using System;
using System.Collections.Generic;
using ln.objects.catalog;

namespace ln.types.odb.ng.storage
{
    public interface IStorage : IDisposable
    {
        bool Open();
        void Close();
        bool IsOpen { get; }

        /// <summary>
        /// Load the specified documentID.
        /// </summary>
        /// <returns>The loaded Document.</returns>
        /// <param name="documentID">Document identifier.</param>
        /// <remarks>
        /// Non caching storage will return the latest version of the document with each call.
        /// Caching storage will return the same Document instance with each call, as long as the document stayed in the cache.
        /// <b>No refreshing is done if a cached instance is returned!</b>
        /// </remarks>
        Document Load(Guid documentID);

        /// <summary>
        /// Refresh the specified document.
        /// </summary>
        /// <returns><see langword="true"/> if the document was refreshed successfully</returns>
        /// <param name="document">Document to be refreshed. Must have been loaded by a call to <c>Load(..)</c> of the same <c>IStorage</c> instance</param>
        /// <remarks>will reload the document from storage and apply the loaded state to this instance.
        /// If <paramref name="document"/> references an instance that has not been returned by a call to <c>Load(..)</c> (e.g. by using <c>Clone()</c>), internal caches may not be affected by the refresh.
        /// </remarks>
        bool Refresh(Document document);

        /// <summary>
        /// Save the specified document.
        /// </summary>
        /// <param name="document">Document to store</param>
        /// <remarks>Non caching storage will store the Document with its full state.
        /// Caching storage, e.g. SessionStorage, may only store changes to storage. Please refer to class specific documentation.
        /// </remarks>
        void Save(Document document);

        /// <summary>
        /// Delete the specified documentID from storage.
        /// </summary>
        /// <param name="documentID">Document identifier</param>
        /// <remarks>Will remove the Document identified by <para>documentID</para> from storage.
        /// </remarks>
        void Delete(Guid documentID);

        IDisposable Lock();

		bool Contains(Guid documentID);
		IEnumerable<Guid> GetDocumentIDs();
		IEnumerable<Guid> GetDocumentIDs(string path,Predicate<ODBEntity> predicate);
        DateTime GetStorageTimestamp(Guid documentID);

		void EnsureIndex(params string[] path);

        bool IsCaching { get; }

    }
}