/**
 * 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.feature.local.keypoints;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
import java.util.StringTokenizer;

import org.openimaj.feature.ByteFV;
import org.openimaj.feature.local.LocalFeature;
import org.openimaj.io.VariableLength;
import org.openimaj.math.geometry.point.Point2d;
import org.openimaj.math.geometry.point.ScaleSpacePoint;

import Jama.Matrix;
import cern.jet.random.Normal;

/**
 * A local interest point with a location, scale, orientation and associated
 * feature. The feature is stored as an array of bytes.
 *
 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
 */
public class Keypoint
implements
Serializable,
ScaleSpacePoint,
LocalFeature<KeypointLocation, ByteFV>,
VariableLength,
Cloneable
{
        static final long serialVersionUID = 1234554345;

        /**
         * Default length of standard SIFT features.
         */
        private final static int DEFAULT_LENGTH = 128;

        /**
         * keypoint feature descriptor (i.e. SIFT)
         */
        public byte[] ivec;

        /**
         * dominant orientation of keypoint
         */
        public float ori;

        /**
         * scale of keypoint
         */
        public float scale;

        /**
         * x-position of keypoint
         */
        public float x;

        /**
         * y-position of keypoint
         */
        public float y;

        /**
         * Construct with the default feature vector length for SIFT (128).
         */
        public Keypoint() {
                this.ivec = new byte[DEFAULT_LENGTH];
        }

        /**
         * Construct with the given feature vector length.
         *
         * @param length
         *            the length of the feature vector
         */
        public Keypoint(int length) {
                if (length < 0)
                        length = DEFAULT_LENGTH;
                this.ivec = new byte[length];
        }

        /**
         * Construct with the given parameters.
         *
         * @param x
         *            the x-ordinate of the keypoint
         * @param y
         *            the y-ordinate of the keypoint
         * @param ori
         *            the orientation of the keypoint
         * @param scale
         *            the scale of the keypoint
         * @param ivec
         *            the feature vector of the keypoint
         */
        public Keypoint(float x, float y, float ori, float scale, byte[] ivec) {
                this.x = x;
                this.y = y;
                this.ori = ori;
                this.scale = scale;
                this.ivec = ivec;
        }

        /**
         * Construct by copying from another {@link Keypoint}
         *
         * @param k
         *            the {@link Keypoint} to copy from
         */
        public Keypoint(Keypoint k) {
                this(k.x, k.y, k.ori, k.scale, Arrays.copyOf(k.ivec, k.ivec.length));
        }

        @Override
        public Float getOrdinate(int dimension) {
                if (dimension == 0)
                        return x;
                if (dimension == 1)
                        return y;
                if (dimension == 2)
                        return scale;
                return null;
        }

        @Override
        public int getDimensions() {
                return 3;
        }

        @Override
        public float getX() {
                return x;
        }

        @Override
        public float getY() {
                return y;
        }

        @Override
        public void setX(float x) {
                this.x = x;
        }

        @Override
        public void setY(float y) {
                this.y = y;
        }

        @Override
        public float getScale() {
                return scale;
        }

        @Override
        public void setScale(float scale) {
                this.scale = scale;
        }

        @Override
        public String toString() {
                return ("Keypoint(" + this.x + ", " + this.y + ", " + this.scale + ", " + this.ori + ")");
        }

        /**
         * Test whether the location of this {@link Keypoint} and another
         * {@link Keypoint} is the same.
         *
         * @param obj
         *            the other keypoint
         * @return true if the locations match; false otherwise.
         */
        public boolean locationEquals(Object obj) {
                if (obj instanceof Keypoint) {
                        final Keypoint kobj = (Keypoint) obj;

                        if (kobj.x == x && kobj.y == y && kobj.scale == scale)
                                return true;
                }

                return super.equals(obj);
        }

        @Override
        public boolean equals(Object obj) {
                if (obj instanceof Keypoint) {
                        final Keypoint kobj = (Keypoint) obj;

                        if (kobj.x == x && kobj.y == y && kobj.scale == scale && Arrays.equals(ivec, kobj.ivec))
                                return true;
                }

                return super.equals(obj);
        }

        @Override
        public int hashCode() {
                int hash = 1;
                hash = hash * 31 + Float.floatToIntBits(y);
                hash = hash * 31 + Float.floatToIntBits(x);
                hash = hash * 31 + Float.floatToIntBits(scale);
                return hash;
        }

        @Override
        public Keypoint clone() {
                final Keypoint clone = new Keypoint();

                clone.x = x;
                clone.ori = ori;
                clone.y = y;
                clone.scale = scale;

                clone.ivec = new byte[ivec.length];
                System.arraycopy(ivec, 0, clone.ivec, 0, ivec.length);

                return clone;
        }

        @Override
        public void copyFrom(Point2d p) {
                setX(p.getX());
                setY(p.getY());
        }

        @Override
        public void writeBinary(DataOutput out) throws IOException {
                getLocation().writeBinary(out);
                out.write(this.ivec);
        }

        @Override
        public void writeASCII(PrintWriter out) throws IOException {
                /* Output data for the keypoint. */
                getLocation().writeASCII(out);
                for (int i = 0; i < ivec.length; i++) {
                        if (i > 0 && i % 20 == 0)
                                out.println();
                        out.print(" " + (ivec[i] + 128));
                }
                out.println();
        }

        @Override
        public void readBinary(DataInput in) throws IOException {
                final KeypointLocation l = getLocation();
                l.readBinary(in);
                setLocation(l);

                in.readFully(ivec);
        }

        @Override
        public void readASCII(Scanner in) throws IOException {
                final KeypointLocation l = getLocation();
                l.readASCII(in);
                setLocation(l);

                int i = 0;
                while (i < ivec.length) {
                        final String line = in.nextLine();
                        final StringTokenizer st = new StringTokenizer(line);

                        while (st.hasMoreTokens()) {
                                ivec[i] = (byte) (Integer.parseInt(st.nextToken()) - 128);
                                i++;
                        }
                }
        }

        @Override
        public byte[] binaryHeader() {
                return "".getBytes();
        }

        @Override
        public String asciiHeader() {
                return "";
        }

        @Override
        public ByteFV getFeatureVector() {
                return new ByteFV(ivec);
        }

        @Override
        public KeypointLocation getLocation() {
                return new KeypointLocation(x, y, ori, scale);
        }

        /**
         * Set the location of this {@link Keypoint}
         *
         * @param location
         *            the location
         */
        public void setLocation(KeypointLocation location) {
                x = location.x;
                y = location.y;
                scale = location.scale;
                ori = location.orientation;
        }

        /**
         * Create a list of {@link Keypoint}s from the input list, but with the
         * positions offset by the given amount.
         *
         * @param keypoints
         *            the input list
         * @param x
         *            the x offset
         * @param y
         *            the y offset
         * @return the new keypoints
         */
        public static List<Keypoint> getRelativeKeypoints(List<Keypoint> keypoints, float x, float y) {
                final List<Keypoint> shifted = new ArrayList<Keypoint>();
                for (final Keypoint old : keypoints) {
                        final Keypoint n = new Keypoint();
                        n.x = old.x - x;
                        n.y = old.y - y;
                        n.ivec = old.ivec;
                        n.scale = old.scale;
                        n.ori = old.ori;
                        shifted.add(n);
                }
                return shifted;
        }

        /**
         * Add Gaussian noise the feature vectors of some features. The original
         * features are untouched; the returned list contains a copy.
         *
         * @param siftFeatures
         *            the input features
         * @param mean
         *            the mean of the noise
         * @param sigma
         *            the standard deviation of the noise
         * @return the noisy keypoints
         */
        public static List<Keypoint> addGaussianNoise(List<Keypoint> siftFeatures, double mean, double sigma) {
                final List<Keypoint> toRet = new ArrayList<Keypoint>();
                for (final Keypoint keypoint : siftFeatures) {
                        final Keypoint kpClone = keypoint.clone();
                        for (int i = 0; i < keypoint.ivec.length; i++) {
                                final double deviation = Normal.staticNextDouble(mean, sigma);
                                int value = 0xff & keypoint.ivec[i];
                                value += deviation;
                                if (value < 0)
                                        value = 0;
                                else if (value > 255)
                                        value = 255;

                                kpClone.ivec[i] = (byte) value;
                        }
                        toRet.add(kpClone);
                }
                return toRet;
        }

        /**
         * Scale a list of keypoints by the given amount. This scales the location
         * and scale of each keypoint. The original features are untouched; the
         * returned list contains a copy.
         *
         * @param keypoints
         *            the input features.
         * @param toScale
         *            the scale factor
         * @return the scaled features.
         */
        public static List<Keypoint> getScaledKeypoints(List<Keypoint> keypoints, int toScale) {
                final List<Keypoint> shifted = new ArrayList<Keypoint>();
                for (final Keypoint old : keypoints) {
                        final Keypoint n = new Keypoint();
                        n.x = old.x * toScale;
                        n.y = old.y * toScale;
                        n.ivec = old.ivec;
                        n.scale = old.scale * toScale;
                        n.ori = old.ori;
                        shifted.add(n);
                }
                return shifted;
        }

        @Override
        public void translate(float x, float y) {
                this.x += x;
                this.y += y;
        }

        @Override
        public Keypoint transform(Matrix transform) {
                float xt = (float) transform.get(0, 0) * getX() + (float) transform.get(0, 1) * getY()
                                + (float) transform.get(0, 2);
                float yt = (float) transform.get(1, 0) * getX() + (float) transform.get(1, 1) * getY()
                                + (float) transform.get(1, 2);
                final float zt = (float) transform.get(2, 0) * getX() + (float) transform.get(2, 1) * getY()
                                + (float) transform.get(2, 2);

                xt /= zt;
                yt /= zt;

                return new Keypoint(xt, yt, this.ori, this.scale, this.ivec.clone());
        }

        @Override
        public Point2d minus(Point2d a) {
                final Keypoint kp = this.clone();
                kp.x = this.x - (int) a.getX();
                kp.y = this.y - (int) a.getY();
                return null;
        }

        @Override
        public void translate(Point2d v) {
                this.translate(v.getX(), v.getY());
        }

        @Override
        public Point2d copy() {
                return clone();
        }

        @Override
        public void setOrdinate(int dimension, Number value) {
                if (dimension == 0)
                        x = value.floatValue();
                if (dimension == 1)
                        y = value.floatValue();
        }
}