using System.Threading.Tasks;

namespace ZB.MOM.WW.CBDDC.Core.Cache
{
    /// <summary>
    /// Defines operations for caching documents by collection and key.
    /// </summary>
    public interface IDocumentCache
    {
        /// <summary>
        /// Clears all cached documents.
        /// </summary>
        void Clear();

        /// <summary>
        /// Gets a cached document by collection and key.
        /// </summary>
        /// <param name="collection">The collection name.</param>
        /// <param name="key">The document key.</param>
        /// <returns>The cached document, or <see langword="null"/> if not found.</returns>
        Task<Document?> Get(string collection, string key);

        /// <summary>
        /// Gets cache hit/miss statistics.
        /// </summary>
        /// <returns>A tuple containing hits, misses, current size, and hit rate.</returns>
        (long Hits, long Misses, int Size, double HitRate) GetStatistics();

        /// <summary>
        /// Removes a cached document by collection and key.
        /// </summary>
        /// <param name="collection">The collection name.</param>
        /// <param name="key">The document key.</param>
        void Remove(string collection, string key);

        /// <summary>
        /// Adds or updates a cached document.
        /// </summary>
        /// <param name="collection">The collection name.</param>
        /// <param name="key">The document key.</param>
        /// <param name="document">The document to cache.</param>
        /// <returns>A task that represents the asynchronous operation.</returns>
        Task Set(string collection, string key, Document document);
    }
}