/* (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.ows;

import static org.geoserver.ows.util.ResponseUtils.baseURL;
import static org.geoserver.ows.util.ResponseUtils.buildSchemaURL;

import java.io.IOException;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.logging.Level;

import javax.servlet.http.HttpServletResponse;

import net.opengis.ows11.ExceptionReportType;
import net.opengis.ows11.Ows11Factory;

import org.geoserver.platform.Service;
import org.geoserver.platform.ServiceException;
import org.geotools.ows.v1_1.OWS;
import org.geotools.ows.v1_1.OWSConfiguration;
import org.geotools.xml.Encoder;


/**
 * A default implementation of {@link ServiceExceptionHandler} which outputs as service exception in a <code>ows:ExceptionReport</code> document.
 * <p>
 * This service exception handler will generate an OWS exception report, see
 * <a href="http://schemas.opengis.net/ows/1.1.0/owsExceptionReport.xsd">owsExceptionReport.xsd</a>.
 * </p>
 *
 * @author Justin Deoliveira, The Open Planning Project
 */
public class OWS11ServiceExceptionHandler extends ServiceExceptionHandler {
    /**
     * verbose exception flag controlling whether the exception stack trace will be included in the
     * encoded ows exception report
     */
    protected boolean verboseExceptions = false;

    /**
     * flag that controls what version to use in the ows exception report.
     */
    protected boolean useServiceVersion = false;

    /**
     * Constructor to be called if the exception is not for a particular service.
     *
     */
    public OWS11ServiceExceptionHandler() {
        super(Collections.EMPTY_LIST);
    }

    /**
     * Constructor to be called if the exception is for a particular service.
     *
     * @param services List of services this handler handles exceptions for.
     */
    public OWS11ServiceExceptionHandler(List services) {
        super(services);
    }
    
    /**
     * Constructor to be called if the exception is for a particular service.
     *
     * @param service Services this handler handles exceptions for
     */
    public OWS11ServiceExceptionHandler(Service service) {
        super(Arrays.asList(service));
    }

    /**
     * Writes out an OWS ExceptionReport document.
     */
    public void handleServiceException(ServiceException exception, Request request) {
        Ows11Factory factory = Ows11Factory.eINSTANCE;

        String version = null;
        if (useServiceVersion && request.getServiceDescriptor() != null) {
            version = request.getServiceDescriptor().getVersion().toString();
        }

        ExceptionReportType report = Ows11Util.exceptionReport( exception, verboseExceptions, version );
        
        HttpServletResponse response = request.getHttpResponse();
        if (!request.isSOAP()) {
            //there will already be a SOAP mime type
            response.setContentType("application/xml");
        }

        //response.setCharacterEncoding( "UTF-8" );
        OWSConfiguration configuration = new OWSConfiguration();

        Encoder encoder = new Encoder(configuration, configuration.schema());
        encoder.setIndenting(true);
        encoder.setIndentSize(2);
        encoder.setLineWidth(60);
        encoder.setOmitXMLDeclaration(request.isSOAP());
        
        String schemaLocation = buildSchemaURL(baseURL(request.getHttpRequest()), "ows/1.1.0/owsAll.xsd");
        encoder.setSchemaLocation(OWS.NAMESPACE, schemaLocation);

        try {
            encoder.encode(report, OWS.ExceptionReport,
                response.getOutputStream());
        } catch (Exception ex) {
            //throw new RuntimeException(ex);
            // Hmm, not much we can do here.  I guess log the fact that we couldn't write out the exception and be done with it...
            LOGGER.log(Level.INFO, "Problem writing exception information back to calling client:", ex);
        } finally {
            try {
                response.getOutputStream().flush();
            } catch (IOException ioe) {
            }
        }
    }

    /**
     * Flag that controls what version to use in the ows exception report.
     * <p>
     * Setting to true will cause the service version to be used rather than the ows spec version.
     * </p>
     */
    public void setUseServiceVersion(boolean useServiceVersion) {
        this.useServiceVersion = useServiceVersion;
    }
}