using System.Globalization;
using System.Threading;
using Godosa.Core.Diagnostics;
using Xunit;

namespace Godosa.Core.Tests.Diagnostics;

public class GpuAndCsvTests
{
    [Fact]
    public void GpuSamples_AverageSeparatelyFromFrames()
    {
        var stats = new FrameTimeStats(capacity: 4);
        stats.Record(0.016, 0.002, 1, 0.0001);
        Assert.Equal(0, stats.Summarize().GpuSamples);
        Assert.Equal(0.0, stats.Summarize().AvgGpuMs);

        stats.RecordGpu(0.001);
        stats.RecordGpu(0.003);

        var s = stats.Summarize();
        Assert.Equal(2, s.GpuSamples);
        Assert.Equal(2.0, s.AvgGpuMs, precision: 9);
    }

    [Fact]
    public void GpuSamples_RollOverTheWindow()
    {
        var stats = new FrameTimeStats(capacity: 2);
        stats.RecordGpu(0.010);
        stats.RecordGpu(0.001);
        stats.RecordGpu(0.003);

        Assert.Equal(2.0, stats.Summarize().AvgGpuMs, precision: 9);
    }

    [Fact]
    public void CsvRow_IsInvariantCulture_MsWithThreeDecimals_GpuBlankWhenUnknown()
    {
        var previous = Thread.CurrentThread.CurrentCulture;
        Thread.CurrentThread.CurrentCulture = new CultureInfo("de-DE"); // comma decimals must not leak in
        try
        {
            Assert.Equal("t_s,frame_ms,work_ms,sim_ticks,sim_ms,gpu_ms", PerfCsv.Header());
            Assert.Equal("12.500,16.667,2.000,1,0.100,1.250", PerfCsv.Row(12.5, 0.0166667, 0.002, 1, 0.0001, 0.00125));
            Assert.Equal("0.000,16.667,2.000,0,0.000,", PerfCsv.Row(0, 0.0166667, 0.002, 0, 0, null));
        }
        finally
        {
            Thread.CurrentThread.CurrentCulture = previous;
        }
    }
}