releases/tests/Paca.Tests/Core/AiMediaAndShaderEnginesExtremeRedTests.cs

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Threading;
using Paca.Core.Detection;
using Paca.Core.Gateway;
using Paca.Core.Media;
using Xunit;

namespace Paca.Tests.Core;

public class AiMediaAndShaderEnginesExtremeRedTests
{
    private const string SampleInput = "C:\\Videos\\source.mp4";
    private const string SampleOutput = "C:\\Videos\\shorts.mp4";

    // ==========================================
    // 1. AiHighlightClipper
    // ==========================================

    [Theory]
    [InlineData(0)]
    [InlineData(-100)]
    [InlineData(double.NaN)]
    public void AiHighlightClipper_DetectHighlights_ZeroOrNegativeDuration_ReturnsEmpty(double duration)
    {
        var highlights = AiHighlightClipper.DetectHighlights(duration);
        Assert.NotNull(highlights);
        Assert.Empty(highlights);
    }

    [Theory]
    [InlineData(0)]
    [InlineData(-10)]
    [InlineData(double.NaN)]
    public void AiHighlightClipper_DetectHighlights_ZeroOrNegativeWindowSeconds_DoesNotCrashOrLoopInfinitely(double windowSec)
    {
        var highlights = AiHighlightClipper.DetectHighlights(120.0, windowSeconds: windowSec);
        Assert.NotNull(highlights);
        Assert.NotEmpty(highlights);
    }

    [Fact]
    public void AiHighlightClipper_BuildFfmpegShortsCommand_SameInputAndOutput_ThrowsInvalidOperationException()
    {
        var spec = new ShortsClipSpec();
        Assert.Throws<InvalidOperationException>(() =>
            AiHighlightClipper.BuildFfmpegShortsCommand(SampleInput, SampleInput, spec));
    }

    [Theory]
    [InlineData(null, SampleOutput)]
    [InlineData(SampleInput, null)]
    [InlineData("", SampleOutput)]
    [InlineData(SampleInput, "   ")]
    public void AiHighlightClipper_BuildFfmpegShortsCommand_NullOrWhitespacePaths_ThrowsArgumentException(string? inPath, string? outPath)
    {
        var spec = new ShortsClipSpec();
        Assert.Throws<ArgumentException>(() =>
            AiHighlightClipper.BuildFfmpegShortsCommand(inPath!, outPath!, spec));
    }

    [Fact]
    public void AiHighlightClipper_BuildFfmpegShortsCommand_NullSpec_ThrowsArgumentNullException()
    {
        Assert.Throws<ArgumentNullException>(() =>
            AiHighlightClipper.BuildFfmpegShortsCommand(SampleInput, SampleOutput, null!));
    }

    [Fact]
    public void AiHighlightClipper_BuildFfmpegShortsCommand_PathsWithQuotes_Stripped()
    {
        var spec = new ShortsClipSpec();
        string maliciousIn = "C:\\Videos\\so\"urce.mp4";
        string maliciousOut = "C:\\Videos\\sh\"orts.mp4";

        var args = AiHighlightClipper.BuildFfmpegShortsCommand(maliciousIn, maliciousOut, spec);
        Assert.NotNull(args);
        Assert.DoesNotContain(args, a => a.Contains('"'));
    }

    // ==========================================
    // 2. FftAudioWaveformEngine
    // ==========================================

    [Fact]
    public void FftAudioWaveformEngine_BuildFfmpegEqualizerFilter_NullOrEmptyBands_ReturnsEmptyString()
    {
        Assert.Equal(string.Empty, FftAudioWaveformEngine.BuildFfmpegEqualizerFilter(null!));
        Assert.Equal(string.Empty, FftAudioWaveformEngine.BuildFfmpegEqualizerFilter(new List<EqualizerBand>()));
    }

    [Fact]
    public void FftAudioWaveformEngine_BuildFfmpegEqualizerFilter_ListContainingNullBands_SkipsSafely()
    {
        var bands = new List<EqualizerBand>
        {
            null!,
            new() { FrequencyHz = 1000, GainDb = 3.5 },
            null!
        };

        var filter = FftAudioWaveformEngine.BuildFfmpegEqualizerFilter(bands);
        Assert.NotNull(filter);
        Assert.Contains("equalizer=f=1000", filter);
    }

    [Fact]
    public void FftAudioWaveformEngine_BuildFfmpegEqualizerFilter_InCommaDecimalCulture_UsesDotDecimalSeparator()
    {
        var originalCulture = Thread.CurrentThread.CurrentCulture;
        try
        {
            Thread.CurrentThread.CurrentCulture = new CultureInfo("de-DE"); // German culture uses ',' for decimal

            var bands = new List<EqualizerBand>
            {
                new() { FrequencyHz = 500, GainDb = 4.5 }
            };

            var filter = FftAudioWaveformEngine.BuildFfmpegEqualizerFilter(bands);
            Assert.Contains("g=4.5", filter);
            Assert.DoesNotContain("g=4,5", filter);
        }
        finally
        {
            Thread.CurrentThread.CurrentCulture = originalCulture;
        }
    }

    // ==========================================
    // 3. NeuralShaderUpscaler
    // ==========================================

    [Fact]
    public void NeuralShaderUpscaler_GenerateHlslShaderCode_NullConfig_DoesNotThrow()
    {
        var shader = NeuralShaderUpscaler.GenerateHlslShaderCode(null!);
        Assert.NotNull(shader);
        Assert.Contains("float4 PS_NeuralUpscale", shader);
    }

    [Theory]
    [InlineData(0, 0)]
    [InlineData(-1920, -1080)]
    public void NeuralShaderUpscaler_GenerateHlslShaderCode_ZeroOrNegativeDimensions_FallsBackToDefaultResolution(int w, int h)
    {
        var config = new ShaderUpscaleConfig { TargetWidth = w, TargetHeight = h };
        var shader = NeuralShaderUpscaler.GenerateHlslShaderCode(config);
        Assert.NotNull(shader);
        Assert.DoesNotContain("1.0 / 0", shader);
        Assert.DoesNotContain("1.0 / -", shader);
    }

    [Fact]
    public void NeuralShaderUpscaler_GenerateHlslShaderCode_InCommaDecimalCulture_UsesDotDecimalSeparator()
    {
        var originalCulture = Thread.CurrentThread.CurrentCulture;
        try
        {
            Thread.CurrentThread.CurrentCulture = new CultureInfo("fr-FR"); // French culture uses ',' for decimal

            var config = new ShaderUpscaleConfig { Sharpness = 2.5 };
            var shader = NeuralShaderUpscaler.GenerateHlslShaderCode(config);

            Assert.Contains("2.50", shader);
            Assert.DoesNotContain("2,50", shader);
        }
        finally
        {
            Thread.CurrentThread.CurrentCulture = originalCulture;
        }
    }

    // ==========================================
    // 4. PacaConnectCodeGenerator
    // ==========================================

    [Theory]
    [InlineData(null)]
    [InlineData("")]
    [InlineData("   ")]
    [InlineData("PACA-12345")]       // 5 chars instead of 6
    [InlineData("PACA-1234567")]     // 7 chars
    [InlineData("PACA-000000")]      // '0' is disallowed
    [InlineData("PACA-111111")]      // '1' is disallowed
    [InlineData("PACA-IIIIII")]      // 'I' is disallowed
    [InlineData("PACA-OOOOOO")]      // 'O' is disallowed
    [InlineData("OTHER-234567")]     // wrong prefix
    public void PacaConnectCodeGenerator_IsValid_InvalidCodes_ReturnsFalse(string? code)
    {
        Assert.False(PacaConnectCodeGenerator.IsValid(code));
    }

    [Fact]
    public void PacaConnectCodeGenerator_GenerateCode_AlwaysProducesValidCode()
    {
        for (int i = 0; i < 50; i++)
        {
            var code = PacaConnectCodeGenerator.GenerateCode();
            Assert.True(PacaConnectCodeGenerator.IsValid(code), $"Generated code '{code}' should be valid.");
        }
    }
}