import 'dart:math' as math;

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

/// ============================================================
/// 【SemicircleProgress】半圆正确率进度环
/// 1:1 对标 Vue components/lProgressCircle/lProgressCircle.vue
/// （report.vue 用法：width 308rpx / height 168rpx / strokeWidth 14 /
///   bgColor #D8DFEB / progressColor #1578FF，上半圆从左到右）
///
/// 尺寸说明（Vue canvas 逻辑像素 → Flutter dp）：
///   308rpx = 154.w，168rpx = 84.h，描边 14px = 7.w，
///   paddingTop 默认 8px = 4.h；
///   radius = min(宽/2 - 描边, 高 - 描边 - paddingTop)
/// ============================================================
class SemicircleProgress extends StatelessWidget {
  const SemicircleProgress({
    super.key,
    required this.percent,
    this.width = 154,
    this.height = 84,
    this.strokeWidth = 10,
    this.paddingTop = 4,
    this.trackColor = const Color(0xFFD8DFEB),
    this.progressColor = const Color(0xFF1578FF),
  });

  /// 0 ~ 100
  final num percent;
  final double width;
  final double height;
  final double strokeWidth;
  final double paddingTop;
  final Color trackColor;
  final Color progressColor;

  @override
  Widget build(BuildContext context) {
    final w = width.w;
    final h = height.h;
    final sw = strokeWidth.w;

    return SizedBox(
      width: w,
      height: h,
      child: CustomPaint(
        size: Size(w, h),
        painter: _SemicirclePainter(
          percent: percent.toDouble().clamp(0, 100),
          strokeWidth: sw,
          paddingTop: paddingTop.h,
          trackColor: trackColor,
          progressColor: progressColor,
        ),
        // 对标 Vue slot：progress-content top 43rpx，居中展示数值
        child: Padding(
          padding: EdgeInsets.only(top: 31.5.h),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              // 大数字 + %（font-50 粗体标题色 + font-24 副色 %，底 10rpx）
              Padding(
                padding: EdgeInsets.only(bottom: 5.h),
                child: RichText(
                  text: TextSpan(
                    children: [
                      TextSpan(
                        text: '${percent % 1 == 0 ? percent.toInt() : percent}',
                        style: TextStyle(
                          fontSize: 25.sp,
                          fontWeight: FontWeight.w600,
                          color: const Color(0xFF1D2B47),
                        ),
                      ),
                      TextSpan(
                        text: '%',
                        style: TextStyle(
                          fontSize: 12.sp,
                          color: const Color(0xFF495A7A),
                        ),
                      ),
                    ],
                  ),
                ),
              ),
              Text(
                '本次正确率',
                style: TextStyle(
                  fontSize: 12.sp,
                  color: const Color(0xFF687FAD),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

class _SemicirclePainter extends CustomPainter {
  const _SemicirclePainter({
    required this.percent,
    required this.strokeWidth,
    required this.paddingTop,
    required this.trackColor,
    required this.progressColor,
  });

  final double percent;
  final double strokeWidth;
  final double paddingTop;
  final Color trackColor;
  final Color progressColor;

  @override
  void paint(Canvas canvas, Size size) {
    final halfStroke = strokeWidth / 2;
    final maxRadiusByWidth = size.width / 2 - strokeWidth;
    final maxRadiusByHeight = size.height - strokeWidth - paddingTop;
    final radius = math.max(0.0, math.min(maxRadiusByWidth, maxRadiusByHeight));
    final centerX = size.width / 2;
    final centerY = size.height - halfStroke;

    final trackPaint = Paint()
      ..style = PaintingStyle.stroke
      ..strokeWidth = strokeWidth
      ..strokeCap = StrokeCap.round
      ..color = trackColor;

    // 背景半圆环：π（左）→ 0（右）
    canvas.drawArc(
      Rect.fromCircle(center: Offset(centerX, centerY), radius: radius),
      math.pi,
      math.pi,
      false,
      trackPaint,
    );

    // 进度弧
    if (percent > 0) {
      final progressPaint = Paint()
        ..style = PaintingStyle.stroke
        ..strokeWidth = strokeWidth
        ..strokeCap = StrokeCap.round
        ..color = progressColor;
      final sweep = math.pi * (percent / 100);
      canvas.drawArc(
        Rect.fromCircle(center: Offset(centerX, centerY), radius: radius),
        math.pi,
        sweep,
        false,
        progressPaint,
      );
    }
  }

  @override
  bool shouldRepaint(covariant _SemicirclePainter oldDelegate) {
    return oldDelegate.percent != percent ||
        oldDelegate.strokeWidth != strokeWidth ||
        oldDelegate.trackColor != trackColor ||
        oldDelegate.progressColor != progressColor;
  }
}