using System;
using System.IO;


namespace TxtFileSizeGenerator
{
    class Program
    {
        static void Main(string[] args)
        {
            while (true)
            {
                Console.WriteLine("Byte, Kb or Mb");
                string ans = Console.ReadLine();
                File.Delete("txt.txt");
                switch (ans.ToLower())
                {
                    case "byte":
                        Console.WriteLine("Successfully Saved");
                        Console.WriteLine("");
                        randomString(1, "byte");
                        break;
                    case "kb":
                        Console.WriteLine("Successfully Saved");
                        Console.WriteLine("");
                        randomString(1, "kb");
                        break;
                    case "mb":
                        Console.WriteLine("");
                        randomString(1024, "mb");
                        break;

                }
            }
        }

        static void randomString(int size, string type)
        {
            Console.WriteLine("How Many?");
            int amount;
            if (!int.TryParse(Console.ReadLine(), out amount))
            {
                Console.WriteLine("Error, this is a text only field");
            }
            else
            {
                char[] letters = "qwertyuiopasdfghjklzxcvbnm1234567890".ToCharArray();
                Random r = new Random();
                string random = string.Empty;
                for (int i = 0; i < 1 * size; i++)
                {
                    random += letters[r.Next(0, 35)].ToString();
                }
                if (type != "byte")
                {
                    for (int i = 0; i < 1024 * amount; i++)
                    {
                        File.AppendAllText("txt.txt", random);
                    }
                    Console.WriteLine("Successfully Saved");
                    System.Threading.Thread.Sleep(2000);
                    Console.Clear();
                }
                else
                {
                    for (int i = 0; i < amount; i++)
                    {
                        File.AppendAllText("txt.txt", random);
                    }
                    Console.WriteLine("Successfully Saved");
                    System.Threading.Thread.Sleep(2000);
                    Console.Clear();
                }
            }
        }
    }
}