using System.Linq;
using System.Text;
using System.IO;
using ICSharpCode.SharpZipLib.Zip;
using System;

namespace Estsh.Core.Util
{
    public class ZipHelper
    {
        /// <summary>
        /// 压缩文件和文件夹
        /// </summary>
        /// <param name="FileToZip">待压缩的文件或文件夹，全路径格式</param>
        /// <param name="ZipedFile">压缩后生成的压缩文件名，全路径格式</param>
        /// <param name="Password">压缩文件的密码</param>
        /// <returns></returns>
        public static bool Zip(String FileToZip, String ZipedFile, String Password)
        {
            if (Directory.Exists(FileToZip))
            {
                return ZipFileDictory(FileToZip, ZipedFile, Password);
            }
            else if (File.Exists(FileToZip))
            {
                return ZipFile(FileToZip, ZipedFile, Password);
            }
            else
            {
                return false;
            }
        }

        /// <summary>
        /// 压缩目录
        /// </summary>
        /// <param name="FolderToZip">待压缩的文件夹，全路径格式</param>
        /// <param name="ZipedFile">压缩后的文件名，全路径格式</param>
        /// <param name="Password">压缩文件的密码</param>
        /// <returns></returns>
        private static bool ZipFileDictory(string FolderToZip, string ZipedFile, String Password)
        {
            bool res = true;
            if (!Directory.Exists(FolderToZip))
            {
                return false;
            }

            ZipOutputStream s = new ZipOutputStream(File.Create(ZipedFile));
            s.Password = Password;
            s.SetLevel(6);
            _CompressFolder(FolderToZip, s, FolderToZip);

            s.Finish();
            s.Close();

            return res;
        }

        /// <summary>
        /// 压缩文件
        /// </summary>
        /// <param name="FileToZip">要进行压缩的文件名</param>
        /// <param name="ZipedFile">压缩后生成的压缩文件名</param>
        /// <returns></returns>
        private static bool ZipFile(string FileToZip, string ZipedFile, String Password)
        {
            bool res = true;
            //如果文件没有找到，则报错
            if (!File.Exists(FileToZip))
            {
                throw new System.IO.FileNotFoundException("指定要压缩的文件: " + FileToZip + " 不存在!");
            }
            ZipOutputStream s = new ZipOutputStream(File.Create(ZipedFile));
            s.Password = Password;
            s.SetLevel(6);
            _AddFile(FileToZip, s, FileToZip);

            s.Finish();
            s.Close();

            return res;
        }

        /// <summary>
        /// 压缩单独文件
        /// </summary>
        /// <param name="FileToZip">要进行压缩的文件名</param>
        /// <param name="zips">压缩后文件的输出流</param>
        /// <param name="zipfolername">被压缩目录名称</param>
        private static void _CreateZipFile(string FileToZip, ZipOutputStream zips, string zipfolername)
        {
            FileStream StreamToZip = null;
            ZipEntry ZipEn = null;

            try
            {
                StreamToZip = new FileStream(FileToZip, FileMode.Open, FileAccess.Read);

                FileToZip = FileToZip.Substring(zipfolername.LastIndexOf("\\") + 1);

                ZipEn = new ZipEntry(FileToZip);
                zips.PutNextEntry(ZipEn);
                byte[] buffer = new byte[16384];
                System.Int32 size = StreamToZip.Read(buffer, 0, buffer.Length);
                zips.Write(buffer, 0, size);
                while (size < StreamToZip.Length)
                {
                    int sizeRead = StreamToZip.Read(buffer, 0, buffer.Length);
                    zips.Write(buffer, 0, sizeRead);
                    size += sizeRead;
                }
            }
            catch (Exception e)
            {
                throw e;
            }
            finally
            {
                if (StreamToZip != null)
                {
                    StreamToZip.Close();
                    StreamToZip = null;
                }
                if (ZipEn != null)
                {
                    ZipEn = null;
                }
            }
        }

        /// <summary>
        ///　压缩某个子文件
        /// </summary>
        /// <param name="fileName"></param>
        /// <param name="zips"></param>
        /// <param name="zipfolername"></param>
        private static void _AddFile(string fileName, ZipOutputStream zips, string zipfolername)
        {
            if (File.Exists(fileName))
            {
                _CreateZipFile(fileName, zips, zipfolername);
            }
        }

        /// <summary>
        /// 压缩某个子文件夹
        /// </summary>
        /// <param name="basePath"></param>
        /// <param name="zips"></param>
        /// <param name="zipfolername"></param>     
        private static void _CompressFolder(string basePath, ZipOutputStream zips, string zipfolername)
        {
            if (File.Exists(basePath))
            {
                _AddFile(basePath, zips, zipfolername);
                return;
            }
            string[] names = Directory.GetFiles(basePath);
            foreach (string fileName in names)
            {
                _AddFile(fileName, zips, zipfolername);
            }

            names = Directory.GetDirectories(basePath);
            foreach (string folderName in names)
            {
                _CompressFolder(folderName, zips, zipfolername);
            }
        }

        /// <summary>
        /// 解压功能(解压压缩文件到指定目录)
        /// </summary>
        /// <param name="FileToUpZip">待解压的文件</param>
        /// <param name="ZipedFolder">指定解压目标目录</param>
        public static void UnZip(string FileToUpZip, string ZipedFolder, string Password)
        {
            byte[] buffer = new byte[2048];
            while (ZipedFolder.LastIndexOf("\\") + 1 == ZipedFolder.Length)//检查路径是否以"\"结尾
            {
                ZipedFolder = ZipedFolder.Substring(0, ZipedFolder.Length - 1);//如果是则去掉末尾的"\"
            }

            using (ZipInputStream zipStream = new ZipInputStream(File.OpenRead(FileToUpZip)))
            {

                //判断Password
                if (Password != null && Password.Length > 0)
                {
                    zipStream.Password = Password;
                }

                ZipEntry zipEntry = null;
                while ((zipEntry = zipStream.GetNextEntry()) != null)
                {
                    string directoryName = Path.GetDirectoryName(zipEntry.Name);
                    string fileName = Path.GetFileName(zipEntry.Name);

                    if (!string.IsNullOrEmpty(directoryName) && !Directory.Exists(ZipedFolder + @"\" + directoryName))
                    {
                        Directory.CreateDirectory(ZipedFolder + @"\" + directoryName);
                    }

                    if (!string.IsNullOrEmpty(fileName))
                    {
                        if (zipEntry.CompressedSize == 0)
                            break;
                        if (zipEntry.IsDirectory)//如果压缩格式为文件夹方式压缩
                        {
                            directoryName = Path.GetDirectoryName(ZipedFolder + @"\" + zipEntry.Name);
                            Directory.CreateDirectory(directoryName);
                        }
                        else//2012-5-28修改，支持单个文件压缩时自己创建目标文件夹
                        {
                            if (!Directory.Exists(ZipedFolder))
                            {
                                Directory.CreateDirectory(ZipedFolder);
                            }
                        }

                        using (FileStream stream = File.Create(ZipedFolder + @"\" + zipEntry.Name))
                        {
                            while (true)
                            {
                                int size = zipStream.Read(buffer, 0, buffer.Length);
                                if (size > 0)
                                {
                                    stream.Write(buffer, 0, size);
                                }
                                else
                                {
                                    break;
                                }
                            }
                        }
                    }
                }
            }
        }

    }
}