using System.Threading;
using Svrnty.CQRS.Events.Abstractions.Correlation;
using System.Threading.Tasks;

namespace Svrnty.CQRS.Events.Abstractions.Correlation;

/// <summary>
/// Storage for correlation ID mappings based on business data keys.
/// Allows workflows to be correlated based on business logic rather than explicit ID passing.
/// </summary>
public interface ICorrelationStore
{
    /// <summary>
    /// Get the correlation ID for a given key.
    /// Returns null if no correlation exists for this key.
    /// </summary>
    /// <param name="keyHash">Hash of the correlation key.</param>
    /// <param name="cancellationToken">Cancellation token.</param>
    /// <returns>The correlation ID if it exists, null otherwise.</returns>
    Task<string?> GetCorrelationIdAsync(string keyHash, CancellationToken cancellationToken = default);

    /// <summary>
    /// Store a correlation ID for a given key.
    /// This creates the mapping between business data and correlation ID.
    /// </summary>
    /// <param name="keyHash">Hash of the correlation key.</param>
    /// <param name="correlationId">The correlation ID to associate with this key.</param>
    /// <param name="cancellationToken">Cancellation token.</param>
    Task SetCorrelationIdAsync(string keyHash, string correlationId, CancellationToken cancellationToken = default);
}