/*
 * Copyright (C) 2016 Didier Clermonté <dclermonte@april.org>
 * Copyright (C) 2016 Christian Pierre Momon <christian.momon@devinsy.fr>
 *
 * This file is part of Siba.
 *
 * Siba is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.dclermonte.siba.model;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

import org.apache.commons.compress.archivers.ArchiveException;
import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
import org.apache.commons.compress.archivers.tar.TarArchiveOutputStream;
import org.apache.commons.compress.compressors.gzip.GzipCompressorOutputStream;
import org.apache.commons.compress.utils.IOUtils;
import org.dclermonte.siba.SibaNullException;

public class SibaManager
{

	public static File backup(final File fileToSave, final File target)
			throws ArchiveException, IOException, SibaNullException
	{
		File result;
		if ((fileToSave == null) || (target == null))
		{
			throw new SibaNullException("Données incomplètes");
		}
		int pathLength = fileToSave.getParentFile().getAbsolutePath().length();

		LocalDateTime date = LocalDateTime.now();
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'H'h'm'mn's's'");
		String textDate = date.format(formatter);
		String outputFileNameWithoutExtension = fileToSave.getName() + "-" + textDate;

		result = new File(target + "/" + outputFileNameWithoutExtension + ".tgz");

		OutputStream gzipOutputStream = new GzipCompressorOutputStream(
				new BufferedOutputStream(new FileOutputStream(result)));
		TarArchiveOutputStream out = new TarArchiveOutputStream(gzipOutputStream);
		directoryToSave(fileToSave, out, pathLength);
		out.close();
		md5(result, target + "/" + outputFileNameWithoutExtension + ".tgz.md5");

		return result;
	}

	public static boolean check(final File choosenFile) throws IOException, NoSuchAlgorithmException
	{
		boolean result;
		FileReader fileReader = new FileReader(choosenFile);
		char[] md5 = new char[32];
		byte[] md5byte = new byte[32];
		char[] fileToCheck = new char[(int) (choosenFile.length()) - 32];
		String md5String = new String();
		for (int index = 0; index < 32; index++)
		{
			md5[index] = (char) fileReader.read();
			md5byte[index] = (byte) md5[index];
			md5String = md5String + md5[index];
		}
		fileReader.read();
		String fileNameToString = new String();
		for (int index = 36; index < (choosenFile.length() + 2); index++)
		{
			fileToCheck[index - 36] = (char) fileReader.read();
			fileNameToString = fileNameToString + fileToCheck[index - 36];
		}

		fileReader.close();
		File fileToCheck1 = new File(choosenFile.getParent() + "/" + fileNameToString);
		byte[] bytedirectoryToSave = new byte[(int) fileToCheck1.length()];
		FileInputStream fileInputStream = new FileInputStream(fileToCheck1);
		for (int index1 = 0; index1 < (fileToCheck1.length()); index1++)
		{
			bytedirectoryToSave[index1] = (byte) fileInputStream.read();
		}
		fileInputStream.close();
		byte[] hash = null;
		StringBuilder hashString = new StringBuilder();
		MessageDigest messageDigest = MessageDigest.getInstance("MD5");
		hash = messageDigest.digest(bytedirectoryToSave);
		for (int index = 0; index < hash.length; index++)
		{
			String hex = Integer.toHexString(hash[index]);
			if (hex.length() == 1)
			{
				hashString.append('0');
				hashString.append(hex.charAt(hex.length() - 1));
			}
			else
			{
				hashString.append(hex.substring(hex.length() - 2));
			}
		}

		if (md5String.equals(hashString.toString()))
		{
			result = true;
		}
		else
		{
			result = false;
		}
		return result;
	}

	public static void directoryToSave(final File directory, final TarArchiveOutputStream outputStream,
			final int pathLength) throws IOException
	{
		for (File file : directory.listFiles())
		{

			if (file.isDirectory())
			{
				directoryToSave(file, outputStream, pathLength);
			}
			else
			{
				TarArchiveEntry tarArchiveEntry = new TarArchiveEntry(file);
				String pathPartiel = file.getPath().substring(pathLength);
				tarArchiveEntry.setName(pathPartiel);
				outputStream.putArchiveEntry(tarArchiveEntry);
				IOUtils.copy(new FileInputStream(file), outputStream);
				outputStream.closeArchiveEntry();

			}
		}

	}

	public static File md5(final File directoryToSave, final String destination) throws IOException
	{
		File result;

		result = new File(destination);
		try
		{
			byte[] bytedirectoryToSave = new byte[(int) directoryToSave.length()];
			FileInputStream fileInputStream = new FileInputStream(directoryToSave);
			for (int index1 = 0; index1 < directoryToSave.length(); index1++)
			{
				bytedirectoryToSave[index1] = (byte) fileInputStream.read();
			}

			byte[] hash = null;
			MessageDigest messageDigest = MessageDigest.getInstance("MD5");
			hash = messageDigest.digest(bytedirectoryToSave);
			StringBuilder hashString = new StringBuilder();
			for (int index = 0; index < hash.length; index++)
			{
				String hex = Integer.toHexString(hash[index]);
				if (hex.length() == 1)
				{
					hashString.append('0');
					hashString.append(hex.charAt(hex.length() - 1));
				}
				else
				{
					hashString.append(hex.substring(hex.length() - 2));
				}
			}
			FileWriter fileWriter = new FileWriter(result);
			fileWriter.write(hashString.toString());
			String newLine = System.getProperty("line.separator");
			fileWriter.append(" " + directoryToSave.getName() + newLine);
			fileWriter.close();
			fileInputStream.close();
		}
		catch (NoSuchAlgorithmException e)
		{
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

		return result;
	}

}