package org.adoxx.utils;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintStream;
import java.io.RandomAccessFile;
import java.util.Scanner;

public class IOUtils {

    public static void writeFile(byte[] data, String filePath, boolean appendData) throws Exception{
        FileOutputStream fos = new FileOutputStream(new File(filePath), appendData);
        fos.write(data);
        fos.flush();
        fos.close();
    }
    
    public static byte[] readFile(String file) throws Exception{
        return readFile(new File(file));
    }
    
    public static byte[] readFile(File file) throws Exception{
        RandomAccessFile raf = new RandomAccessFile(file, "r");
        byte[] ret = new byte[(int)raf.length()];
        raf.read(ret);
        raf.close();
        return ret;
    }
    
    public static void inheritIO(final InputStream src, final PrintStream dest) {
        new Thread(new Runnable() {
            public void run() {
                Scanner sc = new Scanner(src);
                while (sc.hasNextLine()) {
                    dest.println(sc.nextLine());
                }
                sc.close();
            }
        }).start();
    }
    
    public static void copyInputStreamToOutputStream(InputStream input, OutputStream output) throws Exception{
        int n = 0;
        int DEFAULT_BUFFER_SIZE = 1024 * 1024 * 10;
        byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
        while (-1 != (n = input.read(buffer)))
            output.write(buffer, 0, n);
    }
    
    public static byte[] toByteArray(InputStream is) throws Exception{
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        copyInputStreamToOutputStream(is, out);
        byte[] ret = out.toByteArray();
        out.close();
        out = null;
        return ret;
    }
    
    //Memory efficient read from InputStream
    public static byte[] toByteArrayEfficient(InputStream is) throws Exception{
        
        int totEstimatedLength = is.available();
        int DEFAULT_BUFFER_SIZE = totEstimatedLength;
        if(DEFAULT_BUFFER_SIZE == 0)
            DEFAULT_BUFFER_SIZE =  1024 * 1024 * 10;
        
        byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
        int totLength = 0;
        int tmpLength = 0;
        byte[] ret = new byte[0];

        while (-1 != (tmpLength = is.read(buffer))){
            if(totEstimatedLength != 0 && tmpLength == totEstimatedLength) //Se e' vera verra' fatta solo al primo ciclo e non verranno creati ulteriori array, minimizzando la memoria usata.
                return buffer;
            
            totLength += tmpLength;
            byte[] newRet = new byte[totLength];
            System.arraycopy(ret, 0, newRet, 0, ret.length);
            System.arraycopy(buffer, 0, newRet, ret.length, tmpLength);
            ret = newRet;
            System.gc();
        }
        
        System.gc();
        
        return ret;
    }


}