using StellaOps.Scanner.Core;

namespace StellaOps.Scanner.WebService.Services;

/// <summary>
/// Resolves scan metadata from stored scan manifests.
/// </summary>
public sealed class InMemoryScanMetadataRepository : IScanMetadataRepository
{
    private readonly IScanManifestRepository _manifestRepository;

    public InMemoryScanMetadataRepository(IScanManifestRepository manifestRepository)
    {
        _manifestRepository = manifestRepository ?? throw new ArgumentNullException(nameof(manifestRepository));
    }

    public async Task<ScanMetadata?> GetScanMetadataAsync(string scanId, CancellationToken cancellationToken = default)
    {
        if (string.IsNullOrWhiteSpace(scanId))
        {
            return null;
        }

        var manifest = await _manifestRepository
            .GetManifestAsync(scanId.Trim(), cancellationToken: cancellationToken)
            .ConfigureAwait(false);

        if (manifest is null)
        {
            return null;
        }

        return new ScanMetadata(
            BaseDigest: null,
            TargetDigest: NormalizeDigest(manifest.Manifest.ArtifactDigest),
            ScanTime: manifest.Manifest.CreatedAtUtc);
    }

    private static string? NormalizeDigest(string? digest)
    {
        if (string.IsNullOrWhiteSpace(digest))
        {
            return null;
        }

        var normalized = digest.Trim();
        if (!normalized.Contains(':', StringComparison.Ordinal))
        {
            normalized = $"sha256:{normalized}";
        }

        return normalized.ToLowerInvariant();
    }
}