// =============================================================================
/**
 * Print a variety of basic 2D patterns to the console.
 *
 * @author sfkaplan@cs.amherst.edu
 */

public class PrintPattern {
// =============================================================================

    

    // =========================================================================
    // CONSTANTS

    /** The character to use in printing the boundaries of each pattern. */
    final public static char mark = '+';

    /** The character to use in printing the spaces within each pattern. */
    final public static char space = ' ';
    // =========================================================================



    // =========================================================================
    /**
     * The program's entry point.
     *
     * @param args The command-line arguments provided by the user.
     */
    public static void main (String[] args) {

	// If an incorrect number of arguments was provided on the command-line,
	// then print the correct usage and exit.
	if (args.length != 2) {
	    showUsageAndExit();
	}

	// Grab the arguments.
	String shape = args[0];
	int size = 0;
	try {
	    size = Integer.parseInt(args[1]);
	} catch (NumberFormatException e) {
	    showUsageAndExit();
	}

	// Call the appropriate method for the requested pattern.
	if (shape.equals("square")) {
	    printSquare(size);
	} else if (shape.equals("triangle")) {
	    printTriangle(size);
	} else if (shape.equals("octagon")) {
	    printOctagon(size);
	} else if (shape.equals("serpinksi")) {
	    printSierpinkski(size);
	} else {
	    showUsageAndExit();
	}
	
    } // main()
    // =========================================================================



    // =========================================================================
    /**
     * Print the correct form for running this program and exit with an error
     * code.
     */
    public static void showUsageAndExit () {

	System.err.println("USAGE: java PrintPattern " +
			   "<shape [square|triangle|octagon|sierpinkski]> <size>");
	System.exit(1);
	
    } // showUsageAndExit()
    // =========================================================================



    // =========================================================================
    /**
     * Print an empty square with <code>size</code> characters to each side.
     *
     * @param size The size of a the square on each size (as a number of
     *             characters).
     */
    public static void printSquare (int size) {

	for (int i = 0; i < size; i += 1) {
	    System.out.print(mark);
	}
	System.out.println();
	for (int i = 0; i < size - 2; i += 1) {
	    System.out.print(mark);
	    for (int j = 0; j < size - 2; j += 1) {
		System.out.print(space);
	    }
	    System.out.println(mark);
	}
	for (int i = 0; i < size; i += 1) {
	    System.out.print(mark);
	}
	System.out.println();
	
    } // printSquare()
    // =========================================================================



    // =========================================================================
    /**
     * Print an empty isosceles triangle with <code>size</code> characters for
     * the base and height.
     *
     * @param size The size of the base and height of the triangle (as a number
     *             of characters).
     */
    public static void printTriangle (int size) {

	// REPLACE ME WITH REAL CODE!
	System.out.println("Triangles NOT YET IMPLEMENTED!");

    } // printTriangle ()
    // =========================================================================



    // =========================================================================
    /**
     * Print an empty octagon with <code>size</code> characters to each side.
     *
     * @param size The number of characters to each side of the octagon.
     */
    public static void printOctagon (int size) {

	// REPLACE ME WITH REAL CODE!
	System.out.println("Octagon NOT YET IMPLEMENTED!");

    } // printOctagon ()
    // =========================================================================



    // =========================================================================
    /**
     * Print the first <code>rows</code> of Sierpinkski's Gasket as a sequence of
     * <code>mark</code> and <code>space</code> characters.
     *
     * @param rows The number of rows of the gasket to print.
     */
    public static void printSierpinkski (int rows) {

	// REPLACE ME WITH REAL CODE!
	System.out.println("Sierpinkski NOT YET IMPLEMENTED!");

    } // printSierpinkski ()
    // =========================================================================



// =============================================================================
} // class PrintPattern
// =============================================================================