import 'dart:math' as math;

import 'package:flutter/material.dart';

import '../../../core/theme/tokens.dart';
import '../planet_data.dart';

/// TOTAL FPI 오각 그래프 — Figma 명세 「TOTAL FPI 영역」 · 시안 `Frame 1984081147`(232×140).
///
/// *데이터 : TOTAL FPI 값 · 육각형 그래프 · 규칙 : 실시간 데이터 기준 노출*
///
/// 시안 — 다각형 114×108(외곽 #2c2c2e 2 + 안쪽 3단 1), 데이터 면 #5bd4de 20% · 선 1,
/// 꼭짓점 6 #64eff9. 축 이름 42dot Sans 10/500 #dde3e4 는 위 · 좌우 · 아래 두 칸에 놓는다.
/// 지표가 다섯이 아니면 축 이름을 꼭짓점 바깥에 방사형으로 놓는다.
class FpiHexagon extends StatelessWidget {
  const FpiHexagon({super.key, required this.scores, required this.max});

  final List<FpiScore> scores;
  final int max;

  static const size = Size(232, 140);

  @override
  Widget build(BuildContext context) => SizedBox.fromSize(
    size: size,
    child: CustomPaint(
      painter: _HexPainter(
        scores: scores,
        max: max,
        labelStyle: const TextStyle(
          fontFamily: AppFonts.body,
          fontSize: 10,
          fontWeight: FontWeight.w500,
          height: 1,
          color: Color(0xFFDDE3E4),
        ),
      ),
    ),
  );
}

class _HexPainter extends CustomPainter {
  _HexPainter({
    required this.scores,
    required this.max,
    required this.labelStyle,
  });

  final List<FpiScore> scores;
  final int max;
  final TextStyle labelStyle;

  /// 격자 단 비율 — 시안 Polygon 3·4·5(93.9 · 63.9 · 32 / 114).
  static const rings = [1.0, 0.82, 0.56, 0.28];

  @override
  void paint(Canvas canvas, Size size) {
    if (scores.isEmpty) return;
    final n = scores.length;
    // 외접원 반지름 — 오각형 높이 108 = R(1 + cos 36°).
    final radius = 108 / (1 + math.cos(math.pi / 5)) * size.height / 140;
    final center = Offset(size.width / 2, size.height * 16 / 140 + radius);

    Offset at(int i, double r) {
      // 12시 방향에서 시작해 시계 방향.
      final a = -math.pi / 2 + (2 * math.pi * i) / n;
      return center + Offset(math.cos(a) * r, math.sin(a) * r);
    }

    Path poly(double r) {
      final p = Path();
      for (var i = 0; i < n; i++) {
        final o = at(i, r);
        i == 0 ? p.moveTo(o.dx, o.dy) : p.lineTo(o.dx, o.dy);
      }
      return p..close();
    }

    for (final (i, k) in rings.indexed) {
      canvas.drawPath(
        poly(radius * k),
        Paint()
          ..style = PaintingStyle.stroke
          ..strokeWidth = i == 0 ? 2 : 1
          ..color = AppColors.cosmicOutline,
      );
    }

    // 데이터 다각형.
    final data = Path();
    for (var i = 0; i < n; i++) {
      final o = at(i, radius * scores[i].normalized(max));
      i == 0 ? data.moveTo(o.dx, o.dy) : data.lineTo(o.dx, o.dy);
    }
    data.close();
    const line = Color(0xFF5BD4DE);
    canvas
      ..drawPath(data, Paint()..color = line.withValues(alpha: 0.2))
      ..drawPath(
        data,
        Paint()
          ..style = PaintingStyle.stroke
          ..strokeWidth = 1
          ..color = line,
      );

    // 시안 좌표(232×140 기준) — 위 · 오른쪽 · 오른쪽 아래 · 왼쪽 아래 · 왼쪽.
    const anchors = [
      Offset(116, 5),
      Offset(201, 70),
      Offset(179.5, 135),
      Offset(59, 135),
      Offset(25, 70),
    ];
    final sx = size.width / 232, sy = size.height / 140;
    for (var i = 0; i < n; i++) {
      canvas.drawCircle(
        at(i, radius * scores[i].normalized(max)),
        3,
        Paint()..color = AppColors.neonCyan,
      );
      final tp = TextPainter(
        text: TextSpan(text: scores[i].metric.label, style: labelStyle),
        textDirection: TextDirection.ltr,
      )..layout();
      final o = n == 5
          ? Offset(anchors[i].dx * sx, anchors[i].dy * sy)
          : at(i, radius + 14);
      tp.paint(canvas, o - Offset(tp.width / 2, tp.height / 2));
    }
  }

  @override
  bool shouldRepaint(_HexPainter old) => old.scores != scores || old.max != max;
}

/// 그리기 비용 측정용 진입점. 사유는 [galaxyFieldPainterForTest] 와 같다.
@visibleForTesting
CustomPainter fpiHexagonPainterForTest({
  required List<FpiScore> scores,
  required int max,
  TextStyle labelStyle = const TextStyle(fontSize: 10),
}) => _HexPainter(scores: scores, max: max, labelStyle: labelStyle);