import 'package:flutter/material.dart';

import '../theme/app_theme.dart';

/// The service's mark: a sky-blue-to-violet disc with three rising bars. The same drawing as
/// `web/favicon.svg` (a 512 × 512 design scaled to [size]), painted natively so the top bar
/// needs neither an asset nor an SVG package.
class ServiceMark extends StatelessWidget {
  const ServiceMark({this.size = 40, super.key});

  final double size;

  /// The far end of the gradient; the near end is the app accent, [AppTheme.seed].
  static const violet = Color(0xFF7A5CFF);

  @override
  Widget build(BuildContext context) {
    return SizedBox.square(
      dimension: size,
      child: CustomPaint(painter: _MarkPainter()),
    );
  }
}

class _MarkPainter extends CustomPainter {
  // (x, y, width, height) in the 512 design grid, tallest last
  static const _bars = [
    Rect.fromLTWH(132, 281, 64, 100),
    Rect.fromLTWH(224, 211, 64, 170),
    Rect.fromLTWH(316, 131, 64, 250),
  ];

  @override
  void paint(Canvas canvas, Size size) {
    final s = size.width / 512;
    final disc = Offset.zero & size;
    canvas.drawCircle(
      disc.center,
      size.width / 2,
      Paint()
        ..shader = const LinearGradient(
          begin: Alignment.topLeft,
          end: Alignment.bottomRight,
          colors: [AppTheme.seed, ServiceMark.violet],
        ).createShader(disc),
    );
    final white = Paint()..color = Colors.white;
    for (final bar in _bars) {
      canvas.drawRRect(
        RRect.fromRectAndRadius(
          Rect.fromLTWH(
            bar.left * s,
            bar.top * s,
            bar.width * s,
            bar.height * s,
          ),
          Radius.circular(14 * s),
        ),
        white,
      );
    }
  }

  @override
  bool shouldRepaint(_MarkPainter oldDelegate) => false;
}