// Zlib.cs
// ------------------------------------------------------------------
//
// Copyright (c) 2009-2011 Dino Chiesa and Microsoft Corporation.
// All rights reserved.
//
// This code module is part of DotNetZip, a zipfile class library.
//
// ------------------------------------------------------------------
//
// This code is licensed under the Microsoft Public License.
// See the file License.txt for the license details.
// More info on: http://dotnetzip.codeplex.com
//
// ------------------------------------------------------------------
//
// Last Saved: <2011-August-03 19:52:28>
//
// ------------------------------------------------------------------
//
// This module defines classes for ZLIB compression and
// decompression. This code is derived from the jzlib implementation of
// zlib, but significantly modified.  The object model is not the same,
// and many of the behaviors are new or different.  Nonetheless, in
// keeping with the license for jzlib, the copyright to that code is
// included below.
//
// ------------------------------------------------------------------
//
// The following notice applies to jzlib:
//
// Copyright (c) 2000,2001,2002,2003 ymnk, JCraft,Inc. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in
// the documentation and/or other materials provided with the distribution.
//
// 3. The names of the authors may not be used to endorse or promote products
// derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
// FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,
// INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
// OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
// EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// -----------------------------------------------------------------------
//
// jzlib is based on zlib-1.1.3.
//
// The following notice applies to zlib:
//
// -----------------------------------------------------------------------
//
// Copyright (C) 1995-2004 Jean-loup Gailly and Mark Adler
//
//   The ZLIB software is provided 'as-is', without any express or implied
//   warranty.  In no event will the authors be held liable for any damages
//   arising from the use of this software.
//
//   Permission is granted to anyone to use this software for any purpose,
//   including commercial applications, and to alter it and redistribute it
//   freely, subject to the following restrictions:
//
//   1. The origin of this software must not be misrepresented; you must not
//      claim that you wrote the original software. If you use this software
//      in a product, an acknowledgment in the product documentation would be
//      appreciated but is not required.
//   2. Altered source versions must be plainly marked as such, and must not be
//      misrepresented as being the original software.
//   3. This notice may not be removed or altered from any source distribution.
//
//   Jean-loup Gailly jloup@gzip.org
//   Mark Adler madler@alumni.caltech.edu
//
// -----------------------------------------------------------------------

namespace SabreTools.IO.Compression.Deflate
{
#pragma warning disable IDE0002
#pragma warning disable IDE0049
#pragma warning disable IDE2000
#pragma warning disable IDE2002
    internal class SharedUtils
    {
        /// <summary>
        /// Performs an unsigned bitwise right shift with the specified number
        /// </summary>
        /// <param name="number">Number to operate on</param>
        /// <param name="bits">Ammount of bits to shift</param>
        /// <returns>The resulting number from the shift operation</returns>
        public static int URShift(int number, int bits)
        {
            return (int)((uint)number >> bits);
        }

#if NOT
        /// <summary>
        /// Performs an unsigned bitwise right shift with the specified number
        /// </summary>
        /// <param name="number">Number to operate on</param>
        /// <param name="bits">Ammount of bits to shift</param>
        /// <returns>The resulting number from the shift operation</returns>
        public static long URShift(long number, int bits)
        {
            return (long) ((UInt64)number >> bits);
        }
#endif

        /// <summary>
        ///   Reads a number of characters from the current source TextReader and writes
        ///   the data to the target array at the specified index.
        /// </summary>
        ///
        /// <param name="sourceTextReader">The source TextReader to read from</param>
        /// <param name="target">Contains the array of characteres read from the source TextReader.</param>
        /// <param name="start">The starting index of the target array.</param>
        /// <param name="count">The maximum number of characters to read from the source TextReader.</param>
        ///
        /// <returns>
        ///   The number of characters read. The number will be less than or equal to
        ///   count depending on the data available in the source TextReader. Returns -1
        ///   if the end of the stream is reached.
        /// </returns>
        public static System.Int32 ReadInput(System.IO.TextReader sourceTextReader, byte[] target, int start, int count)
        {
            // Returns 0 bytes if not enough space in target
            if (target.Length == 0) return 0;

            char[] charArray = new char[target.Length];
            int bytesRead = sourceTextReader.Read(charArray, start, count);

            // Returns -1 if EOF
            if (bytesRead == 0) return -1;

            for (int index = start; index < start + bytesRead; index++)
                target[index] = (byte)charArray[index];

            return bytesRead;
        }


        internal static byte[] ToByteArray(System.String sourceString)
        {
            return System.Text.UTF8Encoding.UTF8.GetBytes(sourceString);
        }


        internal static char[] ToCharArray(byte[] byteArray)
        {
            return System.Text.UTF8Encoding.UTF8.GetChars(byteArray);
        }
    }

}