ABStemPlayer/AudioCore_Tests/StemWaveformService_RealDecoder_Tests.cs

using AudioCore.Models;
using AudioCore.Impl;

namespace AudioCore_Tests;

[TestClass]
public sealed class StemWaveformService_RealDecoder_Tests
{
    private string GetTestInputPath()
    {
        var baseDir = AppDomain.CurrentDomain.BaseDirectory;
        return Path.Combine(baseDir, "Data", "test_input.mp3");
    }

    private StemTrack CreateStem(string path)
    {
        return new StemTrack
        {
            FilePath = path,
            SampleRate = 44100,
            Channels = 2,
            Duration = TimeSpan.FromSeconds(10),
            Name = "TestStem",
            Type = StemType.Other
        };
    }

    [TestMethod]
    public void TestInputFileExists()
    {
        var path = GetTestInputPath();
        Assert.IsTrue(File.Exists(path));
    }

    [TestMethod]
    public async Task ComputeWaveform_RealDecoder_ReturnsCorrectLength()
    {
        var path = GetTestInputPath();
        var pool = new AudioBufferPool();

        var reader = new FfmpegAudioReader(path);
        var stem = CreateStem(path);

        using var decoder = new StemDecoder(reader, pool, stem, blockSize: 4096);

        var service = new StemWaveformService(pool);

        int segments = 20;
        var result = await service.ComputeWaveformAsync(stem, decoder, segments);

        Assert.HasCount(segments, result);
    }

    [TestMethod]
    public async Task ComputeWaveform_RealDecoder_ProducesNonZeroValues()
    {
        var path = GetTestInputPath();
        var pool = new AudioBufferPool();

        var reader = new FfmpegAudioReader(path);
        var stem = CreateStem(path);

        using var decoder = new StemDecoder(reader, pool, stem, blockSize: 4096);

        var service = new StemWaveformService(pool);

        var result = await service.ComputeWaveformAsync(stem, decoder, 10);

        bool anyNonZero = false;
        foreach (var v in result)
        {
            if (v > 0f)
            {
                anyNonZero = true;
                break;
            }
        }

        Assert.IsTrue(anyNonZero);
    }

    [TestMethod]
    public async Task ComputeWaveform_RealDecoder_CallsSeekAndReset()
    {
        var path = GetTestInputPath();
        var pool = new AudioBufferPool();

        var reader = new FfmpegAudioReader(path);
        var stem = CreateStem(path);

        using var decoder = new StemDecoder(reader, pool, stem, blockSize: 4096);

        var service = new StemWaveformService(pool);

        var result = await service.ComputeWaveformAsync(stem, decoder, 5);

        Assert.HasCount(5, result);
    }

    [TestMethod]
    public async Task ComputeWaveform_RealDecoder_HandlesLargeSegmentCount()
    {
        var path = GetTestInputPath();
        var pool = new AudioBufferPool();

        var reader = new FfmpegAudioReader(path);
        var stem = CreateStem(path);

        using var decoder = new StemDecoder(reader, pool, stem, blockSize: 4096);

        var service = new StemWaveformService(pool);

        var result = await service.ComputeWaveformAsync(stem, decoder, 200);

        Assert.HasCount(200, result);
    }
}