package org.peterd.util;
	
	import java.awt.Dimension;
	import java.util.Random;
	
	
	public final class Misc {
		private Misc() {}
		
		public static boolean equal(Object a, Object b) {
			if (a == null || b == null) {

				return a == b;
			} else {

				return a.equals(b);
			}
		}
	
		public static <E> E or(E a, E b) {
			if (a == null) return b;
			else return a;
		}
		
		public static boolean arraysEqual(Object[] a, Object[] b) {
			if (a.length != b.length) return false;
			for (int i = 0; i < a.length; i++) {
				if (!Misc.equal(a[i],b[i])) return false;
			}
			return true;
		}
		
		public static <X extends Comparable<X>> boolean arraySorted(X[] a) {
			for (int i = 0; i < a.length - 1; i++) {
				if (a[i].compareTo(a[i+1]) > 0) return false;
			}
			return true;
		}
		
		public static void randomlyPermute(Object[] a) {
			int i = a.length;
			while (i > 1) {
				int idx = random.nextInt(i);
				i--;
				Object tmp = a[idx];
				a[idx] = a[i];
				a[i] = tmp;
			}
		}
		
		public static <E> E randomElementOf(E[] a) {
			if (a.length == 0) {
				throw new IllegalArgumentException("Cannot take random element from 0-length array");
			}
			return a[random.nextInt(a.length)];
		}
		
		public static Random random = new Random();
		
		
		public static Dimension maxDimensions(Dimension a, Dimension b) {
			return new Dimension(Math.max(a.width, b.width),
					             Math.max(a.height, b.height));
		}
		
		public static void appendNSpaces(StringBuilder b, int n) {
			for (int i = 0; i < n; i++) {
				b.append(' ');
			}
		}
	}