using ClaudeDo.Ui.Views.Islands;
using Xunit;

namespace ClaudeDo.Ui.Tests;

public class ListsAutoScrollTests
{
    [Fact]
    public void Middle_of_viewport_does_not_scroll() =>
        Assert.Equal(0, ListsAutoScroll.Delta(300, 600));

    [Fact]
    public void Top_band_scrolls_up_and_speeds_up_towards_the_edge()
    {
        var near = ListsAutoScroll.Delta(30, 600);
        var edge = ListsAutoScroll.Delta(0, 600);
        Assert.True(near < 0);
        Assert.True(edge < near);
    }

    [Fact]
    public void Bottom_band_scrolls_down_and_speeds_up_towards_the_edge()
    {
        var near = ListsAutoScroll.Delta(570, 600);
        var edge = ListsAutoScroll.Delta(600, 600);
        Assert.True(near > 0);
        Assert.True(edge > near);
    }

    [Fact]
    public void Pointer_outside_the_viewport_is_clamped_to_max_step() =>
        Assert.Equal(ListsAutoScroll.Delta(0, 600), ListsAutoScroll.Delta(-50, 600));

    [Fact]
    public void Tiny_or_empty_viewport_is_safe()
    {
        Assert.Equal(0, ListsAutoScroll.Delta(0, 0));
        Assert.True(ListsAutoScroll.Delta(5, 20) < 0);
    }
}