meeting-assistant/MeetingAssistant.Tests/PyannoteSpeakerIdentityMatchValidatorTests.cs

using MeetingAssistant;
using MeetingAssistant.Recording;
using MeetingAssistant.Speakers;
using MeetingAssistant.Transcription;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;
using NAudio.Wave;

namespace MeetingAssistant.Tests;

public sealed class PyannoteSpeakerIdentityMatchValidatorTests
{
    [Fact]
    public async Task ValidatorRejectsSampleWhenPyannoteReportsMultipleSpeakers()
    {
        var commandRunner = new CapturingCommandRunner(
            """
            __MEETING_ASSISTANT_PYANNOTE_JSON_START__
            [{"start":0.0,"end":10.0,"speaker":"SPEAKER_00"},{"start":10.0,"end":20.0,"speaker":"SPEAKER_01"}]
            __MEETING_ASSISTANT_PYANNOTE_JSON_END__
            """);
        var validator = CreateValidator(commandRunner);

        var valid = await validator.ValidateSampleAsync(CreateWav(TimeSpan.FromSeconds(20)), CancellationToken.None);

        Assert.False(valid);
    }

    [Fact]
    public async Task ValidatorAcceptsMatchWhenPyannoteAssignsKnownAndUnknownSamplesToSameSpeaker()
    {
        var commandRunner = new CapturingCommandRunner(
            """
            __MEETING_ASSISTANT_PYANNOTE_JSON_START__
            [{"start":0.0,"end":1.0,"speaker":"SPEAKER_00"},{"start":2.0,"end":3.0,"speaker":"SPEAKER_00"}]
            __MEETING_ASSISTANT_PYANNOTE_JSON_END__
            """);
        var validator = CreateValidator(commandRunner);
        var wav = CreateWav(TimeSpan.FromSeconds(1));

        var valid = await validator.ValidateMatchAsync(
            new SpeakerIdentityMatchValidationRequest("Guest03", 42, wav, [wav]),
            CancellationToken.None);

        Assert.True(valid);
    }

    [Fact]
    public async Task DisabledValidatorDoesNotRunPyannote()
    {
        var commandRunner = new CapturingCommandRunner("");
        var validator = CreateValidator(commandRunner, enabled: false);

        var valid = await validator.ValidateSampleAsync(CreateWav(TimeSpan.FromSeconds(1)), CancellationToken.None);

        Assert.True(valid);
        Assert.Empty(commandRunner.Commands);
    }

    private static PyannoteSpeakerIdentityMatchValidator CreateValidator(
        CapturingCommandRunner commandRunner,
        bool enabled = true)
    {
        var finalizer = new PyannoteTranscriptFinalizer(
            commandRunner,
            Options.Create(new MeetingAssistantOptions()),
            NullLogger<PyannoteTranscriptFinalizer>.Instance);
        return new PyannoteSpeakerIdentityMatchValidator(
            finalizer,
            Options.Create(new MeetingAssistantOptions
            {
                SpeakerIdentification = new SpeakerIdentificationOptions
                {
                    PyannoteValidation = new SpeakerIdentityPyannoteValidationOptions
                    {
                        Enabled = enabled,
                        MinimumSingleSpeakerCoverage = 0.90,
                        MinimumMatchingKnownSnippetRatio = 1,
                        Diarization = new PyannoteDiarizationOptions
                        {
                            Enabled = true,
                            BuildImage = false,
                            DockerCommand = "docker",
                            Image = "meeting-assistant-pyannote:local",
                            ModelsFolder = Path.Combine(
                                Path.GetTempPath(),
                                "meeting-assistant-tests",
                                Guid.NewGuid().ToString("N"),
                                "models"),
                            Token = "hf_test",
                            TokenEnv = "",
                            CommandTimeout = TimeSpan.FromMinutes(1),
                            AlignmentMode = PyannoteAlignmentMode.PyannoteTurns
                        }
                    }
                }
            }),
            NullLogger<PyannoteSpeakerIdentityMatchValidator>.Instance);
    }

    private static byte[] CreateWav(TimeSpan duration)
    {
        const int sampleRate = 16000;
        using var stream = new MemoryStream();
        using (var writer = new WaveFileWriter(stream, new WaveFormat(sampleRate, 16, 1)))
        {
            var bytes = new byte[(int)(duration.TotalSeconds * sampleRate * sizeof(short))];
            writer.Write(bytes, 0, bytes.Length);
        }

        return stream.ToArray();
    }

    private sealed class CapturingCommandRunner : ICommandRunner
    {
        private readonly string output;

        public CapturingCommandRunner(string output)
        {
            this.output = output;
        }

        public IReadOnlyList<CapturedCommand> Commands { get; private set; } = [];

        public Task<CommandResult> RunAsync(
            string fileName,
            IReadOnlyList<string> arguments,
            CancellationToken cancellationToken,
            IReadOnlyDictionary<string, string>? environment = null)
        {
            Commands = Commands.Append(new CapturedCommand(fileName, arguments)).ToList();
            return Task.FromResult(new CommandResult(0, output, ""));
        }
    }

    private sealed record CapturedCommand(string FileName, IReadOnlyList<string> Arguments);
}