// -----------------------------------------------------------------------------
// SbomParserTests.cs
// Sprint: SPRINT_8200_0013_0003_SCAN_sbom_intersection_scoring
// Task: SBOM-8200-007
// Description: Unit tests for SBOM parsing and PURL extraction
//              Supports CycloneDX 1.4-1.7 and SPDX 2.2-2.3, 3.0
// -----------------------------------------------------------------------------

using System.Text;
using FluentAssertions;
using Microsoft.Extensions.Logging;
using Moq;
using StellaOps.Concelier.SbomIntegration.Models;
using StellaOps.Concelier.SbomIntegration.Parsing;
using Xunit;


using StellaOps.TestKit;
namespace StellaOps.Concelier.SbomIntegration.Tests;

public class SbomParserTests
{
    private readonly SbomParser _parser;

    public SbomParserTests()
    {
        var loggerMock = new Mock<ILogger<SbomParser>>();
        _parser = new SbomParser(loggerMock.Object);
    }

    #region CycloneDX Tests

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task ParseAsync_CycloneDX_ExtractsPurls()
    {
        // Arrange
        var cycloneDxContent = """
        {
            "bomFormat": "CycloneDX",
            "specVersion": "1.6",
            "version": 1,
            "metadata": {
                "component": {
                    "type": "application",
                    "name": "myapp",
                    "version": "1.0.0"
                }
            },
            "components": [
                {
                    "type": "library",
                    "name": "lodash",
                    "version": "4.17.21",
                    "purl": "pkg:npm/lodash@4.17.21"
                },
                {
                    "type": "library",
                    "name": "express",
                    "version": "4.18.2",
                    "purl": "pkg:npm/express@4.18.2"
                }
            ]
        }
        """;

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(cycloneDxContent));

        // Act
        var result = await _parser.ParseAsync(stream, SbomFormat.CycloneDX);

        // Assert
        result.Should().NotBeNull();
        result.PrimaryName.Should().Be("myapp");
        result.PrimaryVersion.Should().Be("1.0.0");
        result.Purls.Should().HaveCount(2);
        result.Purls.Should().Contain("pkg:npm/lodash@4.17.21");
        result.Purls.Should().Contain("pkg:npm/express@4.18.2");
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task ParseAsync_CycloneDX_HandlesNestedComponents()
    {
        // Arrange
        var cycloneDxContent = """
        {
            "bomFormat": "CycloneDX",
            "specVersion": "1.5",
            "components": [
                {
                    "type": "library",
                    "name": "parent",
                    "version": "1.0.0",
                    "purl": "pkg:npm/parent@1.0.0",
                    "components": [
                        {
                            "type": "library",
                            "name": "child",
                            "version": "2.0.0",
                            "purl": "pkg:npm/child@2.0.0"
                        }
                    ]
                }
            ]
        }
        """;

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(cycloneDxContent));

        // Act
        var result = await _parser.ParseAsync(stream, SbomFormat.CycloneDX);

        // Assert
        result.Purls.Should().Contain("pkg:npm/parent@1.0.0");
        result.Purls.Should().Contain("pkg:npm/child@2.0.0");
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task ParseAsync_CycloneDX_SkipsComponentsWithoutPurl()
    {
        // Arrange
        var cycloneDxContent = """
        {
            "bomFormat": "CycloneDX",
            "specVersion": "1.6",
            "components": [
                {
                    "type": "library",
                    "name": "with-purl",
                    "version": "1.0.0",
                    "purl": "pkg:npm/with-purl@1.0.0"
                },
                {
                    "type": "library",
                    "name": "without-purl",
                    "version": "1.0.0"
                }
            ]
        }
        """;

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(cycloneDxContent));

        // Act
        var result = await _parser.ParseAsync(stream, SbomFormat.CycloneDX);

        // Assert
        result.Purls.Should().HaveCount(1);
        result.Purls.Should().Contain("pkg:npm/with-purl@1.0.0");
        result.UnresolvedComponents.Should().HaveCount(1);
        result.UnresolvedComponents[0].Name.Should().Be("without-purl");
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task ParseAsync_CycloneDX_DeduplicatesPurls()
    {
        // Arrange
        var cycloneDxContent = """
        {
            "bomFormat": "CycloneDX",
            "specVersion": "1.6",
            "components": [
                {
                    "type": "library",
                    "purl": "pkg:npm/lodash@4.17.21"
                },
                {
                    "type": "library",
                    "purl": "pkg:npm/lodash@4.17.21"
                }
            ]
        }
        """;

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(cycloneDxContent));

        // Act
        var result = await _parser.ParseAsync(stream, SbomFormat.CycloneDX);

        // Assert
        result.Purls.Should().HaveCount(1);
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task ParseAsync_CycloneDX17_ExtractsPurls()
    {
        // Arrange - CycloneDX 1.7 format
        var cycloneDxContent = """
        {
            "bomFormat": "CycloneDX",
            "specVersion": "1.7",
            "version": 1,
            "metadata": {
                "component": {
                    "type": "application",
                    "name": "myapp",
                    "version": "2.0.0"
                }
            },
            "components": [
                {
                    "type": "library",
                    "name": "axios",
                    "version": "1.6.0",
                    "purl": "pkg:npm/axios@1.6.0"
                }
            ]
        }
        """;

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(cycloneDxContent));

        // Act
        var result = await _parser.ParseAsync(stream, SbomFormat.CycloneDX);

        // Assert
        result.Should().NotBeNull();
        result.PrimaryName.Should().Be("myapp");
        result.Purls.Should().Contain("pkg:npm/axios@1.6.0");
    }

    #endregion

    #region SPDX Tests

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task ParseAsync_SPDX_ExtractsPurls()
    {
        // Arrange
        var spdxContent = """
        {
            "spdxVersion": "SPDX-2.3",
            "SPDXID": "SPDXRef-DOCUMENT",
            "name": "myapp-sbom",
            "packages": [
                {
                    "SPDXID": "SPDXRef-Package-npm-lodash",
                    "name": "lodash",
                    "versionInfo": "4.17.21",
                    "externalRefs": [
                        {
                            "referenceCategory": "PACKAGE-MANAGER",
                            "referenceType": "purl",
                            "referenceLocator": "pkg:npm/lodash@4.17.21"
                        }
                    ]
                },
                {
                    "SPDXID": "SPDXRef-Package-npm-express",
                    "name": "express",
                    "versionInfo": "4.18.2",
                    "externalRefs": [
                        {
                            "referenceCategory": "PACKAGE-MANAGER",
                            "referenceType": "purl",
                            "referenceLocator": "pkg:npm/express@4.18.2"
                        }
                    ]
                }
            ]
        }
        """;

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(spdxContent));

        // Act
        var result = await _parser.ParseAsync(stream, SbomFormat.SPDX);

        // Assert
        result.Purls.Should().HaveCount(2);
        result.Purls.Should().Contain("pkg:npm/lodash@4.17.21");
        result.Purls.Should().Contain("pkg:npm/express@4.18.2");
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task ParseAsync_SPDX_IgnoresNonPurlExternalRefs()
    {
        // Arrange
        var spdxContent = """
        {
            "spdxVersion": "SPDX-2.3",
            "packages": [
                {
                    "SPDXID": "SPDXRef-Package",
                    "name": "mypackage",
                    "externalRefs": [
                        {
                            "referenceCategory": "SECURITY",
                            "referenceType": "cpe23Type",
                            "referenceLocator": "cpe:2.3:a:vendor:product:1.0:*:*:*:*:*:*:*"
                        },
                        {
                            "referenceCategory": "PACKAGE-MANAGER",
                            "referenceType": "purl",
                            "referenceLocator": "pkg:npm/mypackage@1.0.0"
                        }
                    ]
                }
            ]
        }
        """;

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(spdxContent));

        // Act
        var result = await _parser.ParseAsync(stream, SbomFormat.SPDX);

        // Assert
        result.Purls.Should().HaveCount(1);
        result.Purls.Should().Contain("pkg:npm/mypackage@1.0.0");
        result.Cpes.Should().HaveCount(1);
        result.Cpes.Should().Contain("cpe:2.3:a:vendor:product:1.0:*:*:*:*:*:*:*");
    }

    #endregion

    #region Format Detection Tests

    [Trait("Category", TestCategories.Unit)]
        [Theory]
    [InlineData("1.4")]
    [InlineData("1.5")]
    [InlineData("1.6")]
    [InlineData("1.7")]
    public async Task DetectFormatAsync_CycloneDX_DetectsAllVersions(string specVersion)
    {
        // Arrange
        var content = $$"""
        {
            "bomFormat": "CycloneDX",
            "specVersion": "{{specVersion}}",
            "components": []
        }
        """;

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(content));

        // Act
        var result = await _parser.DetectFormatAsync(stream);

        // Assert
        result.IsDetected.Should().BeTrue();
        result.Format.Should().Be(SbomFormat.CycloneDX);
        result.SpecVersion.Should().Be(specVersion);
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task DetectFormatAsync_SPDX2_DetectsFormat()
    {
        // Arrange
        var content = """
        {
            "spdxVersion": "SPDX-2.3",
            "packages": []
        }
        """;

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(content));

        // Act
        var result = await _parser.DetectFormatAsync(stream);

        // Assert
        result.IsDetected.Should().BeTrue();
        result.Format.Should().Be(SbomFormat.SPDX);
        result.SpecVersion.Should().Be("SPDX-2.3");
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task DetectFormatAsync_UnknownFormat_ReturnsNotDetected()
    {
        // Arrange
        var content = """
        {
            "unknownField": "value"
        }
        """;

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(content));

        // Act
        var result = await _parser.DetectFormatAsync(stream);

        // Assert
        result.IsDetected.Should().BeFalse();
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task DetectFormatAsync_InvalidJson_ReturnsNotDetected()
    {
        // Arrange
        var content = "not valid json {{{";

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(content));

        // Act
        var result = await _parser.DetectFormatAsync(stream);

        // Assert
        result.IsDetected.Should().BeFalse();
    }

    #endregion

    #region PURL Ecosystem Tests

    [Trait("Category", TestCategories.Unit)]
        [Theory]
    [InlineData("pkg:npm/lodash@4.17.21")]
    [InlineData("pkg:pypi/requests@2.28.0")]
    [InlineData("pkg:maven/org.apache.commons/commons-lang3@3.12.0")]
    [InlineData("pkg:nuget/Newtonsoft.Json@13.0.1")]
    [InlineData("pkg:cargo/serde@1.0.150")]
    [InlineData("pkg:golang/github.com/gin-gonic/gin@1.9.0")]
    [InlineData("pkg:gem/rails@7.0.4")]
    [InlineData("pkg:deb/debian/openssl@1.1.1n-0+deb11u3")]
    [InlineData("pkg:rpm/fedora/kernel@5.19.0-43.fc37")]
    [InlineData("pkg:apk/alpine/openssl@1.1.1q-r0")]
    public async Task ParseAsync_CycloneDX_SupportsVariousEcosystems(string purl)
    {
        // Arrange
        var content = $$"""
        {
            "bomFormat": "CycloneDX",
            "specVersion": "1.6",
            "components": [
                {
                    "type": "library",
                    "purl": "{{purl}}"
                }
            ]
        }
        """;

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(content));

        // Act
        var result = await _parser.ParseAsync(stream, SbomFormat.CycloneDX);

        // Assert
        result.Purls.Should().Contain(purl);
    }

    #endregion

    #region Edge Cases

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task ParseAsync_EmptyComponents_ReturnsEmptyPurls()
    {
        // Arrange
        var content = """
        {
            "bomFormat": "CycloneDX",
            "specVersion": "1.6",
            "components": []
        }
        """;

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(content));

        // Act
        var result = await _parser.ParseAsync(stream, SbomFormat.CycloneDX);

        // Assert
        result.Purls.Should().BeEmpty();
        result.TotalComponents.Should().Be(0);
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task ParseAsync_NullStream_ThrowsArgumentNullException()
    {
        // Act & Assert
        await Assert.ThrowsAsync<ArgumentNullException>(() =>
            _parser.ParseAsync(null!, SbomFormat.CycloneDX));
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task ParseAsync_ExtractsCpes()
    {
        // Arrange
        var content = """
        {
            "bomFormat": "CycloneDX",
            "specVersion": "1.6",
            "components": [
                {
                    "type": "library",
                    "name": "openssl",
                    "cpe": "cpe:2.3:a:openssl:openssl:1.1.1:*:*:*:*:*:*:*",
                    "purl": "pkg:deb/debian/openssl@1.1.1"
                }
            ]
        }
        """;

        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(content));

        // Act
        var result = await _parser.ParseAsync(stream, SbomFormat.CycloneDX);

        // Assert
        result.Cpes.Should().HaveCount(1);
        result.Cpes.Should().Contain("cpe:2.3:a:openssl:openssl:1.1.1:*:*:*:*:*:*:*");
    }

    #endregion
}