using System;
using System.Security.Cryptography;
using System.Text;

namespace Dough.Utilities
{
    public static class Random
    {
        private const string RandomStringCharacters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        private static readonly char[] RandomPasswordCharacters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890".ToCharArray();

        public static string String(int length)
        {
            var stringChars = new char[length];
            var random = new System.Random();

            for (var i = 0; i < stringChars.Length; i++)
                stringChars[i] = RandomStringCharacters[random.Next(RandomStringCharacters.Length)];
            
            return new string(stringChars);
        }
        
        public static string Password(int length)
        {
            var data = new byte[4*length];
            using (var crypto = new RNGCryptoServiceProvider())
            {
                crypto.GetBytes(data);
            }
            var result = new StringBuilder(length);
            for (var i = 0; i < length; i++)
            {
                var rnd = BitConverter.ToUInt32(data, i * 4);
                var idx = rnd % RandomPasswordCharacters.Length;
                result.Append(RandomPasswordCharacters[idx]);
            }

            return result.ToString();        
        }
        
        public static int Number(int length)
        {
            var random = new System.Random();
            return random.Next(0, length);
        }
        
        public static string NumericalString(int length)
        {
            var stringChars = new char[length];
            var random = new System.Random();

            for (var i = 0; i < stringChars.Length; i++)
                stringChars[i] = RandomStringCharacters[random.Next(RandomStringCharacters.Length)];
            
            return new string(stringChars);
        }

    }
}