Implemented the ability to flatten directories, esp useful with nested folders in archives.

API/Extensions/DirectoryInfoExtensions.cs

@@ -1,11 +1,65 @@
-namespace API.Extensions
+using System;
+using System.IO;
+
+namespace API.Extensions
 {
     public static class DirectoryInfoExtensions
     {
-        public static void Empty(this System.IO.DirectoryInfo directory)
+        public static void Empty(this DirectoryInfo directory)
         {
-            foreach(System.IO.FileInfo file in directory.EnumerateFiles()) file.Delete();
-            foreach(System.IO.DirectoryInfo subDirectory in directory.EnumerateDirectories()) subDirectory.Delete(true);
+            foreach(FileInfo file in directory.EnumerateFiles()) file.Delete();
+            foreach(DirectoryInfo subDirectory in directory.EnumerateDirectories()) subDirectory.Delete(true);
+        }
+
+        /// <summary>
+        /// Flattens all files in subfolders to the passed directory recursively.
+        /// 
+        /// 
+        /// foo<para />
+        /// ├── 1.txt<para />
+        /// ├── 2.txt<para />
+        /// ├── 3.txt<para />
+        /// ├── 4.txt<para />
+        /// └── bar<para />
+        ///     ├── 1.txt<para />
+        ///     ├── 2.txt<para />
+        ///     └── 5.txt<para />
+        /// 
+        /// becomes:<para />
+        /// foo<para />
+        /// ├── 1.txt<para />
+        /// ├── 2.txt<para />
+        /// ├── 3.txt<para />
+        /// ├── 4.txt<para />
+        ///     ├── bar_1.txt<para />
+        ///     ├── bar_2.txt<para />
+        ///     └── bar_5.txt<para />
+        /// </summary>
+        /// <param name="directory"></param>
+        public static void Flatten(this DirectoryInfo directory)
+        {
+            FlattenDirectory(directory, directory);
+        }
+
+        private static void FlattenDirectory(DirectoryInfo root, DirectoryInfo directory)
+        {
+            if (!root.FullName.Equals(directory.FullName)) // I might be able to replace this with root === directory
+            {
+                foreach (var file in directory.EnumerateFiles())
+                {
+                    if (file.Directory == null) continue;
+                    var newName = $"{file.Directory.Name}_{file.Name}";
+                    var newPath = Path.Join(root.FullName, newName);
+                    Console.WriteLine($"Renaming/Moving file to: {newPath}");
+                    file.MoveTo(newPath);
+
+                }
+            }
+            
+            foreach (var subDirectory in directory.EnumerateDirectories())
+            {
+                FlattenDirectory(root, subDirectory);
+            }
         }
     }
 }