using System;
namespace ln.type.arithmetics
{
	public static class Words
	{

		public static UInt16[] Add(UInt16[] a, UInt16 b)
		{
			UInt16[] b2 = new ushort[a.Length];
			b2[0] = b;
			return Add(a, b2);
		}
		public static UInt16[] Add(UInt16[] a, int b)
		{
			UInt16[] b2 = new ushort[a.Length];
			b2[0] = (ushort)(b & 0xffff);
			if (b2.Length > 1)
				b2[1] = (ushort)((b >> 16) & 0xffff);

			return Add(a, b2);
		}

		public static UInt16[] Add(UInt16[] a, UInt16[] b)
		{
			UInt16[] result = new ushort[a.Length > b.Length ? a.Length : b.Length];
			int m = 0;

			for (int n = 0; n < result.Length; n++)
			{
				m += (n < a.Length ? a[n] : 0) + (n < b.Length ? b[n] : 0);
				result[n] = (ushort)(m & 0xFFFF);
				m >>= 16;
			}

			return result;
		}

		public static UInt16[] Del(UInt16[] a, UInt16 b)
		{
			UInt16[] b2 = new ushort[a.Length];
			b2[0] = b;
			return Del(a, b2);
		}
		public static UInt16[] Del(UInt16[] a, int b)
		{
			UInt16[] b2 = new ushort[a.Length];
			b2[0] = (ushort)(b & 0xffff);
			if (b2.Length > 1)
				b2[1] = (ushort)((b >> 16) & 0xffff);

			return Del(a, b2);
		}
		public static UInt16[] Del(UInt16[] a, UInt16[] b)
		{
			UInt16[] result = new ushort[a.Length > b.Length ? a.Length : b.Length];
			int m = 0;

			for (int n = 0; n < result.Length; n++)
			{
				m += (n < a.Length ? a[n] : 0) - (n < b.Length ? b[n] : 0);
				result[n] = (ushort)(m & 0xFFFF);
				m >>= 16;
			}

			return result;
		}
		public static UInt16[] And(UInt16[] a, UInt16[] b)
		{
			UInt16[] result = new ushort[a.Length > b.Length ? a.Length : b.Length];

			for (int n = 0; n < result.Length; n++)
			{
				result[n] = (ushort)((n < a.Length ? a[n] : 0) & (n < b.Length ? b[n] : 0));
			}

			return result;
		}
		public static UInt16[] Or(UInt16[] a, UInt16[] b)
		{
			UInt16[] result = new ushort[a.Length > b.Length ? a.Length : b.Length];

			for (int n = 0; n < result.Length; n++)
			{
				result[n] = (ushort)((n < a.Length ? a[n] : 0) | (n < b.Length ? b[n] : 0));
			}

			return result;
		}

		public static UInt16[] SHL(UInt16[] src,int shift)
		{
			UInt16[] result = new ushort[src.Length];
			int step = (shift >> 4);
			shift &= 0xF;

			uint m = 0;

			for (int n = 0; (n+step) < src.Length; n++)
			{
				m |= src[n];
				m <<= shift;

				result[n + step] |= (ushort)(m & 0xFFFF);
				m >>= 16;
			}

			return result;
		}



		public static ushort[] BigEndian(this ushort[] bytes)
		{
			if (BitConverter.IsLittleEndian)
			{
				bytes = bytes.Slice(0);
				Array.Reverse(bytes);
			}
			return bytes;
		}

	}
}