import 'dart:ui';

import 'package:flutter/material.dart';

import '../utils/Colors.dart';

/// A clock face drawn as a string of dots traced along each digit's outline —
/// the runner's signature readout. Only digits and ':' are drawn.
class DotDigits extends StatelessWidget {
  final String value;

  /// Glyph height in logical pixels.
  final double height;

  final Color? color;

  const DotDigits({
    super.key,
    required this.value,
    this.height = 64,
    this.color,
  });

  @override
  Widget build(BuildContext context) {
    final _DotDigitsPainter painter =
        _DotDigitsPainter(value, height, color ?? colorInk);

    return CustomPaint(size: painter.measure(), painter: painter);
  }
}

class _DotDigitsPainter extends CustomPainter {
  final String value;

  final double height;

  final Color color;

  _DotDigitsPainter(this.value, this.height, this.color);

  /// Glyphs live in a 1 × 1.6 box.
  double get _scale => height / 1.6;

  double get _digitWidth => _scale * 1.0;

  double get _colonWidth => _scale * 0.5;

  double get _tracking => _scale * 0.34;

  Size measure() {
    double width = 0;
    for (int i = 0; i < value.length; i++) {
      width = width + (value[i] == ':' ? _colonWidth : _digitWidth);
      if (i != value.length - 1) {
        width = width + _tracking;
      }
    }
    return Size(width + height * 0.08, height + height * 0.08);
  }

  @override
  void paint(Canvas canvas, Size size) {
    final double dot = height * 0.036;
    final double gap = height * 0.082;
    final Paint paint = Paint()..color = color;

    canvas.translate(height * 0.04, height * 0.04);

    double x = 0;
    for (int i = 0; i < value.length; i++) {
      final String glyph = value[i];

      if (glyph == ':') {
        canvas.drawCircle(
            Offset(x + _colonWidth / 2, _scale * 0.52), dot * 1.25, paint);
        canvas.drawCircle(
            Offset(x + _colonWidth / 2, _scale * 1.12), dot * 1.25, paint);
        x = x + _colonWidth + _tracking;
        continue;
      }

      final Path? outline = _glyph(glyph);
      if (outline != null) {
        final Path placed = outline.transform(
            (Matrix4.identity()
                  ..translateByDouble(x, 0, 0, 1)
                  ..scaleByDouble(_scale, _scale, 1, 1))
                .storage);

        for (PathMetric metric in placed.computeMetrics()) {
          final int count = (metric.length / gap).floor().clamp(1, 400);
          final double step = metric.length / count;
          final int last = metric.isClosed ? count - 1 : count;
          for (int n = 0; n <= last; n++) {
            final Tangent? tangent = metric.getTangentForOffset(n * step);
            if (tangent != null) {
              canvas.drawCircle(tangent.position, dot, paint);
            }
          }
        }
      }

      x = x + _digitWidth + _tracking;
    }
  }

  Path? _glyph(String glyph) {
    switch (glyph) {
      case '0':
        return Path()
          ..addRRect(RRect.fromRectAndRadius(
              const Rect.fromLTWH(0, 0, 1, 1.6), const Radius.circular(0.5)));
      case '1':
        return Path()
          ..moveTo(0.22, 0.32)
          ..lineTo(0.6, 0)
          ..lineTo(0.6, 1.6);
      case '2':
        return Path()
          ..moveTo(0.03, 0.4)
          ..cubicTo(0.06, 0.02, 0.97, 0.0, 0.97, 0.44)
          ..cubicTo(0.97, 0.8, 0.05, 1.08, 0.0, 1.6)
          ..lineTo(1.0, 1.6);
      case '3':
        return Path()
          ..moveTo(0.04, 0.26)
          ..cubicTo(0.2, -0.06, 0.95, 0.0, 0.95, 0.4)
          ..cubicTo(0.95, 0.68, 0.66, 0.78, 0.4, 0.78)
          ..cubicTo(0.76, 0.78, 1.0, 0.92, 1.0, 1.2)
          ..cubicTo(1.0, 1.66, 0.18, 1.7, 0.0, 1.34);
      case '4':
        return Path()
          ..moveTo(0.76, 1.6)
          ..lineTo(0.76, 0.0)
          ..lineTo(0.0, 1.12)
          ..lineTo(1.0, 1.12);
      case '5':
        return Path()
          ..moveTo(0.92, 0.0)
          ..lineTo(0.14, 0.0)
          ..lineTo(0.06, 0.72)
          ..cubicTo(0.36, 0.54, 1.0, 0.6, 1.0, 1.08)
          ..cubicTo(1.0, 1.66, 0.2, 1.7, 0.0, 1.36);
      case '6':
        return Path()
          ..moveTo(0.86, 0.14)
          ..cubicTo(0.44, -0.12, 0.0, 0.24, 0.0, 1.1)
          ..addOval(const Rect.fromLTWH(0.0, 0.66, 1.0, 0.94));
      case '7':
        return Path()
          ..moveTo(0.0, 0.0)
          ..lineTo(1.0, 0.0)
          ..lineTo(0.34, 1.6);
      case '8':
        return Path()
          ..addOval(const Rect.fromLTWH(0.08, 0.0, 0.84, 0.74))
          ..addOval(const Rect.fromLTWH(0.0, 0.74, 1.0, 0.86));
      case '9':
        return Path()
          ..addOval(const Rect.fromLTWH(0.0, 0.0, 1.0, 0.94))
          ..moveTo(1.0, 0.5)
          ..cubicTo(1.0, 1.36, 0.56, 1.72, 0.14, 1.46);
      default:
        return null;
    }
  }

  @override
  bool shouldRepaint(covariant _DotDigitsPainter oldDelegate) {
    return oldDelegate.value != value ||
        oldDelegate.height != height ||
        oldDelegate.color != color;
  }
}