using StellaOps.Bench.ScannerAnalyzers;
using StellaOps.Bench.ScannerAnalyzers.Baseline;
using StellaOps.Bench.ScannerAnalyzers.Reporting;
using Xunit;

namespace StellaOps.Bench.ScannerAnalyzers.Tests;

public sealed class BenchmarkScenarioReportTests
{
    [Fact]
    public void RegressionRatio_ComputedWhenBaselinePresent()
    {
        var result = new ScenarioResult(
            "scenario",
            "Scenario",
            SampleCount: 5,
            MeanMs: 10,
            P95Ms: 12,
            MaxMs: 20,
            Iterations: 5,
            ThresholdMs: 5000);

        var baseline = new BaselineEntry(
            "scenario",
            Iterations: 5,
            SampleCount: 5,
            MeanMs: 8,
            P95Ms: 11,
            MaxMs: 15);

        var report = new BenchmarkScenarioReport(result, baseline, regressionLimit: 1.2);

        Assert.True(report.MaxRegressionRatio.HasValue);
        Assert.Equal(20d / 15d, report.MaxRegressionRatio.Value, 6);
        Assert.True(report.RegressionBreached);
        Assert.Contains("+33.3%", report.BuildRegressionFailureMessage());
    }

    [Fact]
    public void RegressionRatio_NullWhenBaselineMissing()
    {
        var result = new ScenarioResult(
            "scenario",
            "Scenario",
            SampleCount: 5,
            MeanMs: 10,
            P95Ms: 12,
            MaxMs: 20,
            Iterations: 5,
            ThresholdMs: 5000);

        var report = new BenchmarkScenarioReport(result, baseline: null, regressionLimit: 1.2);

        Assert.Null(report.MaxRegressionRatio);
        Assert.False(report.RegressionBreached);
        Assert.Null(report.BuildRegressionFailureMessage());
    }
}