/**
 * 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;

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

/**
 * A feature-vector representation of an enumeration
 *
 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
 *
 * @param <T>
 *            type of underlying enumeration
 */
public class EnumFV<T extends Enum<T>> implements FeatureVector {
        private static final long serialVersionUID = 1L;
        private T enumValue;

        /**
         * Construct the feature with the given value
         *
         * @param value
         *            the value
         */
        public EnumFV(T value) {
                this.enumValue = value;
        }

        @Override
        public void readBinary(DataInput in) throws IOException {
                try {
                        @SuppressWarnings("unchecked")
                        final Class<T> clz = (Class<T>) Class.forName(in.readUTF());
                        final String name = in.readUTF();
                        this.enumValue = Enum.valueOf(clz, name);
                } catch (final ClassNotFoundException e) {
                        throw new RuntimeException(e);
                }
        }

        @Override
        public void readASCII(Scanner in) throws IOException {
                try {
                        @SuppressWarnings("unchecked")
                        final Class<T> clz = (Class<T>) Class.forName(in.nextLine());
                        final String name = in.nextLine();
                        this.enumValue = Enum.valueOf(clz, name);
                } catch (final ClassNotFoundException e) {
                        throw new RuntimeException(e);
                }
        }

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

        @Override
        public String asciiHeader() {
                return getClass().getName() + " ";
        }

        @Override
        public void writeBinary(DataOutput out) throws IOException {
                out.writeUTF(enumValue.getDeclaringClass().getName());
                out.writeUTF(enumValue.toString());
        }

        @Override
        public void writeASCII(PrintWriter out) throws IOException {
                out.println(enumValue.getDeclaringClass().getName());
                out.println(enumValue.toString());
        }

        @Override
        public Enum<T> getVector() {
                return enumValue;
        }

        @Override
        public int length() {
                return enumValue.getDeclaringClass().getEnumConstants().length;
        }

        @Override
        public DoubleFV normaliseFV(double[] min, double[] max) {
                return asDoubleFV().normaliseFV(min, max);
        }

        @Override
        public DoubleFV normaliseFV(double min, double max) {
                return asDoubleFV().normaliseFV(min, max);
        }

        @Override
        public DoubleFV normaliseFV() {
                return asDoubleFV().normaliseFV();
        }

        @Override
        public DoubleFV normaliseFV(double p) {
                return asDoubleFV().normaliseFV(p);
        }

        @Override
        public DoubleFV asDoubleFV() {
                return new DoubleFV(asDoubleVector());
        }

        @Override
        public double[] asDoubleVector() {
                final double[] vec = new double[length()];
                vec[enumValue.ordinal()] = 1;
                return vec;
        }

        @Override
        public double getAsDouble(int i) {
                if (enumValue.ordinal() == i)
                        return 1;
                return 0;
        }

        @SuppressWarnings("unchecked")
        @Override
        public void setFromDouble(int i, double v) {
                if (v == 1) {
                        try {
                                enumValue = (T) this.getClass().getField("enumValue").getType().getEnumConstants()[i];
                        } catch (final Exception e) {
                                throw new RuntimeException(e);
                        }
                }
        }

        @Override
        public EnumFV<T> newInstance() {
                return new EnumFV<T>(enumValue);
        }
}