/**
 * Copyright (C) 2010-2017 Gordon Fraser, Andrea Arcuri and EvoSuite
 * contributors
 *
 * This file is part of EvoSuite.
 *
 * EvoSuite is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3.0 of the License, or
 * (at your option) any later version.
 *
 * EvoSuite is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with EvoSuite. If not, see <http://www.gnu.org/licenses/>.
 */
package org.evosuite.symbolic.solver.avm;

import static org.junit.Assert.*;

import java.util.Collection;
import java.util.Collections;

import org.evosuite.RandomizedTC;
import org.evosuite.symbolic.expr.Comparator;
import org.evosuite.symbolic.expr.Constraint;
import org.evosuite.symbolic.expr.Operator;
import org.evosuite.symbolic.expr.StringConstraint;
import org.evosuite.symbolic.expr.bv.IntegerConstant;
import org.evosuite.symbolic.expr.bv.StringBinaryComparison;
import org.evosuite.symbolic.expr.str.StringConstant;
import org.evosuite.symbolic.expr.str.StringVariable;
import org.evosuite.symbolic.solver.DistanceEstimator;
import org.junit.Test;

public class TestStringDistance extends RandomizedTC {

	private static final double DELTA =0;// Math.pow(1,-10000000);


	@Test
	public void testEquals() {
		final String str1 = "abc";
		final String str2 = "abcd";
		Collection<Constraint<?>> cnstr = createConstraints(str1, str2);
		double distance = DistanceEstimator.getDistance(cnstr);
		assertTrue(0.5 == distance);
	}

	@Test
	public void testEquals2() {
		final String str1 = "abcd";
		final String str2 = "abc";
		Collection<Constraint<?>> cnstr = createConstraints(str1, str2);
		double distance = DistanceEstimator.getDistance(cnstr);
		assertTrue(0.5 == distance);
	}

	@Test
	public void testEquals3() {
		final String str1 = "abc";
		final String str2 = "abcde";
		Collection<Constraint<?>> cnstr = createConstraints(str1, str2);
		double distance = DistanceEstimator.getDistance(cnstr);
		assertEquals(0.666666666666666666 , distance, DELTA);
	}
	
	@Test
	public void testEquals4() {
		final String str1 = "abc";
		final String str2 = "xbc";
		Collection<Constraint<?>> cnstr = createConstraints(str1, str2);
		double distance = DistanceEstimator.getDistance(cnstr);
		assertEquals(0.48936170212765956 , distance, DELTA);
	}

	@Test
	public void testEquals5() {
		final String str1 = "abc";
		final String str2 = "xbc";
		Collection<Constraint<?>> cnstr1 = createConstraints(str1, str2);
		double distance1 = DistanceEstimator.getDistance(cnstr1);

		final String str3 = "abc";
		final String str4 = "abcd";
		Collection<Constraint<?>> cnstr2 = createConstraints(str3, str4);
		double distance2 = DistanceEstimator.getDistance(cnstr2);

		assertTrue(distance1<distance2);
	}

	

	@Test
	public void testEquals6() {
		final String str1 = "abc";
		final String str2 = "xbc";
		Collection<Constraint<?>> cnstr1 = createConstraints(str1, str2);
		double distance1 = DistanceEstimator.getDistance(cnstr1);

		final String str3 = "abc";
		final String str4 = "bbc";
		Collection<Constraint<?>> cnstr2 = createConstraints(str3, str4);
		double distance2 = DistanceEstimator.getDistance(cnstr2);

		assertTrue(distance2<distance1);
	}

	@Test
	public void testEquals7() {
		final String str1 = "s";
		final String str2 = "test";
		Collection<Constraint<?>> cnstr1 = createConstraints(str1, str2);
		double distance1 = DistanceEstimator.getDistance(cnstr1);

		final String str3 = "t";
		final String str4 = "test";
		Collection<Constraint<?>> cnstr2 = createConstraints(str3, str4);
		double distance2 = DistanceEstimator.getDistance(cnstr2);

		assertTrue(distance1>distance2);
	}

	@Test
	public void testEquals8() {
		final String str1 = "test";
		final String str2 = "est";
		Collection<Constraint<?>> cnstr1 = createConstraints(str1, str2);
		double distance1 = DistanceEstimator.getDistance(cnstr1);

		final String str3 = "test";
		final String str4 = "estx";
		Collection<Constraint<?>> cnstr2 = createConstraints(str3, str4);
		double distance2 = DistanceEstimator.getDistance(cnstr2);

		assertTrue(distance1>distance2);
	}
	
	private Collection<Constraint<?>> createConstraints(final String str1,
			final String str2) {
		StringVariable var1 = new StringVariable("var0", str1);
		StringConstant const1 = new StringConstant(str2);
		StringBinaryComparison comp = new StringBinaryComparison(var1,
				Operator.EQUALS, const1, 0L);
		IntegerConstant zero = new IntegerConstant(0);
		StringConstraint stringConstraint = new StringConstraint(comp,
				Comparator.NE, zero);
		Collection<Constraint<?>> cnstr = Collections
				.<Constraint<?>> singletonList(stringConstraint);
		return cnstr;
	}

}