package org.openslx.util;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.charset.StandardCharsets;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
import org.apache.commons.compress.archivers.tar.TarArchiveOutputStream;

public class TarArchiveUtil
{

	private TarArchiveUtil()
	{
	}

	public static class TarArchiveReader implements AutoCloseable
	{
		private final TarArchiveInputStream tarInputStream;
		private TarArchiveEntry currentEntry = null;

		public TarArchiveReader( InputStream in ) throws IOException
		{
			this( in, true, false );
		}

		public TarArchiveReader( InputStream in, boolean isBuffered, boolean isCompressed ) throws IOException
		{
			InputStream stream = in;
			if ( isBuffered ) {
				stream = new BufferedInputStream( stream );
			}

			if ( isCompressed ) {
				stream = new GZIPInputStream( stream );
			}

			this.tarInputStream = new TarArchiveInputStream( stream );
		}

		public boolean hasNextEntry() throws IOException
		{
			this.currentEntry = this.tarInputStream.getNextTarEntry();
			if ( this.currentEntry != null ) {
				return true;
			} else {
				return false;
			}
		}

		public String getEntryName()
		{
			if ( this.currentEntry == null )
				return null;

			return this.currentEntry.getName();
		}

		public byte[] readCurrentEntry() throws IOException
		{
			ByteArrayOutputStream output = new ByteArrayOutputStream();
			byte[] rawData = new byte[ 1024 ];
			int count = 0;

			while ( ( count = this.tarInputStream.read( rawData ) ) != -1 ) {
				output.write( rawData, 0, count );
			}

			return output.toByteArray();
		}

		@Override
		public void close() throws IOException
		{
			tarInputStream.close();
		}

	}

	public static class TarArchiveWriter implements AutoCloseable
	{
		private final TarArchiveOutputStream tarOutputStream;

		public TarArchiveWriter( OutputStream out ) throws IOException
		{
			this( out, true, true );
		}

		public TarArchiveWriter( OutputStream out, boolean isBuffered, boolean isCompressed ) throws IOException
		{
			OutputStream stream = out;

			if ( isBuffered ) {
				stream = new BufferedOutputStream( stream );
			}

			if ( isCompressed ) {
				stream = new GZIPOutputStream( stream );
			}

			this.tarOutputStream = new TarArchiveOutputStream( stream );
		}

		public void writeFile( String filename, String data ) throws IOException
		{

			if ( data == null )
				return;
			putFile( filename, data.getBytes( StandardCharsets.UTF_8 ) );
		}

		public void writeFile( String filename, byte[] data ) throws IOException
		{
			if ( data == null )
				return;
			putFile( filename, data );
		}

		private void putFile( String filename, byte[] data ) throws IOException
		{
			if ( data == null )
				return;

			TarArchiveEntry entry = new TarArchiveEntry( filename );
			entry.setSize( data.length );
			entry.setModTime( System.currentTimeMillis() );
			entry.setMode( 0644 );
			tarOutputStream.putArchiveEntry( entry );
			tarOutputStream.write( data );
			tarOutputStream.closeArchiveEntry();
		}

		@Override
		public void close() throws IOException
		{
			tarOutputStream.close();
		}
	}
}