using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using ICSharpCode.SharpZipLib;
using ICSharpCode.SharpZipLib.Zip;
using ICSharpCode.SharpZipLib.Checksum;
using System.Web;

namespace BLL
{
    public class UploadZipService
    {
        /// 
        /// 递归压缩文件夹方法
        /// 
        private static bool ZipFileDictory(string FolderToZip, ZipOutputStream s, string ParentFolderName)
        {
            bool res = true;
            string[] folders, filenames;
            ZipEntry entry = null;
            FileStream fs = null;
            Crc32 crc = new Crc32();

            try
            {

                //创建当前文件夹
                entry = new ZipEntry(Path.Combine(ParentFolderName, Path.GetFileName(FolderToZip) + "/").Replace("\\", "/")); //加上 “/” 才会当成是文件夹创建

                s.PutNextEntry(entry);
                s.Flush();


                //先压缩文件，再递归压缩文件夹 
                filenames = Directory.GetFiles(FolderToZip);
                foreach (string file in filenames)
                {
                    //打开压缩文件
                    fs = File.OpenRead(file);

                    byte[] buffer = new byte[fs.Length];
                    fs.Read(buffer, 0, buffer.Length);
                    entry = new ZipEntry(Path.Combine(ParentFolderName, Path.GetFileName(FolderToZip) + "/" + Path.GetFileName(file)).Replace("\\", "/"));
                    entry.CompressionMethod = CompressionMethod.Stored;
                    entry.DateTime = DateTime.Now;
                    entry.Size = fs.Length;
                    fs.Close();

                    crc.Reset();
                    crc.Update(buffer);

                    entry.Crc = crc.Value;

                    s.PutNextEntry(entry);

                    s.Write(buffer, 0, buffer.Length);
                }

                folders = Directory.GetDirectories(FolderToZip);
                foreach (string folder in folders)
                {
                    if (!ZipFileDictory(folder, s, Path.Combine(ParentFolderName, Path.GetFileName(FolderToZip)).Replace("\\", "/")))
                    {
                        return false;
                    }
                }

            }
            catch
            {
                res = false;
            }
            finally
            {
                if (fs != null)
                {
                    fs.Close();
                    fs = null;
                }
                if (entry != null)
                {
                    entry = null;
                }

                GC.Collect();
                GC.Collect(1);
            }
            return res;
        }

        /// 
        /// 压缩目录
        /// 
        /// 待压缩的文件夹，全路径格式
        /// 压缩后的文件名，全路径格式
        /// 
        private static bool ZipFileDictory(string FolderToZip, string ZipedFile, String Password)
        {
            bool res;
            if (!Directory.Exists(FolderToZip))
            {
                return false;
            }

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

            res = ZipFileDictory(FolderToZip, s, "");

            s.Finish();
            s.Close();
            s.Dispose();
            s = null;
            return res;
        }

        /// 
        /// 压缩文件
        /// 
        /// 要进行压缩的文件名
        /// 压缩后生成的压缩文件名
        /// 
        private static bool ZipFile(string FileToZip, string ZipedFile, String Password)
        {
            //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!");
            }
            //FileStream fs = null;
            FileStream ZipFile = null;
            ZipOutputStream ZipStream = null;
            ZipEntry ZipEntry = null;

            bool res = true;
            try
            {
                ZipFile = File.OpenRead(FileToZip);
                byte[] buffer = new byte[ZipFile.Length];
                ZipFile.Read(buffer, 0, buffer.Length);
                ZipFile.Close();

                ZipFile = File.Create(ZipedFile);
                ZipStream = new ZipOutputStream(ZipFile);
                ZipStream.Password = Password;
                ZipEntry = new ZipEntry(Path.GetFileName(FileToZip));
                ZipStream.PutNextEntry(ZipEntry);
                ZipStream.SetLevel(6);

                ZipStream.Write(buffer, 0, buffer.Length);
            }
            catch
            {
                res = false;
            }
            finally
            {
                if (ZipEntry != null)
                {
                    ZipEntry = null;
                }
                if (ZipStream != null)
                {
                    ZipStream.Finish();
                    ZipStream.Close();
                }
                if (ZipFile != null)
                {
                    ZipFile.Close();
                    ZipFile = null;
                }
                GC.Collect();
                GC.Collect(1);
            }

            return res;
        }

        /// 
        /// 压缩文件 和 文件夹
        /// 
        /// 待压缩的文件或文件夹，全路径格式
        /// 压缩后生成的压缩文件名，全路径格式
        /// 
        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>
        /// 解压zip格式的文件。
        /// </summary>
        /// <param name="zipFilePath">压缩文件路径</param>
        /// <param name="unZipDir">解压文件存放路径,为空时默认与压缩文件同一级目录下，跟压缩文件同名的文件夹</param>
        /// <param name="err">出错信息</param>
        /// <returns>解压是否成功</returns>
        public static bool UnZipFile(string zipFilePath, string unZipDir, out string err)
        {
            err = "";
            if (zipFilePath == string.Empty)
            {
                err = "压缩文件不能为空！";
                return false;
            }
            if (!File.Exists(zipFilePath))
            {
                err = "压缩文件不存在！";
                return false;
            }
            //解压文件夹为空时默认与压缩文件同一级目录下，跟压缩文件同名的文件夹
            if (unZipDir == string.Empty)
                unZipDir = zipFilePath.Replace(Path.GetFileName(zipFilePath), Path.GetFileNameWithoutExtension(zipFilePath));
            if (!unZipDir.EndsWith("\\"))//如果解压文件存放路径结尾没\时将\加上去
                unZipDir += "\\";
            if (!Directory.Exists(unZipDir))//判断如果解压文件存放路径没有则创建
                Directory.CreateDirectory(unZipDir);
            try
            {
                using (ZipInputStream s = new ZipInputStream(File.OpenRead(zipFilePath)))
                {
                    ZipEntry theEntry;

                    while ((theEntry = s.GetNextEntry()) != null)
                    {

                        string directoryName = Path.GetDirectoryName(theEntry.Name);
                        string fileName = Path.GetFileName(theEntry.Name);
                        if (directoryName.Length > 0)
                        {
                            Directory.CreateDirectory(unZipDir + directoryName);
                        }
                        if (!directoryName.EndsWith("\\"))
                            directoryName += "\\";
                        if (fileName != String.Empty)
                        {
                            using (FileStream streamWriter = File.Create(unZipDir + theEntry.Name))
                            {

                                int size = 2048;
                                byte[] data = new byte[2048];
                                while (true)
                                {
                                    size = s.Read(data, 0, data.Length);
                                    if (size > 0)
                                    {
                                        streamWriter.Write(data, 0, size);
                                    }
                                    else
                                    {
                                        break;
                                    }
                                }
                                streamWriter.Dispose();
                                streamWriter.Close();
                            }

                        }

                    }
                    s.Dispose();
                    s.Close();
                }

            }
            catch (Exception ex)
            {
                err = ex.Message;
                return false;
            }
            return true;
        }
    }

}