namespace FeedbackGeneratorQQ.Utils
{
   using System;
   using System.Collections.Generic;
   using System.Linq;
   using System.Security.Cryptography;

   public static class RandomGenerator
   {
      private static readonly RNGCryptoServiceProvider CryptRng = new RNGCryptoServiceProvider();
      const long _max = (1 + (long)uint.MaxValue);

      /// <summary>
      /// Gets random integer number from the given interval
      /// </summary>
      /// <param name="minValue"> Min value (including) </param>
      /// <param name="maxValue"> Max value (excluding) </param>
      /// <returns> Returns random integer number </returns>
      public static int GetRandomNumber(int minValue, int maxValue)
      {
         if (minValue == maxValue)
         {
            return minValue;
         }

         byte[] bytes = new byte[4];
         long diff = maxValue - minValue;
         while (true)
         {
            CryptRng.GetBytes(bytes);
            uint rand = BitConverter.ToUInt32(bytes, 0);
            
            long remainder = _max % diff;
            if (rand < _max - remainder)
            {
               return (int)(minValue + (rand % diff));
            }
         }
      }

      public static IList<T> Shuffle<T>(this IList<T> list)
      {
         return list.OrderBy(a => GetRandomNumber(0, list.Count * 3)).ToList();
      }
   }
}