// Tests for tipVelocityWidthScale (physical tip model).

import 'package:flutter_test/flutter_test.dart';

import 'package:badnote/editor/engine/brush.dart';
import 'package:badnote/editor/engine/pen_physics.dart';

void main() {
  group('tipVelocityWidthScale', () {
    test('idle speed leaves all brushes at 1.0', () {
      for (final k in BrushKind.values) {
        expect(tipVelocityWidthScale(k, 0.0), closeTo(1.0, 1e-9));
      }
    });

    test('fountain thins more than ballpoint at the same speed', () {
      const speed = 2.0; // reference fast handwriting
      final fountain = tipVelocityWidthScale(BrushKind.fountainPen, speed);
      final ballpoint = tipVelocityWidthScale(BrushKind.ballpoint, speed);
      expect(fountain, closeTo(0.85, 1e-9));
      expect(ballpoint, closeTo(0.98, 1e-9));
      expect(fountain, lessThan(ballpoint));
    });

    test('highlighter ignores velocity', () {
      expect(tipVelocityWidthScale(BrushKind.highlighter, 5.0), 1.0);
    });

    test('NaN / negative speed treated as idle', () {
      expect(tipVelocityWidthScale(BrushKind.fountainPen, double.nan), 1.0);
      expect(tipVelocityWidthScale(BrushKind.fountainPen, -1.0), 1.0);
    });
  });
}