/* (c) 2014 Open Source Geospatial Foundation - all rights reserved
 * (c) 2001 - 2013 OpenPlans
 * This code is licensed under the GPL 2.0 license, available at the root
 * application directory.
 */
package org.geoserver.wms.featureinfo;

import java.io.IOException;
import java.io.OutputStream;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Collections;
import java.util.Iterator;

import net.opengis.wfs.FeatureCollectionType;
import net.opengis.wfs.GetFeatureType;
import net.opengis.wfs.QueryType;
import net.opengis.wfs.WfsFactory;

import org.geoserver.config.GeoServer;
import org.geoserver.platform.Operation;
import org.geoserver.platform.Service;
import org.geoserver.platform.ServiceException;
import org.geoserver.wfs.xml.GML2OutputFormat;
import org.geoserver.wms.GetFeatureInfoRequest;
import org.geoserver.wms.WMS;
import org.geotools.data.simple.SimpleFeatureCollection;
import org.geotools.feature.FeatureCollection;
import org.geotools.gml2.bindings.GML2EncodingUtils;

/**
 * A GetFeatureInfo response handler specialized in producing GML data for a GetFeatureInfo request.
 * 
 * <p>
 * This class does not deals directly with GML encoding. Instead, it works by taking the
 * FeatureResults produced in <code>execute()</code> and constructs a <code>GetFeaturesResult</code>
 * wich is passed to a <code>GML2FeatureResponseDelegate</code>, as if it where the result of a
 * GetFeature WFS request.
 * </p>
 * 
 * @author Gabriel Roldan
 */
public class GML2FeatureInfoOutputFormat extends GetFeatureInfoOutputFormat {
    /**
     * The MIME type of the format this response produces: <code>"application/vnd.ogc.gml"</code>
     */
    public static final String FORMAT = "application/vnd.ogc.gml";

    private WMS wms;

    /**
     * Default constructor, sets up the supported output format string.
     */
    public GML2FeatureInfoOutputFormat(final WMS wms) {
        super(FORMAT);
        this.wms = wms;
    }

    protected GML2FeatureInfoOutputFormat(WMS wms, String format) {
        super(format);
        this.wms = wms;
    }

    /**
     * Takes the <code>FeatureResult</code>s generated by the <code>execute</code> method in the
     * superclass and constructs a <code>GetFeaturesResult</code> wich is passed to a
     * <code>GML2FeatureResponseDelegate</code>.
     * 
     * @see AbstractFeatureInfoResponse#writeTo(OutputStream)
     */
    @SuppressWarnings({ "rawtypes", "unchecked" })
    @Override
    public void write(FeatureCollectionType results, GetFeatureInfoRequest fInfoReq,
            OutputStream out) throws ServiceException, IOException {

        // the 'response' object we'll pass to our OutputFormat
        FeatureCollectionType features = WfsFactory.eINSTANCE.createFeatureCollectionType();

        // the 'request' object we'll pass to our OutputFormat
        GetFeatureType gfreq = WfsFactory.eINSTANCE.createGetFeatureType();
        gfreq.setBaseUrl(fInfoReq.getBaseUrl());

        for (Iterator i = results.getFeature().iterator(); i.hasNext();) {
            FeatureCollection fc = (FeatureCollection) i.next();
            features.getFeature().add(fc);

            QueryType qt = WfsFactory.eINSTANCE.createQueryType();
            String crs = GML2EncodingUtils.epsgCode(fc.getSchema().getCoordinateReferenceSystem());
            if (crs != null) {
                final String srsName = "EPSG:" + crs;
                try {
                    qt.setSrsName(new URI(srsName));
                } catch (URISyntaxException e) {
                    throw new ServiceException(
                        "Unable to determite coordinate system for featureType " + 
                            fc.getSchema().getName() + ".  Schema told us '" + srsName + "'", e);
                }
            }
            gfreq.getQuery().add(qt);

        }

        // this is a dummy wrapper around our 'request' object so that the new Dispatcher will
        // accept it.
        Service serviceDesc = new Service("wms", null, null, Collections.EMPTY_LIST);
        Operation opDescriptor = new Operation("", serviceDesc, null, new Object[] { gfreq });

        final GeoServer gs = wms.getGeoServer();
        GML2OutputFormat format = new GML2OutputFormat(gs);
        format.write(features, out, opDescriptor);
    }

}