using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.IO.Compression;

using System.IO;

using System.Diagnostics;

namespace ConsoleApp1

{

    class Program

    {

        static void Main(string[] args)

        {

            DecompressDemo();

            Console.ReadLine();

        }                

        private static void CompressDemo()

        {

            string source = @"D:\";

            string[] files = Directory.GetFiles(source, "*", SearchOption.AllDirectories);

            if(files!=null && files.Any())

            {

                foreach(var file in files)

                {

                    CompressFile(file);

                }

            }

        }

        private static void CompressFile(string file)

        {

            Console.WriteLine($"Start to compress {file}");

            Stopwatch sw = new Stopwatch();

            sw.Start();

            string compressedFullName = Path.Combine(Path.GetDirectoryName(file), Path.GetFileNameWithoutExtension(file)) + ".zip";

            if (File.Exists(compressedFullName))

            {

                File.Delete(compressedFullName);

            }

            Task compressTask = Task.Run(() =>

            {

                using (FileStream fs = File.Open(file, FileMode.Open))

                {

                    using (FileStream compressedFileStream = File.Create(compressedFullName))

                    {

                        using (GZipStream gZipStream = new GZipStream(compressedFileStream, CompressionMode.Compress))

                        {

                            fs.CopyTo(gZipStream);

                        }

                    }

                }

            });

            compressTask.Wait();

            sw.Stop();

            if (compressTask.IsCompleted)

            {

                Console.WriteLine($"{file} has been compressed successfully,cost:{sw.ElapsedMilliseconds} ElapsedMilliseconds!");

            }

        }

        private static void DecompressDemo()

        {

            string source = @"D:\";

            string[] compressedFiles = Directory.GetFiles(source, "*.zip");

            if (compressedFiles != null && compressedFiles.Any())

            {

                foreach (var file in compressedFiles)

                {

                    DecompressFile(file);

                }

            }

        }

        private static void DecompressFile(string file)

        {

            Console.WriteLine($"Start to decompress {file}");

            Stopwatch decompressSW = new Stopwatch();

            decompressSW.Start();

            string newFileName = Path.Combine(Path.GetDirectoryName(file)) + Guid.NewGuid().ToString() + Path.GetFileNameWithoutExtension(file);

            Task decompressTask = Task.Run(() =>

            {

                using (FileStream fs = File.Open(file, FileMode.Open))

                {

                    using (FileStream decompressedStream = File.Create(newFileName))

                    {

                        using (GZipStream gzipdecompressedStream = new GZipStream(fs, CompressionMode.Decompress))

                        {

                            gzipdecompressedStream.CopyTo(decompressedStream);

                        }

                    }

                }

            });

            decompressTask.Wait();

            if(decompressTask.IsCompleted)

            {

                decompressSW.Stop();

                Console.WriteLine($"Decompress as {newFileName} cost {decompressSW.ElapsedMilliseconds} milliseconds");

            }

        }

    }

}