// Helene Martin, CSE 142
// Several methods that return booleans

// goal: demonstrate that boolean is a type like any other
// show examples of 1-line boolean methods that increase readability
// show "boolean zen"
import java.util.*;

public class BooleanDemo {
	public static void main(String[] args) {
		Scanner console = new Scanner(System.in);
		System.out.print("What's your age? ");
		int age = console.nextInt();
		boolean canVote = age >= 18;
		System.out.println(canVote);
		boolean isSunny = true;
		
		if (canVote && isSunny) {
			System.out.println("To the polls!");
		}
		
		System.out.println(isPrime(age));
		
		// full coverage tests for bothOdd
		System.out.println();
		System.out.println("testing bothOdd");
		System.out.println(bothOdd(12, 14));
		System.out.println(bothOdd(13, 14));
		System.out.println(bothOdd(12, 13));
		System.out.println(bothOdd(13, 15));
		
		// should also test isVowel and isNonVowel
	}
	
	// isPrime returns true if parameter is prime, false otherwise
	public static boolean isPrime(int value) {
		return factors(value) == 2; // very zen
		
		// bad boolean zen:
		/*if (prime) { // prime == true
			return true;
		} else {		// prime == false
			return false;
		}*/
		
		/*boolean prime = factors == 2;
		return prime;*/
	}
	
	// counts and returns the factors of a given number
	public static int factors(int value) {
		int factors = 0;
		for (int i = 1; i <= value; i++) {
			if (value % i == 0) {
				factors++;
			}
		}
		return factors;
	}
	
	// bothOdd returns true if both parameters are odd, false otherwise
	public static boolean bothOdd(int val1, int val2) {
		// boolean firstOdd = val1 % 2 != 0;
		// boolean secondOdd = val2 % 2 != 0;
		// return firstOdd && secondOdd;
		return val1 % 2 != 0 && val2 % 2 != 0;
	}
	
	// isVowel returns whether a String is a vowel (a, e, i, o, or u), 
	// case-insensitively.
	public static boolean isVowel(String s) {
		s = s.toLowerCase(); // or use equalsIgnoreCase
		return s.equals("a") || s.equals("e") || s.equals("i") 
				|| s.equals("o") || s.equals("u");
	}
	
	// isNonVowel returns whether a String is any character except a vowel.
	public static boolean isNonVowel(String s) {
		//s = s.toLowerCase();
		//return !s.equals("a") && !s.equals("e" ... De Morgan's law
		return !isVowel(s);
	}
}