using AcDream.App.Rendering.Gpu.Vk;

namespace AcDream.App.Tests.Rendering.Gpu.Vk;

/// <summary>
/// Campaign V slice V9: the probe harness's bounded-run decision.
///
/// <para>The harness presents until its window closes, which is right at a desk
/// and impossible in CI — nothing there ever closes a window.
/// <c>ACDREAM_VULKAN_PROBE_FRAMES</c> gives it a frame budget instead. Every
/// other line of the harness needs a window and a driver; this decision does
/// not, so it is tested here rather than left to the lavapipe job to discover.
/// </para>
/// </summary>
public sealed class VulkanBringUpBudgetTests
{
    /// <summary>
    /// The interactive default. An unset or malformed budget is zero, and zero
    /// must never retire the loop, or the developer diagnostic this harness
    /// exists for would close itself the moment it opened.
    /// </summary>
    [Theory]
    [InlineData(0)]
    [InlineData(-1)]
    public void ANonPositiveBudgetNeverRetires(int budget)
    {
        Assert.False(
            VulkanBringUpHost.ShouldRetire(
                budget,
                presentedFrames: 10_000,
                capturesScreenshot: true,
                screenshotRequested: true));
    }

    [Fact]
    public void TheLoopRunsUntilTheBudgetIsReached()
    {
        Assert.False(
            VulkanBringUpHost.ShouldRetire(
                frameBudget: 30,
                presentedFrames: 29,
                capturesScreenshot: false,
                screenshotRequested: false));
        Assert.True(
            VulkanBringUpHost.ShouldRetire(
                frameBudget: 30,
                presentedFrames: 30,
                capturesScreenshot: false,
                screenshotRequested: false));
    }

    /// <summary>
    /// The invariant the CI render gate rests on: a run that owes a PNG cannot
    /// exit before the capture has been attempted. The harness captures at frame
    /// four, so a budget below that would otherwise exit with an empty artifact
    /// directory and a green step — the one outcome an unattended render gate
    /// must never produce.
    /// </summary>
    [Fact]
    public void ARunThatOwesAScreenshotStaysOpenUntilItHasBeenAttempted()
    {
        Assert.False(
            VulkanBringUpHost.ShouldRetire(
                frameBudget: 2,
                presentedFrames: 2,
                capturesScreenshot: true,
                screenshotRequested: false));
        Assert.True(
            VulkanBringUpHost.ShouldRetire(
                frameBudget: 2,
                presentedFrames: 4,
                capturesScreenshot: true,
                screenshotRequested: true));
    }

    /// <summary>
    /// With no artifact directory there is no PNG to wait for, so the budget is
    /// the only term.
    /// </summary>
    [Fact]
    public void ARunWithNoArtifactDirectoryRetiresOnTheBudgetAlone()
    {
        Assert.True(
            VulkanBringUpHost.ShouldRetire(
                frameBudget: 1,
                presentedFrames: 1,
                capturesScreenshot: false,
                screenshotRequested: false));
    }
}