgeInsets.zero,
          bordered: true,
          backgroundColor: colors.bgPage,
        ),
        // TODO: 暂不支持录入，后续开放
        // const SizedBox(height: 16),
        // FormFieldRow(
        //   label: l10n.get('validUntil'),
        //   value: _validUntil,
        //   hint: l10n.get('pleaseSelect'),
        //   onTap: () => _pickDate((d) => setState(() => _validUntil = d)),
        // ),
        // const SizedBox(height: 16),
        // FormFieldRow(
        //   label: l10n.get('relatedContractNo'),
        //   value: _referenceNoController.text,
        //   hint: l10n.get('optional'),
        //   onTap: () => _showTextInput(
        //     l10n.get('relatedContractNo'),
        //     (v) => setState(() {
        //       _referenceNoController.text = v;
        //       _referenceNoController.selection = TextSelection.fromPosition(
        //         TextPosition(offset: v.length),
        //       );
        //     }),
        //     initialText: _referenceNoController.text,
        //   ),
        // ),
        const SizedBox(height: 16),
        _label(l10n.get('remark')),
        const SizedBox(height: 8),
        TDTextarea(
          controller: _remarkController,
          focusNode: _remarkFocus,
          hintText: l10n.get('enterRemark'),
          maxLines: 3,
          minLines: 1,
          maxLength: 500,
          indicator: true,
          padding: EdgeInsets.zero,
          bordered: true,
          backgroundColor: colors.bgPage,
        ),
      ],
    );
  }

  Widget _buildUrgencyRadio(AppLocalizations l10n) {
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    return Row(
      children: Urgency.values.asMap().entries.map((e) {
        final sel = _urgency == e.value.value;
        final isCritical = e.value.value == Urgency.critical.value;
        final activeColor = isCritical ? colors.danger : colors.primary;
        return Padding(
          padding: EdgeInsets.only(right: e.key < 2 ? 24 : 0),
          child: GestureDetector(
            behavior: HitTestBehavior.opaque,
            onTap: () => setState(() => _urgency = e.value.value),
            child: Row(
              mainAxisSize: MainAxisSize.min,
              children: [
                Container(
                  width: 18,
                  height: 18,
                  decoration: BoxDecoration(
                    shape: BoxShape.circle,
                    border: Border.all(
                      color: sel ? activeColor : colors.textPlaceholder,
                      width: 2,
                    ),
                  ),
                  child: sel
                      ? Center(
                          child: Container(
                            width: 8,
                            height: 8,
                            decoration: BoxDecoration(
                              shape: BoxShape.circle,
                              color: activeColor,
                            ),
                          ),
                        )
                      : null,
                ),
                const SizedBox(width: 6),
                Text(
                  l10n.get(e.value.labelKey),
                  style: TextStyle(
                    fontSize: AppFontSizes.subtitle,
                    color: sel ? activeColor : colors.textPrimary,
                  ),
                ),
              ],
            ),
          ),
        );
      }).toList(),
    );
  }

  // ═══ 2. 费用明细 ═══
  Widget _buildDetailsSection(AppLocalizations l10n) {
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    return FormSection(
      title: l10n.get('expenseDetails'),
      leadingIcon: Icons.receipt_long_outlined,
      showAction: !_refDataLoading,
      actionText: l10n.get('add'),
      onActionTap: _showDetailDialog,
      children: [
        if (_details.isEmpty)
          Padding(
            padding: const EdgeInsets.symmetric(vertical: 8),
            child: Text(
              l10n.get('noDetailHint'),
              style: TextStyle(
                fontSize: AppFontSizes.subtitle,
                color: colors.textPlaceholder,
              ),
            ),
          )
        else
          ..._details.asMap().entries.map((e) {
            final d = e.value;
            return GestureDetector(
              onTap: () => _showDetailDialog(editIndex: e.key),
              child: Container(
              margin: const EdgeInsets.symmetric(vertical: 8),
              padding: const EdgeInsets.all(12),
              decoration: BoxDecoration(
                color: colors.bgPage,
                borderRadius: BorderRadius.circular(8),
              ),
              child: Row(
                children: [
                  Expanded(
                    flex: 3,
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          d.categoryName,
                          style: TextStyle(
                            fontSize: AppFontSizes.subtitle,
                            color: colors.textPrimary,
                          ),
                        ),
                        if (d.purpose.isNotEmpty)
                          Text(
                            d.purpose,
                            maxLines: 2,
                            overflow: TextOverflow.ellipsis,
                            style: TextStyle(
                              fontSize: AppFontSizes.caption,
                              color: colors.textPrimary,
                            ),
                          ),
                        const SizedBox(height: 4),
                        Text(
                          '¥${d.estimatedAmount.toStringAsFixed(2)}',
                          style: TextStyle(
                            fontSize: AppFontSizes.caption,
                            fontWeight: FontWeight.w600,
                            color: colors.amountPrimary,
                          ),
                        ),
                        if (d.projectName.isNotEmpty)
                          Text(
                            '${d.projectName}  |  ${d.acctSubjectName}',
                            style: TextStyle(
                              fontSize: AppFontSizes.caption,
                              color: colors.textSecondary,
                            ),
                          ),
                        if (d.remark.isNotEmpty)
                          Text(
                            d.remark,
                            maxLines: 1,
                            overflow: TextOverflow.ellipsis,
                            style: TextStyle(
                              fontSize: AppFontSizes.caption,
                              color: colors.textPlaceholder,
                            ),
                          ),
                      ],
                    ),
                  ),
                  GestureDetector(
                    onTap: () => setState(() => _details.removeAt(e.key)),
                    child: Container(
                      width: 24,
                      height: 24,
                      decoration: BoxDecoration(
                        color: colors.primaryLight,
                        shape: BoxShape.circle,
                      ),
                      child: Icon(
                        Icons.close,
                        size: 14,
                        color: colors.primary700,
                      ),
                    ),
                  ),
                ],
              ),
            ),
            );
          }),
        const SizedBox(height: 8),
        Container(
          height: 36,
          padding: const EdgeInsets.symmetric(vertical: 8),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              Text(
                l10n.get('total'),
                style: TextStyle(
                  fontSize: AppFontSizes.body,
                  fontWeight: FontWeight.w600,
                  color: colors.textPrimary,
                ),
              ),
              Text(
                '¥${_totalAmount().toStringAsFixed(2)}',
                style: TextStyle(
                  fontSize: AppFontSizes.subtitle,
                  fontWeight: FontWeight.w700,
                  color: colors.amountPrimary,
                ),
              ),
            ],
          ),
        ),
      ],
    );
  }

  double _totalAmount() =>
      _details.fold(0, (s, d) => s + d.estimatedAmount);

  Future<void> _showDetailDialog({int? editIndex}) async {
    final l10n = AppLocalizations.of(context);
    if (_costTypes.isEmpty) {
      TDToast.showText(l10n.get('noCostTypeData'), context: context);
      return;
    }
    ExpenseDetailData? initialData;
    if (editIndex != null) {
      final d = _details[editIndex];
      initialData = ExpenseDetailData(
        category: d.category,
        categoryName: d.categoryName,
        acctSubjectId: d.acctSubjectId,
        acctSubjectName: d.acctSubjectName,
        purpose: d.purpose,
        projectId: d.projectId,
        projectName: d.projectName,
        costDeptId: d.costDeptId,
        costDeptName: d.costDeptName,
        startDate: d.startDate,
        endDate: d.endDate,
        estimatedAmount: d.estimatedAmount,
        remark: d.remark,
      );
    }
    final result = await ExpenseApplyDetailDialog.show(
      context,
      categories: _dialogCategories,
      projects: _dialogProjects,
      costDepts: _dialogCostDepts,
      l10n: l10n,
      initialData: initialData,
    );
    if (result != null && mounted) {
      setState(() {
        final item = _DetailItem(
          id: editIndex != null ? _details[editIndex].id : _detailIdCounter++,
          category: result.category,
          categoryName: result.categoryName,
          acctSubjectId: result.acctSubjectId,
          acctSubjectName: result.acctSubjectName,
          purpose: result.purpose,
          projectId: result.projectId,
          projectName: result.projectName,
          costDeptId: result.costDeptId,
          costDeptName: result.costDeptName,
          startDate: result.startDate,
          endDate: result.endDate,
          estimatedAmount: result.estimatedAmount,
          remark: result.remark,
        );
        if (editIndex != null) {
          _details[editIndex] = item;
        } else {
          _details.add(item);
        }
      });
    }
  }

  // ═══ 3. 附件上传 ═══

  Widget _buildAttachmentSection(AppLocalizations l10n) {
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    return FormSection(
      title: l10n.get('attachmentUpload'),
      leadingIcon: Icons.attach_file_outlined,
      children: [
        Text(
          l10n.get('maxAttachment'),
          style: TextStyle(
            fontSize: AppFontSizes.caption,
            color: colors.textPlaceholder,
          ),
        ),
        const SizedBox(height: 8),
        AttachmentPicker(
          controller: _attachmentController,
          maxImageSizeMB: 10,
          maxFileSizeMB: 20,
          allowedExtensions: const [
            'pdf', 'doc', 'docx', 'xls', 'xlsx', 'ppt', 'pptx', 'txt',
          ],
          onFileRejected: (file, reason) {
            if (context.mounted) {
              TDToast.showText(reason, context: context);
            }
          },
        ),
      ],
    );
  }

  void _showDeptPicker() {
    if (_departments.isEmpty) {
      TDToast.showText(AppLocalizations.of(context).get('noData'), context: context);
      return;
    }
    final l10n = AppLocalizations.of(context);
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    final labels = _departments.map((d) => d.name).toList();
    TDPicker.showMultiPicker(
      context,
      title: l10n.get('applyDept'),
      backgroundColor: colors.bgCard,
      data: [labels],
      onConfirm: (selected) {
        if (selected.isNotEmpty && selected[0] is int) {
          final idx = selected[0] as int;
          if (idx >= 0 && idx < labels.length) {
            Navigator.of(context).pop();
            setState(() {
              _selectedDeptId = _departments[idx].dep;
              _selectedDeptName = _departments[idx].name;
            });
          }
        }
      },
    );
  }

  // ═══ API 数据 → 弹窗类型转换 ═══

  List<CostCategory> get _dialogCategories => _costTypes
      .map((c) => CostCategory(
            code: c.typeNo,
            nameKey: c.typeName,
            acctSubjectId: c.accNo,
            acctSubjectName: c.accName,
          ))
      .toList();

  List<Project> get _dialogProjects => _projects
      .map((p) => Project(id: int.tryParse(p.objNo) ?? 0, name: p.name))
      .toList();

  List<CostDept> get _dialogCostDepts => _departments
      .map((d) => CostDept(id: d.dep, name: d.name))
      .toList();

  // ═══ 4. 底部操作栏 ═══
  Widget _buildBottomBar(AppLocalizations l10n) {
    return ActionBar(
      showLeft: false,
      centerLabel: l10n.get('saveDraft'),
      rightLabel: l10n.get('submit'),
      centerTextOnly: true,
      onCenterTap: () async {
        try {
          await _saveDraftToStorage();
          if (mounted) _forcePop();
        } catch (_) {
          if (mounted) {
            TDToast.showFail(l10n.get('saveFailed'), context: context);
          }
        }
      },
      onRightTap: () async {
        final err = _validate(l10n);
        if (err.isNotEmpty) {
          TDToast.showText(err.first, context: context);
          return;
        }
        SubmittingDialog.show(context);
        try {
          final data = _buildSubmitData();
          await ref.read(expenseApplyApiProvider).submit(data);
          await DraftStorage.delete(_draftKey);
          if (mounted) {
            SubmittingDialog.hide(context);
            TDToast.showSuccess(l10n.get('submittedAwaitingApproval'), context: context);
            GoRouter.of(context).go('/expense-apply/list');
          }
        } catch (_) {
          if (mounted) {
            SubmittingDialog.hide(context);
            TDToast.showFail(l10n.get('submitFailedRetry'), context: context);
          }
        }
      },
    );
  }

  Map<String, dynamic> _buildSubmitData() {
    // 紧急程度映射：normal→1, urgent→2, critical→3
    String priority;
    switch (_urgency) {
      case 'urgent':
        priority = '2';
        break;
      case 'critical':
        priority = '3';
        break;
      default:
        priority = '1';
    }

    return {
      'HeadData': {
        'AE_DD': _today(),
        'PRIORITY': priority,
        'AMTN_YJ': _totalAmount(),
        'REASON': _purposeController.text.trim(),
        'REM': _remarkController.text,
        'DEP': _selectedDeptId,
        'USR': HostAppChannel.usr,
      },
      'BodyData1': _details.asMap().entries.map((e) {
        final i = e.key;
        final d = e.value;
        return {
          'ITM': i + 1,
          'SQ_MAN': HostAppChannel.usr,
          'TYPE_NO': d.category,
          'AMTN_YJ': d.estimatedAmount,
          'ACC_NO': d.acctSubjectId,
          'ACC_NAME': d.acctSubjectName,
          'DEP': d.costDeptId,
          'OBJ_NO': d.projectId > 0 ? d.projectId.toString() : '',
          'START_DD': d.startDate,
          'END_DD': d.endDate,
          'REM': d.remark.isNotEmpty ? d.remark : d.purpose,
        };
      }).toList(),
    };
  }

  List<String> _validate(AppLocalizations l10n) {
    final e = <String>[];
    if (_purposeController.text.trim().isEmpty) {
      e.add(l10n.get('enterApplyReason'));
    }
    if (_details.isEmpty) e.add(l10n.get('addAtLeastOneDetail'));
    return e;
  }

  void _doPop() {
    if (_hasUnsaved()) {
      final l10n = AppLocalizations.of(context);
      _showConfirmDialog(
        l10n.get('confirmExit'),
        l10n.get('unsavedContentWarning'),
        l10n.get('continueEditing'),
        l10n.get('discardAndExit'),
        () async {
          await DraftStorage.delete(_draftKey);
          if (!mounted) return;
          setState(() => _clearLocalState());
          _forcePop();
        },
      );
    } else {
      _forcePop();
    }
  }

  void _forcePop() {
    _isPoppingToNative = true;
    SystemNavigator.pop();
  }

  bool _hasUnsaved() =>
      _purposeController.text.isNotEmpty ||
      _details.isNotEmpty ||
      _attachmentController.files.isNotEmpty ||
      _referenceNoController.text.isNotEmpty ||
      _remarkController.text.isNotEmpty ||
      _urgency != Urgency.normal.value ||
      _validUntil.isNotEmpty ||
      _selectedDeptId.isNotEmpty;

  void _clearLocalState() {
    _urgency = Urgency.normal.value;
    _purposeController.clear();
    _validUntil = '';
    _referenceNoController.clear();
    _remarkController.clear();
    _details.clear();
    _detailIdCounter = 1;
    _attachmentController.clear();
    _selectedDeptId = '';
    _selectedDeptName = '';
  }

  void _unfocus() => FocusScope.of(context).unfocus();

  // ═══ 通用弹窗方法 ═══
  void _showConfirmDialog(
    String title,
    String content,
    String leftText,
    String rightText,
    VoidCallback onConfirm,
  ) {
    _unfocus();
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    showDialog(
      context: context,
      useRootNavigator: true,
      builder: (ctx) => TDAlertDialog(
        title: title,
        content: content,
        buttonStyle: TDDialogButtonStyle.text,
        leftBtn: TDDialogButtonOptions(
          title: leftText,
          titleColor: colors.primary,
          action: () => Navigator.pop(ctx),
        ),
        rightBtn: TDDialogButtonOptions(
          title: rightText,
          titleColor: colors.danger,
          action: () {
            Navigator.pop(ctx);
            onConfirm();
          },
        ),
      ),
    );
  }

  // TODO: 有效期至 / 关联合同号 暂不支持，方法暂时注释
  // void _showTextInput(
  //   String title,
  //   Function(String) onConfirm, {
  //   String initialText = '',
  // }) {
  //   ...
  // }

  // void _pickDate(Function(String) onPick) {
  //   ...
  // }

  Widget _label(String t, {bool required = false}) {
    final colors = Theme.of(context).extension<AppColorsExtension>()!;
    return Text.rich(
      TextSpan(
        children: [
          TextSpan(
            text: t,
            style: TextStyle(
              fontSize: AppFontSizes.subtitle,
              color: colors.textSecondary,
            ),
          ),
          if (required)
            TextSpan(
              text: ' *',
              style: TextStyle(
                fontSize: AppFontSizes.subtitle,
                color: colors.danger,
              ),
            ),
        ],
      ),
    );
  }

  String _today() {
    final n = DateTime.now();
    return '${n.year}-${n.month.toString().padLeft(2, '0')}-${n.day.toString().padLeft(2, '0')}';
  }
}

class _DetailItem {
  final int id;
  final String category;
  final String categoryName;
  final String acctSubjectId;
  final String acctSubjectName;
  final String purpose;
  final int projectId;
  final String projectName;
  final String costDeptId;
  final String costDeptName;
  final String startDate;
  final String endDate;
  final double estimatedAmount;
  final String remark;
  const _DetailItem({
    required this.id,
    required this.category,
    required this.categoryName,
    required this.acctSubjectId,
    required this.acctSubjectName,
    required this.purpose,
    required this.projectId,
    required this.projectName,
    required this.costDeptId,
    required this.costDeptName,
    required this.startDate,
    required this.endDate,
    required this.estimatedAmount,
    required this.remark,
  });
}