package de.lmu.ifi.dbs.elki.index.tree.spatial;

/*
 This file is part of ELKI:
 Environment for Developing KDD-Applications Supported by Index-Structures

 Copyright (C) 2012
 Ludwig-Maximilians-Universität München
 Lehr- und Forschungseinheit für Datenbanksysteme
 ELKI Development Team

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU Affero General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program 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 Affero General Public License for more details.

 You should have received a copy of the GNU Affero General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;

import de.lmu.ifi.dbs.elki.data.NumberVector;
import de.lmu.ifi.dbs.elki.database.ids.DBID;
import de.lmu.ifi.dbs.elki.index.tree.AbstractLeafEntry;

/**
 * Represents an entry in a leaf node of a spatial index. A SpatialLeafEntry
 * consists of an id (representing the unique id of the underlying data object)
 * and the values of the underlying data object.
 * 
 * @author Elke Achtert
 */
public class SpatialPointLeafEntry extends AbstractLeafEntry implements SpatialEntry {
  private static final long serialVersionUID = 1;

  /**
   * The values of the underlying data object.
   */
  private double[] values;

  /**
   * Empty constructor for serialization purposes.
   */
  public SpatialPointLeafEntry() {
    super();
  }

  /**
   * Constructs a new LeafEntry object with the given parameters.
   * 
   * @param id the unique id of the underlying data object
   * @param values the values of the underlying data object
   */
  public SpatialPointLeafEntry(DBID id, double[] values) {
    super(id);
    this.values = values;
  }

  /**
   * Constructor from number vector
   *
   * @param id Object id
   * @param vector Number vector
   */
  public SpatialPointLeafEntry(DBID id, NumberVector<?, ?> vector) {
    super(id);
    int dim = vector.getDimensionality();
    this.values = new double[dim];
    for(int i = 0; i < dim; i++) {
      values[i] = vector.doubleValue(i + 1);
    }
  }

  @Override
  public int getDimensionality() {
    return values.length;
  }

  /**
   * @return the value at the specified dimension
   */
  @Override
  public double getMin(int dimension) {
    return values[dimension - 1];
  }

  /**
   * @return the value at the specified dimension
   */
  @Override
  public double getMax(int dimension) {
    return values[dimension - 1];
  }

  /**
   * Returns the values of the underlying data object of this entry.
   * 
   * @return the values of the underlying data object of this entry
   */
  public double[] getValues() {
    return values;
  }

  /**
   * Calls the super method and writes the values of this entry to the specified
   * stream.
   * 
   * @param out the stream to write the object to
   * @throws java.io.IOException Includes any I/O exceptions that may occur
   */
  @Override
  public void writeExternal(ObjectOutput out) throws IOException {
    super.writeExternal(out);
    out.writeInt(values.length);
    for(double v : values) {
      out.writeDouble(v);
    }
  }

  /**
   * Calls the super method and reads the values of this entry from the
   * specified input stream.
   * 
   * @param in the stream to read data from in order to restore the object
   * @throws java.io.IOException if I/O errors occur
   * @throws ClassNotFoundException If the class for an object being restored
   *         cannot be found.
   */
  @Override
  public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
    super.readExternal(in);
    values = new double[in.readInt()];
    for(int d = 0; d < values.length; d++) {
      values[d] = in.readDouble();
    }
  }
}