import java.util.Scanner;
import java.io.*;

/**
 * This is a quick and dirty program to reformat a .ppm file generated by
 * the GIMP so that the RGB values are in three columns instead of just one.
 *
 * Input is a filename with no extension. The program adds the extension ".ppm"
 * to create the input file name, and creates an additional, reformatted output file
 * with "-3col.ppm" tacked onto the filename.
 *
 */
public class FixPPMFile {
	public static void main(String[] args) {
		
		//Get filename from commandline or use hardcoded name
		String filename = "";
		if (args.length > 0)
			filename = args[0];
		else {
			filename = "fixme";
			// could also prompt user for another filename here instead ...
		}
		String infile = filename + ".ppm";
		String outfile = filename + "-3col.ppm";
		
		Scanner in = null;
		try {
			in = new Scanner(new File(infile));
		} catch (Exception e) {
			System.err.println("Can't open input file: " + infile);
			System.exit(-1);
		}

		PrintWriter pw = null;
		try {
			pw = new PrintWriter(new FileWriter(outfile));
		} catch (Exception e) {
			System.err.println("Can't open output file: " + outfile);
			System.exit(-1);
		}
		
		// Read the first four header lines and output these verbatim
		for (int i = 0; i < 4; i++) {
			String line = in.nextLine();
			pw.println(line);
		}
		
		// Add some comments so students don't edit the wrong thing when using a
		// spreadsheet
		pw.println("# Do not edit above this line!");
		pw.println("# Below this line are Red Green Blue columns");
		
		// Read the rest of the data in the file, one value per line,
		// outputting the values 3 to a line.
		int count = 0;
		while (in.hasNextLine()) {
			pw.print(in.nextLine());
			if (count == 2) {
				pw.println();
				count = 0;
			} else {
				pw.print(" ");
				count++;
			}
		}
		
		// All done, clean up
		in.close();
		pw.close();
	}
}