package genericsexample;

import java.util.Comparator;

// class that knows how to compare HCCClasses to each other 
// based on number of credits
public class ClassCreditComparator implements Comparator<HCCClass> {

	// method for comparing classes, 
	// class is bigger if it has more credits
	// if same number of credits, fall back on compareTo from HCCClass
	public int compare(HCCClass class1, HCCClass class2) {
		// take care of null cases
		if (class1 == null && class2 == null) {
			return 0;
		}
		if (class1 == null) {
			return -1;
		}
		if (class2 == null) {
			return 1;
		}

		// determine difference in number of credits
		int diffCredits = class1.getCredits() - class2.getCredits();

		// if there is a difference, use that as comparison value		
		if (diffCredits != 0) {
			return diffCredits;
		}
		
		// otherwise, credits are the same, use compareTo from HCCClass
		return class1.compareTo(class2);
		
		
		
	}

}