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

class RadarChart extends StatelessWidget {
  final List<List<double>> data; // 存储多个数据集
  final List<String> labels; // 每个角的标签
  final double maxValue; // 数据的最大值，用来统一尺度

  const RadarChart({
    Key? key,
    required this.data,
    required this.labels,
    this.maxValue = 100,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return CustomPaint(
      size: Size(300, 300), // 图表的大小
      painter: RadarChartPainter(
        data: data,
        labels: labels,
        maxValue: maxValue,
      ),
    );
  }
}

class RadarChartPainter extends CustomPainter {
  final List<List<double>> data;
  final List<String> labels;
  final double maxValue;

  RadarChartPainter({
    required this.data,
    required this.labels,
    required this.maxValue,
  });

  @override
  void paint(Canvas canvas, Size size) {
    Paint paintLine = Paint()
      ..color = Colors.blue
      ..style = PaintingStyle.stroke
      ..strokeWidth = 2;

    Paint axisPaint = Paint()
      ..color = Colors.grey.withOpacity(0.5)
      ..strokeWidth = 1;

    double centerX = size.width / 2;
    double centerY = size.height / 2;
    double radius = size.width / 2;

    int numOfPoints = labels.length;

    // 绘制雷达图的轴线
    for (int i = 0; i < numOfPoints; i++) {
      double angle = (2 * pi / numOfPoints) * i;
      double x = centerX + radius * cos(angle);
      double y = centerY + radius * sin(angle);

      // 画轴线
      canvas.drawLine(Offset(centerX, centerY), Offset(x, y), axisPaint);

      // 绘制标签
      TextPainter tp = TextPainter(
        text: TextSpan(
          text: labels[i],
          style: TextStyle(color: Colors.black, fontSize: 12),
        ),
        textDirection: ui.TextDirection.ltr,
      );
      tp.layout();
      tp.paint(canvas, Offset(x + 8, y - 8)); // 设置标签位置
    }

    // 绘制多个数据集
    for (int i = 0; i < data.length; i++) {
      Paint fillPaint = Paint()
        ..color = Colors.primaries[i % Colors.primaries.length].withOpacity(0.3)
        ..style = PaintingStyle.fill;

      Paint linePaint = Paint()
        ..color = Colors.primaries[i % Colors.primaries.length]
        ..style = PaintingStyle.stroke
        ..strokeWidth = 2;

      List<Offset> points = [];
      for (int j = 0; j < numOfPoints; j++) {
        double angle = (2 * pi / numOfPoints) * j;
        double pointRadius = (data[i][j] / maxValue) * radius;
        double x = centerX + pointRadius * cos(angle);
        double y = centerY + pointRadius * sin(angle);

        points.add(Offset(x, y));
      }

      // 画出数据连接线
      Path path = Path()..addPolygon(points, true);
      canvas.drawPath(path, linePaint);
      canvas.drawPath(path, fillPaint);
    }
  }

  @override
  bool shouldRepaint(covariant CustomPainter oldDelegate) => true;
}