/*
    MultiwayBranch6.java
    David G. Klick
    September 21, 2007
    CIS 111
 
    Demonstrates switch statement with fall-through
    (purposefully missing 'break' statements). This
    version takes leap years into account. This version
    also has some basic input error checking.
*/

public class MultiwayBranch6 extends CIS111App {
    public static void main(String[] args) {
        int days = 0;
        int month = 0;
        int year = 0;
        boolean valid = true;
        
        // get month and check for validity
        month = getInt("What month number is it? ");
        if ( (month < 1) || (month > 12)) {
           println("Invalid month specified");
           valid = false;
        }

        // get year and check for validity
        if (valid) {
           year = getInt("What year is it? ");
           if (year < 1900) {
              println("Year must be 1900 or greater");
              valid = false;
           }
        }
        
        // do number of days in month calculation
        if (valid) {
           switch (month) {
               case  1: 
               case  3: 
               case  5: 
               case  7: 
               case  8: 
               case  10: 
               case  12: 
                  days = 31;
                  break;
               case  4: 
               case  6: 
               case  9: 
               case 11: 
                  days = 30;
                  break;
               case  2:
                 if ( ((year % 4 == 0) && !(year % 100 == 0))
                     || (year % 400 == 0)) {
                     days = 29;
                  } else {
                     days = 28;
                  }
                  break;
               default:
                  // should never get here since we have a previous check
                  println("*Invalid month specified*");
                  valid = false;
           }
        }
        
        // display results
        if (valid) {
           print(month + "/" + year + " has " + days + " days");
        }
    }
}