using System;
using System.Text;

namespace BaseNcoding
{
	public static class StringGenerator
	{
		private const string LettersAndDigits = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

		public static string GetAlphabet(int charsCount)
		{
			var result = new StringBuilder(charsCount);
			int i = 0;
			int count = 0;
			do
			{
				char c = (char)i;
				if (!char.IsControl(c) && !char.IsWhiteSpace(c))
				{
					result.Append(c);
					count++;
				}
				i++;
			}
			while (count < charsCount);

			return result.ToString();
		}

		public static string GetRandom(int size, bool onlyLettersAndDigits)
		{
			Random r = new Random();
			if (onlyLettersAndDigits)
			{
				var result = new char[size];
				for (int i = 0; i < size; i++)
					result[i] = LettersAndDigits[r.Next(LettersAndDigits.Length)];
				return new string(result);
			}

			var data = new byte[size];
			for (int i = 0; i < size; i++)
				data[i] = (byte) r.Next(32, 127);
			var encoding = new ASCIIEncoding();
			return encoding.GetString(data);
		}
	}
}