using System.Text;

namespace BitStrap
{
	public static class BitHelper
	{
		private const int IntSize = 32;

		private static readonly int[] randIntsArray = new int[32];

		private static readonly bool[] bitsArray = new bool[32];

		private static readonly StringBuilder stringBuilder = new StringBuilder(32);

		private static readonly FastRandom fastRandom = new FastRandom();

		public static string ToBinaryString(this int v)
		{
			stringBuilder.Length = 0;
			for (int i = 0; i < 32; i++)
			{
				int num = 1 << i;
				bitsArray[i] = (v & num) != 0;
			}
			for (int num2 = 31; num2 >= 0; num2--)
			{
				stringBuilder.Append((!bitsArray[num2]) ? '0' : '1');
			}
			return stringBuilder.ToString();
		}

		public static int ShuffleBits(int num, int key, int offset = 0)
		{
			fastRandom.SetSeed(key);
			num += offset;
			for (int i = 0; i < 32; i++)
			{
				int nextInt = fastRandom.GetNextInt();
				num = SwapBits(num, i, nextInt % 32);
			}
			return num;
		}

		public static int UnshuffleBits(int num, int key, int offset = 0)
		{
			fastRandom.SetSeed(key);
			for (int i = 0; i < 32; i++)
			{
				randIntsArray[i] = fastRandom.GetNextInt();
			}
			for (int num2 = 31; num2 >= 0; num2--)
			{
				int num3 = randIntsArray[num2];
				num = SwapBits(num, num2, num3 % 32);
			}
			return num - offset;
		}

		public static int SwapBits(int num, int indexA, int indexB)
		{
			int num2 = 1 << indexA;
			int num3 = 1 << indexB;
			bool flag = (num & num2) != 0;
			bool flag2 = (num & num3) != 0;
			num = ((!flag) ? (num & ~num3) : (num | num3));
			num = ((!flag2) ? (num & ~num2) : (num | num2));
			return num;
		}
	}
}