// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : Swapping.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Helpers.
//
// --[ Description ] ----------------------------------------------------------
//
//     Byte-swapping methods.
//
// --[ License ] --------------------------------------------------------------
//
//     This library is free software; you can redistribute it and/or modify
//     it under the terms of the GNU Lesser General Public License as
//     published by the Free Software Foundation; either version 2.1 of the
//     License, or (at your option) any later version.
//
//     This library is distributed in the hope that it will be useful, but
//     WITHOUT ANY WARRANTY; without even the implied warranty of
//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
//     Lesser General Public License for more details.
//
//     You should have received a copy of the GNU Lesser General Public
//     License along with this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2016 Natalia Portillo
// ****************************************************************************/

using System;

namespace DiscImageChef
{
    public static class Swapping
    {
        public static byte[] SwapTenBytes(byte[] source)
        {
            byte[] destination = new byte[8];

            destination[0] = source[9];
            destination[1] = source[8];
            destination[2] = source[7];
            destination[3] = source[6];
            destination[4] = source[5];
            destination[5] = source[4];
            destination[6] = source[3];
            destination[7] = source[2];
            destination[8] = source[1];
            destination[9] = source[0];

            return destination;
        }

        public static byte[] SwapEightBytes(byte[] source)
        {
            byte[] destination = new byte[8];

            destination[0] = source[7];
            destination[1] = source[6];
            destination[2] = source[5];
            destination[3] = source[4];
            destination[4] = source[3];
            destination[5] = source[2];
            destination[6] = source[1];
            destination[7] = source[0];

            return destination;
        }

        public static byte[] SwapFourBytes(byte[] source)
        {
            byte[] destination = new byte[4];

            destination[0] = source[3];
            destination[1] = source[2];
            destination[2] = source[1];
            destination[3] = source[0];

            return destination;
        }

        public static byte[] SwapTwoBytes(byte[] source)
        {
            byte[] destination = new byte[2];

            destination[0] = source[1];
            destination[1] = source[0];

            return destination;
        }

        public static UInt32 PDPFromLittleEndian(UInt32 x)
        {
            return ((x & 0xffff) << 16) | ((x & 0xffff0000) >> 16);
        }

        public static UInt32 PDPFromBigEndian(UInt32 x)
        {
            return ((x & 0xff00ff) << 8) | ((x & 0xff00ff00) >> 8);
        }
    }
}