Implement media path scheme

src/Umbraco.Core/IO/IMediaPathScheme.cs

@@ -0,0 +1,41 @@
+using System;
+
+namespace Umbraco.Core.IO
+{
+    /// <summary>
+    /// Represents a media file path scheme.
+    /// </summary>
+    public interface IMediaPathScheme
+    {
+        // fixme
+        // to anyone finding this code: YES the Initialize() method is CompletelyBroken™ (temporal whatever)
+        // but at the moment, the media filesystem wants a scheme which wants a filesystem, and it's all
+        // convoluted due to how filesystems are managed in FileSystems - clear that part first!
+
+        /// <summary>
+        /// Initialize.
+        /// </summary>
+        void Initialize(IFileSystem filesystem);
+
+        /// <summary>
+        /// Gets a media file path.
+        /// </summary>
+        /// <param name="itemGuid">The (content, media) item unique identifier.</param>
+        /// <param name="propertyGuid">The property type unique identifier.</param>
+        /// <param name="filename">The file name.</param>
+        /// <param name="previous">A previous filename.</param>
+        /// <returns>The filesystem-relative complete file path.</returns>
+        string GetFilePath(Guid itemGuid, Guid propertyGuid, string filename, string previous = null);
+
+        /// <summary>
+        /// Gets the directory that can be deleted when the file is deleted.
+        /// </summary>
+        /// <param name="filepath">The filesystem-relative path of the file.</param>
+        /// <returns>The filesystem-relative path of the directory.</returns>
+        /// <remarks>
+        /// <para>The directory, and anything below it, will be deleted.</para>
+        /// <para>Can return null (or empty) when no directory should be deleted.</para>
+        /// </remarks>
+        string GetDeleteDirectory(string filepath);
+    }
+}