nj/app/lib/features/stickers/views/sticker_library_page.dart

// 贴纸库页面 — 贴纸包浏览 + 分类 Tab

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:nuanji_app/core/theme/app_colors.dart';
import 'package:nuanji_app/data/remote/api_client.dart';
import '../bloc/sticker_bloc.dart';

/// 贴纸库页面 — 分类浏览贴纸包
class StickerLibraryPage extends StatefulWidget {
  const StickerLibraryPage({super.key});

  @override
  State<StickerLibraryPage> createState() => _StickerLibraryPageState();
}

class _StickerLibraryPageState extends State<StickerLibraryPage> {
  late final StickerBloc _bloc;

  @override
  void initState() {
    super.initState();
    _bloc = StickerBloc(api: context.read<ApiClient>());
    _bloc.load();
  }

  @override
  void dispose() {
    _bloc.dispose();
    super.dispose();
  }

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

    return Scaffold(
      appBar: AppBar(title: const Text('贴纸库')),
      body: ListenableBuilder(
        listenable: _bloc,
        builder: (context, _) {
          final state = _bloc.state;

          if (state.isLoading) {
            return const Center(child: CircularProgressIndicator());
          }

          if (state.errorMessage != null) {
            return Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Icon(Icons.error_outline, size: 48, color: colorScheme.error),
                  const SizedBox(height: 16),
                  FilledButton.tonal(
                    onPressed: _bloc.load,
                    child: const Text('重试'),
                  ),
                ],
              ),
            );
          }

          final categories = state.categories;

          return Column(
            children: [
              // 分类选择器（横向滚动 Chips）
              SizedBox(
                height: 48,
                child: ListView(
                  scrollDirection: Axis.horizontal,
                  padding: const EdgeInsets.symmetric(horizontal: 16),
                  children: categories.map((cat) {
                    final isSelected = cat == state.selectedCategory;
                    return Padding(
                      padding: const EdgeInsets.only(right: 8),
                      child: FilterChip(
                        selected: isSelected,
                        label: Text(cat),
                        onSelected: (_) => _bloc.selectCategory(cat),
                        selectedColor: colorScheme.primaryContainer,
                        checkmarkColor: colorScheme.primary,
                      ),
                    );
                  }).toList(),
                ),
              ),
              const SizedBox(height: 8),

              // 贴纸包网格
              Expanded(
                child: state.filteredPacks.isEmpty
                    ? const Center(child: Text('暂无贴纸包'))
                    : GridView.builder(
                        padding: const EdgeInsets.all(16),
                        gridDelegate:
                            const SliverGridDelegateWithFixedCrossAxisCount(
                          crossAxisCount: 2,
                          mainAxisSpacing: 12,
                          crossAxisSpacing: 12,
                          childAspectRatio: 0.85,
                        ),
                        itemCount: state.filteredPacks.length,
                        itemBuilder: (context, index) {
                          return _StickerPackCard(
                            pack: state.filteredPacks[index],
                            colorScheme: colorScheme,
                          );
                        },
                      ),
              ),
            ],
          );
        },
      ),
    );
  }
}

/// 贴纸包卡片
class _StickerPackCard extends StatelessWidget {
  const _StickerPackCard({
    required this.pack,
    required this.colorScheme,
  });

  final StickerPack pack;
  final ColorScheme colorScheme;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    return Card(
      elevation: 0,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(16),
        side: BorderSide(color: colorScheme.outlineVariant),
      ),
      child: InkWell(
        onTap: () {
          ScaffoldMessenger.of(context).showSnackBar(
            SnackBar(content: Text('打开贴纸包: ${pack.name}')),
          );
        },
        borderRadius: BorderRadius.circular(16),
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              // 贴纸包封面图标
              Container(
                width: 64,
                height: 64,
                decoration: BoxDecoration(
                  color: colorScheme.primaryContainer.withValues(alpha: 0.3),
                  borderRadius: BorderRadius.circular(16),
                ),
                alignment: Alignment.center,
                child: Text(
                  pack.coverImageUrl != null ? '🎨' : pack.displayCover,
                  style: const TextStyle(fontSize: 32),
                ),
              ),
              const SizedBox(height: 12),
              // 名称
              Text(
                pack.name,
                style: theme.textTheme.titleSmall?.copyWith(
                  fontWeight: FontWeight.w600,
                ),
                maxLines: 1,
                overflow: TextOverflow.ellipsis,
              ),
              const SizedBox(height: 4),
              // 数量和价格标签
              Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Text(
                    '${pack.stickerCount} 张',
                    style: theme.textTheme.bodySmall?.copyWith(
                      color: colorScheme.onSurface.withValues(alpha: 0.5),
                    ),
                  ),
                  if (!pack.isFree) ...[
                    const SizedBox(width: 8),
                    Container(
                      padding: const EdgeInsets.symmetric(
                          horizontal: 6, vertical: 2),
                      decoration: BoxDecoration(
                        color: AppColors.accent.withValues(alpha: 0.15),
                        borderRadius: BorderRadius.circular(6),
                      ),
                      child: Text(
                        '积分',
                        style: theme.textTheme.labelSmall?.copyWith(
                          color: AppColors.accent,
                        ),
                      ),
                    ),
                  ],
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}