import 'package:flutter/material.dart';
import 'package:flutter_svg/flutter_svg.dart';

// class FloatingSvgIcon extends StatefulWidget {
//   final String assetPath; // SVG 图标路径
//   final double width; // 宽度
//   final double height; // 高度
//   final Duration duration; // 浮动周期
//   final double floatOffset; // 浮动高度（单位：比例）
//   final VoidCallback? onTap; // 点击事件

//   const FloatingSvgIcon({
//     super.key,
//     required this.assetPath,
//     this.width = 60,
//     this.height = 60,
//     this.duration = const Duration(milliseconds: 800),
//     this.floatOffset = 0.02,
//     this.onTap,
//   });

//   @override
//   State<FloatingSvgIcon> createState() => _FloatingSvgIconState();
// }

// class _FloatingSvgIconState extends State<FloatingSvgIcon>
//     with SingleTickerProviderStateMixin {
//   late final AnimationController _controller;
//   late final Animation<Offset> _animation;

//   @override
//   void initState() {
//     super.initState();

//     _controller = AnimationController(
//       vsync: this,
//       duration: widget.duration,
//     )..repeat(reverse: true);

//     _animation = Tween<Offset>(
//       begin: Offset(0, -widget.floatOffset),
//       end: Offset(0, widget.floatOffset),
//     ).animate(CurvedAnimation(
//       parent: _controller,
//       curve: Curves.easeInOut,
//     ));
//   }

//   @override
//   void dispose() {
//     _controller.dispose();
//     super.dispose();
//   }

//   // 计算阴影缩放因子，范围大致从 0.8 ~ 1.2
//   double getShadowScale(double dy) {
//     return 1 - dy * 0.25; // dy 为负时，scale > 1，dy 为正时，scale < 1
//   }

//   // 计算阴影透明度，范围大致从 0.3 ~ 0.7
//   double getShadowOpacity(double dy) {
//     return 0.5 - dy * 0.3;
//   }

//   @override
//   Widget build(BuildContext context) {
//     return AnimatedBuilder(
//       animation: _controller,
//       builder: (context, child) {
//         final dy = _animation.value.dy;

//         final shadowScale = getShadowScale(dy).clamp(0.8, 1.2);
//         final shadowOpacity = getShadowOpacity(dy).clamp(0.3, 0.7);

//         return SlideTransition(
//           position: _animation,
//           child: GestureDetector(
//             onTap: widget.onTap,
//             child: SizedBox(
//               width: widget.width,
//               height: widget.height + widget.height * 0.3, // 多留点高度给阴影
//               child: Stack(
//                 alignment: Alignment.topCenter,
//                 children: [
//                   // 阴影在底部，椭圆形，随浮动缩放和透明度变化
//                   Positioned(
//                     bottom: 0,
//                     child: Transform.scale(
//                       scale: shadowScale,
//                       child: Opacity(
//                         opacity: shadowOpacity,
//                         child: Container(
//                           width: widget.width * 0.6,
//                           height: widget.height * 0.08,
//                           decoration: BoxDecoration(
//                             color: Colors.black54,
//                             borderRadius:
//                                 BorderRadius.circular(widget.height * 0.075),
//                             boxShadow: [
//                               BoxShadow(
//                                 color: Colors.black26,
//                                 blurRadius: 8,
//                                 spreadRadius: 1,
//                               ),
//                             ],
//                           ),
//                         ),
//                       ),
//                     ),
//                   ),

//                   // SVG图标
//                   Positioned(
//                     top: 0,
//                     child: SizedBox(
//                       width: widget.width,
//                       height: widget.height,
//                       child: SvgPicture.asset(
//                         widget.assetPath,
//                         fit: BoxFit.fill,
//                       ),
//                     ),
//                   ),
//                 ],
//               ),
//             ),
//           ),
//         );
//       },
//     );
//   }
// }

import 'package:flutter/material.dart';
import 'package:flutter_svg/flutter_svg.dart';

class FloatingSvgIcon extends StatefulWidget {
  final String assetPath; // SVG 图标路径
  final double width; // 宽度
  final double height; // 高度
  final Duration duration; // 浮动周期
  final double floatOffset; // 浮动高度（单位：比例）
  final VoidCallback? onTap; // 点击事件

  const FloatingSvgIcon({
    super.key,
    required this.assetPath,
    this.width = 60,
    this.height = 60,
    this.duration = const Duration(milliseconds: 800),
    this.floatOffset = 0.02,
    this.onTap,
  });

  @override
  State<FloatingSvgIcon> createState() => _FloatingSvgIconState();
}

class _FloatingSvgIconState extends State<FloatingSvgIcon>
    with SingleTickerProviderStateMixin {
  late final AnimationController _controller;
  late final Animation<Offset> _animation;

  @override
  void initState() {
    super.initState();

    _controller = AnimationController(
      vsync: this,
      duration: widget.duration,
    )..repeat(reverse: true);

    _animation = Tween<Offset>(
      begin: Offset(0, -widget.floatOffset),
      end: Offset(0, widget.floatOffset),
    ).animate(CurvedAnimation(
      parent: _controller,
      curve: Curves.easeInOut,
    ));
  }

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

  // // 计算阴影缩放因子，范围大致从 0.8 ~ 1.2
  // double getShadowScale(double dy) {
  //   // dy 是当前偏移，负表示向上，正表示向下
  //   // 上浮时阴影变小，下落时阴影变大
  //   return (1 - dy * 5).clamp(0.8, 1.2);
  // }

  // // 计算阴影透明度，范围大致从 0.3 ~ 0.7
  // double getShadowOpacity(double dy) {
  //   return (0.5 - dy * 1.5).clamp(0.3, 0.7);
  // }
  double getShadowScale(double dy) {
    // dy负时（上浮）阴影变小，正时（下落）阴影变大
    return (1 + dy * 5).clamp(0.8, 1.2);
  }

  double getShadowOpacity(double dy) {
    return (0.5 + dy * 1.5).clamp(0.3, 0.7);
  }

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _controller,
      builder: (context, child) {
        final dy = _animation.value.dy;

        final shadowScale = getShadowScale(dy);
        final shadowOpacity = getShadowOpacity(dy);

        return SizedBox(
          width: widget.width,
          height: widget.height + widget.height * 0.3, // 留出阴影空间
          child: Stack(
            alignment: Alignment.topCenter,
            children: [
              // 固定底部投影，大小随动画变化
              Positioned(
                bottom: 4,
                child: Transform.scale(
                  scale: shadowScale,
                  child: Opacity(
                    opacity: shadowOpacity,
                    child: Container(
                      width: widget.width * 0.5,
                      height: widget.height * 0.12,
                      decoration: BoxDecoration(
                        color: Colors.black,
                        borderRadius:
                            BorderRadius.circular(widget.height * 0.1),
                        boxShadow: const [
                          BoxShadow(
                            color: Colors.black38,
                            blurRadius: 12,
                            spreadRadius: 0,
                            offset: Offset(0, 2),
                          ),
                        ],
                      ),
                    ),
                  ),
                ),
              ),

              // SVG图标上下浮动
              SlideTransition(
                position: _animation,
                child: GestureDetector(
                  onTap: widget.onTap,
                  child: SizedBox(
                    width: widget.width,
                    height: widget.height,
                    child: SvgPicture.asset(
                      widget.assetPath,
                      fit: BoxFit.fill,
                    ),
                  ),
                ),
              ),
            ],
          ),
        );
      },
    );
  }
}