/**
 * Driver.java
 *
 * The driver for our command line argument example
 *
 * @author Chris Wolf
 * @version 1.0.0 (September 1, 2019)
 * @contact chriswolfdesign@gmail.com
 */
public class Driver {
    /**
     * main method
     *
     * @param args 0 -- the number of times to iterate through the for loop
     *             1 -- the string we are printing out
     */
    public static void main(String[] args) {
        // user must enter two command line arguments
        if (args.length != 2) {
            System.out.println("Usage: java Driver <iterations> <phrase>");
            System.exit(1);
        }

        // second command line argument must be an integer
        if (!isNumeric(args[0])) {
            System.out.println("ERROR -- iterations must be an integer");
            System.exit(2);
        }

        // third command line argument must not be empty
        if (args[1].equals("") || args[1].equals(" ")) {
            System.out.println("ERROR -- phrase must not be empty");
            System.exit(3);
        }

        // if all command line arguments are correct, continue
        for (int i = 0; i < Integer.parseInt(args[0]); i++) {
            System.out.println(args[1]);
        }
    }

    /**
     * Checks to see if the string passed in a valid integer
     *
     * @param number the string we are checking
     *
     * @return true if the string is numeric, false otherwise
     */
    private static boolean isNumeric(String number) {
        try {
            int num = Integer.parseInt(number);
            return true;
        } catch (NumberFormatException nfe) {
            return false;
        }
    }
}