// Copyright (C) 2024, The Duplicati Team
// https://duplicati.com, hello@duplicati.com
// 
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// copy of this software and associated documentation files (the "Software"), 
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// and/or sell copies of the Software, and to permit persons to whom the 
// Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in 
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// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
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using System;
using System.Linq;
using System.Collections.Generic;
using Duplicati.Library.Interface;
using Duplicati.Library.Common.IO;

namespace Duplicati.Library.Compression
{
    /// <summary>
    /// This class exposes a local directory as a file archive.
    /// Used only internally for debugging, cannot be used as a storage method.
    /// </summary>
    public class FileArchiveDirectory : ICompression
    {
        string m_folder;

        /// <summary>
        /// Constructs a new FileArchive
        /// </summary>
        /// <param name="basefolder">The folder to base the archive on</param>
        public FileArchiveDirectory(string basefolder)
        {
            m_folder = Util.AppendDirSeparator(basefolder);
        }

        #region IFileArchive Members

        /// <summary>
        /// Unsupported filename extension property, throws a MissingMethodException
        /// </summary>
        public string FilenameExtension { get { throw new MissingMethodException(); } }
        /// <summary>
        /// Unsupported displayname property, throws a MissingMethodException
        /// </summary>
        public string DisplayName { get { throw new MissingMethodException(); } }
        /// <summary>
        /// Unsupported description property, throws a MissingMethodException
        /// </summary>
        public string Description { get { throw new MissingMethodException(); } }
        /// <summary>
        /// Unsupported supported commands property, throws a MissingMethodException
        /// </summary>
        public IList<ICommandLineArgument> SupportedCommands { get { throw new MissingMethodException(); } }

        /// <summary>
        /// Returns a list of files in the archive
        /// </summary>
        /// <param name="prefix">An optional prefix that is used to filter the list</param>
        /// <returns>A filtered list of filenames</returns>
        public string[] ListFiles(string prefix)
        {
            if (prefix == null) prefix = "";
            return Utility.Utility.EnumerateFiles(System.IO.Path.Combine(m_folder, prefix)).ToArray();
        }

        /// <summary>
        /// Returns a list of files in the archive
        /// </summary>
        /// <param name="prefix">An optional prefix that is used to filter the list</param>
        /// <returns>A filtered list of filenames</returns>
        public IEnumerable<KeyValuePair<string, long>> ListFilesWithSize(string prefix)
        {
            if (prefix == null) prefix = "";
            List<KeyValuePair<string, long>> res = new List<KeyValuePair<string,long>>();
            foreach(string s in Utility.Utility.EnumerateFiles(System.IO.Path.Combine(m_folder, prefix)))
                res.Add(new KeyValuePair<string, long>(s, new System.IO.FileInfo(s).Length));

            return res;

        }

        /// <summary>
        /// Opens the file for reading
        /// </summary>
        /// <param name="file">The name of the file</param>
        /// <returns>A stream with the file contents</returns>
        public System.IO.Stream OpenRead(string file)
        {
            return System.IO.File.OpenRead(System.IO.Path.Combine(m_folder, file));
        }

        /// <summary>
        /// Creates a new empty file
        /// </summary>
        /// <param name="file">The name of the file to create</param>
        /// <param name="hint">A hint to the compressor as to how compressible the file data is</param>
        /// <param name="lastWrite">The time the file was last written</param>
        /// <returns>The stream used to access the file</returns>
        public System.IO.Stream CreateFile(string file, CompressionHint hint, DateTime lastWrite)
        {
            string path = System.IO.Path.Combine(m_folder, file);
            System.IO.Stream res = System.IO.File.Create(path);

            //TODO: This should actually be set when closing the stream
            System.IO.File.SetLastWriteTime(path, lastWrite);
            return res;
        }
        
        /// <summary>
        /// Returns a value that indicates if the file exists
        /// </summary>
        /// <param name="file">The name of the file to test existence for</param>
        /// <returns>True if the file exists, false otherwise</returns>
        public bool FileExists(string file)
        {
            return System.IO.File.Exists(System.IO.Path.Combine(m_folder, file));
        }

        /// <summary>
        /// Gets the current size of the archive
        /// </summary>
        public long Size
        {
            get { return Utility.Utility.GetDirectorySize(m_folder); }
        }

        /// <summary>
        /// Gets the last write time for a file
        /// </summary>
        /// <param name="file">The name of the file to query</param>
        /// <returns>The last write time for the file</returns>
        public DateTime GetLastWriteTime(string file)
        {
            return System.IO.File.GetLastWriteTime(System.IO.Path.Combine(m_folder, file));
        }

        /// <summary>
        /// The size of the current unflushed buffer
        /// </summary>
        public long FlushBufferSize { get { return 0; } }

        #endregion

        #region IDisposable Members

        /// <summary>
        /// Disposes the instance
        /// </summary>
        public void Dispose()
        {
            m_folder = null;
        }

        #endregion
    }
}