/**
    *
    * @date 2014-10-23        
    *
    * @author 邓尹平
    *
    * @par 成员列表类 说明
    * 主要负责管理成员 提供搜索\排序和操作的方法
    * 
    * @par 版权声明
    * 深圳市多元世纪信息技术有限公司 版权所有
    * 
    * @see 使用此类时参照一些其他类可以写在这里
    * 
    * @todo 该类有待完成的任务 一条条列出 完成一条删除一条
    *
    * @bug 该类已知的Bug一条条列出 完成一条删除一条
    *
*/

using System;
using System.IO;
using System.IO.Compression;

namespace Muchinfo.PC.Common.Bosn
{
    /// <summary>
    /// 压缩  解压功能组件
    /// </summary>
    public static class ZipHelper
    {
        #region Fields

        private const int BufferLength = 1024;

        #endregion Fields

        #region Methods

        #region Public Static Methods

        /// <summary>
        /// 压缩文件
        /// </summary>
        /// <param name="sourceFile">需要压缩的文件</param>
        /// <param name="zippedFile">压缩后的文件</param>
        /// <exception cref="ArgumentNullException">参数为空异常</exception>
        /// <exception cref="FileNotFoundException">需要压缩的文件不存在</exception>
        public static void Compress(string sourceFile, string zippedFile)
        {
            if (string.IsNullOrEmpty(sourceFile))
                throw new ArgumentNullException("sourceFile");

            if (string.IsNullOrEmpty(zippedFile))
                throw new ArgumentNullException("zippedFile");

            if (File.Exists(sourceFile))
            {
                var streamSource = new FileStream(sourceFile, FileMode.Open, FileAccess.Read, FileShare.Read);
                var streamZipped = new FileStream(zippedFile, FileMode.Create, FileAccess.ReadWrite, FileShare.Read);

                Compress(streamSource, streamZipped);
                streamSource.Close();
                streamZipped.Close();
            }
            else
            {
                throw new FileNotFoundException("需要压缩的文件不存在.", "sourceFile");
            }
        }

        /// <summary>
        /// 压缩流
        /// </summary>
        /// <param name="source">需要压缩的流</param>
        /// <param name="zipped">压缩后的流</param>
        /// <exception cref="ArgumentNullException">参数为空异常</exception>   
        /// <exception cref="ArgumentException">无法读取需要压缩的流以及无法写入压缩的流.</exception>   
        public static void Compress(Stream source, Stream zipped)
        {
            if (source == null)
                throw new ArgumentNullException("source");

            if (zipped == null)
                throw new ArgumentNullException("zipped");

            if (!source.CanRead)
                throw new ArgumentException("无法读取需要压缩的流.", "source");

            if (!zipped.CanWrite)
                throw new ArgumentException("无法写入压缩的流.", "zipped");

            var zipper = new GZipStream(zipped, CompressionMode.Compress);

            var readBuffer = new byte[BufferLength];
            int readCount = source.Read(readBuffer, 0, BufferLength);

            while (readCount != 0)
            {
                zipper.Write(readBuffer, 0, readCount);
                readCount = source.Read(readBuffer, 0, BufferLength);
            }

            zipper.Close();
        }

        /// <summary>
        /// 压缩字节数组
        /// </summary>
        /// <param name="source">需要压缩的字节数组</param>
        /// <exception cref="ArgumentNullException">参数为空异常</exception>      
        /// <exception cref="ArgumentException">需要压缩的字节数组长度不正确</exception>
        /// <returns>压缩后的字节数组</returns>
        public static byte[] Compress(byte[] source)
        {
            if (source == null)
                throw new ArgumentNullException("source");

            if (source.Length == 0)
                throw new ArgumentException("需要压缩的字节数组长度不正确.", "source");

            var streamSource = new MemoryStream(source);

            var streamZipped = new MemoryStream();

            Compress(streamSource, streamZipped);

            streamSource.Close();
            streamZipped.Position = 0;
            byte[] zipped = streamZipped.ToArray();
            streamZipped.Close();

            return zipped;
        }

        /// <summary>
        /// 解压文件
        /// </summary>
        /// <param name="targetFile">解压的文件</param>
        /// <param name="zippedFile">压缩的文件</param>
        /// <exception cref="ArgumentNullException">参数为空异常</exception>
        /// <exception cref="FileNotFoundException">需要压缩的文件不存在</exception>
        public static void Decompress(string zippedFile, string targetFile)
        {
            if (string.IsNullOrEmpty(targetFile))
                throw new ArgumentNullException("targetFile");

            if (string.IsNullOrEmpty(zippedFile))
                throw new ArgumentNullException("zippedFile");

            if (File.Exists(zippedFile))
            {
                var streamTarget = new FileStream(targetFile, FileMode.Create, FileAccess.ReadWrite, FileShare.Read);
                var streamZipped = new FileStream(zippedFile, FileMode.Open, FileAccess.Read, FileShare.Read);

                Decompress(streamZipped, streamTarget);

                streamTarget.Close();

                streamZipped.Close();
            }
            else
            {
                throw new FileNotFoundException("需要压缩的文件不存在.", "sourceFile");
            }
        }

        /// <summary>
        /// 解压缩流
        /// </summary>
        /// <param name="target">需要压缩的流</param>
        /// <param name="zipped">压缩的流</param>
        /// <exception cref="ArgumentNullException">参数为空异常</exception>      
        /// <exception cref="ArgumentException">无法读取压缩的流以及无法写入解压的流.</exception>   
        public static void Decompress(Stream zipped, Stream target)
        {
            if (target == null)
                throw new ArgumentNullException("target");

            if (zipped == null)
                throw new ArgumentNullException("zipped");

            if (!zipped.CanRead)
                throw new ArgumentException("无法读取压缩的流.", "zipped");

            if (!target.CanWrite)
                throw new ArgumentException("无法写入解压的流.", "target");

            var zipper = new GZipStream(zipped, CompressionMode.Decompress);

            var readBuffer = new byte[BufferLength];
            int readCount = zipper.Read(readBuffer, 0, BufferLength);

            while (readCount != 0)
            {
                target.Write(readBuffer, 0, readCount);
                readCount = zipper.Read(readBuffer, 0, BufferLength);
            }
            target.Position = 0;
            zipper.Close();
        }

        /// <summary>
        /// 解压缩字节数组
        /// </summary>
        /// <param name="zipped">需要解压缩的字节数组</param>
        /// <exception cref="ArgumentNullException">参数为空异常</exception>      
        /// <exception cref="ArgumentException">压缩的字节数组长度不正确</exception>
        /// <returns>解压缩后的字节数组</returns>
        public static byte[] Decompress(byte[] zipped)
        {
            if (zipped == null)
                throw new ArgumentNullException("zipped");

            if (zipped.Length == 0)
                throw new ArgumentException("压缩的字节数组长度不正确.", "zipped");

            var streamTarget = new MemoryStream();

            var streamZipped = new MemoryStream(zipped);

            Decompress(streamZipped, streamTarget);

            streamZipped.Close();
            streamTarget.Position = 0;
            byte[] target = streamTarget.ToArray();
            streamTarget.Close();

            return target;
        }

        #endregion Public Static Methods

        #endregion Methods
    }
}