package edu.neu.ccs.evergreen.model;

import static junit.framework.Assert.assertEquals;
import static org.junit.Assert.fail;

import org.junit.Test;

/**
 * Test the constraints returned by the factory are correct.
 */
public class ConstraintFactoryTest {

	private void tryRank3(int rank, int v_2, int v_1, int v_0) {
		assertEquals(rank, ConstraintFactory.createOr(0,
				new int[] { v_0, v_1, v_2 }, 1).getRelationNumber());
	}

	/**
	 * Test Or constraint of rank 3.
	 */
	@Test
	public void testCreateOrRankRelation3() {
		tryRank3(254, 3, 2, 1);
		tryRank3(253, 3, 2, -1);
		tryRank3(251, 3, -2, 1);
		tryRank3(247, 3, -2, -1);
		tryRank3(239, -3, 2, 1);
		tryRank3(223, -3, 2, -1);
		tryRank3(191, -3, -2, 1);
		tryRank3(127, -3, -2, -1);
	}

	private void tryRank2(int rank, int v_1, int v_0) {
		assertEquals(rank, ConstraintFactory.createOr(0,
				new int[] { v_0, v_1 }, 1).getRelationNumber());
	}

	/**
	 * Test Or constraint of rank 2.
	 */
	@Test
	public void testCreateOrRankRelation2() {
		tryRank2(238, 2, 1);
		tryRank2(221, 2, -1);
		tryRank2(187, -2, 1);
		tryRank2(119, -2, -1);
	}

	private void tryRank1(int rank, int v_0) {
		assertEquals(rank, ConstraintFactory.createOr(0, new int[] { v_0 }, 1)
				.getRelationNumber());
	}

	/**
	 * Test Or constraint of rank 1.
	 */
	@Test
	public void testCreateOrRankRelation1() {
		tryRank1(170, 1);
		tryRank1(85, -1);
	}

	private void tryImpliesRank3(int rank, int v_2, int v_1, int v_0) {
		assertEquals(rank, ConstraintFactory.createImplies(0,
				new int[] { v_0, v_1, v_2 }, 1).getRelationNumber());
	}

	/**
	 * Test implies constraint of rank 3.
	 */
	@Test
	public void testCreateImpliesRankRelation() {
		tryImpliesRank3(169, 3, 2, 1);
		tryImpliesRank3(166, 3, -2, 1);
		tryImpliesRank3(154, -3, 2, 1);
		tryImpliesRank3(106, -3, -2, 1);
	}

	/**
	 * Test a bad variable in the constraint.
	 */
	@Test
	public void testBadVar() {
		try {
			new Constraint(0, 255, new int[] { 1, 2, 1 }, 1);
			fail("No error");
		} catch (IllegalArgumentException illegalArgumentException) {
		}
	}

	/**
	 * Test positions in constraint.
	 */
	@Test
	public void testPosition() {
		Constraint constraint = new Constraint(0, 255, new int[] { 1, 2, 3 }, 0);
		assertEquals(2, constraint.getPosition(3));
		assertEquals(1, constraint.getPosition(2));
		assertEquals(0, constraint.getPosition(1));
	}

}