import 'package:flutter/material.dart';
import '../models/subscription_model.dart';
import '../widgets/subscription_card.dart';
import '../widgets/category_header_widget.dart';

/// 카테고리별로 구독 목록을 표시하는 위젯
class SubscriptionListWidget extends StatelessWidget {
  final Map<String, List<SubscriptionModel>> categorizedSubscriptions;
  final AnimationController fadeController;

  const SubscriptionListWidget({
    Key? key,
    required this.categorizedSubscriptions,
    required this.fadeController,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    // 카테고리 키 목록 (정렬된)
    final categories = categorizedSubscriptions.keys.toList();

    return SliverList(
      delegate: SliverChildBuilderDelegate(
        (context, index) {
          final category = categories[index];
          final subscriptions = categorizedSubscriptions[category]!;

          return Padding(
            padding: const EdgeInsets.only(bottom: 8.0),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                // 카테고리 헤더
                Padding(
                  padding: const EdgeInsets.fromLTRB(20, 16, 20, 8),
                  child: CategoryHeaderWidget(
                    categoryName: category,
                    subscriptionCount: subscriptions.length,
                    totalCost: subscriptions.fold(
                      0.0,
                      (sum, sub) => sum + sub.monthlyCost,
                    ),
                  ),
                ),
                // 카테고리별 구독 목록
                FadeTransition(
                  opacity: Tween<double>(begin: 0.0, end: 1.0).animate(
                      CurvedAnimation(
                          parent: fadeController, curve: Curves.easeIn)),
                  child: ListView.builder(
                    physics: const NeverScrollableScrollPhysics(),
                    shrinkWrap: true,
                    padding: const EdgeInsets.symmetric(horizontal: 16),
                    itemCount: subscriptions.length,
                    itemBuilder: (context, subIndex) {
                      // 각 구독의 지연값 계산 (순차적으로 나타나도록)
                      final delay = 0.05 * subIndex;
                      final animationBegin = 0.2;
                      final animationEnd = 1.0;
                      final intervalStart = delay;
                      final intervalEnd = intervalStart + 0.4;

                      // 간격 계산 (0.0~1.0 사이의 값으로 정규화)
                      final intervalStartNormalized =
                          intervalStart.clamp(0.0, 0.9);
                      final intervalEndNormalized = intervalEnd.clamp(0.1, 1.0);

                      return FadeTransition(
                        opacity: Tween<double>(
                                begin: animationBegin, end: animationEnd)
                            .animate(CurvedAnimation(
                                parent: fadeController,
                                curve: Interval(intervalStartNormalized,
                                    intervalEndNormalized,
                                    curve: Curves.easeOut))),
                        child: Padding(
                          padding: const EdgeInsets.only(bottom: 12.0),
                          child: SubscriptionCard(
                            subscription: subscriptions[subIndex],
                          ),
                        ),
                      );
                    },
                  ),
                ),
              ],
            ),
          );
        },
        childCount: categories.length,
      ),
    );
  }
}

/// 여러 Sliver 위젯을 하나의 위젯으로 감싸는 도우미 위젯
class MultiSliver extends StatelessWidget {
  final List<Widget> children;

  const MultiSliver({
    Key? key,
    required this.children,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return SliverList(
      delegate: SliverChildBuilderDelegate(
        (context, index) {
          if (index >= children.length) return null;
          return children[index];
        },
        childCount: children.length,
      ),
    );
  }
}