/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.math4.genetics;


import java.util.ArrayList;
import java.util.Iterator;

import org.apache.commons.math4.exception.NotPositiveException;
import org.apache.commons.math4.exception.NumberIsTooLargeException;
import org.apache.commons.math4.exception.NumberIsTooSmallException;
import org.apache.commons.math4.genetics.BinaryChromosome;
import org.apache.commons.math4.genetics.Chromosome;
import org.apache.commons.math4.genetics.ListPopulation;
import org.apache.commons.math4.genetics.Population;
import org.junit.Assert;
import org.junit.Test;

public class ListPopulationTest {

    @Test
    public void testGetFittestChromosome() {
        Chromosome c1 = new Chromosome() {
            @Override
            public double fitness() {
                return 0;
            }
        };
        Chromosome c2 = new Chromosome() {
            @Override
            public double fitness() {
                return 10;
            }
        };
        Chromosome c3 = new Chromosome() {
            @Override
            public double fitness() {
                return 15;
            }
        };

        ArrayList<Chromosome> chromosomes = new ArrayList<> ();
        chromosomes.add(c1);
        chromosomes.add(c2);
        chromosomes.add(c3);

        ListPopulation population = new ListPopulation(chromosomes, 10) {
            @Override
            public Population nextGeneration() {
                // not important
                return null;
            }
        };

        Assert.assertEquals(c3, population.getFittestChromosome());
    }

    @Test
    public void testChromosomes() {
        final ArrayList<Chromosome> chromosomes = new ArrayList<> ();
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));

        final ListPopulation population = new ListPopulation(10) {
            @Override
            public Population nextGeneration() {
                // not important
                return null;
            }
        };

        population.addChromosomes(chromosomes);

        Assert.assertEquals(chromosomes, population.getChromosomes());
        Assert.assertEquals(chromosomes.toString(), population.toString());

        population.setPopulationLimit(50);
        Assert.assertEquals(50, population.getPopulationLimit());
    }

    @Test(expected = NotPositiveException.class)
    public void testSetPopulationLimit() {
        final ListPopulation population = new ListPopulation(10) {
            @Override
            public Population nextGeneration() {
                // not important
                return null;
            }
        };

        population.setPopulationLimit(-50);
    }

    @Test(expected = NotPositiveException.class)
    public void testConstructorPopulationLimitNotPositive() {
        new ListPopulation(-10) {
            @Override
            public Population nextGeneration() {
                // not important
                return null;
            }
        };
    }

    @Test(expected = NotPositiveException.class)
    public void testChromosomeListConstructorPopulationLimitNotPositive() {
        final ArrayList<Chromosome> chromosomes = new ArrayList<> ();
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));
        new ListPopulation(chromosomes, -10) {
            @Override
            public Population nextGeneration() {
                // not important
                return null;
            }
        };
    }

    @Test(expected = NumberIsTooLargeException.class)
    public void testConstructorListOfChromosomesBiggerThanPopulationSize() {
        final ArrayList<Chromosome> chromosomes = new ArrayList<> ();
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));
        new ListPopulation(chromosomes, 1) {
            @Override
            public Population nextGeneration() {
                // not important
                return null;
            }
        };
    }

    @Test(expected=NumberIsTooLargeException.class)
    public void testAddTooManyChromosomes() {
        final ArrayList<Chromosome> chromosomes = new ArrayList<> ();
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));

        final ListPopulation population = new ListPopulation(2) {
            @Override
            public Population nextGeneration() {
                // not important
                return null;
            }
        };

        population.addChromosomes(chromosomes);
    }

    @Test(expected=NumberIsTooLargeException.class)
    public void testAddTooManyChromosomesSingleCall() {

        final ListPopulation population = new ListPopulation(2) {
            @Override
            public Population nextGeneration() {
                // not important
                return null;
            }
        };

        for (int i = 0; i <= population.getPopulationLimit(); i++) {
            population.addChromosome(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));
        }
    }

    @Test(expected = UnsupportedOperationException.class)
    public void testIterator() {
        final ArrayList<Chromosome> chromosomes = new ArrayList<>();
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));

        final ListPopulation population = new ListPopulation(10) {
            @Override
            public Population nextGeneration() {
                // not important
                return null;
            }
        };

        population.addChromosomes(chromosomes);

        final Iterator<Chromosome> iter = population.iterator();
        while (iter.hasNext()) {
            iter.next();
            iter.remove();
        }
    }

    @Test(expected=NumberIsTooSmallException.class)
    public void testSetPopulationLimitTooSmall() {
        final ArrayList<Chromosome> chromosomes = new ArrayList<> ();
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));
        chromosomes.add(new DummyBinaryChromosome(BinaryChromosome.randomBinaryRepresentation(3)));

        final ListPopulation population = new ListPopulation(chromosomes, 3) {
            @Override
            public Population nextGeneration() {
                // not important
                return null;
            }
        };

        population.setPopulationLimit(2);
    }

}