/*
 *
 * (c) Copyright Ascensio System Limited 2010-2020
 *
 * This program is freeware. You can redistribute it and/or modify it under the terms of the GNU 
 * General Public License (GPL) version 3 as published by the Free Software Foundation (https://www.gnu.org/copyleft/gpl.html). 
 * In accordance with Section 7(a) of the GNU GPL its Section 15 shall be amended to the effect that 
 * Ascensio System SIA expressly excludes the warranty of non-infringement of any third-party rights.
 *
 * THIS PROGRAM IS DISTRIBUTED WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY OR
 * FITNESS FOR A PARTICULAR PURPOSE. For more details, see GNU GPL at https://www.gnu.org/copyleft/gpl.html
 *
 * You can contact Ascensio System SIA by email at sales@onlyoffice.com
 *
 * The interactive user interfaces in modified source and object code versions of ONLYOFFICE must display 
 * Appropriate Legal Notices, as required under Section 5 of the GNU GPL version 3.
 *
 * Pursuant to Section 7 § 3(b) of the GNU GPL you must retain the original ONLYOFFICE logo which contains 
 * relevant author attributions when distributing the software. If the display of the logo in its graphic 
 * form is not reasonably feasible for technical reasons, you must include the words "Powered by ONLYOFFICE" 
 * in every copy of the program you distribute. 
 * Pursuant to Section 7 § 3(e) we decline to grant you any rights under trademark law for use of our trademarks.
 *
*/

namespace ASC.Data.Backup
{
    public class ZipWriteOperator : IDataWriteOperator
    {
        private readonly GZipOutputStream _gZipOutputStream;
        private readonly TarOutputStream _tarOutputStream;
        private readonly Stream _file;
        private readonly TempStream _tempStream;

        public ZipWriteOperator(TempStream tempStream, string targetFile)
        {
            _file = new FileStream(targetFile, FileMode.Create);
            _gZipOutputStream = new GZipOutputStream(_file);
            _tarOutputStream = new TarOutputStream(_gZipOutputStream, Encoding.UTF8);
            _tempStream = tempStream;
        }

        public void WriteEntry(string key, Stream stream)
        {
            using (var buffered = _tempStream.GetBuffered(stream))
            {
                var entry = TarEntry.CreateTarEntry(key);
                entry.Size = buffered.Length;
                _tarOutputStream.PutNextEntry(entry);
                buffered.Position = 0;
                buffered.CopyTo(_tarOutputStream);
                _tarOutputStream.CloseEntry();
            }
        }

        public void Dispose()
        {
            _tarOutputStream.Close();
            _tarOutputStream.Dispose();
        }
    }

    public class ZipReadOperator : IDataReadOperator
    {
        private readonly string _tmpDir;

        public ZipReadOperator(string targetFile)
        {
            _tmpDir = Path.Combine(Path.GetDirectoryName(targetFile), Path.GetFileNameWithoutExtension(targetFile).Replace('>', '_').Replace(':', '_').Replace('?', '_'));

            using (var stream = File.OpenRead(targetFile))
            using (var reader = new GZipInputStream(stream))
            using (var tarOutputStream = TarArchive.CreateInputTarArchive(reader, Encoding.UTF8))
            {
                tarOutputStream.ExtractContents(_tmpDir);
            }

            File.Delete(targetFile);
        }

        public Stream GetEntry(string key)
        {
            var filePath = Path.Combine(_tmpDir, key);

            return File.Exists(filePath) 
                ? File.Open(filePath, FileMode.Open, FileAccess.ReadWrite, FileShare.Read) 
                : null;
        }

        public IEnumerable<string> GetEntries(string key)
        {
            var path = Path.Combine(_tmpDir, key);
            var files = Directory.EnumerateFiles(path);

            return files;
        }

        public void Dispose()
        {
            if (Directory.Exists(_tmpDir))
            {
                Directory.Delete(_tmpDir, true);
            }
        }
    }
}