/*
 * 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.instances;

public class DenseInstanceData implements InstanceData {

  /**
   * Instantiates a new dense instance data.
   *
   * @param array
   *          the array
   */
  public DenseInstanceData(double[] array) {
    this.attributeValues = array;
  }

  /**
   * Instantiates a new dense instance data.
   *
   * @param length
   *          the length
   */
  public DenseInstanceData(int length) {
    this.attributeValues = new double[length];
  }

  /**
   * Instantiates a new dense instance data.
   */
  public DenseInstanceData() {
    this(0);
  }

  /** The attribute values. */
  protected double[] attributeValues;

  /**
   * Num attributes.
   *
   * @return the int
   */
  @Override
  public int numAttributes() {
    return this.attributeValues.length;
  }

  /**
   * Value.
   *
   * @param indexAttribute
   *          the index attribute
   * @return the double
   */
  @Override
  public double value(int indexAttribute) {
    if (this.attributeValues.length <= indexAttribute)
      return this.attributeValues[this.attributeValues.length - 1];

    return this.attributeValues[indexAttribute];
  }

  /**
   * Checks if is missing.
   *
   * @param indexAttribute
   *          the index attribute
   * @return true, if is missing
   */
  @Override
  public boolean isMissing(int indexAttribute) {
    return Double.isNaN(this.value(indexAttribute));
  }

  /**
   * Num values.
   *
   * @return the int
   */
  @Override
  public int numValues() {
    return numAttributes();
  }

  /**
   * Index.
   *
   * @param indexAttribute
   *          the index attribute
   * @return the int
   */
  @Override
  public int index(int indexAttribute) {
    return indexAttribute;
  }

  /**
   * Value sparse.
   *
   * @param indexAttribute
   *          the index attribute
   * @return the double
   */
  @Override
  public double valueSparse(int indexAttribute) {
    return value(indexAttribute);
  }

  /**
   * Checks if is missing sparse.
   *
   * @param indexAttribute
   *          the index attribute
   * @return true, if is missing sparse
   */
  @Override
  public boolean isMissingSparse(int indexAttribute) {
    return isMissing(indexAttribute);
  }

  /**
   * To double array.
   *
   * @return the double[]
   */
  @Override
  public double[] toDoubleArray() {
    return attributeValues;
  }

  /**
   * Sets the value.
   *
   * @param attributeIndex
   *          the attribute index
   * @param d
   *          the d
   */
  @Override
  public void setValue(int attributeIndex, double d) {
    this.attributeValues[attributeIndex] = d;
  }

  @Override
  public void deleteAttributeAt(int index) {

    double[] newValues = new double[attributeValues.length - 1];

    System.arraycopy(attributeValues, 0, newValues, 0, index);
    if (index < attributeValues.length - 1) {
      System.arraycopy(attributeValues, index + 1, newValues, index,
          attributeValues.length - (index + 1));
    }
    attributeValues = newValues;
  }

  @Override
  public void insertAttributeAt(int index) {
    if ((index < 0) || (index > numAttributes())) {
      throw new IllegalArgumentException("Can't insert attribute: index out "
          + "of range");
    }
    double[] newValues = new double[attributeValues.length + 1];

    System.arraycopy(attributeValues, 0, newValues, 0, index);
    newValues[index] = Double.NaN; //Missing Value
    System.arraycopy(attributeValues, index, newValues, index + 1,
        attributeValues.length - index);
    attributeValues = newValues;

  }

  @Override
  public InstanceData copy() {
    return new DenseInstanceData(this.attributeValues);
  }

}