Application: gvSIG desktop

/* gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2005 IVER T.I. and Generalitat Valenciana.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib??ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

package org.gvsig.remoteclient.wcs;

import java.io.ByteArrayInputStream;

import java.io.File;

import java.io.IOException;

import java.net.MalformedURLException;

import java.net.URL;

import java.util.ArrayList;

import java.util.Hashtable;

import java.util.StringTokenizer;

import org.gvsig.compat.CompatLocator;

import org.gvsig.compat.lang.StringUtils;

import org.gvsig.compat.net.ICancellable;

import org.gvsig.remoteclient.exceptions.ServerErrorException;

import org.gvsig.remoteclient.exceptions.WCSException;

import org.gvsig.remoteclient.ogc.OGCProtocolHandler;

import org.gvsig.remoteclient.ogc.OGCServiceInformation;

import org.gvsig.remoteclient.utils.ExceptionTags;

import org.gvsig.remoteclient.utils.Utilities;

import org.gvsig.remoteclient.wcs.request.WCSDescribeCoverageRequest;

import org.gvsig.remoteclient.wcs.request.WCSGetCoverageRequest;

import org.kxml2.io.KXmlParser;

import org.xmlpull.v1.XmlPullParserException;

/**

 *

 * @author jaume

 *

 */

public abstract class WCSProtocolHandler extends OGCProtocolHandler {

        /**

         * Encoding used to parse different xml documents.

         */

        protected String encoding = "UTF-8";

        protected Hashtable layerPool = new Hashtable();

        /**

     * WCS metadata

     */

    protected WCSServiceInformation serviceInfo = new WCSServiceInformation();

    private static final StringUtils stringUtils = CompatLocator.getStringUtils();

        /*

         * (non-Javadoc)

         * @see org.gvsig.remoteClient.OGCProtocolHandler#setHost(java.lang.String)

         */

        public void setHost(String host) {

                try {

                        // Validates the URL if doesn't produces an exception

                        new URL(host);

                        int index = host.indexOf("?");

                        if (index == -1)

                                super.setHost(host);

                        else

                                super.setHost(host.substring(0, index));

                }

                catch (MalformedURLException m) {

                        // Bad URL -> hold it

                        super.setHost(host);

                }

        }

        /**

     * <p>

     * Builds a GetCapabilities request that is sent to the WCS

     * the response will be parse to extract the data needed by the

     * WCS client.

     * </p>

     * @param override, if true the cache is ignored

     */

    public void getCapabilities(WCSStatus status, boolean override, ICancellable cancel) {

           URL request = null;

            try {

                request = new URL(buildCapabilitiesRequest(status));

            }

            catch(Exception e) {

                e.printStackTrace();

            }

            try {

                    if (override)

                        downloader.removeURL(request);

                    File f =  downloader.downloadFile(request,"wcs_capabilities.xml", cancel);

                    if (f!=null)

                            parseCapabilities(f);

            } catch(Exception e) {

                    e.printStackTrace();

            }

    }

    /**

     * Builds a complete URL-string that can be used to send a GetCapabilities request.

     * @return String

     */

    private String buildCapabilitiesRequest(WCSStatus status) {

            StringBuffer req = new StringBuffer();

                String symbol = null;

                String onlineResource;

                if (status == null || status.getOnlineResource() == null)

                        onlineResource = getHost();

                else

                        onlineResource = status.getOnlineResource();

                symbol = getSymbol(onlineResource);

                req.append(onlineResource).append(symbol).append("REQUEST=GetCapabilities&SERVICE=WCS&");

                req.append("VERSION=").append(getVersion()).append("&EXCEPTIONS=XML");

                return req.toString();

    }

    /**

     * parses the data retrieved by the DescribeCoverage XML document

     */

    public abstract boolean parseDescribeCoverage(File f);

    /**

     * Send a DescribeCoverage request using the settings passed in the status argument.

     * If status is null, then default settings are used.

     * @param override

     * @return String

     */

    public void describeCoverage(WCSStatus status, boolean override, ICancellable cancel) {

       try {

               WCSDescribeCoverageRequest request = createDescribeCoverageRequest(status);

           File f = request.sendRequest(cancel);

                if (f!=null)

                        parseDescribeCoverage(f);

        } catch(Exception e) {

                e.printStackTrace();

        }

    }

    /**

     * Send a GetCoverage request using the settings passed in the status.

     * @return String

     */

    public File getCoverage(WCSStatus status, ICancellable cancel) throws ServerErrorException, WCSException {

            try

                {

                        //TODO:

                        //pass this buildXXXRequest to the WCSProtocolHandlerXXX: The request can depend on the WCS version.

                        WCSGetCoverageRequest request = createGetCoverageRequest(status);

            File f = request.sendRequest(cancel);

            if (f!=null && Utilities.isTextFile(f)) {

                byte[] data = fileToBytes(f);

                            WCSException wcsEx = null;

                    String exceptionMessage = parseException(data);

                if (exceptionMessage==null)

                {

                         String error = new String(data);

                        int pos = error.indexOf("<?xml");

                        if (pos!= -1)

                        {

                                String xml = error.substring(pos,error.length());

                                exceptionMessage = parseException(xml.getBytes());

                        }

                    if (exceptionMessage == null)

                            exceptionMessage = new String(data);

                }

                     wcsEx = new WCSException(exceptionMessage);

                    wcsEx.setWCSMessage(new String(data));

                    // Since it is an error file, It must be deleted from the cache

                    downloader.removeURL(request);

                throw wcsEx;

            }

                        return f;

                }

                catch(IOException e)

                {

                        e.printStackTrace();

            throw new ServerErrorException();

                }

    }

    /**

     * Parses the WCS Exception document.

     * @param bytes, byte[]

     * @return

     */

    private String parseException(byte[] data) {

            // TODO: a?? est? fusilat del WMS, comprovar que funciona.

            ArrayList errors = new ArrayList();

        KXmlParser kxmlParser = new KXmlParser();

        try

        {

            kxmlParser.setInput(new ByteArrayInputStream(data), encoding);

            kxmlParser.nextTag();

            int tag;

            if ( kxmlParser.getEventType() != KXmlParser.END_DOCUMENT )

            {

                kxmlParser.require(KXmlParser.START_TAG, null, ExceptionTags.EXCEPTION_ROOT);

                tag = kxmlParser.nextTag();

                 while(tag != KXmlParser.END_DOCUMENT)

                 {

                     switch(tag)

                     {

                        case KXmlParser.START_TAG:

                            if (kxmlParser.getName().compareTo(ExceptionTags.SERVICE_EXCEPTION)==0){

                                String errorCode = kxmlParser.getAttributeValue("", ExceptionTags.CODE);

                                errorCode = (errorCode != null) ? "["+errorCode+"] " : "";

                                String errorMessage = kxmlParser.nextText();

                                errors.add(errorCode+errorMessage);

                            }

                            break;

                        case KXmlParser.END_TAG:

                            break;

                     }

                     tag = kxmlParser.nextTag();

                 }

                 //kxmlParser.require(KXmlParser.END_DOCUMENT, null, null);

            }

        }

        catch(XmlPullParserException parser_ex){

            parser_ex.printStackTrace();

        }

        catch (IOException ioe) {

            ioe.printStackTrace();

        }

        String message = errors.size()>0? "" : null;

        for (int i = 0; i < errors.size(); i++) {

            message += (String) errors.get(i)+"\n";

        }

        return message;

        }        

    /**

     * Builds the GetCapabilitiesRequest according to the OGC WCS Specifications

     * without a VERSION, to get the highest version than a WCS supports.

     */

    public static String buildCapabilitiesSuitableVersionRequest(String _host, String _version) {

                int index = _host.indexOf('?');

                if (index > -1) {

                        String host = _host.substring(0, index + 1);

                        String query = _host.substring(index + 1, _host.length());

                        StringTokenizer tokens = new StringTokenizer(query, "&");

                        String newQuery = "", token;

                        // If there is a field or a value with spaces, (and then it's on different tokens) -> unify them

                        while (tokens.hasMoreTokens()) {

                                token = tokens.nextToken().trim();

                                if (token.toUpperCase().compareTo("REQUEST=GETCAPABILITIES") == 0)

                                        continue;

                                if (token.toUpperCase().compareTo("SERVICE=WCS") == 0)

                                        continue;

                                if ((_version != null) && (_version.length() > 0)) {

                                    if (token.toUpperCase().compareTo("VERSION=" + _version) == 0)

                                            continue;

                                }

                                if (token.toUpperCase().compareTo("EXCEPTIONS=XML") == 0)

                                        continue;

                                newQuery += token + "&";

                        }

                _host = host + newQuery;

                }

                else {

                        _host += "?";

                }

            if ((_version != null) && (_version.compareTo("") != 0))

                    _host += "REQUEST=GetCapabilities&SERVICE=WCS&VERSION=" + _version + "&EXCEPTIONS=XML";

            else

                    _host += "REQUEST=GetCapabilities&SERVICE=WCS&EXCEPTIONS=XML";

            return stringUtils.replaceAll(_host, " ", "%20");

    }

        public ArrayList getFormats() {

                return new ArrayList(serviceInfo.formats);

        }       

        public Hashtable getLayers() {

                return layerPool;

        }

        public abstract WCSDescribeCoverageRequest createDescribeCoverageRequest(WCSStatus status);

        public abstract WCSGetCoverageRequest createGetCoverageRequest(WCSStatus status);

        /* (non-Javadoc)

         * @see org.gvsig.remoteclient.ogc.OGCProtocolHandler#getServiceInformation()

         */        

        public OGCServiceInformation getServiceInformation() {

                return serviceInfo;

        }        

}