/*  Package GeoTools/WMS Implementation
 *  Copyright (C) 2001 Cameron Shorter (camerons@users.sourceforge.net)q
 *                     Artur Hefczyc (kobit@users.sourceforge.net)
 *
 *  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.
 *
 * $Id: RemoteWMS.java,v 1.11 2001/11/18 15:57:54 kobit Exp $
 * $Author: kobit $
 * $Date: 2001/11/18 15:57:54 $
 */

package uk.ac.leeds.ccg.ogc;

import java.util.*;
import java.io.*;
import java.net.*;

/**
 * Class <code>RemoteWMS</code> provides an interface for the standard
 * <i>Web Map Server</i> (WMS) protocols as defined by the
 * <a href="http://opengis.org">Open GIS Consortium</a>.
 * It is an bridge between a remote WMS
 * and <code>GeoTools</code> client. Implemented methods of this
 * class convert <i>Web Map Server</i> data representation to
 * <code>GeoTools</code> client data reprezentation.<br/>
 * This class should be used in conjunction with <code>WMSLayer</code>
 * @see uk.ac.leeds.ccg.ogc.WMSLayer
 *
 * @author <a href="mailto:camerons@users.sourceforge.net">Cameron Shorter</a>
 * @author <a href="mailto:kobit@users.sourceforge.net">Artur Hefczyc</a>
 * @version $Revision: 1.11 $
 */
public class RemoteWMS extends RemoteOGC
{
    /**
     * Creates a new <code>RemoteWMS</code> instance.  This constructor will
     * trigger a GETCAPABILITIES to determine the remainder of its parameters.
     *
     * @param server an <code>URL</code> value
     * @param proxy an <code>URL</code> value
     */
    public RemoteWMS(URL server, URL proxy) {
        super(server,proxy);
    }

    /**
     * Creates a new <code>RemoteWMS</code> instance.  This constructor will
     * trigger a GETCAPABILITIES to determine the remainder of its parameters.
     *
     * @param server an <code>URL</code> value
     * @param proxy an <code>URL</code> value
     */
    public RemoteWMS(URL server) {
        super(server);
    }

    /**
     * Creates a new <code>RemoteWMS</code> instance.  This constructor
     * does not require a GETCAPABILITIES call to obtain remaining parameters.
     *
     * @param server an <code>URL</code> value
     * @param proxy an <code>URL</code> value
     * @param SRS the Spacial Reference System.  See OGC Spec for description.
     * @param Version the version of the OGC spec being used.  See OGC Spec for
     * description.
     */
    public RemoteWMS(URL server, URL proxy, String SRS, String version) {
        super(server,proxy,SRS,version);
    }

    /**
     * <code>getExternalLayers</code> method returns <code>ArrayList</code>
     * with <code>ExternalWMSLayers</code> objects.
     *
     * @return an <code>ArrayList</code> with <code>ExternalWMSLayers</code>
     *         objects.
     * @exception IOException if an error occurs
     */
    public ArrayList getExternalLayers() throws IOException {
        if(capabilities == null)
          getCapabilities();
        if (capabilities != null) {
          return capabilities.getAvailableLayers();
        } // end of if (capabilities != null)
        else {
          return null;
        } // end of if (capabilities != null)else
        
    }

    /**
   * <code>getWMSLayer</code> method creates WMSLayer instance from
   * data downloaded from <code>WebMapService</code>. To do it
   * it must build query for web server, send request and receive data.
   * This method can take lonk period of time (even infinite if we don't
   * read data from the network in separate thread and use better HTTP
   * implementation).<br/>
   * Mr Cameron prefers to use <code>GeoRectangle</code> class instead
   * of using x, y, w, h. I don't like this idea, becouse most of
   * ogc package is <code>GeoTools</code> library independent and it
   * is worth to keep it that. There is only one class which must use
   * <code>GeoTools</code> package it is <code>WMSLayer</code>.
   *
   * @param ext_layer an <code>ExternalWMSLayer</code> value
   * @param format a <code>WMSFormat</code> value
   * @param x a <code>double</code> value
   * @param y a <code>double</code> value
   * @param width a <code>double</code> value
   * @param height a <code>double</code> value
   * @return a <code>WMSLayer</code> class instance created from data
   *         received from <code>WebMapService</code>. I think that
   *         this method should better return
   *         <code>uk.ac.leeds.ccg.geotools.Layer</code> instead of
   *         <code>WMSLayer</code>.
   */
  public WMSLayer getWMSLayer(ExternalWMSLayer [] ext_layers,
                              WMSFormat format,
                              double x, double y, double width, double height)
                              //throws IOException
  {
    //If we haven't capabilities file then we should download it
    try {
      if(capabilities == null) getCapabilities();
    } catch(IOException ioe) { ioe.printStackTrace(); }
    //if(webMap != null) {
      //String file_name = new String(ext_layer.getLayerName()+"-"+
                                    //x+"_"+y+"_"+width+"_"+height+"."+
                                    //format.getFormatExtension());
      //if(!new File(file_name).exists()) {
        //String query = webMap.wmsLayerQuery(ext_layer, format, x, y, width, height);
        //if(remoteConnection == null)
          //remoteConnection = new RemoteConnection(server, proxy);
        //int query_result = remoteConnection.sendQuery(query);
        //if(query_result != RemoteConnection.RESPONSE_ERROR)
          //remoteConnection.saveContent(file_name);
      //}
    //  return webMap.getWMSLayer(ext_layers, format, x, y, width, height,
    //						server+"?WMTVER=1.0&REQUEST=map&SRS=EPSG%3A4326");
    //}
    return null;
  }


}
/*
 * Changes in file:
 *
 * $Log: RemoteWMS.java,v $
 * Revision 1.11  2001/11/18 15:57:54  kobit
 * Use of simple-jprotocols package instead of java.net, DTD validating switched OFF, default version if WMS implementation is set to 1.0.0
 *
 * Revision 1.10  2001/10/24 09:42:24  kobit
 * Some minor changes for working according to new design
 *
 *
 */