/* Copyright 2009-2016 David Hadka
 *
 * This file is part of the MOEA Framework.
 *
 * The MOEA Framework 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 of the License, or (at your
 * option) any later version.
 *
 * The MOEA Framework 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 General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with the MOEA Framework.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.moeaframework.core;

import java.io.File;
import java.io.IOException;

import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.moeaframework.TestThresholds;
import org.moeaframework.TestUtils;
import org.moeaframework.core.variable.BinaryVariable;
import org.moeaframework.core.variable.Grammar;
import org.moeaframework.core.variable.Permutation;
import org.moeaframework.core.variable.RealVariable;

/**
 * Tests the {@link PopulationIO} class.
 */
public class PopulationIOTest {

	/**
	 * The shared population used for testing, initialized to contain two
	 * solutions.
	 */
	private Population population;

	/**
	 * Constructs any shared objects used by this class.
	 */
	@Before
	public void setUp() {
		population = new Population();

		Solution s1 = new Solution(4, 1, 2);
		s1.setVariable(0, new BinaryVariable(10));
		s1.setVariable(1, new Grammar(5));
		s1.setVariable(2, new Permutation(5));
		s1.setVariable(3, new RealVariable(0.0, 1.0));
		s1.setObjective(0, 1.0);
		s1.setConstraint(0, 0.0);
		s1.setConstraint(1, 1.0);

		Solution s2 = new Solution(new double[] { 1.0, -1.0 });

		population.add(s1);
		population.add(s2);
	}

	/**
	 * Removes references to any shared objects for garbage collection.
	 */
	@After
	public void tearDown() {
		population = null;
	}

	/**
	 * Tests the {@link PopulationIO#writeObjectives} and
	 * {@link PopulationIO#readObjectives} methods to ensure the objectives are
	 * stored and retrieved correctly.
	 * 
	 * @throws IOException should not occur
	 */
	@Test
	public void testWriteReadObjectives() throws IOException {
		File file = TestUtils.createTempFile();

		PopulationIO.writeObjectives(file, population);
		Population population2 = PopulationIO.readObjectives(file);

		Assert.assertEquals(population.size(), population2.size());

		for (int i = 0; i < population.size(); i++) {
			Assert.assertArrayEquals(population.get(i).getObjectives(),
					population2.get(i).getObjectives(),
					TestThresholds.SOLUTION_EPS);
		}
	}

	/**
	 * Tests the {@link PopulationIO#write} and {@link PopulationIO#read}
	 * methods to ensure the objectives are stored and retrieved correctly.
	 * 
	 * @throws IOException should not occur
	 */
	@Test
	public void testWriteRead() throws IOException {
		File file = TestUtils.createTempFile();

		PopulationIO.write(file, population);
		TestUtils.assertEquals(population, PopulationIO.read(file));
		Population population2 = PopulationIO.read(file);

		Assert.assertEquals(population.size(), population2.size());
	}
	
	/**
	 * Tests {@link PopulationIO#readObjectives} to ensure it correctly
	 * parses files that contain extra whitespace characters.
	 * 
	 * @throws IOException should not occur
	 */
	@Test
	public void testReadWhitespace() throws IOException {
		File file = TestUtils.createTempFile("0   1 \t 2\n\t   3 4 5 \t\n");
		Population population = PopulationIO.readObjectives(file);
		
		Assert.assertArrayEquals(new double[] {0.0, 1.0, 2.0},
				population.get(0).getObjectives(), Settings.EPS);
		Assert.assertArrayEquals(new double[] {3.0, 4.0, 5.0},
				population.get(1).getObjectives(), Settings.EPS);
	}

}