YahooMediaSearchCommand.java

/* Copyright (2007-2012) Schibsted ASA
 * This file is part of Possom.
 *
 *   Possom is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   Possom is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with Possom.  If not, see <http://www.gnu.org/licenses/>.
 */
package no.sesat.search.mode.command;

import no.sesat.search.result.BasicResultList;
import no.sesat.search.result.BasicResultItem;
import no.sesat.search.mode.config.YahooMediaCommandConfig;
import java.util.Map;
import java.text.MessageFormat;
import java.net.URLEncoder;
import java.io.UnsupportedEncodingException;
import java.io.IOException;
import java.net.SocketTimeoutException;
import no.sesat.search.result.ResultItem;
import no.sesat.search.result.ResultList;
import org.apache.log4j.Logger;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

/**
 * Command for searching images and videos using Yahoo! as a provider.
 *
 * Yahoo API documentation can be found here:
 * https://dev.sesat.no/confluence/display/TECHDEV/Yahoo+Media+Search
 *
 * @version $Id$
 */
public final class YahooMediaSearchCommand extends AbstractYahooSearchCommand {

    private static final Logger LOG = Logger.getLogger(YahooMediaSearchCommand.class);

    private static final String COMMAND_URL_PATTERN =
            "/std_xmls_a00?type=any&query={0}&offset={1}&custid1={2}&hits={3}&ocr={4}&catalog={5}&encoding=utf-8";

    private static final String ERR_FAILED_CREATING_URL = "Failed to encode URL";

    private static final String RESULT_HEADER_ELEMENT = "GRP";
    private static final String TOTAL_HITS_ATTR = "TOT";
    private static final String RESULT_ELEMENT = "RES";

    private static final String URL_ENCODING = "UTF-8";

    private static final String YAHOO_SIZE_PARAM = "dimensions";
    private static final String SIZE_PARAM = "sz";
    private static final String OCR_PARAM = "ocr";

    private static final String FIELD_THUMB_HEIGHT = "thumb_height";
    private static final String FIELD_THUMB_WIDTH = "thumb_width";

    private static final String ATTRIBUTE_THUMB_GEO = "TGEO";

    /**
     * provides a mapping betweeen sizes defined by us
     * and sizes defined by yahoo. Currently one to one.
     */
    private static enum ImageMapping {
        SMALL ("small"),
        MEDIUM ("medium"),
        LARGE ("large"),
        WALLPAPER ("wallpaper"),
        WIDEWALLPAPER ("widewallpaper");

        private final String sizes;

        ImageMapping(final String sizes) {
            this.sizes = sizes;
        }

        /**
         * Getter for property 'sizes'.
         *
         * @return Value for property 'sizes'.
         */
        public String getSizes() {
            return sizes;
        }
    }

    /**
     * Create new yahoo media command.
     *
     * @param cxt Context to execute in.
     */
    public YahooMediaSearchCommand(final Context cxt) {

        super(cxt);

        setXmlRestful(
                new AbstractXmlRestful(cxt) {
                    public String createRequestURL() {

                        String query = YahooMediaSearchCommand.this.getTransformedQuery();

                        final YahooMediaCommandConfig cfg = (YahooMediaCommandConfig) cxt.getSearchConfiguration();

                        if (cfg.getSite().length() > 0) {
                            query += " +site:" + cfg.getSite();
                        }

                        try {

                            final String ocr = YahooMediaSearchCommand.this.getSingleParameter(OCR_PARAM) != null
                                    ? YahooMediaSearchCommand.this.getSingleParameter(OCR_PARAM)
                                    : cfg.getOcr();

                            String url = MessageFormat.format(
                                    COMMAND_URL_PATTERN,
                                    URLEncoder.encode(query, URL_ENCODING),
                                    YahooMediaSearchCommand.this.getOffset(),
                                    YahooMediaSearchCommand.this.getPartnerId(),
                                    cfg.getResultsToReturn(),
                                    ocr,
                                    cfg.getCatalog());

                            if (YahooMediaSearchCommand.this.getSingleParameter(SIZE_PARAM) != null
                                    && !YahooMediaSearchCommand.this.getSingleParameter(SIZE_PARAM).equals("")) {

                                final ImageMapping mapping = ImageMapping.valueOf(
                                        YahooMediaSearchCommand.this.getSingleParameter(SIZE_PARAM).toUpperCase());

                                if (mapping != null) {
                                    url += "&" + YAHOO_SIZE_PARAM + "=" + mapping.getSizes();
                                }
                            }

                            return url;

                        } catch (final UnsupportedEncodingException e) {
                            throw new SearchCommandException(ERR_FAILED_CREATING_URL, e);
                        }
                    }
                });
    }

    public ResultList<ResultItem> execute() {
        try {

            final Document doc = getXmlRestful().getXmlResult();
            final ResultList<ResultItem> searchResult = new BasicResultList<ResultItem>();

            if (doc != null) {

                searchResult.setHitCount(0);

                final Element searchResponseE = doc.getDocumentElement();
                final Element resultHeaderE = (Element) searchResponseE.getElementsByTagName(RESULT_HEADER_ELEMENT).item(0);

                if (resultHeaderE != null) {

                    searchResult.setHitCount(Integer.parseInt(resultHeaderE.getAttribute(TOTAL_HITS_ATTR)));

                    final NodeList list = searchResponseE.getElementsByTagName(RESULT_ELEMENT);

                    for (int i = 0; i < list.getLength(); ++i) {
                        final Element listing = (Element) list.item(i);
                        searchResult.addResult(createItem(listing));
                    }
                }
            }

            searchResult.addField("generatedQuery", getQueryRepresentation());

            return searchResult;

        } catch (SocketTimeoutException ste) {

            LOG.error(getSearchConfiguration().getId() +  " --> " + ste.getMessage());
            return new BasicResultList<ResultItem>();

        } catch (final IOException e) {
            throw new SearchCommandException(e);

        } catch (final SAXException e) {
            throw new SearchCommandException(e);
        }
    }


    protected ResultItem createItem(final Element listing) {
        final BasicResultItem item = new BasicResultItem();

        for (final Map.Entry<String,String> entry : context.getSearchConfiguration().getResultFieldMap().entrySet()){

            // Special case for thumb width & height.
            if (entry.getKey().equals(FIELD_THUMB_HEIGHT)) {
                final String geometry = listing.getAttribute(ATTRIBUTE_THUMB_GEO);
                final String height = geometry.substring(geometry.indexOf("x") + 1);
                item.addField(entry.getValue(), height);
            } else if (entry.getKey().equals(FIELD_THUMB_WIDTH)) {
                final String geometry = listing.getAttribute(ATTRIBUTE_THUMB_GEO);
                final String width = geometry.substring(0, geometry.indexOf("x"));
                item.addField(entry.getValue(), width);
            } else {

                final String field = listing.getAttribute(entry.getKey().toUpperCase());

                if (!"".equals(field)) {
                    item.addField(entry.getValue(), field);
                }
            }
        }

        return item;
    }
}