/**
 * 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.dataset;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import net.billylieurance.azuresearch.AbstractAzureSearchQuery.AZURESEARCH_FORMAT;
import net.billylieurance.azuresearch.AzureSearchImageQuery;
import net.billylieurance.azuresearch.AzureSearchImageResult;

import org.openimaj.data.dataset.ReadableListDataset;
import org.openimaj.data.identity.Identifiable;
import org.openimaj.image.Image;
import org.openimaj.io.HttpUtils;
import org.openimaj.io.InputStreamObjectReader;
import org.openimaj.util.api.auth.common.BingAPIToken;

/**
 * Image datasets dynamically created from the Bing search API.
 * 
 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
 * 
 * @param <IMAGE>
 *            The type of {@link Image} instance held by the dataset.
 */
public class BingImageDataset<IMAGE extends Image<?, IMAGE>> extends ReadableListDataset<IMAGE, InputStream>
                implements
                        Identifiable
{
        List<AzureSearchImageResult> images;
        AzureSearchImageQuery query;

        protected BingImageDataset(InputStreamObjectReader<IMAGE> reader, List<AzureSearchImageResult> results,
                        AzureSearchImageQuery query)
        {
                super(reader);
                this.images = results;
                this.query = query;
        }

        @Override
        public IMAGE getInstance(int index) {
                return read(getImage(index));
        }

        private IMAGE read(AzureSearchImageResult next) {
                if (next == null)
                        return null;

                InputStream stream = null;
                try {
                        final String imageURL = next.getMediaUrl();
                        stream = HttpUtils.readURL(new URL(imageURL));

                        return reader.read(stream);
                } catch (final IOException e) {
                        throw new RuntimeException(e);
                } finally {
                        try {
                                if (stream != null)
                                        stream.close();
                        } catch (final IOException e) {
                                // ignore
                        }
                }
        }

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

        /**
         * Get the underlying {@link AzureSearchImageResult} objects that back the
         * dataset.
         * 
         * @return the underlying {@link AzureSearchImageResult} objects
         */
        public List<AzureSearchImageResult> getImages() {
                return images;
        }

        /**
         * Get the specific underlying {@link AzureSearchImageResult} for the given
         * index.
         * 
         * @param index
         *            the index
         * @return the specific {@link AzureSearchImageResult} for the given index.
         */
        public AzureSearchImageResult getImage(int index) {
                return images.get(index);
        }

        private static List<AzureSearchImageResult> performSinglePageQuery(AzureSearchImageQuery query) {
                query.setFormat(AZURESEARCH_FORMAT.XML);
                query.doQuery();

                return query.getQueryResult().getASRs();
        }

        private static List<AzureSearchImageResult> performQuery(AzureSearchImageQuery query, int number) {
                if (number <= 0)
                        number = 1000;

                query.setPage(0);
                query.setPerPage(50);
                query.setFormat(AZURESEARCH_FORMAT.XML);

                final List<AzureSearchImageResult> images = new ArrayList<AzureSearchImageResult>();
                for (int i = 0; i < 20; i++) {
                        final List<AzureSearchImageResult> res = performSinglePageQuery(query);

                        if (res == null || res.size() == 0)
                                break;

                        images.addAll(res);

                        if (images.size() >= number)
                                break;
                }

                if (images.size() <= number)
                        return images;
                return images.subList(0, number);
        }

        /**
         * Perform a search with the given query. The appid must have been set
         * externally.
         * 
         * @see AzureSearchImageQuery#setAppid(String)
         * 
         * @param reader
         *            the reader with which to load the images
         * @param query
         *            the query
         * @param number
         *            the target number of results; the resultant dataset may
         *            contain fewer images than specified.
         * @return a new {@link BingImageDataset} created from the query.
         */
        public static <IMAGE extends Image<?, IMAGE>> BingImageDataset<IMAGE> create(InputStreamObjectReader<IMAGE> reader,
                        AzureSearchImageQuery query, int number)
        {
                return new BingImageDataset<IMAGE>(reader, performQuery(query, number), query);
        }

        /**
         * Perform a search with the given query. The given api token will be used
         * to set the appid in the query object.
         * 
         * @param reader
         *            the reader with which to load the images
         * @param token
         *            the api authentication token
         * @param query
         *            the query
         * @param number
         *            the target number of results; the resultant dataset may
         *            contain fewer images than specified.
         * @return a new {@link BingImageDataset} created from the query.
         */
        public static <IMAGE extends Image<?, IMAGE>> BingImageDataset<IMAGE> create(InputStreamObjectReader<IMAGE> reader,
                        BingAPIToken token, AzureSearchImageQuery query, int number)
        {
                query.setAppid(token.accountKey);
                return new BingImageDataset<IMAGE>(reader, performQuery(query, number), query);
        }

        /**
         * Perform a search with the given query string and filters.
         * 
         * @param reader
         *            the reader with which to load the images
         * @param token
         *            the api authentication token
         * @param query
         *            the query
         * @param imageFilters
         *            the image filters
         * @param number
         *            the target number of results; the resultant dataset may
         *            contain fewer images than specified.
         * @return a new {@link BingImageDataset} created from the query.
         */
        public static <IMAGE extends Image<?, IMAGE>> BingImageDataset<IMAGE> create(InputStreamObjectReader<IMAGE> reader,
                        BingAPIToken token, String query, String imageFilters, int number)
        {
                final AzureSearchImageQuery aq = new AzureSearchImageQuery();
                aq.setAppid(token.accountKey);
                aq.setQuery(query);
                if (imageFilters != null)
                        aq.setImageFilters(imageFilters);

                return new BingImageDataset<IMAGE>(reader, performQuery(aq, number), aq);
        }

        /**
         * Perform a search with the given query string.
         * 
         * @param reader
         *            the reader with which to load the images
         * @param token
         *            the api authentication token
         * @param query
         *            the query
         * @param number
         *            the target number of results; the resultant dataset may
         *            contain fewer images than specified.
         * @return a new {@link BingImageDataset} created from the query.
         */
        public static <IMAGE extends Image<?, IMAGE>> BingImageDataset<IMAGE> create(InputStreamObjectReader<IMAGE> reader,
                        BingAPIToken token, String query, int number)
        {
                final AzureSearchImageQuery aq = new AzureSearchImageQuery();
                aq.setAppid(token.accountKey);
                aq.setQuery(query);

                return new BingImageDataset<IMAGE>(reader, performQuery(aq, number), aq);
        }

        @Override
        public String getID() {
                return query.getQuery();
        }
}