package com.google.common.base;

import static org.junit.Assert.*;

import java.util.HashSet;
import java.util.Set;

import org.junit.Test;

public class TestPredicates {

	@Test
	public void alwaysFalseTest() {
		Predicate<Character> pred = Predicates.alwaysFalse();
		CharMatcher matcher = CharMatcher.forPredicate(pred);
		assertFalse(matcher.matches('A'));
	}
	
	@Test
	public void alwaysTrueTest() {
		Predicate<Character> pred = Predicates.alwaysFalse();
		CharMatcher matcher = CharMatcher.forPredicate(pred);
		assertFalse(matcher.matches('-'));
	}
	
	@Test
	public void andTest() {
		Predicate<Character> letterPredicate = new Predicate<Character>() {

			@Override
			public boolean apply(Character input) {
				return Character.isLetter(input);
			}
		};
		Predicate<Character> aPredicate = new Predicate<Character>() {

			@Override
			public boolean apply(Character input) {
				return input == 'B';
			}
		};
		Set<Predicate<Character>> components = new HashSet<Predicate<Character>>();
		components.add(letterPredicate);
		components.add(aPredicate);
		Predicate<Character> pred = Predicates.and(components);
		CharMatcher matcher = CharMatcher.forPredicate(pred);
		assertFalse(matcher.matches('A'));
		assertFalse(matcher.matches('8'));
		assertTrue(matcher.matches('B'));
	}
	
	@Test
	public void composeTest() {
		Predicate<Character> letterPredicate = new Predicate<Character>() {

			@Override
			public boolean apply(Character input) {
				if(input == null) return false;
				return Character.isLetter(input);
			}
		};
		Function<Integer, Character> f = new Function<Integer, Character>() {
			
			@Override
			public Character apply(Integer input) {
				if(input >= 65 && input <= 90)
					return Character.valueOf((char)input.intValue());
				return null;
			}
		};
		Predicate<Integer> pred = Predicates.compose(letterPredicate, f);
		assertFalse(pred.apply(5));
		assertTrue(pred.apply(65));
		assertTrue(pred.apply(70));
		assertTrue(pred.apply(90));
		assertFalse(pred.apply(91));
	}
	
	@Test
	public void equalToTest() {
		Character target = new Character('A');
		Character noTarget = new Character('B');
		Predicate<Character> pred = Predicates.equalTo(target);
		assertFalse(pred.apply(noTarget));
		assertTrue(pred.apply(target));
	}
	
	@Test
	public void inTest() {
		Character t1 = new Character('A');
		Character t2 = new Character('B');
		Character t3 = new Character('C');
		Set<Character> collection = new HashSet<Character>();
		collection.add(t1);
		collection.add(t2);
		Predicate<Character> pred = Predicates.in(collection);
		assertFalse(pred.apply(t3));
		assertTrue(pred.apply(t1));
		assertTrue(pred.apply(t2));
	}
	
	@Test
	public void notTest() {
		Predicate<Character> letterPredicate = new Predicate<Character>() {

			@Override
			public boolean apply(Character input) {
				if(input == null) return false;
				return Character.isLetter(input);
			}
		};
		Predicate<Character> pred = Predicates.not(letterPredicate);
		Character t1 = new Character('6');
		Character t2 = new Character('B');
		assertTrue(pred.apply(t1));
		assertFalse(pred.apply(t2));
	}
	
	@Test
	public void orTest() {
		Predicate<Character> letterPredicate = new Predicate<Character>() {

			@Override
			public boolean apply(Character input) {
				return Character.isLetter(input);
			}
		};
		Predicate<Character> aPredicate = new Predicate<Character>() {

			@Override
			public boolean apply(Character input) {
				return input == 'B';
			}
		};
		Set<Predicate<Character>> components = new HashSet<Predicate<Character>>();
		components.add(letterPredicate);
		components.add(aPredicate);
		Predicate<Character> pred = Predicates.or(components);
		CharMatcher matcher = CharMatcher.forPredicate(pred);
		assertTrue(matcher.matches('A'));
		assertFalse(matcher.matches('8'));
		assertTrue(matcher.matches('B'));
	}
}