/**
    * Copyright (c) 2011, The University of Southampton and the individual contributors.
    * All rights reserved.
    *
    * Redistribution and use in source and binary forms, with or without modification,
    * are permitted provided that the following conditions are met:
    *
    *   * 	Redistributions of source code must retain the above copyright notice,
    * 	this list of conditions and the following disclaimer.
   *
   *   *	Redistributions in binary form must reproduce the above copyright notice,
   * 	this list of conditions and the following disclaimer in the documentation
   * 	and/or other materials provided with the distribution.
   *
   *   *	Neither the name of the University of Southampton nor the names of its
   * 	contributors may be used to endorse or promote products derived from this
   * 	software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package org.openimaj.image.analysis.watershed;
  
  import java.util.HashSet;
  import java.util.Set;
  
  import org.openimaj.image.analysis.watershed.feature.ComponentFeature;
  import org.openimaj.image.analysis.watershed.feature.PixelsFeature;
  import org.openimaj.image.pixel.IntValuePixel;
  import org.openimaj.image.pixel.Pixel;
  
  /**
   * Represents a region or set of pixels (the name is based on the Microsoft
   * paper)
   *
   * @author David Dupplaw (dpd@ecs.soton.ac.uk)
   * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
   *
   */
  public class Component implements Cloneable
  {
  	/** Whether this component represents an MSER */
  	public boolean isMSER = false;
  
  	/** List of features representing this component */
  	public ComponentFeature[] features;
  
  	/**
  	 * The pivot pixel
  	 */
  	public IntValuePixel pivot;
  	private int size = 0;
  
  	/**
  	 * Default constructor.
  	 *
  	 * @param p
  	 *            The grey level of the component
  	 * @param featureClasses
  	 *            the list of features to create for the component
  	 */
  	@SafeVarargs
  	public Component(IntValuePixel p, Class<? extends ComponentFeature>... featureClasses)
  	{
  		this.pivot = p;
  
  		features = new ComponentFeature[featureClasses.length];
  		for (int i = 0; i < featureClasses.length; i++) {
  			try {
  				features[i] = featureClasses[i].newInstance();
  			} catch (final Exception e) {
  				throw new AssertionError(e);
  			}
  		}
  	}
  
  	/**
  	 * {@inheritDoc}
  	 *
  	 * @see java.util.AbstractCollection#toString()
  	 */
  	@Override
  	public String toString()
  	{
  		return "Comp@" + super.hashCode() + "(px:" + size + ",gl:" + pivot.value + ")";
  	};
  
  	/**
  	 * Add a pixel to the component
  	 *
  	 * @param p
 	 *            the pixel to add
 	 */
 	public void accumulate(IntValuePixel p) {
 		size++;
 
 		for (final ComponentFeature f : features) {
 			f.addSample(p);
 		}
 	}
 
 	/**
 	 * Merge another component with this one
 	 *
 	 * @param p
 	 *            the component to merge into this
 	 */
 	public void merge(Component p) {
 		size += p.size();
 
 		for (int i = 0; i < features.length; i++) {
 			features[i].merge(p.features[i]);
 		}
 	}
 
 	/**
 	 * The size of the component (i.e. the number of pixels)
 	 *
 	 * @return the size of the component
 	 */
 	public int size() {
 		return size;
 	}
 
 	/**
 	 * Get the pixels in the component. If the component contains a
 	 * {@link PixelsFeature} then the pixels will be returned from that;
 	 * otherwise a set containing just the pivot pixel will be returned.
 	 *
 	 * @return the pixels in the component if possible, or just the pivot pixel
 	 */
 	public Set<Pixel> getPixels() {
 		for (final ComponentFeature f : features) {
 			if (f instanceof PixelsFeature)
 				return ((PixelsFeature) f).pixels;
 		}
 
 		final Set<Pixel> pix = new HashSet<Pixel>(1);
 		pix.add(pivot);
 		return pix;
 	}
 
 	@Override
 	public Component clone() {
 		Component result;
 		try {
 			result = (Component) super.clone();
 			result.features = new ComponentFeature[features.length];
 			for (int i = 0; i < features.length; i++)
 				result.features[i] = features[i].clone();
 
 			// result.pixels = pixels.clone();
 
 			return result;
 		} catch (final CloneNotSupportedException e) {
 			throw new AssertionError(e);
 		}
 	}
 
 	/**
 	 * Get the feature at the given index
 	 *
 	 * @param index
 	 *            the index
 	 * @return the feature at the given index or null if it doesn't exist
 	 */
 	public ComponentFeature getFeature(int index) {
 		if (index >= features.length)
 			return null;
 
 		return features[index];
 	}
 
 	/**
 	 * Get the feature matching the given class if it exists. If more than one
 	 * feature of the given class exists, then the first will be returned.
 	 *
 	 * @param <T>
 	 *            the class of the feature
 	 * @param featureClass
 	 *            the class of the feature
 	 * @return the feature with the given class; or null if no feature is found
 	 */
 	@SuppressWarnings("unchecked")
 	public <T extends ComponentFeature> T getFeature(Class<T> featureClass) {
 		for (final ComponentFeature f : features)
 			if (f.getClass().isAssignableFrom(featureClass))
 				return (T) f;
 
 		return null;
 	}
 }