using AcDream.App.UI;

namespace AcDream.App.Tests.UI;

public sealed class UiScrollablePanelTests
{
    [Fact]
    public void LayoutScrollableChildren_ClipsRowsOutsideViewport()
    {
        var panel = new UiScrollablePanel { Width = 100, Height = 40, LineHeight = 20 };
        for (int i = 0; i < 4; i++)
            panel.AddChild(new UiPanel { Top = i * 20, Width = 100, Height = 20 });

        panel.LayoutScrollableChildren();
        Assert.True(panel.Children[0].Visible);
        Assert.True(panel.Children[1].Visible);
        Assert.False(panel.Children[2].Visible);

        panel.Scroll.SetScrollY(20);
        panel.LayoutScrollableChildren();
        Assert.False(panel.Children[0].Visible);
        Assert.True(panel.Children[1].Visible);
        Assert.True(panel.Children[2].Visible);
    }

    [Fact]
    public void ScrollEvent_MovesByLineHeight()
    {
        var panel = new UiScrollablePanel { Width = 100, Height = 40, LineHeight = 20 };
        for (int i = 0; i < 4; i++)
            panel.AddChild(new UiPanel { Top = i * 20, Width = 100, Height = 20 });
        panel.LayoutScrollableChildren();

        var e = new UiEvent(0u, panel, UiEventType.Scroll, Data0: -1);
        Assert.True(panel.OnEvent(in e));

        Assert.Equal(20, panel.Scroll.ScrollY);
    }
}