package aktortest;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;



public class Aktortest {

    /* CONSTANT VALUES */
    private final static int cColorCount    = 3;
    private final static int cRedOffset     = 0;
    private final static int cGreenOffset   = 1;
    private final static int cBlueOffset    = 2;

    private final static boolean cIsVerbose = true;



/* ################################################################################################### */
/* WORKING METHODS */
    /**
     * Executes the Split Pixel exercise
     * @param input = byte array, with pixels to split
     * @param pRedFileName  = string of filename where the red pixels have to saved to
     * @param pGreenFileName    = string of filename where the green pixels have to saved to
     * @param pBlueFileName = string of filename where the blue pixels have to saved to
     * @throws IOException
     */
    public static void SplitPixel(byte[] input, String pRedFileName, String pGreenFileName, String pBlueFileName) throws IOException
    {
        /* DECLARING THE NEEDED VARIABLES */
        int lArrayLength = input.length;

        byte[] lRedPixel    = new byte[lArrayLength /cColorCount];
        byte[] lGreenPixel  = new byte[lArrayLength /cColorCount];
        byte[] lBluePixel   = new byte[lArrayLength /cColorCount];

        if(cIsVerbose)
            System.out.println("Starting splitting an array of Length: " + lArrayLength);


        /* DO THE ACTUAL SPLITTING */
        for(int i = 0; i < lArrayLength; i += cColorCount)
        {
            lRedPixel[i /cColorCount]   = input[i +cRedOffset];
            lGreenPixel[i /cColorCount] = input[i +cGreenOffset];
            lBluePixel[i /cColorCount]  = input[i +cBlueOffset];
        }

        /* WRITE RESULTS TO THE GIVEN FILES */
        writeBinaryFile(pRedFileName,   lRedPixel);
        writeBinaryFile(pGreenFileName, lGreenPixel);
        writeBinaryFile(pBlueFileName,  lBluePixel);

        if(cIsVerbose)
            System.out.println("Splitted the Array succesfully.\n" +
                                       "Wrote the results to: " + pRedFileName + " (red pixels), "
                                                                + pGreenFileName + "(green pixels), "
                                                                + pBlueFileName + "(blue pixels)");
    }
/* ################################################################################################### */


/* ################################################################################################### */
/* BINARY FILE METHODS */
    /**
     * Read in the given Binary file
     * @param aFileName
     * @return array of read bytes
     * @throws IOException
     */
    static byte[] readBinaryFile(String aFileName) throws IOException {
        Path path = Paths.get(aFileName);
        return Files.readAllBytes(path);
    }

    /**
     * Writes the given array to the specified File
     * @param aFileName
     * @param pContent
     * @throws IOException
     */
    static void writeBinaryFile(String aFileName, byte[] pContent) throws IOException {
        Path path = Paths.get(aFileName);
        Files.write(path, pContent);
    }
/* ################################################################################################### */

    /**
     * @param args
     * @throws IOException
     */
    public static void main(String[] args)  {

        if(args[0].equals("-d"))
        {
            /*
             * args[0] =    "-d"
             * args[1] =    input file
             * args[2] =    red output file
             * args[3] =    green output file
             * args[4] =    blue output file
             */

            try {

                /* READ IN ALL BYTES */
                if(cIsVerbose)
                    System.out.println("Read the file: " + args[1]);
                byte[] buffer = readBinaryFile(args[1]);

                /* WRITE TO THE ACCORDING FILES */
                if(cIsVerbose)
                    System.out.println("Successfully read the file.");
                SplitPixel(buffer, args[2], args[3], args[4]);


            } catch (Exception e)
            {
                System.out.println(e);
            }
        }
        else if(args[0].equals("-c"))
        {
            /*
             * args[0] =    "-c"
             */

            /* DO WHATEVER -c HAS TO DO */
        }
    }
}