using System;
using System.IO;

namespace RandomNamesGenerator
{
    internal class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Write path to folder with files to rename (like \"C:\\Users\\*Username*\\Pictures\"):");
            string folderPath = Console.ReadLine();
            IEnumerable<string> files = Directory.EnumerateFiles(folderPath);

            Console.WriteLine("If you want to rename all files in folder, than write \"all\"");
            Console.WriteLine("If you want to rename only specific files, write file extension (like \".png\")");
            Console.WriteLine("What files do you want to rename: ");
            string fileExtension = Console.ReadLine();

            foreach (string file in files)
            {
                FileInfo fileInfo = new FileInfo(file);
                if (fileExtension == "all") {
                    string finalFileName = Path.GetRandomFileName();
                    File.Move(file, $"{folderPath}\\{finalFileName}{fileInfo.Extension}");
                }
                else if (fileInfo.Extension == fileExtension){
                    string finalFileName = Path.GetRandomFileName();
                    File.Move(file, $"{folderPath}\\{finalFileName}{fileExtension}");
                }
            }
        }
    }
}