// =============================================================================
// CycloneDxParserTests.cs
// Golden-file tests for CycloneDX SBOM parsing
// Part of Task T24: Golden-file tests for determinism
// =============================================================================

using FluentAssertions;
using StellaOps.AirGap.Importer.Reconciliation;
using StellaOps.AirGap.Importer.Reconciliation.Parsers;

namespace StellaOps.AirGap.Importer.Tests.Reconciliation;

public sealed class CycloneDxParserTests
{
    private static readonly string FixturesPath = Path.Combine(
        AppDomain.CurrentDomain.BaseDirectory,
        "Reconciliation", "Fixtures");

    [Fact]
    public async Task ParseAsync_ValidCycloneDx_ExtractsAllSubjects()
    {
        // Arrange
        var parser = new CycloneDxParser();
        var filePath = Path.Combine(FixturesPath, "sample.cdx.json");

        // Skip if fixtures not available
        if (!File.Exists(filePath))
        {
            return;
        }

        // Act
        var result = await parser.ParseAsync(filePath);

        // Assert
        result.IsSuccess.Should().BeTrue();
        result.Format.Should().Be(SbomFormat.CycloneDx);
        result.SpecVersion.Should().Be("1.6");
        result.SerialNumber.Should().Be("urn:uuid:3e671687-395b-41f5-a30f-a58921a69b79");
        result.GeneratorTool.Should().Contain("syft");

        // Should have 3 subjects with SHA-256 hashes (primary + 2 components)
        result.Subjects.Should().HaveCount(3);

        // Verify subjects are sorted by digest
        result.Subjects.Should().BeInAscendingOrder(s => s.Digest, StringComparer.Ordinal);
    }

    [Fact]
    public async Task ParseAsync_ExtractsPrimarySubject()
    {
        // Arrange
        var parser = new CycloneDxParser();
        var filePath = Path.Combine(FixturesPath, "sample.cdx.json");

        if (!File.Exists(filePath))
        {
            return;
        }

        // Act
        var result = await parser.ParseAsync(filePath);

        // Assert
        result.PrimarySubject.Should().NotBeNull();
        result.PrimarySubject!.Name.Should().Be("test-app");
        result.PrimarySubject.Version.Should().Be("1.0.0");
        result.PrimarySubject.Digest.Should().StartWith("sha256:");
    }

    [Fact]
    public async Task ParseAsync_SubjectDigestsAreNormalized()
    {
        // Arrange
        var parser = new CycloneDxParser();
        var filePath = Path.Combine(FixturesPath, "sample.cdx.json");

        if (!File.Exists(filePath))
        {
            return;
        }

        // Act
        var result = await parser.ParseAsync(filePath);

        // Assert - all digests should be normalized sha256:lowercase format
        foreach (var subject in result.Subjects)
        {
            subject.Digest.Should().StartWith("sha256:");
            subject.Digest[7..].Should().MatchRegex("^[a-f0-9]{64}$");
        }
    }

    [Fact]
    public void DetectFormat_CycloneDxFile_ReturnsCycloneDx()
    {
        var parser = new CycloneDxParser();
        parser.DetectFormat("test.cdx.json").Should().Be(SbomFormat.CycloneDx);
        parser.DetectFormat("test.bom.json").Should().Be(SbomFormat.CycloneDx);
    }

    [Fact]
    public void DetectFormat_NonCycloneDxFile_ReturnsUnknown()
    {
        var parser = new CycloneDxParser();
        parser.DetectFormat("test.spdx.json").Should().Be(SbomFormat.Unknown);
        parser.DetectFormat("test.json").Should().Be(SbomFormat.Unknown);
    }

    [Fact]
    public async Task ParseAsync_Deterministic_SameOutputForSameInput()
    {
        // Arrange
        var parser = new CycloneDxParser();
        var filePath = Path.Combine(FixturesPath, "sample.cdx.json");

        if (!File.Exists(filePath))
        {
            return;
        }

        // Act - parse twice
        var result1 = await parser.ParseAsync(filePath);
        var result2 = await parser.ParseAsync(filePath);

        // Assert - results should be identical
        result1.Subjects.Select(s => s.Digest)
            .Should().BeEquivalentTo(result2.Subjects.Select(s => s.Digest));

        result1.Subjects.Select(s => s.Name)
            .Should().BeEquivalentTo(result2.Subjects.Select(s => s.Name));

        // Order should be the same
        result1.Subjects.Select(s => s.Digest).Should().Equal(result2.Subjects.Select(s => s.Digest));
    }
}