/* ====================================================================
   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
==================================================================== */

/* ================================================================
 * About NPOI
 * Author: Tony Qu 
 * Author's email: tonyqus (at) gmail.com 
 * Author's Blog: tonyqus.wordpress.com.cn (wp.tonyqus.cn)
 * HomePage: http://www.codeplex.com/npoi
 * Contributors:
 * 
 * ==============================================================*/

namespace HH.WMS.Utils.NPOI.Util
{
    using System;
    using System.IO;
    using HH.WMS.Utils.NPOI.POIFS.NIO;

    public class IOUtils
    {
        /// <summary>
        /// Reads all the data from the input stream, and returns
        /// the bytes Read.
        /// </summary>
        /// <param name="stream">The stream.</param>
        /// <returns></returns>
        /// <remarks>Tony Qu changed the code</remarks>
        public static byte[] ToByteArray(Stream stream)
        {
            using (MemoryStream baos = new MemoryStream())
            {
                byte[] buffer = new byte[4096];
                int read = -2;
                while (read != -1 && read != 0)
                {
                    read = stream.Read(buffer, 0, buffer.Length);
                    if (read > 0)
                    {
                        baos.Write(buffer, 0, read);
                    }
                }

                return baos.ToArray();
            }
        }
		   public static byte[] ToByteArray(ByteBuffer buffer, int length)
        {
            if (buffer.HasBuffer && buffer.Offset == 0)
            {
                // The backing array should work out fine for us
                return buffer.Buffer;
            }

            byte[] data = new byte[length];
            buffer.Read(data);
            return data;
        }


        /// <summary>
        /// Reads the fully.
        /// </summary>
        /// <param name="stream">The stream.</param>
        /// <param name="b">The b.</param>
        /// <returns></returns>
        public static int ReadFully(Stream stream, byte[] b)
        {
            return ReadFully(stream, b, 0, b.Length);
        }

        /// <summary>
        /// Same as the normal 
        /// <c>in.Read(b, off, len)</c>
        /// , but tries to ensure that the entire len number of bytes is Read.
        /// If the end of file is reached before any bytes are Read, returns -1.
        /// If the end of the file is reached after some bytes are
        /// Read, returns the number of bytes Read.
        /// If the end of the file isn't reached before len
        /// bytes have been Read, will return len bytes.
        /// </summary>
        /// <param name="stream">The stream.</param>
        /// <param name="b">The b.</param>
        /// <param name="off">The off.</param>
        /// <param name="len">The len.</param>
        /// <returns></returns>

        public static int ReadFully(Stream stream, byte[] b, int off, int len)
        {
            int total = 0;
            while (true)
            {
                int got = stream.Read(b, off + total, len - total - off);
                total += got;
                if (stream.Position == stream.Length)
                {
                    return total;
                }
                if (total == len)
                {
                    return total;
                }
            }

        }

        /// <summary>
        /// Copies all the data from the given InputStream to the OutputStream. It
        /// leaves both streams open, so you will still need to close them once done.
        /// </summary>
        /// <param name="inp"></param>
        /// <param name="out1"></param>
        public static void Copy(Stream inp, Stream out1)
        {
            byte[] buff = new byte[4096];
            inp.Position = 0;
            int count;
            while ((count = inp.Read(buff, 0, buff.Length)) != -1)
            {
                if (count > 0)
                {
                    out1.Write(buff, 0, count);
                }
            }
        }

        public static long CalculateChecksum(byte[] data)
        {
            CRC32 sum = new CRC32();
            return (long)sum.ByteCRC(ref data);
        }
    }
}