/**
 * 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.feature.local;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.AbstractList;
import java.util.List;
import java.util.Scanner;

import org.openimaj.feature.FloatFV;
import org.openimaj.feature.local.list.LocalFeatureList;
import org.openimaj.feature.normalisation.Normaliser;
import org.openimaj.util.array.ArrayUtils;

/**
 * This class is designed as a wrapper around any form of local feature and
 * provides a way of exposing that feature as a {@link FloatFV}, without the
 * cost of necessarily storing the underlying feature as a {@link FloatFV}. For
 * example, this can be used to make a Keypoint look like it's backed by a float
 * array rather than a byte array, without incurring the four-times increase in
 * storage this would incur.
 * <p>
 * The implementation also allows a normalisation process to occur during
 * conversion through a {@link Normaliser}.
 *
 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
 *
 * @param <L>
 *            The type of {@link Location}
 */
public class FloatLocalFeatureAdaptor<L extends Location> implements LocalFeature<L, FloatFV> {
        LocalFeature<L, ?> localFeature;
        Normaliser<FloatFV> normaliser;

        /**
         * Construct a new {@link FloatLocalFeatureAdaptor} with the given
         * underlying feature
         *
         * @param localFeature
         *            the underlying feature
         */
        public FloatLocalFeatureAdaptor(LocalFeature<L, ?> localFeature) {
                this.localFeature = localFeature;
        }

        /**
         * Construct a new {@link FloatLocalFeatureAdaptor} with the given
         * underlying feature and normaliser.
         *
         * @param localFeature
         *            the underlying feature
         * @param normaliser
         *            the normaliser
         */
        public FloatLocalFeatureAdaptor(LocalFeature<L, ?> localFeature, Normaliser<FloatFV> normaliser) {
                this.localFeature = localFeature;
                this.normaliser = normaliser;
        }

        @Override
        public void readASCII(Scanner in) throws IOException {
                throw new UnsupportedOperationException();
        }

        @Override
        public String asciiHeader() {
                throw new UnsupportedOperationException();
        }

        @Override
        public void readBinary(DataInput in) throws IOException {
                throw new UnsupportedOperationException();
        }

        @Override
        public byte[] binaryHeader() {
                throw new UnsupportedOperationException();
        }

        @Override
        public void writeASCII(PrintWriter out) throws IOException {
                throw new UnsupportedOperationException();
        }

        @Override
        public void writeBinary(DataOutput out) throws IOException {
                throw new UnsupportedOperationException();
        }

        @Override
        public FloatFV getFeatureVector() {
                final FloatFV fv = new FloatFV(ArrayUtils.convertToFloat(localFeature.getFeatureVector().asDoubleFV().values));

                if (normaliser != null)
                        normaliser.normalise(fv);

                return fv;
        }

        @Override
        public L getLocation() {
                return localFeature.getLocation();
        }

        @Override
        public boolean equals(Object obj) {
                if (!(obj instanceof FloatLocalFeatureAdaptor))
                        return false;

                return ((FloatLocalFeatureAdaptor<?>) obj).localFeature.equals(localFeature);
        }

        /*
         * (non-Javadoc)
         *
         * @see java.lang.Object#hashCode()
         */
        @Override
        public int hashCode() {
                final int prime = 31;
                int result = 1;
                result = prime * result + ((localFeature == null) ? 0 : localFeature.hashCode());
                return result;
        }

        /**
         * Produce a {@link LocalFeatureList} of {@link FloatLocalFeatureAdaptor} by
         * wrapping the input list, and dynamically wrapping with the
         * {@link FloatLocalFeatureAdaptor}s on demand.
         *
         * @param list
         *            the input list
         * @return the wrapped list
         */
        public static <L extends Location> List<FloatLocalFeatureAdaptor<L>> wrap(
                        final List<? extends LocalFeature<L, ?>> list)
                        {
                return wrap(list, null);
                        }

        /**
         * Produce a {@link LocalFeatureList} of {@link FloatLocalFeatureAdaptor} by
         * wrapping the input list, and dynamically wrapping with the
         * {@link FloatLocalFeatureAdaptor}s on demand.
         *
         * @param list
         *            the input list
         * @return the wrapped list
         */
        public static List<FloatLocalFeatureAdaptor<?>> wrapUntyped(
                        final List<? extends LocalFeature<?, ?>> list)
                        {
                return wrapUntyped(list, null);
                        }

        /**
         * Produce a {@link LocalFeatureList} of {@link FloatLocalFeatureAdaptor} by
         * wrapping the input list, and dynamically wrapping with the
         * {@link FloatLocalFeatureAdaptor}s on demand.
         *
         * @param list
         *            the input list
         * @param normaliser
         *            the normaliser
         * @return the wrapped list
         */
        public static <L extends Location> List<FloatLocalFeatureAdaptor<L>> wrap(
                        final List<? extends LocalFeature<L, ?>> list, final Normaliser<FloatFV> normaliser)
                        {
                final List<FloatLocalFeatureAdaptor<L>> out = new AbstractList<FloatLocalFeatureAdaptor<L>>() {

                        @Override
                        public FloatLocalFeatureAdaptor<L> get(int index) {
                                return new FloatLocalFeatureAdaptor<L>(list.get(index), normaliser);
                        }

                        @Override
                        public int size() {
                                return list.size();
                        }
                };

                return out;
                        }

        /**
         * Produce a {@link LocalFeatureList} of {@link FloatLocalFeatureAdaptor} by
         * wrapping the input list, and dynamically wrapping with the
         * {@link FloatLocalFeatureAdaptor}s on demand.
         *
         * @param list
         *            the input list
         * @param normaliser
         *            the normaliser
         * @return the wrapped list
         */
        public static List<FloatLocalFeatureAdaptor<?>> wrapUntyped(
                        final List<? extends LocalFeature<?, ?>> list, final Normaliser<FloatFV> normaliser)
                        {
                final List<FloatLocalFeatureAdaptor<?>> out = new AbstractList<FloatLocalFeatureAdaptor<?>>() {

                        @SuppressWarnings("unchecked")
                        @Override
                        public FloatLocalFeatureAdaptor<?> get(int index) {
                                return new FloatLocalFeatureAdaptor<Location>((LocalFeature<Location, ?>) list.get(index), normaliser);
                        }

                        @Override
                        public int size() {
                                return list.size();
                        }
                };

                return out;
                        }
}