//	Spludlow Software
//	Copyright © Samuel P. Ludlow 2020 All Rights Reserved
//	Distributed under the terms of the GNU General Public License version 3
//	Distributed WITHOUT ANY WARRANTY; without implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE
//	https://www.spludlow.co.uk/LICENCE.TXT
//	The Spludlow logo is a registered trademark of Samuel P. Ludlow and may not be used without permission
//	v1.14

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Spludlow
{
	public class RandomKeys
	{
		private static string LettersCharacters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
		private static string DigitsCharacters = "1234567890";
		private static string AlphaNumericCharacters = "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ";
		private static string PasswordCharacters = "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!£$%^&*()-+=[]{};:@#<>,./?";

		private static Random _Random = new Random();
		public static string Password()
		{
			return Password(32);
		}
		public static string Password(int length)
		{
			return Make(PasswordCharacters, length);
		}
		public static string Letters(int length)
		{
			return Make(LettersCharacters, length);
		}
		public static string Digits(int length)
		{
			return Make(DigitsCharacters, length);
		}
		public static string AlphaNumeric(int length)
		{
			return Make(AlphaNumericCharacters, length);
		}
		public static string Make(string characters, int length)
		{
			StringBuilder text = new StringBuilder();

			for (int step = 0; step < length; ++step)
			{
				int index;

				lock (_Random)
					index = _Random.Next(characters.Length);

				text.Append(characters[index]);
			}
				

			return text.ToString();
		}
	}
}