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

ThemeData blackSlider(BuildContext context) {
  return Theme.of(context).copyWith(
      sliderTheme: SliderThemeData(
          rangeThumbShape:
              const RectRangeSliderThumbShape(enabledThumbRadius: 8),
          thumbShape: const RectSliderThumbShape(enabledThumbRadius: 8),
          thumbColor: Colors.grey[800],
          activeTrackColor: Colors.grey[700],
          inactiveTrackColor: Colors.grey[400],
          activeTickMarkColor: Colors.white,
          inactiveTickMarkColor: Colors.white));
}

class RectRangeSliderThumbShape extends RangeSliderThumbShape {
  const RectRangeSliderThumbShape({
    this.enabledThumbRadius = 10.0,
    this.disabledThumbRadius,
    this.elevation = 1.0,
    this.pressedElevation = 6.0,
  });

  final double enabledThumbRadius;

  final double? disabledThumbRadius;
  double get _disabledThumbRadius => disabledThumbRadius ?? enabledThumbRadius;

  final double elevation;

  final double pressedElevation;

  @override
  Size getPreferredSize(bool isEnabled, bool isDiscrete) {
    return Size.fromRadius(
        isEnabled == true ? enabledThumbRadius : _disabledThumbRadius);
  }

  @override
  void paint(
    PaintingContext context,
    Offset center, {
    required Animation<double> activationAnimation,
    required Animation<double> enableAnimation,
    bool isDiscrete = false,
    bool isEnabled = false,
    bool? isOnTop,
    required SliderThemeData sliderTheme,
    TextDirection? textDirection,
    Thumb? thumb,
    bool? isPressed,
  }) {
    assert(sliderTheme.showValueIndicator != null);
    assert(sliderTheme.overlappingShapeStrokeColor != null);

    final Canvas canvas = context.canvas;
    final Tween<double> radiusTween = Tween<double>(
      begin: _disabledThumbRadius,
      end: enabledThumbRadius,
    );
    final ColorTween colorTween = ColorTween(
      begin: sliderTheme.disabledThumbColor,
      end: sliderTheme.thumbColor,
    );
    final double radius = radiusTween.evaluate(enableAnimation);
    final Tween<double> elevationTween = Tween<double>(
      begin: elevation,
      end: pressedElevation,
    );

    if (isOnTop ?? false) {
      final Paint strokePaint = Paint()
        ..color = sliderTheme.overlappingShapeStrokeColor!
        ..strokeWidth = 1.0
        ..style = PaintingStyle.stroke;
      canvas.drawRect(
          Rect.fromCenter(
              center: center, width: 2 * radius, height: 2 * radius),
          strokePaint);
    }

    final Color color = colorTween.evaluate(enableAnimation)!;

    final double evaluatedElevation =
        isPressed! ? elevationTween.evaluate(activationAnimation) : elevation;
    final Path shadowPath = Path()
      ..addArc(
          Rect.fromCenter(
              center: center, width: 2 * radius, height: 2 * radius),
          0,
          pi * 2);
    canvas.drawShadow(shadowPath, Colors.black, evaluatedElevation, true);

    canvas.drawRect(
      Rect.fromCenter(center: center, width: 2 * radius, height: 2 * radius),
      Paint()..color = color,
    );
  }
}

class RectSliderThumbShape extends SliderComponentShape {
  const RectSliderThumbShape({
    this.enabledThumbRadius = 10.0,
    this.disabledThumbRadius,
    this.elevation = 1.0,
    this.pressedElevation = 6.0,
  });

  final double enabledThumbRadius;

  final double? disabledThumbRadius;
  double get _disabledThumbRadius => disabledThumbRadius ?? enabledThumbRadius;

  final double elevation;

  final double pressedElevation;

  @override
  Size getPreferredSize(bool isEnabled, bool isDiscrete) {
    return Size.fromRadius(
        isEnabled == true ? enabledThumbRadius : _disabledThumbRadius);
  }

  @override
  void paint(
    PaintingContext context,
    Offset center, {
    required Animation<double> activationAnimation,
    required Animation<double> enableAnimation,
    required bool isDiscrete,
    required TextPainter labelPainter,
    required RenderBox parentBox,
    required SliderThemeData sliderTheme,
    required TextDirection textDirection,
    required double value,
    required double textScaleFactor,
    required Size sizeWithOverflow,
  }) {
    assert(sliderTheme.disabledThumbColor != null);
    assert(sliderTheme.thumbColor != null);

    final Canvas canvas = context.canvas;
    final Tween<double> radiusTween = Tween<double>(
      begin: _disabledThumbRadius,
      end: enabledThumbRadius,
    );
    final ColorTween colorTween = ColorTween(
      begin: sliderTheme.disabledThumbColor,
      end: sliderTheme.thumbColor,
    );

    final Color color = colorTween.evaluate(enableAnimation)!;
    final double radius = radiusTween.evaluate(enableAnimation);

    final Tween<double> elevationTween = Tween<double>(
      begin: elevation,
      end: pressedElevation,
    );

    final double evaluatedElevation =
        elevationTween.evaluate(activationAnimation);
    final Path path = Path()
      ..addArc(
          Rect.fromCenter(
              center: center, width: 2 * radius, height: 2 * radius),
          0,
          pi * 2);
    canvas.drawShadow(path, Colors.black, evaluatedElevation, true);

    canvas.drawRect(
      Rect.fromCenter(center: center, width: 2 * radius, height: 2 * radius),
      Paint()..color = color,
    );
  }
}