using AcDream.App.UI;

namespace AcDream.App.Tests.UI;

public class UiChatViewTests
{
    [Fact]
    public void ClampScroll_PinsToZero_WhenContentFitsView()
    {
        // 5 lines of content in a taller view → nothing to scroll, pinned at 0.
        Assert.Equal(0f, UiChatView.ClampScroll(50f, contentHeight: 80f, viewHeight: 200f));
        Assert.Equal(0f, UiChatView.ClampScroll(0f, contentHeight: 80f, viewHeight: 200f));
    }

    [Fact]
    public void ClampScroll_CapsAtContentMinusView_WhenOverflowing()
    {
        // Content 500, view 200 → max scrollback is 300px (oldest line at top).
        Assert.Equal(300f, UiChatView.ClampScroll(1000f, contentHeight: 500f, viewHeight: 200f));
        Assert.Equal(120f, UiChatView.ClampScroll(120f, contentHeight: 500f, viewHeight: 200f));
    }

    [Fact]
    public void ClampScroll_NeverNegative()
    {
        Assert.Equal(0f, UiChatView.ClampScroll(-50f, contentHeight: 500f, viewHeight: 200f));
    }
}