/** ups2.java  (calculates the girth)
  *
  * CS7 - practicing with java functions
  *
  * This program asks the user for package details and produces a 
  * classification according to the ups rules.  To find out more
  * about these guidelines, visit:
  * 
  * http://www.ups.com/content/us/en/resources/prepare/weight_size.html
  * 
  * Issues:
  *   - DOUBLES SHOULD PROBABLY BE USED FOR EXTRA PRECISION
  */

// Javadoc comments are also used.  See p.131 in JBD.
 
import tio.*;

class ups2 {

	/** main() handles the top level control.  It calls various
	  * methods to determine the proper classification for the
	  * user's packages.
	  */
	public static void main (String[] args) {
		
		char answer='y';	// user's choice.
		int weight, height, width, length, girth;

		while (answer=='y' || answer=='Y') {

		  // get the package specifications
		  System.out.println("Please enter the package specifications."); 
		  weight = getPosInt("  weight (lbs): ");
		  height = getPosInt("  height  (in): ");
		  width  = getPosInt("  width   (in): ");
		  length = getPosInt("  length  (in): ");
		  System.out.println();

		  // calculate & display girth
		  girth = calcGirth(height, width);
		  System.out.println("The girth is " + girth);

		  System.out.println();
		  System.out.print("Do you have another package to classify? (y/n) ");
		  Console.in.readLine();		// flush out the CR
		  answer = (char) Console.in.readChar();
		}


	} // end main()


	/** getPosInt() reads an integer from the user and rereads while the
	  * number is not positive.
	  *
	  * @param prompt The string to present to the user prior to input.
	  * @return The positive integer.
	  */
	public static int getPosInt(String prompt) {
		System.out.print(prompt);
		int n = Console.in.readInt();
		while (n <= 0) {
		  System.out.print("Please enter a postive value: ");
		  n = Console.in.readInt();
		}
		return n;
	} // end getPosInt()

	
	/** calcGirth() returns the girth of a package, which is the distance
	  * around a package, perpendicular to the length (the longest edge).
	  *
	  * @param ht The height of the package in inches.
	  * @param wd The width of the package in inches.
	  * @return The girth of the package.
	  */
	public static int calcGirth(int ht, int wd) {
		return (ht*2 + wd*2);
	} // end calcGirth()

	
} // end ups class
	

/* SAMPLE RUN:

$ java ups2
Please enter the package specifications.
  weight (lbs): 20
  height  (in): 22
  width   (in): 19
  length  (in): 28

The girth is 82

Do you have another package to classify? (y/n) y
Please enter the package specifications.
  weight (lbs): 18
  height  (in): 2
  width   (in): 4
  length  (in): 10

The girth is 12

Do you have another package to classify? (y/n) n
$

*/