How to Rename FolderNames and FileNames with matching strings Recursively

Question

My application generates files in the following directory structure

FolderMatchALeve1
-FileMatchALevel2_A.cs
-FileMatchALevel2_B.cs
-FolderMatchALevel2
--FileMatchALevel3_A.txt
--FileMatchALevel3_B.txt

I am looking for a way to rename the directory structure, with the following change – Change “MatchA” to “AMatch”.

So the result should look like so after executing the program:

FolderAMatchLeve1
-FileAMatchLevel2_A.cs
-FileAMatchLevel2_B.cs
-FolderAMatchLevel2
--FileAMatchLevel3_A.txt
--FileAMatchLevel3_B.txt

So far in my quest to find a solution, I have been unsuccessful. Please help me find a solution to this.

I need this solution in C# Winforms because of maintaining a legacy product at our company.

Edit:

Additional Information

1. I need to make this change each time someone runs our program.

2. I need to do this to 3350 files

Question Summary:

In short, while recursively(or iteratively) going through each directory, I want it to rename files whose names match with matching strings and then after coming out, rename the directory, if it too has a name matching the string (for all partial or complete matches).

Answer 1

Quick and Dirty (but working)

public static class DirectoryRenamer
{
    public static void RenameDirectoryTree( string path, Func<string, string> renamingRule )
    {
        var di = new DirectoryInfo( path );
        RenameDirectoryTree( di, renamingRule );
    }

    public static void RenameDirectoryTree( DirectoryInfo directory, Func<string, string> renamingRule )
    {
        InternalRenameDirectoryTree( directory, renamingRule );

        var currentName = directory.Name;
        var newName = renamingRule( currentName );
        if ( currentName != newName )
        {
            var newDirname = Path.Combine( directory.Parent.FullName, newName );
            directory.MoveTo( newDirname );
        }
    }

    static void InternalRenameDirectoryTree( DirectoryInfo di, Func<string, string> renamingRule )
    {
        foreach ( var item in di.GetFileSystemInfos() )
        {
            var subdir = item as DirectoryInfo;
            if ( subdir != null )
            {
                InternalRenameDirectoryTree( subdir, renamingRule );

                var currentName = subdir.Name;
                var newName = renamingRule( currentName );
                if ( currentName != newName )
                {
                    var newDirname = Path.Combine( subdir.Parent.FullName, newName );
                    subdir.MoveTo( newDirname );
                }
            }

            var file = item as FileInfo;
            if ( file != null )
            {
                var currentName = Path.GetFileNameWithoutExtension( file.Name );
                var newName = renamingRule( currentName );
                if ( currentName != newName )
                {
                    var newFilename = Path.Combine( file.DirectoryName, newName + file.Extension );
                    file.MoveTo( newFilename );
                }
            }
        }
    }
}

sample usage

class Program
{
    static void Main( string[] args )
    {
        DirectoryRenamer.RenameDirectoryTree( 
            @"C:\Test\FolderMatchALevel", 
            name => name.Replace( "MatchA", "AMatch" ) );
    }
}