package JavaIO;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.Random;

public class IspitSeptemvri2015termin1 {

	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub

		work("dekemvri","rez");
	}

	public static void rekurzijaBrisenje(File papka) {

		File[] lista = papka.listFiles();

		for (File f : lista) {

			if(f.isFile()){
				f.delete();
			}

			else if (f.isDirectory())
			{
				rekurzijaBrisenje(f);
				f.delete();
			}
		}

	}

	public static void work(String in_value, String out_value) throws IOException {

		File in = new File(in_value);

		if(!in.exists())
			return;
		if(!in.isDirectory())
			return;

		File out = new File(out_value);


		if (out.exists()) {
			if(out.isDirectory())
				rekurzijaBrisenje(out);
			else
				return;
		}
		else
			out.mkdirs();

		File rezultat = new File(out,"big.bin");
		if(!rezultat.exists())
			rezultat.createNewFile();

		File[] lista = in.listFiles();

		for (File f : lista) {

			long golemina = f.length();
			float goleminaKB = (float) golemina / 1024;

			if(f.isFile() && f.getName().endsWith(".txt")) {

				if (goleminaKB < 10) {
					copy(f,out);
				}

				else {
					System.out.println(f.getName());

					File tmp = getRandomFile(in,".bin");

					tmp.createNewFile();

					readFromSourceWriteToDestination(rezultat,tmp);

					rezultat.delete();

					rezultat.createNewFile();

					readFromSourceWriteToDestination(f, rezultat);

					readFromSourceAppendToDestination(tmp,rezultat);
					tmp.delete();
				}

			}

			else if (f.isDirectory())
				work(in.getAbsolutePath(),out.getAbsolutePath());

		}
	}

	private static void readFromSourceAppendToDestination(File source,	File destination) throws IOException {
		// TODO Auto-generated method stub


		RandomAccessFile vlez = null;
		RandomAccessFile izlez = null;

		try {

			vlez = new RandomAccessFile(source, "r");

			izlez = new RandomAccessFile(destination, "rw");

			izlez.seek(izlez.length());

			int b = 0;

			while ((b=vlez.read()) != -1)
				izlez.write(b);



		}
		finally {
			if(vlez!=null)
				vlez.close();
			if(izlez!=null)
				izlez.close();
		}


	}

	public static void readFromSourceWriteToDestination (File source,File destination) throws IOException {

		RandomAccessFile vlez = null;
		RandomAccessFile izlez = null;

		try {

			vlez = new RandomAccessFile(source, "r");

			izlez = new RandomAccessFile(destination, "rw");

			int b = 0;

			while ((b=vlez.read()) != -1)
				izlez.write(b);



		}
		finally {
			if(vlez!=null)
				vlez.close();
			if(izlez!=null)
				izlez.close();
		}

	}

	public static File getRandomFile(File source, String ekstenzija) throws IOException {
		File[] lista = source.listFiles();
		String tmp = "tmp";
		int randomNumber = getRandomValue(1, 100);
		String fileName = tmp + randomNumber + ekstenzija;
		while (sourceContainsFileName(source, fileName)) {
			randomNumber = getRandomValue(1, 100);
			fileName = tmp + randomNumber + ekstenzija;

		}

		File tmpFile = new File(source, fileName);
		tmpFile.createNewFile();
		return tmpFile;

	}

	public static int getRandomValue(int min, int max)

	{
		Random r = new Random();
		int result = r.nextInt(max - min) + min;
		return result;
	}

	public static boolean sourceContainsFileName(File source, String fileName) {
		File[] lista = source.listFiles();
		for (File f : lista) {
			if (f.getName().equals(fileName))
				return true;

		}
		return false;

	}


	public static void copy(File vleznaDatoteka, File destination) throws IOException {
		// TODO Auto-generated method stub

		File nov = new File(destination, vleznaDatoteka.getName());

		if(nov.exists()){
			System.out.println("datotekata " + vleznaDatoteka.getName() + " vekje postoi");

		} else  {
			nov.createNewFile();

			BufferedReader vlez = null;
			BufferedWriter izlez = null;

			try {
				vlez = new BufferedReader(new FileReader(vleznaDatoteka));
				izlez = new BufferedWriter(new FileWriter(nov));

				String line;

				while((line = vlez.readLine()) != null)
					izlez.write(line + "\r\n");
			}
			finally {
				if(vlez!=null)
					vlez.close();
				if(izlez!=null)
					izlez.close();
			}
		}
	}

}