/**
 * 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
         */
        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;
        }
}