import 'dart:io';

import 'package:flutter/material.dart' hide AssetImage;
import 'package:flutter/services.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';
import 'package:image_picker/image_picker.dart';
import 'package:path_provider/path_provider.dart';
import 'package:permission_handler/permission_handler.dart';
import 'package:shadcn_ui/shadcn_ui.dart';
import 'package:uuid/uuid.dart';
import 'package:wechat_assets_picker/wechat_assets_picker.dart';

import '../../../common/domain/metal_type.dart';
import '../../../common/domain/money.dart';
import '../../../common/widgets/prototype_ui.dart';
import '../../market/application/market_controller.dart';
import '../application/asset_portfolio_controller.dart';
import '../data/asset_models.dart';

enum AssetFormMode { create, edit }

class AssetFormPage extends ConsumerStatefulWidget {
  const AssetFormPage.create({super.key})
    : mode = AssetFormMode.create,
      holding = null;

  const AssetFormPage.edit({super.key, required this.holding})
    : mode = AssetFormMode.edit;

  final AssetFormMode mode;
  final GoldAssetHolding? holding;

  bool get isEdit => mode == AssetFormMode.edit;

  @override
  ConsumerState<AssetFormPage> createState() => _AssetFormPageState();
}

class _AssetFormPageState extends ConsumerState<AssetFormPage> {
  static const _cats = [
    AssetCategory.bar,
    AssetCategory.necklace,
    AssetCategory.ring,
    AssetCategory.bracelet,
    AssetCategory.bean,
    AssetCategory.earring,
    AssetCategory.silverware,
    AssetCategory.platinumPiece,
  ];

  static const _metalPurities = {
    MetalType.gold: ['足金9999', '足金999', '22K', '18K'],
    MetalType.platinum: ['PT990', 'PT950'],
    MetalType.silver: ['999银', '925银'],
  };

  final _costCtrl = TextEditingController();
  final _noteCtrl = TextEditingController();
  final _dateCtrl = TextEditingController(text: '2025-08-12');
  final _channelCtrl = TextEditingController(text: '银行');
  final _picker = ImagePicker();
  final _images = <AssetImage>[];
  final _uuid = const Uuid();

  AssetCategory _cat = AssetCategory.bar;
  MetalType _metal = MetalType.gold;
  int _purityIndex = 0;
  double _gram = 50;
  bool _optionalExpanded = false;

  static const _maxImages = 9;

  GoldAssetHolding? get _holding => widget.holding;
  bool get _isEdit => widget.isEdit;
  bool get _isImageLimitReached => _images.length >= _maxImages;
  String get _imageLimitText => '最多可添加 $_maxImages 张图片';

  @override
  void initState() {
    super.initState();
    final holding = _holding;
    if (holding != null) {
      _optionalExpanded = true;
      _cat = holding.category;
      _metal = holding.metal;
      _purityIndex = _purityIndexFor(holding);
      _gram = holding.weightGram;
      _costCtrl.text = holding.costAmount?.toStringAsFixed(0) ?? '';
      _dateCtrl.text = holding.purchaseDate == null
          ? ''
          : _formatDate(holding.purchaseDate!);
      _channelCtrl.text = holding.channel ?? '';
      _noteCtrl.text = holding.note ?? '';
      _images.addAll(holding.images);
    }
  }

  @override
  void dispose() {
    _costCtrl.dispose();
    _noteCtrl.dispose();
    _dateCtrl.dispose();
    _channelCtrl.dispose();
    super.dispose();
  }

  int _purityIndexFor(GoldAssetHolding holding) {
    final options = _metalPurities[holding.metal]!;
    final index = options.indexOf(holding.purityLabel);
    return index < 0 ? 0 : index;
  }

  List<String> get _purityOptions => _metalPurities[_metal]!;

  String get _purity =>
      _purityOptions[_purityIndex.clamp(0, _purityOptions.length - 1)];

  double _factorFor(String purity) {
    return switch (purity) {
      '足金9999' => 0.9999,
      '足金999' => 0.999,
      '22K' => 0.916,
      '18K' => 0.75,
      'PT990' => 0.99,
      'PT950' => 0.95,
      '999银' => 0.999,
      '925银' => 0.925,
      _ => 1,
    };
  }

  String _nameForSelection() {
    return switch (_cat) {
      AssetCategory.bar => '投资金条',
      AssetCategory.necklace => '${_metal.label}项链',
      AssetCategory.ring => '${_metal.label}戒指',
      AssetCategory.bracelet => '${_metal.label}手镯',
      AssetCategory.bean => '金豆',
      AssetCategory.earring => '${_metal.label}耳环',
      AssetCategory.silverware => '银饰',
      AssetCategory.platinumPiece => 'PT饰品',
    };
  }

  String _formatDate(DateTime value) {
    return '${value.year}-${value.month.toString().padLeft(2, '0')}-${value.day.toString().padLeft(2, '0')}';
  }

  DateTime? _parseDate(String value) {
    if (value.isEmpty) return null;
    return DateTime.tryParse(value);
  }

  Future<void> pickDate(BuildContext context) async {
    final today = DateTime.now();
    final parsed = _parseDate(_dateCtrl.text.trim()) ??
        _holding?.purchaseDate ??
        today;
    final initialDate = parsed.isBefore(DateTime(2000))
        ? DateTime(2000)
        : parsed.isAfter(today)
            ? today
            : parsed;
    final picked = await showDatePicker(
      context: context,
      initialDate: initialDate,
      firstDate: DateTime(2000),
      lastDate: today,
      initialEntryMode: DatePickerEntryMode.calendarOnly,
      locale: const Locale('zh'),
    );
    if (picked == null || !mounted) return;
    setState(() {
      _dateCtrl.text = _formatDate(picked);
    });
  }

  Future<void> _showImageSourceSheet() async {
    if (!mounted) return;
    showModalBottomSheet<void>(
      context: context,
      backgroundColor: Colors.white,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(18)),
      ),
      builder: (ctx) => SafeArea(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            const SizedBox(height: 8),
            Container(
              width: 38,
              height: 4,
              decoration: BoxDecoration(
                color: const Color(0xFFE3DFD4),
                borderRadius: BorderRadius.circular(999),
              ),
            ),
            const SizedBox(height: 14),
            ListTile(
              leading: const Icon(Icons.camera_alt_outlined),
              title: const Text('拍照'),
              onTap: () {
                Navigator.of(ctx).pop();
                _handleTakePhoto();
              },
            ),
            ListTile(
              leading: const Icon(Icons.photo_library_outlined),
              title: const Text('从相册选择'),
              onTap: () {
                Navigator.of(ctx).pop();
                _handlePickFromGallery();
              },
            ),
            const SizedBox(height: 8),
            ListTile(
              title: const Text(
                '取消',
                textAlign: TextAlign.center,
                style: TextStyle(color: Color(0xFF8A8780)),
              ),
              onTap: () => Navigator.of(ctx).pop(),
            ),
          ],
        ),
      ),
    );
  }

  Future<void> _handleTakePhoto() async {
    final granted = await _requestCameraPermission();
    if (!granted) {
      _showPermissionDeniedDialog('相机');
      return;
    }
    final file = await _picker.pickImage(
      source: ImageSource.camera,
      imageQuality: 80,
      maxWidth: 2048,
    );
    if (file == null) return;
    await _addPickedFile(file);
  }

  Future<void> _handlePickFromGallery() async {
    final availableSlots = _maxImages - _images.length;
    if (availableSlots <= 0) return;

    final assets = await AssetPicker.pickAssets(
      context,
      pickerConfig: AssetPickerConfig(
        maxAssets: availableSlots,
        requestType: RequestType.image,
        themeColor: const Color(0xFFB5862A),
      ),
    );
    if (assets == null || assets.isEmpty) return;

    final pickedImages = <AssetImage>[];
    for (final asset in assets.take(availableSlots)) {
      final file = await asset.file;
      if (file == null) continue;
      pickedImages.add(await _assetImageFromSourceFile(file));
    }
    if (pickedImages.isEmpty || !mounted) return;

    setState(() => _images.addAll(pickedImages));
  }

  Future<void> _addPickedFile(XFile file) async {
    if (_images.length >= _maxImages) return;
    final image = await _assetImageFromXFile(file);
    if (!mounted) return;
    setState(() => _images.add(image));
  }

  Future<AssetImage> _assetImageFromXFile(XFile file) {
    return _assetImageFromSourceFile(File(file.path));
  }

  Future<AssetImage> _assetImageFromSourceFile(File sourceFile) async {
    final localId =
        'img${DateTime.now().microsecondsSinceEpoch}${_uuid.v4().split('-').first}';
    final extension = _extensionForPath(sourceFile.path);
    final directory = await getApplicationSupportDirectory();
    final imageDirectory = Directory('${directory.path}/asset_images');
    if (!await imageDirectory.exists()) {
      await imageDirectory.create(recursive: true);
    }
    final copiedFile = await sourceFile.copy(
      '${imageDirectory.path}/$localId$extension',
    );

    return AssetImage(
      localId: localId,
      localPath: copiedFile.path,
      createdAt: DateTime.now(),
    );
  }

  String _extensionForPath(String path) {
    final fileName = path.split(Platform.pathSeparator).last;
    final dotIndex = fileName.lastIndexOf('.');
    if (dotIndex <= 0 || dotIndex == fileName.length - 1) return '.jpg';
    return fileName.substring(dotIndex);
  }

  Future<bool> _requestCameraPermission() async {
    final status = await Permission.camera.status;
    if (status.isGranted) return true;
    final result = await Permission.camera.request();
    return result.isGranted;
  }

  void _showPermissionDeniedDialog(String target) {
    if (!mounted) return;
    showDialog<void>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('权限不足'),
        content: Text('无法访问$target，请在系统设置中开启权限。'),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(ctx).pop(),
            child: const Text('取消'),
          ),
          TextButton(
            onPressed: () {
              Navigator.of(ctx).pop();
              openAppSettings();
            },
            child: const Text('去设置'),
          ),
        ],
      ),
    );
  }

  void _removeImage(String localId) {
    setState(() => _images.removeWhere((item) => item.localId == localId));
  }

  void _save() {
    final cost = double.tryParse(_costCtrl.text.trim());
    final parsedDate = DateTime.tryParse(_dateCtrl.text.trim());
    final channel = _channelCtrl.text.trim();
    final note = _noteCtrl.text.trim();
    final messenger = ScaffoldMessenger.maybeOf(context);

    if (_isEdit) {
      final holding = _holding!;
      ref
          .read(assetPortfolioControllerProvider.notifier)
          .updateHolding(
            GoldAssetHolding(
              id: holding.id,
              name: holding.name,
              metal: holding.metal,
              category: holding.category,
              purity: holding.purity,
              purityLabel: holding.purityLabel,
              weightGram: _gram,
              images: List<AssetImage>.unmodifiable(_images),
              costAmount: cost,
              purchaseDate: parsedDate,
              channel: channel.isEmpty ? null : channel,
              note: note.isEmpty ? null : note,
              createdAt: holding.createdAt,
              updatedAt: DateTime.now(),
              status: holding.status,
            ),
          );
      messenger?.showSnackBar(
        const SnackBar(content: Text('已保存修改 · 总值已重算')),
      );
      Navigator.of(context).pop();
      return;
    }

    final holding = GoldAssetHolding(
      id: 'h${DateTime.now().microsecondsSinceEpoch}',
      name: _nameForSelection(),
      metal: _metal,
      category: _cat,
      purity: _factorFor(_purity),
      purityLabel: _purity,
      weightGram: _gram,
      costAmount: cost,
      purchaseDate: parsedDate,
      channel: channel.isEmpty ? null : channel,
      note: note.isEmpty ? null : note,
      images: List<AssetImage>.unmodifiable(_images),
      createdAt: DateTime.now(),
      updatedAt: DateTime.now(),
    );
    ref.read(assetPortfolioControllerProvider.notifier).addHolding(holding);
    messenger?.showSnackBar(
      const SnackBar(content: Text('已添加 · 总估值已重算')),
    );
    Navigator.of(context).pop();
  }

  Widget _buildImageTile(AssetImage image) {
    return Stack(
      children: [
        ClipRRect(
          borderRadius: BorderRadius.circular(12),
          child: Image.file(
            File(image.localPath),
            width: 84,
            height: 84,
            fit: BoxFit.cover,
          ),
        ),
        Positioned(
          top: 6,
          right: 6,
          child: GestureDetector(
            onTap: () => _removeImage(image.localId),
            child: Container(
              width: 22,
              height: 22,
              decoration: const BoxDecoration(
                color: Color(0xAA000000),
                shape: BoxShape.circle,
              ),
              child: const Icon(Icons.close, size: 14, color: Colors.white),
            ),
          ),
        ),
      ],
    );
  }

  Widget _buildImagesSection() {
    return Container(
      width: double.infinity,
      padding: const EdgeInsets.all(14),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: const Color(0xFFECEAE3), width: 0.5),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          if (_images.isEmpty) ...[
            GestureDetector(
              onTap: _showImageSourceSheet,
              child: Row(
                children: [
                  Container(
                    width: 60,
                    height: 60,
                    decoration: BoxDecoration(
                      borderRadius: BorderRadius.circular(11),
                      border: Border.all(
                        color: const Color(0xFFD3CDBE),
                        width: 0.5,
                      ),
                    ),
                    child: const Icon(
                      Icons.camera_alt_outlined,
                      color: Color(0xFFB3AFA5),
                    ),
                  ),
                  const SizedBox(width: 10),
                  const Expanded(
                    child: Text(
                      '添加发票 / 实物照片（选填，仅存本机）',
                      style: TextStyle(fontSize: 12, color: Color(0xFFB3AFA5)),
                    ),
                  ),
                ],
              ),
            ),
            const SizedBox(height: 8),
            const Text(
              '支持发票、收据、金条证书、实物照片。',
              style: TextStyle(fontSize: 12, color: Color(0xFFB3AFA5)),
            ),
          ] else ...[
            const Text(
              '凭证照片',
              style: TextStyle(fontSize: 13, color: Color(0xFF8A8780)),
            ),
            const SizedBox(height: 12),
            Wrap(
              spacing: 8,
              runSpacing: 8,
              children: [
                for (final image in _images) _buildImageTile(image),
                if (!_isImageLimitReached)
                  GestureDetector(
                    onTap: _showImageSourceSheet,
                    child: Container(
                      width: 84,
                      height: 84,
                      decoration: BoxDecoration(
                        color: const Color(0xFFF6ECD6),
                        borderRadius: BorderRadius.circular(12),
                      ),
                      child: Column(
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: const [
                          Icon(Icons.add, color: Color(0xFFB5862A)),
                          SizedBox(height: 5),
                          Text(
                            '继续补充',
                            textAlign: TextAlign.center,
                            style: TextStyle(
                              fontSize: 11,
                              color: Color(0xFFB5862A),
                            ),
                          ),
                        ],
                      ),
                    ),
                  ),
                if (_isImageLimitReached)
                  Container(
                    width: 84,
                    height: 84,
                    decoration: BoxDecoration(
                      color: const Color(0xFFF2F0EA),
                      borderRadius: BorderRadius.circular(12),
                      border: Border.all(
                        color: const Color(0xFFE3DFD4),
                        width: 0.5,
                      ),
                    ),
                    alignment: Alignment.center,
                    child: const Icon(
                      Icons.check_circle_outline,
                      color: Color(0xFFB3AFA5),
                    ),
                  ),
              ],
            ),
            const SizedBox(height: 8),
            Text(
              _imageLimitText,
              style: const TextStyle(fontSize: 12, color: Color(0xFFB3AFA5)),
            ),
          ],
        ],
      ),
    );
  }

  Widget _buildCreateBody(BuildContext context, ShadColorScheme cs) {
    final market = ref.watch(marketControllerProvider);
    final quote = market.quotes.firstWhere((item) => item.metal == _metal);
    final value = _gram * _factorFor(_purity) * quote.spotPrice;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      mainAxisSize: MainAxisSize.min,
      children: [
        const Text('选择品类', style: TextStyle(fontSize: 13, color: Color(0xFF8A8780))),
        const SizedBox(height: 10),
        Wrap(
          spacing: 9,
          runSpacing: 9,
          children: [
            for (final cat in _cats)
              _Chip(
                label: cat.label,
                selected: cat == _cat,
                onTap: () => setState(() {
                  _cat = cat;
                  if (cat == AssetCategory.silverware) {
                    _metal = MetalType.silver;
                  } else if (cat == AssetCategory.platinumPiece) {
                    _metal = MetalType.platinum;
                  } else {
                    _metal = MetalType.gold;
                  }
                  _purityIndex = 0;
                }),
              ),
          ],
        ),
        const SizedBox(height: 16),
        Container(
          padding: const EdgeInsets.fromLTRB(16, 13, 16, 13),
          decoration: BoxDecoration(
            color: Colors.white,
            border: Border.all(color: const Color(0xFFE3D6B4), width: 0.5),
            borderRadius: BorderRadius.circular(13),
          ),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              const Text(
                '金属 / 纯度',
                style: TextStyle(fontSize: 13, color: Color(0xFF8A8780)),
              ),
              GestureDetector(
                onTap: () => setState(() {
                  _purityIndex = (_purityIndex + 1) % _purityOptions.length;
                }),
                child: Row(
                  children: [
                    Text(
                      '${_metal.label} · $_purity',
                      style: const TextStyle(
                        fontSize: 14,
                        fontWeight: FontWeight.w600,
                      ),
                    ),
                    const SizedBox(width: 7),
                    const Icon(
                      Icons.unfold_more,
                      size: 16,
                      color: Color(0xFFB3AFA5),
                    ),
                  ],
                ),
              ),
            ],
          ),
        ),
        const SizedBox(height: 16),
        const Text('克重(克)', style: TextStyle(fontSize: 13, color: Color(0xFF8A8780))),
        const SizedBox(height: 9),
        Row(
          children: [
            _StepButton(
              icon: Icons.remove,
              onTap: () => setState(() => _gram = (_gram - 1).clamp(1, 200)),
            ),
            const SizedBox(width: 12),
            Expanded(
              child: Container(
                padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
                decoration: BoxDecoration(
                  color: Colors.white,
                  border: Border.all(color: const Color(0xFFE3D6B4), width: 0.5),
                  borderRadius: BorderRadius.circular(13),
                ),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  crossAxisAlignment: CrossAxisAlignment.end,
                  children: [
                    Text(
                      _gram.toStringAsFixed(_gram % 1 == 0 ? 0 : 1),
                      style: const TextStyle(
                        fontSize: 32,
                        fontWeight: FontWeight.w600,
                        height: 1,
                      ),
                    ),
                    const SizedBox(width: 6),
                    const Padding(
                      padding: EdgeInsets.only(bottom: 2),
                      child: Text(
                        '克',
                        style: TextStyle(fontSize: 15, color: Color(0xFF8A8780)),
                      ),
                    ),
                  ],
                ),
              ),
            ),
            const SizedBox(width: 12),
            _StepButton(
              icon: Icons.add,
              onTap: () => setState(() => _gram = (_gram + 1).clamp(1, 200)),
            ),
          ],
        ),
        Slider(
          min: 1,
          max: 200,
          value: _gram.clamp(1, 200),
          onChanged: (value) => setState(() => _gram = value),
          activeColor: const Color(0xFFB5862A),
          inactiveColor: const Color(0xFFECEAE3),
        ),
        const SizedBox(height: 8),
        Container(
          padding: const EdgeInsets.fromLTRB(16, 15, 16, 16),
          decoration: BoxDecoration(
            color: const Color(0xFFF6ECD6),
            borderRadius: BorderRadius.circular(14),
          ),
          child: Row(
            children: [
              const Expanded(
                child: Text(
                  '实时材料价值',
                  style: TextStyle(fontSize: 13, color: Color(0xFF7A5B12)),
                ),
              ),
              Text(
                formatCny(value),
                style: const TextStyle(fontSize: 24, fontWeight: FontWeight.w600),
              ),
            ],
          ),
        ),
        const SizedBox(height: 14),
        GestureDetector(
          onTap: () => setState(() => _optionalExpanded = !_optionalExpanded),
          child: Container(
            padding: const EdgeInsets.fromLTRB(16, 13, 16, 13),
            decoration: BoxDecoration(
              color: cs.card,
              borderRadius: BorderRadius.circular(14),
              border: Border.all(color: cs.border, width: 0.5),
            ),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Text(
                  '选填:买入成本 · 日期 · 渠道 · 备注 · 照片',
                  style: TextStyle(fontSize: 13, color: cs.mutedForeground),
                ),
                Icon(
                  _optionalExpanded ? Icons.expand_less : Icons.expand_more,
                  color: cs.mutedForeground,
                  size: 18,
                ),
              ],
            ),
          ),
        ),
        if (_optionalExpanded) ...[
          const SizedBox(height: 12),
          _FieldRow(
            label: '买入成本(含工费)',
            child: TextField(
              controller: _costCtrl,
              keyboardType: const TextInputType.numberWithOptions(
                decimal: true,
              ),
              inputFormatters: [
                FilteringTextInputFormatter.allow(RegExp(r'[0-9.]')),
              ],
              decoration: const InputDecoration(
                border: InputBorder.none,
                isDense: true,
                hintText: '选填',
              ),
              textAlign: TextAlign.right,
            ),
          ),
          const SizedBox(height: 10),
          _FieldRow(
            label: '购买日期',
            child: TextField(
              controller: _dateCtrl,
              readOnly: true,
              onTap: () => pickDate(context),
              decoration: const InputDecoration(
                border: InputBorder.none,
                isDense: true,
                hintText: 'YYYY-MM-DD',
              ),
              textAlign: TextAlign.right,
            ),
          ),
          const SizedBox(height: 10),
          _FieldRow(
            label: '购买渠道',
            child: Wrap(
              spacing: 7,
              runSpacing: 7,
              alignment: WrapAlignment.end,
              children: [
                for (final channel in ['银行', '金店', '电商', '回收市场', '其他'])
                  _Chip(
                    label: channel,
                    selected: _channelCtrl.text == channel,
                    onTap: () => setState(() => _channelCtrl.text = channel),
                  ),
              ],
            ),
          ),
          const SizedBox(height: 10),
          _FieldRow(
            label: '备注',
            child: TextField(
              controller: _noteCtrl,
              decoration: const InputDecoration(
                border: InputBorder.none,
                isDense: true,
                hintText: '点击填写',
              ),
              textAlign: TextAlign.right,
            ),
          ),
          const SizedBox(height: 10),
          _buildImagesSection(),
        ],
        const SizedBox(height: 16),
      ],
    );
  }

  Widget _buildEditBody(BuildContext context, ShadColorScheme cs) {
    final holding = _holding!;
    final market = ref.watch(marketControllerProvider);
    final quote = market.quotes.firstWhere((item) => item.metal == holding.metal);
    final value = _gram * holding.purity * quote.spotPrice;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      mainAxisSize: MainAxisSize.min,
      children: [
        PrototypeCard(
          child: Row(
            children: [
              Text(
                '金属 / 纯度',
                style: TextStyle(fontSize: 13, color: cs.mutedForeground),
              ),
              const Spacer(),
              Text(
                '${holding.metal.label} · ${holding.purityLabel}',
                style: const TextStyle(fontSize: 14, fontWeight: FontWeight.w600),
              ),
            ],
          ),
        ),
        const SizedBox(height: 16),
        const Text('克重(克)', style: TextStyle(fontSize: 13, color: Color(0xFF8A8780))),
        const SizedBox(height: 9),
        Container(
          padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 16),
          decoration: BoxDecoration(
            color: Colors.white,
            border: Border.all(color: const Color(0xFFE3D6B4), width: 0.5),
            borderRadius: BorderRadius.circular(13),
          ),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.end,
            children: [
              Text(
                _gram.toStringAsFixed(_gram % 1 == 0 ? 0 : 1),
                style: const TextStyle(
                  fontSize: 32,
                  fontWeight: FontWeight.w600,
                  height: 1,
                ),
              ),
              const SizedBox(width: 6),
              const Padding(
                padding: EdgeInsets.only(bottom: 2),
                child: Text(
                  '克',
                  style: TextStyle(fontSize: 15, color: Color(0xFF8A8780)),
                ),
              ),
            ],
          ),
        ),
        Slider(
          min: 1,
          max: 200,
          value: _gram.clamp(1, 200),
          onChanged: (value) => setState(() => _gram = value),
          activeColor: const Color(0xFFB5862A),
          inactiveColor: const Color(0xFFECEAE3),
        ),
        const SizedBox(height: 8),
        Container(
          padding: const EdgeInsets.fromLTRB(16, 15, 16, 16),
          decoration: BoxDecoration(
            color: const Color(0xFFF6ECD6),
            borderRadius: BorderRadius.circular(14),
          ),
          child: Row(
            children: [
              const Expanded(
                child: Text(
                  '实时材料价值',
                  style: TextStyle(fontSize: 13, color: Color(0xFF7A5B12)),
                ),
              ),
              Text(
                formatCny(value),
                style: const TextStyle(fontSize: 24, fontWeight: FontWeight.w600),
              ),
            ],
          ),
        ),
        const SizedBox(height: 14),
        _FieldRow(
          label: '买入成本(含工费)',
          child: TextField(
            controller: _costCtrl,
            keyboardType: const TextInputType.numberWithOptions(decimal: true),
            inputFormatters: [
              FilteringTextInputFormatter.allow(RegExp(r'[0-9.]')),
            ],
            textAlign: TextAlign.right,
            decoration: const InputDecoration(
              border: InputBorder.none,
              isDense: true,
              hintText: '选填',
            ),
          ),
        ),
        const SizedBox(height: 10),
        _FieldRow(
          label: '购买日期',
          child: TextField(
            controller: _dateCtrl,
            readOnly: true,
            onTap: () => pickDate(context),
            textAlign: TextAlign.right,
            decoration: const InputDecoration(
              border: InputBorder.none,
              isDense: true,
              hintText: 'YYYY-MM-DD',
            ),
          ),
        ),
        const SizedBox(height: 10),
        _FieldRow(
          label: '购买渠道',
          child: Wrap(
            spacing: 7,
            runSpacing: 7,
            alignment: WrapAlignment.end,
            children: [
              for (final channel in ['银行', '金店', '电商', '回收市场', '其他'])
                _Chip(
                  label: channel,
                  selected: _channelCtrl.text == channel,
                  onTap: () => setState(() => _channelCtrl.text = channel),
                ),
            ],
          ),
        ),
        const SizedBox(height: 10),
        _FieldRow(
          label: '备注',
          child: TextField(
            controller: _noteCtrl,
            textAlign: TextAlign.right,
            decoration: const InputDecoration(
              border: InputBorder.none,
              isDense: true,
              hintText: '点击填写',
            ),
          ),
        ),
        const SizedBox(height: 10),
        _buildImagesSection(),
        const SizedBox(height: 16),
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    final cs = ShadTheme.of(context).colorScheme;

    return Scaffold(
      backgroundColor: const Color(0xFFFBFAF7),
      appBar: AppBar(
        backgroundColor: const Color(0xFFFBFAF7),
        surfaceTintColor: Colors.transparent,
        elevation: 0,
        scrolledUnderElevation: 0,
        centerTitle: true,
        title: Text(
          _isEdit ? '编辑·${_holding!.name}' : '添加资产',
          style: const TextStyle(fontSize: 17, fontWeight: FontWeight.w600),
        ),
        leading: IconButton(
          onPressed: () => Navigator.of(context).pop(),
          icon: const Icon(Icons.chevron_left, size: 20),
        ),
      ),
      body: SafeArea(
        top: false,
        child: ListView(
          padding: const EdgeInsets.fromLTRB(0, 8, 0, 24),
          children: [
            PrototypeFrame(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: [
                  if (_isEdit) _buildEditBody(context, cs)
                  else _buildCreateBody(context, cs),
                  Row(
                    children: [
                      Expanded(
                        child: FilledButton(
                          onPressed: _save,
                          child: Text(_isEdit ? '保存修改' : '保存'),
                        ),
                      ),
                    ],
                  ),
                  const SizedBox(height: 10),
                  Text(
                    _isEdit ? '修改后会即时重算资产总值' : '添加后会即时重算资产总值',
                    textAlign: TextAlign.center,
                    style: TextStyle(fontSize: 11, color: cs.mutedForeground),
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class _Chip extends StatelessWidget {
  const _Chip({
    required this.label,
    required this.selected,
    required this.onTap,
  });

  final String label;
  final bool selected;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: onTap,
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 11, vertical: 6),
        decoration: BoxDecoration(
          color: selected ? const Color(0xFFF6ECD6) : Colors.white,
          borderRadius: BorderRadius.circular(999),
          border: Border.all(
            color: selected ? const Color(0xFFE3D6B4) : const Color(0xFFECEAE3),
            width: 0.5,
          ),
        ),
        child: Text(
          label,
          style: TextStyle(
            fontSize: 12,
            fontWeight: selected ? FontWeight.w600 : FontWeight.w500,
            color: selected ? const Color(0xFF7A5B12) : const Color(0xFF5F5E5A),
          ),
        ),
      ),
    );
  }
}

class _StepButton extends StatelessWidget {
  const _StepButton({required this.icon, required this.onTap});

  final IconData icon;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: onTap,
      child: Container(
        width: 34,
        height: 34,
        decoration: BoxDecoration(
          color: Colors.white,
          borderRadius: BorderRadius.circular(10),
          border: Border.all(color: const Color(0xFFE3D6B4), width: 0.5),
        ),
        child: Icon(icon, size: 18, color: const Color(0xFFB5862A)),
      ),
    );
  }
}

class _FieldRow extends StatelessWidget {
  const _FieldRow({required this.label, required this.child});

  final String label;
  final Widget child;

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.fromLTRB(14, 12, 14, 12),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: const Color(0xFFECEAE3), width: 0.5),
      ),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.center,
        children: [
          Text(
            label,
            style: const TextStyle(fontSize: 13, color: Color(0xFF8A8780)),
          ),
          const SizedBox(width: 10),
          Expanded(child: child),
        ],
      ),
    );
  }
}