using System.Reflection;

namespace StellaOps.BinaryIndex.GroundTruth.SecDb.Tests.Fixtures;

/// <summary>
/// Provides access to deterministic test fixtures for offline testing.
/// </summary>
public static class FixtureProvider
{
    private static readonly string FixturesPath;

    static FixtureProvider()
    {
        var assemblyDir = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!;
        FixturesPath = Path.Combine(assemblyDir, "Fixtures");

        // Also try the source directory for development
        if (!Directory.Exists(FixturesPath))
        {
            var sourceDir = FindSourceFixturesDirectory();
            if (sourceDir is not null)
            {
                FixturesPath = sourceDir;
            }
        }
    }

    /// <summary>
    /// Get sample SecDB YAML content for main repository.
    /// </summary>
    public static string GetSampleSecDbMain()
    {
        var path = Path.Combine(FixturesPath, "main.yaml");
        if (!File.Exists(path))
        {
            // Return inline fixture if file doesn't exist
            return SampleSecDbMainContent;
        }
        return File.ReadAllText(path);
    }

    /// <summary>
    /// Get sample SecDB YAML content for community repository.
    /// </summary>
    public static string GetSampleSecDbCommunity()
    {
        var path = Path.Combine(FixturesPath, "community.yaml");
        if (!File.Exists(path))
        {
            return SampleSecDbCommunityContent;
        }
        return File.ReadAllText(path);
    }

    /// <summary>
    /// Get a fixture file as a stream.
    /// </summary>
    public static Stream GetFixtureStream(string name)
    {
        var path = Path.Combine(FixturesPath, name);
        if (!File.Exists(path))
        {
            throw new FileNotFoundException($"Fixture not found: {path}");
        }
        return File.OpenRead(path);
    }

    /// <summary>
    /// Check if a fixture exists.
    /// </summary>
    public static bool FixtureExists(string name)
    {
        var path = Path.Combine(FixturesPath, name);
        return File.Exists(path);
    }

    private static string? FindSourceFixturesDirectory()
    {
        var dir = Directory.GetCurrentDirectory();
        while (dir is not null)
        {
            var candidate = Path.Combine(dir, "src", "BinaryIndex", "__Tests",
                "StellaOps.BinaryIndex.GroundTruth.SecDb.Tests", "Fixtures");
            if (Directory.Exists(candidate))
            {
                return candidate;
            }
            dir = Directory.GetParent(dir)?.FullName;
        }
        return null;
    }

    /// <summary>
    /// Inline sample SecDB main.yaml content for deterministic testing.
    /// Based on Alpine SecDB format.
    /// </summary>
    private const string SampleSecDbMainContent = """
        distroversion: v3.19
        reponame: main
        urlprefix: https://dl-cdn.alpinelinux.org/alpine/v3.19/main
        packages:
          - pkg: curl
            secfixes:
              8.5.0-r0:
                - CVE-2023-46218 Improper validation of HTTP headers
                - CVE-2023-46219 Double free in async URL resolver
              8.4.0-r0:
                - CVE-2023-38545 SOCKS5 heap buffer overflow
              8.1.2-r0:
                - CVE-2023-27535 FTP injection vulnerability
          - pkg: openssl
            secfixes:
              3.1.4-r3:
                - CVE-2024-0727 PKCS12 decoding crash
              3.1.4-r0:
                - CVE-2023-5678 Denial of service
              3.1.2-r0:
                - CVE-2023-3817 Excessive time checking DH parameters
          - pkg: linux-lts
            secfixes:
              6.1.67-r0:
                - CVE-2023-6817 Use-after-free in netfilter
                - CVE-2023-6606 Out-of-bounds read in SMB
              6.1.64-r0:
                - CVE-2023-5717 User-mode root exploit via perf
        """;

    /// <summary>
    /// Inline sample SecDB community.yaml content.
    /// </summary>
    private const string SampleSecDbCommunityContent = """
        distroversion: v3.19
        reponame: community
        urlprefix: https://dl-cdn.alpinelinux.org/alpine/v3.19/community
        packages:
          - pkg: go
            secfixes:
              1.21.5-r0:
                - CVE-2023-45283 Path traversal on Windows
                - CVE-2023-45284 Runtime panic in crypto/tls
              1.21.4-r0:
                - CVE-2023-44487 HTTP/2 rapid reset attack
          - pkg: nodejs
            secfixes:
              20.10.0-r0:
                - CVE-2023-46809 Permissions policy bypass
              20.9.0-r0:
                - CVE-2023-38552 Integrity bypass via TLS/HTTPS
          - pkg: chromium
            secfixes:
              120.0.6099.71-r0:
                - CVE-2023-6702 Type confusion in V8
              119.0.6045.199-r0:
                - CVE-2023-6345 Integer overflow in Skia
          - pkg: unfixed-example
            secfixes:
              "0":
                - CVE-2023-99999 Example unfixed vulnerability
        """;
}

/// <summary>
/// Test fixture constants for SecDB tests.
/// </summary>
public static class FixtureConstants
{
    // Sample package info
    public const string SamplePackageCurl = "curl";
    public const string SamplePackageOpenssl = "openssl";
    public const string SamplePackageGo = "go";
    public const string SamplePackageNodejs = "nodejs";

    // Sample branches
    public const string SampleBranchV319 = "v3.19";
    public const string SampleBranchEdge = "edge";

    // Sample repositories
    public const string SampleRepoMain = "main";
    public const string SampleRepoCommunity = "community";

    // Expected CVE counts
    public const int ExpectedCurlCveCount = 4;
    public const int ExpectedOpensslCveCount = 3;

    // Sample CVEs
    public const string SampleCveCurl = "CVE-2023-46218";
    public const string SampleCveOpenssl = "CVE-2024-0727";
    public const string SampleCveUnfixed = "CVE-2023-99999";
}