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

class ScoreProgressChart extends StatelessWidget {
  // 历史成绩列表，按时间排序
  final List<Map<String, dynamic>> historyScores;
  final double height;
  final Color lineColor;
  final Color fillColor;

  const ScoreProgressChart({
    super.key,
    required this.historyScores,
    this.height = 60.0,
    this.lineColor = Colors.blue,
    this.fillColor = Colors.blueAccent,
  });

  @override
  Widget build(BuildContext context) {
    if (historyScores.isEmpty) {
      return SizedBox(height: height);
    }

    // 提取达成率数据 (achievement / 10000)
    // 假设 historyScores 已经按时间正序排列
    final List<double> achievements = historyScores.map((s) {
      int ach = s['achievement'] ?? 0;
      return ach / 10000.0;
    }).toList();

    // 找出最小值和最大值以确定 Y 轴范围，为了美观，稍微扩大一点范围
    double minVal = achievements.reduce(min);
    double maxVal = achievements.reduce(max);

    // 如果所有分数一样，给一个默认范围
    if (minVal == maxVal) {
      minVal = max(0, minVal - 1.0);
      maxVal = min(101.0, maxVal + 1.0);
    } else {
      // 增加一点上下边距
      double range = maxVal - minVal;
      minVal = max(0, minVal - range * 0.1);
      maxVal = min(101.0, maxVal + range * 0.1);
    }

    return SizedBox(
      height: height,
      child: CustomPaint(
        size: Size.infinite,
        painter: _ChartPainter(
          achievements: achievements,
          minVal: minVal,
          maxVal: maxVal,
          lineColor: lineColor,
          fillColor: fillColor.withOpacity(0.2),
        ),
      ),
    );
  }
}

class _ChartPainter extends CustomPainter {
  final List<double> achievements;
  final double minVal;
  final double maxVal;
  final Color lineColor;
  final Color fillColor;

  _ChartPainter({
    required this.achievements,
    required this.minVal,
    required this.maxVal,
    required this.lineColor,
    required this.fillColor,
  });

  @override
  void paint(Canvas canvas, Size size) {
    // ✅ 修复1：数据不足直接返回
    if (achievements.length < 1) return;

    final paint = Paint()
      ..color = lineColor
      ..strokeWidth = 2.0
      ..style = PaintingStyle.stroke
      ..strokeCap = StrokeCap.round;

    final fillPaint = Paint()
      ..color = fillColor
      ..style = PaintingStyle.fill;

    final path = Path();
    final fillPath = Path();

    double width = size.width;
    double height = size.height;
    double range = maxVal - minVal;
    if (range == 0) range = 1; // 防止除以0

    // 计算每个点的坐标
    List<Offset> points = [];
    for (int i = 0; i < achievements.length; i++) {
      double x;
      if (achievements.length == 1) {
        x = width / 2; // ✅ 修复2：只有1个点时，放中间
      } else {
        x = (i / (achievements.length - 1)) * width;
      }

      // Y轴翻转，因为Canvas原点在左上角
      double normalizedY = (achievements[i] - minVal) / range;
      double y = height - (normalizedY * height);

      // ✅ 修复3：防止 NaN / 无限大
      if (x.isNaN || x.isInfinite) x = 0;
      if (y.isNaN || y.isInfinite) y = height / 2;

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

    // 构建折线路径
    path.moveTo(points.first.dx, points.first.dy);
    fillPath.moveTo(points.first.dx, height); // 填充从底部开始
    fillPath.lineTo(points.first.dx, points.first.dy);

    for (int i = 1; i < points.length; i++) {
      path.lineTo(points[i].dx, points[i].dy);
      fillPath.lineTo(points[i].dx, points[i].dy);
    }

    // 闭合填充路径
    fillPath.lineTo(points.last.dx, height);
    fillPath.close();

    // 绘制填充
    canvas.drawPath(fillPath, fillPaint);
    // 绘制折线
    canvas.drawPath(path, paint);

    // 可选：绘制最后一个点的高亮圆点
    final dotPaint = Paint()..color = lineColor;
    final lastPoint = points.last;
    // ✅ 修复4：绘制前校验，彻底杜绝NaN崩溃
    if (!lastPoint.dx.isNaN && !lastPoint.dy.isNaN) {
      canvas.drawCircle(lastPoint, 3.0, dotPaint);
    }
  }

  @override
  bool shouldRepaint(covariant _ChartPainter oldDelegate) {
    return oldDelegate.achievements != achievements ||
        oldDelegate.minVal != minVal ||
        oldDelegate.maxVal != maxVal;
  }
}