using System;
using System.IO;

namespace StellaOps.Scanner.Surface.FS;

/// <summary>
/// Configuration settings for the manifest store.
/// </summary>
public sealed class SurfaceManifestStoreOptions
{
    /// <summary>
    /// Gets or sets the root directory used to persist manifest payloads. When <c>null</c>,
    /// the value falls back to the surface cache root.
    /// </summary>
    public string? RootDirectory { get; set; }

    /// <summary>
    /// Gets or sets the URI scheme emitted for manifest pointers.
    /// </summary>
    public string Scheme { get; set; } = "cas";

    /// <summary>
    /// Gets or sets the bucket name portion of manifest URIs.
    /// </summary>
    public string Bucket { get; set; } = "surface-cache";

    /// <summary>
    /// Gets or sets the prefix used before tenant segments within manifest URIs.
    /// </summary>
    public string Prefix { get; set; } = "manifests";

    internal string ResolveRoot(SurfaceCacheOptions cacheOptions)
    {
        var root = RootDirectory;
        if (string.IsNullOrWhiteSpace(root))
        {
            root = Path.Combine(cacheOptions.ResolveRoot(), "manifests");
        }

        return root!;
    }

    internal string ToUri(string tenantSegment, string digestHex)
        => $"{Scheme}://{Bucket}/{Prefix}/{tenantSegment}/{digestHex[..2]}/{digestHex[2..4]}/{digestHex}.json";
}