deepdrft/DeepDrftTests/WaveformResolutionTests.cs

using DeepDrftContent.Processors;

namespace DeepDrftTests;

/// <summary>
/// Behavioral tests for the duration-derived high-res bucket-count derivation. The contract: capture at
/// a constant time resolution (≈333 samples/sec) so a 333 ms max-zoom window holds enough samples on any
/// track length, clamped to a sane floor (short/degenerate tracks) and an upper cap (extreme outliers).
/// Applies to every track (Mix, Session, Cut) under the per-track model — phase-12 §5.
/// </summary>
[TestFixture]
public class WaveformResolutionTests
{
    [Test]
    public void BucketCountForDuration_TypicalTrack_CapturesAtTargetDensity()
    {
        // 3 minutes × 333/s = 59,940 — a typical short track, comfortably inside [floor, cap].
        var buckets = WaveformResolution.BucketCountForDuration(180.0);

        Assert.That(buckets, Is.EqualTo((int)Math.Ceiling(180.0 * WaveformResolution.SamplesPerSecond)));
        Assert.That(buckets, Is.EqualTo(59_940));
    }

    [Test]
    public void BucketCountForDuration_SixtyMinuteTrack_ProducesAboutOnePointTwoMillion()
    {
        // 60 min × 333/s = 1,198,800 ≈ 1.2M samples (≈1.2 MB datum), still under the cap.
        var buckets = WaveformResolution.BucketCountForDuration(3600.0);

        Assert.That(buckets, Is.EqualTo(1_198_800));
        Assert.That(buckets, Is.LessThan(WaveformResolution.MaxBucketCount));
    }

    [Test]
    public void BucketCountForDuration_OverHundredMinutes_ClampsToCap()
    {
        // 120 min × 333/s = 2,397,600 > cap → clamps to the cap.
        var buckets = WaveformResolution.BucketCountForDuration(7200.0);

        Assert.That(buckets, Is.EqualTo(WaveformResolution.MaxBucketCount));
    }

    [Test]
    public void BucketCountForDuration_NearZeroDuration_HitsFloor()
    {
        // 0.1 s × 333/s = 34 buckets, far below the floor → clamps up to the floor.
        var buckets = WaveformResolution.BucketCountForDuration(0.1);

        Assert.That(buckets, Is.EqualTo(WaveformResolution.MinBucketCount));
    }

    [Test]
    public void BucketCountForDuration_ZeroDuration_HitsFloor()
    {
        Assert.That(WaveformResolution.BucketCountForDuration(0.0), Is.EqualTo(WaveformResolution.MinBucketCount));
    }

    [Test]
    public void BucketCountForDuration_NegativeOrNaN_HitsFloor()
    {
        Assert.Multiple(() =>
        {
            Assert.That(WaveformResolution.BucketCountForDuration(-5.0), Is.EqualTo(WaveformResolution.MinBucketCount));
            Assert.That(WaveformResolution.BucketCountForDuration(double.NaN), Is.EqualTo(WaveformResolution.MinBucketCount));
        });
    }

    [Test]
    public void BucketCountForDuration_DurationAtFloorBoundary_ReturnsFloorThenGrows()
    {
        // floor / 333 = 6.15 s is the duration where the derived count meets the floor exactly.
        const double floorBoundarySeconds = (double)WaveformResolution.MinBucketCount / WaveformResolution.SamplesPerSecond;

        // Just below the boundary clamps to the floor; just above derives above the floor.
        Assert.Multiple(() =>
        {
            Assert.That(WaveformResolution.BucketCountForDuration(floorBoundarySeconds - 0.1), Is.EqualTo(WaveformResolution.MinBucketCount));
            Assert.That(WaveformResolution.BucketCountForDuration(floorBoundarySeconds + 1.0), Is.GreaterThan(WaveformResolution.MinBucketCount));
        });
    }

    [Test]
    public void BucketCountForDuration_DurationAtCapBoundary_ReturnsCap()
    {
        // cap / 333 = 6006.006 s is the duration where the derived count meets the cap exactly.
        const double capBoundarySeconds = (double)WaveformResolution.MaxBucketCount / WaveformResolution.SamplesPerSecond;

        Assert.Multiple(() =>
        {
            Assert.That(WaveformResolution.BucketCountForDuration(capBoundarySeconds + 1.0), Is.EqualTo(WaveformResolution.MaxBucketCount));
            Assert.That(WaveformResolution.BucketCountForDuration(capBoundarySeconds - 10.0), Is.LessThan(WaveformResolution.MaxBucketCount));
        });
    }
}