package org.apache.samoa.instances;

/*
 * #%L
 * SAMOA
 * %%
 * Copyright (C) 2014 - 2015 Apache Software Foundation
 * %%
 * Licensed 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.
 * #L%
 */

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class AttributesInformation implements Serializable {

  /**
   * The attribute information.
   */
  protected List<Attribute> attributes;
  protected List<Integer> indexValues;
  /**
   * The number of attributes.
   */
  protected int numberAttributes;

  /**
   * The attribute used for default for numerical values
   */
  protected Attribute defaultNumericAttribute;

  public AttributesInformation(AttributesInformation chunk) {
    this.attributes = chunk.attributes;
    this.indexValues = chunk.indexValues;
    this.numberAttributes = chunk.numberAttributes;
  }

  public AttributesInformation(List<Attribute> v, List<Integer> i, int numberAttributes) {
    this.attributes = v;
    this.indexValues = i;
    this.numberAttributes = numberAttributes;
  }

  public AttributesInformation(List<Attribute> v, int numberAttributes) {
    this.attributes = v;
    this.indexValues = new ArrayList<Integer>(numberAttributes);
    for (int i = 0; i < numberAttributes; i++) {
      this.indexValues.add(i);
    }
    this.numberAttributes = numberAttributes;
  }

  public AttributesInformation() {
    this.attributes = null;
    this.indexValues = null;
    this.numberAttributes = 0;
    this.defaultNumericAttribute = null;
  }

  /**
   * Attribute.
   *
   * @param indexAttribute the index Attribute
   * @return the attribute
   */
  public Attribute attribute(int indexAttribute) {
    if (this.attributes == null) {
      //All attributes are numeric
      return defaultNumericAttribute();
    }
    int location = locateIndex(indexAttribute);
    if (location == -1) {
      //if there is not attribute information, it is numeric
      return defaultNumericAttribute();
    }
    return attributes.get(location);
  }

  public void add(Attribute attribute, int value) {
    this.attributes.add(attribute);
    this.indexValues.add(value);
  }

  /**
   * Sets the attribute information.
   *
   * @param v the new attribute information
   */
  public void setAttributes(List<Attribute> v) {
    this.attributes = v;
    this.numberAttributes=v.size();
  }

  /**
   * Locates the greatest index that is not greater than the given index.
   *
   * @return the internal index of the attribute index. Returns -1 if no index
   * with this property could be found
   */
  public int locateIndex(int index) {

    int min = 0;
    int max = this.indexValues.size() - 1;

    if (max == -1) {
      return -1;
    }

    // Binary search
    while ((this.indexValues.get(min) <= index) && (this.indexValues.get(max) >= index)) {
      int current = (max + min) / 2;
      if (this.indexValues.get(current) > index) {
        max = current - 1;
      } else if (this.indexValues.get(current) < index) {
        min = current + 1;
      } else {
        return current;
      }
    }
    if (this.indexValues.get(max) < index) {
      return max;
    } else {
      return min - 1;
    }
  }

  private Attribute defaultNumericAttribute() {
    if (this.defaultNumericAttribute == null) {
      this.defaultNumericAttribute = new Attribute("default");
    }
    return this.defaultNumericAttribute;
  }

  public void setAttributes(List<Attribute> v, List<Integer> indexValues) {
    this.attributes = v;
    this.numberAttributes=v.size();	
    this.indexValues=indexValues;
  }

}