package org.apache.samoa.moa.cluster;

/*
 * #%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.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Random;

import org.apache.samoa.instances.Instance;
import org.apache.samoa.moa.AbstractMOAObject;

public abstract class Cluster extends AbstractMOAObject {

  private static final long serialVersionUID = 1L;

  private double id = -1;
  private double gtLabel = -1;

  private Map<String, String> measure_values;

  public Cluster() {
    this.measure_values = new HashMap<>();
  }

  /**
   * @return the center of the cluster
   */
  public abstract double[] getCenter();

  /**
   * Returns the weight of this cluster, not neccessarily normalized. It could, for instance, simply return the number
   * of points contined in this cluster.
   * 
   * @return the weight
   */
  public abstract double getWeight();

  /**
   * Returns the probability of the given point belonging to this cluster.
   * 
   * @param instance
   * @return a value between 0 and 1
   */
  public abstract double getInclusionProbability(Instance instance);

  // TODO: for non sphere cluster sample points, find out MIN MAX neighbours
  // within cluster
  // and return the relative distance
  // public abstract double getRelativeHullDistance(Instance instance);

  @Override
  public void getDescription(StringBuilder sb, int i) {
    sb.append("Cluster Object");
  }

  public void setId(double id) {
    this.id = id;
  }

  public double getId() {
    return id;
  }

  public boolean isGroundTruth() {
    return gtLabel != -1;
  }

  public void setGroundTruth(double truth) {
    gtLabel = truth;
  }

  public double getGroundTruth() {
    return gtLabel;
  }

  /**
   * Samples this cluster by returning a point from inside it.
   * 
   * @param random
   *          a random number source
   * @return an Instance that lies inside this cluster
   */
  public abstract Instance sample(Random random);

  public void setMeasureValue(String measureKey, String value) {
    measure_values.put(measureKey, value);
  }

  public void setMeasureValue(String measureKey, double value) {
    measure_values.put(measureKey, Double.toString(value));
  }

  public String getMeasureValue(String measureKey) {
    if (measure_values.containsKey(measureKey))
      return measure_values.get(measureKey);
    else
      return "";
  }

  protected void getClusterSpecificInfo(List<String> infoTitle, List<String> infoValue) {
    infoTitle.add("ClusterID");
    infoValue.add(Integer.toString((int) getId()));

    infoTitle.add("Type");
    infoValue.add(getClass().getSimpleName());

    double c[] = getCenter();
    if (c != null)
      for (int i = 0; i < c.length; i++) {
        infoTitle.add("Dim" + i);
        infoValue.add(Double.toString(c[i]));
      }

    infoTitle.add("Weight");
    infoValue.add(Double.toString(getWeight()));

  }

  public String getInfo() {
    List<String> infoTitle = new ArrayList<>();
    List<String> infoValue = new ArrayList<>();
    getClusterSpecificInfo(infoTitle, infoValue);

    StringBuilder sb = new StringBuilder();

    // Cluster properties
    sb.append("<html>");
    sb.append("<table>");
    int i = 0;
    while (i < infoTitle.size() && i < infoValue.size()) {
      sb.append("<tr><td>" + infoTitle.get(i) + "</td><td>" + infoValue.get(i) + "</td></tr>");
      i++;
    }
    sb.append("</table>");

    // Evaluation info
    sb.append("<br>");
    sb.append("<b>Evaluation</b><br>");
    sb.append("<table>");
    for (Object o : measure_values.entrySet()) {
      Map.Entry e = (Map.Entry) o;
      sb.append("<tr><td>" + e.getKey() + "</td><td>" + e.getValue() + "</td></tr>");
    }
    sb.append("</table>");
    sb.append("</html>");
    return sb.toString();
  }

}