import "package:flutter_test/flutter_test.dart";
import "package:garage_ui/theme/theme_data.dart";

// The gap scale is derived from controlGap, and the claim that makes that the
// right base is that two tokens which were authored by hand long before the
// scale existed land exactly on steps of it. If someone retunes controlGap,
// containerGap or containerPadding and that stops being true, the base unit
// has drifted and the scale is lying about where it comes from.
void main() {
  for (final density in const [Density(), Density.normal()]) {
    final name = density.control.name;

    test("$name: gapMd is containerGap, gapXl is containerPadding", () {
      expect(density.gapMd, density.containerGap);
      expect(density.gapXl, density.containerPadding);
    });

    test("$name: the scale climbs and stays on whole pixels", () {
      final steps = [
        density.gapXxs,
        density.gapXs,
        density.gapSm,
        density.gapMd,
        density.gapLg,
        density.gapXl,
        density.gapXxl,
      ];
      for (var i = 1; i < steps.length; i++) {
        expect(steps[i], greaterThan(steps[i - 1]),
            reason: "step $i should be bigger than the one before it");
      }
      for (final s in steps) {
        expect(s, s.roundToDouble(), reason: "$s is not a whole pixel");
      }
    });
  }

  test("compact lands on the sizes the style guide observed in real use", () {
    const d = Density();
    expect([d.gapXxs, d.gapXs, d.gapSm, d.gapMd, d.gapLg, d.gapXl, d.gapXxl],
        [2.0, 4.0, 6.0, 8.0, 12.0, 16.0, 24.0]);
  });
}