/*
 * 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.samoa.core;

import static org.hamcrest.CoreMatchers.*;
import static org.junit.Assert.*;

import org.apache.samoa.core.DoubleVector;
import org.junit.Before;
import org.junit.Test;

public class DoubleVectorTest {
  private DoubleVector emptyVector, array5Vector;

  @Before
  public void setUp() {
    emptyVector = new DoubleVector();
    array5Vector = new DoubleVector(new double[] { 1.1, 2.5, 0, 4.7, 0 });
  }

  @Test
  public void testGetArrayRef() {
    assertThat(emptyVector.getArrayRef(), notNullValue());
    assertTrue(emptyVector.getArrayRef() == emptyVector.getArrayRef());
    assertEquals(5, array5Vector.getArrayRef().length);
  }

  @Test
  public void testGetArrayCopy() {
    double[] arrayRef;
    arrayRef = emptyVector.getArrayRef();
    assertTrue(arrayRef != emptyVector.getArrayCopy());
    assertThat(arrayRef, is(equalTo(emptyVector.getArrayCopy())));

    arrayRef = array5Vector.getArrayRef();
    assertTrue(arrayRef != array5Vector.getArrayCopy());
    assertThat(arrayRef, is(equalTo(array5Vector.getArrayCopy())));
  }

  @Test
  public void testNumNonZeroEntries() {
    assertEquals(0, emptyVector.numNonZeroEntries());
    assertEquals(3, array5Vector.numNonZeroEntries());
  }

  @Test(expected = IndexOutOfBoundsException.class)
  public void testGetValueOutOfBound() {
    @SuppressWarnings("unused")
    double value = emptyVector.getArrayRef()[0];
  }

  @Test()
  public void testSetValue() {
    // test automatic vector enlargement
    emptyVector.setValue(0, 1.0);
    assertEquals(1, emptyVector.getArrayRef().length);
    assertEquals(1.0, emptyVector.getArrayRef()[0], 0.0); // should be exactly the same, so delta=0.0

    emptyVector.setValue(5, 5.5);
    assertEquals(6, emptyVector.getArrayRef().length);
    assertEquals(2, emptyVector.numNonZeroEntries());
    assertEquals(5.5, emptyVector.getArrayRef()[5], 0.0); // should be exactly the same, so delta=0.0
  }

  @Test
  public void testAddToValue() {
    array5Vector.addToValue(2, 5.0);
    assertEquals(5, array5Vector.getArrayRef()[2], 0.0); // should be exactly the same, so delta=0.0

    // test automatic vector enlargement
    emptyVector.addToValue(0, 1.0);
    assertEquals(1, emptyVector.getArrayRef()[0], 0.0); // should be exactly the same, so delta=0.0
  }

  @Test
  public void testSumOfValues() {
    assertEquals(1.1 + 2.5 + 4.7, array5Vector.sumOfValues(), Double.MIN_NORMAL);
  }

}