using Grpc.Core;

namespace Robotico.Nexus.Client;

/// <summary>Builds per-call gRPC metadata (logical database + optional bearer) for wire calls.</summary>
internal static class NexusCallMetadata
{
    /// <summary>gRPC metadata key for logical database selection (matches Nexus server-side convention).</summary>
    internal const string DatabaseKey = "x-nexus-database";

    /// <summary>Builds headers for a single RPC bound to <paramref name="databaseName"/>.</summary>
    internal static Metadata Build(string databaseName, string? bearerToken)
    {
        Metadata metadata = new() { { DatabaseKey, databaseName } };
        if (!string.IsNullOrWhiteSpace(bearerToken))
        {
            string value = bearerToken.StartsWith("Bearer ", StringComparison.OrdinalIgnoreCase)
                ? bearerToken
                : "Bearer " + bearerToken;
            metadata.Add("Authorization", value);
        }

        return metadata;
    }
}