import 'package:flutter/material.dart';

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:one_key/res/colors.dart';

class CustomTabIndicator extends Decoration {
  /// Create an underline style selected tab indicator.
  ///
  /// The [borderSide] and [insets] arguments must not be null.
  const CustomTabIndicator(
      {this.borderSide = const BorderSide(width: 2.0, color: Colors.white),
      this.insets = EdgeInsets.zero,
      this.width,
      this.radius,
      this.color})
      : assert(borderSide != null),
        assert(insets != null);

  /// The color and weight of the horizontal line drawn below the selected tab.
  final BorderSide borderSide;

  final double radius;

  final double width;

  final Color color;

  /// Locates the selected tab's underline relative to the tab's boundary.
  ///
  /// The [TabBar.indicatorSize] property can be used to define the
  /// tab indicator's bounds in terms of its (centered) tab widget with
  /// [TabIndicatorSize.label], or the entire tab with [TabIndicatorSize.tab].
  final EdgeInsetsGeometry insets;

  @override
  Decoration lerpFrom(Decoration a, double t) {
    if (a is CustomTabIndicator) {
      return CustomTabIndicator(
        borderSide: BorderSide.lerp(a.borderSide, borderSide, t),
        insets: EdgeInsetsGeometry.lerp(a.insets, insets, t),
      );
    }
    return super.lerpFrom(a, t);
  }

  @override
  Decoration lerpTo(Decoration b, double t) {
    if (b is CustomTabIndicator) {
      return CustomTabIndicator(
        borderSide: BorderSide.lerp(borderSide, b.borderSide, t),
        insets: EdgeInsetsGeometry.lerp(insets, b.insets, t),
      );
    }
    return super.lerpTo(b, t);
  }

  @override
  _UnderlinePainter createBoxPainter([VoidCallback onChanged]) {
    return _UnderlinePainter(this, onChanged);
  }
}

class _UnderlinePainter extends BoxPainter {
  _UnderlinePainter(this.decoration, VoidCallback onChanged)
      : assert(decoration != null),
        super(onChanged);

  final CustomTabIndicator decoration;

  BorderSide get borderSide => decoration.borderSide;
  EdgeInsetsGeometry get insets => decoration.insets;

  // Rect _indicatorRectFor(Rect rect, TextDirection textDirection) {
  //   assert(rect != null);
  //   assert(textDirection != null);
  //   final Rect indicator = insets.resolve(textDirection).deflateRect(rect);

  //   //取中间坐标
  //   double cw = (indicator.left + indicator.right) / 2;
  //   return Rect.fromLTWH(
  //       cw - decoration.width / 2,
  //       indicator.bottom - borderSide.width,
  //       decoration.width,
  //       borderSide.width);
  // }
  Rect _indicatorRectFor(Rect rect, TextDirection textDirection) {
    assert(rect != null);
    assert(textDirection != null);
    final Rect indicator = insets.resolve(textDirection).deflateRect(rect);
    return Rect.fromLTWH(
      indicator.left,
      indicator.bottom - borderSide.width,
      indicator.width,
      borderSide.width,
    );
  }

  // @override
  // void paint(Canvas canvas, Offset offset, ImageConfiguration configuration) {
  //   assert(configuration != null);
  //   assert(configuration.size != null);
  //   final Rect rect = offset & configuration.size;
  //   final TextDirection textDirection = configuration.textDirection;
  //   final Rect indicator =
  //       _indicatorRectFor(rect, textDirection).deflate(borderSide.width / 2.0);
  //   final RRect rrect =
  //       RRect.fromRectAndRadius(indicator, Radius.circular(40.0));
  //   Gradient gradient = LinearGradient(colors: [
  //     MyColours.color_3BBFF5,
  //     MyColours.color_57a0ff,
  //   ]);
  //   final Paint paint = borderSide.toPaint()..strokeCap = StrokeCap.square;
  //   canvas.drawLine(Offset(rrect.left, rrect.bottom),
  //       Offset(rrect.right, rrect.bottom), paint);
  // canvas.drawRRect(
  //     rrect,
  //     Paint()
  //       ..style = PaintingStyle.fill
  //       ..shader = gradient.createShader(rect));

  // // Gradient gradient =
  // //     LinearGradient(colors: [Colors.red[200], Colors.red[800]]);
  //     Gradient gradient = LinearGradient(colors: [
  //   MyColours.color_3BBFF5,
  //   MyColours.color_57a0ff,
  // ]);
  // canvas.drawLine(rect.left, p2, paint)
  // canvas.drawRRect(
  //     rrect,
  //     Paint()
  //       ..style = PaintingStyle.fill
  //       ..shader = gradient.createShader(rect));
  // }
  //  void paint(Canvas canvas, Offset offset, ImageConfiguration configuration) {
  //   assert(configuration != null);
  //   assert(configuration.size != null);
  //   final Rect rect = offset & configuration.size;
  //   final TextDirection textDirection = configuration.textDirection;
  //    Gradient gradient = LinearGradient(colors: [
  //     MyColours.color_3BBFF5,
  //     MyColours.color_57a0ff,
  //   ]);
  //   final Rect indicator = _indicatorRectFor(rect, textDirection).deflate(borderSide.width / 2.0);
  //   final Paint paint = borderSide.toPaint()..strokeCap = StrokeCap.square ..shader = gradient.createShader(rect);
  //   canvas.drawLine(indicator.bottomLeft, indicator.bottomRight, paint);
  // }

  @override
  void paint(Canvas canvas, Offset offset, ImageConfiguration configuration) {
    assert(configuration != null);
    assert(configuration.size != null);
    final Rect rect = offset & configuration.size;
    final RRect rRect = RRect.fromRectAndRadius(
        Rect.fromLTWH(
            rect.left + (rect.width - ScreenUtil().setWidth(48 * 2)) / 2,
            rect.top + rect.height - ScreenUtil().setWidth(20),
            ScreenUtil().setWidth(48 * 2),
            ScreenUtil().setWidth(6)),
        Radius.circular(decoration.radius));
    Gradient gradient = LinearGradient(
      begin: Alignment.topLeft,
      end: Alignment.bottomRight,
      colors: [
        MyColours.color_199095,
        MyColours.color_199095,
      ],
    );
    canvas.drawRRect(
        rRect,
        Paint()
          ..style = PaintingStyle.fill
          ..shader = gradient.createShader(rect));
  }
}