using System;
using System.Formats.Tar;
using FileCompression.Interfaces;
using FileCompression.Utils;

namespace FileCompression.Services.Strategies;

public class TarGzStrategy : ICompressionStrategy
{
    public void CompressFile(string sourcePath, string destinationPath, string basePath)
    {
        Console.WriteLine($"Compressing {sourcePath} to {destinationPath} using tar and gzip.");
        string tempPath = Path.GetTempFileName();
        using (var tempStream = new FileStream(tempPath, FileMode.Create, FileAccess.Write))
        using (var tempWriter = new TarWriter(tempStream, TarEntryFormat.Pax))
        {
            // Copy existing entries to temp file
            if (File.Exists(destinationPath))
            {
                using (var originalStream = new FileStream(destinationPath, FileMode.Open, FileAccess.Read))
                using (var tarReader = new TarReader(originalStream, leaveOpen: false))
                {
                    TarEntry? entry;
                    while ((entry = tarReader.GetNextEntry()) is not null)
                    {
                        tempWriter.WriteEntry(entry);
                    }
                }
            }

            // Add new entry
            string entryName = ArchiveUtils.EntryFromPath(sourcePath.AsSpan(basePath.Length));
            tempWriter.WriteEntry(sourcePath, entryName);
        }

        File.Copy(tempPath, destinationPath, overwrite: true);
        File.Delete(tempPath);

    }

    public void CompressDirectory(string sourcePath, string destinationPath, string basePath)
    {
        Console.WriteLine($"Compressing {sourcePath} to {destinationPath} using tar and gzip.");
        string tempPath = Path.GetTempFileName();
        using (var tempStream = new FileStream(tempPath, FileMode.Create, FileAccess.Write))
        using (var tempWriter = new TarWriter(tempStream, TarEntryFormat.Pax))
        {
            // Copy existing entries to temp file
            if (File.Exists(destinationPath))
            {
                using (var originalStream = new FileStream(destinationPath, FileMode.Open, FileAccess.Read))
                using (var tarReader = new TarReader(originalStream, leaveOpen: false))
                {
                    TarEntry? entry;
                    while ((entry = tarReader.GetNextEntry()) is not null)
                    {
                        tempWriter.WriteEntry(entry);
                    }
                }
            }

            // Add new entry
            string entryName = ArchiveUtils.EntryFromPath(sourcePath.AsSpan(basePath.Length), appendPathSeparator: true);
            tempWriter.WriteEntry(sourcePath, entryName);
        }

    }
}