/*  Package GeoTools/OGC Implementation
 *  Copyright (C) 2001 Cameron Shorter (camerons@users.sourceforge.net)
 *                     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: RemoteOGC.java,v 1.18 2001/12/21 11:46:47 ianturton Exp $
 * $Author: ianturton $
 * $Date: 2001/12/21 11:46:47 $
 */

package uk.ac.leeds.ccg.ogc;

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

/**
 * Class <code>RemoteOGC</code> provides an interface for the standard
 * protocols defined by the
 * <a href="http://opengis.org">Open GIS Consortium</a>, eg a Web Map Server
 * (WMS).  It is an bridge between a remote OGC Services
 * and <code>GeoTools</code> client. Implemented methods of this
 * class convert <i>OGC Services</i> data representation to
 * <code>GeoTools</code> client data representation.<br/>
 * <p>
 * For application which use <code>GeoTools</code> and this ogc package
 * <code>RemoteOGC</code> acts as bridge between <code>GeoTools</code>
 * map data reprezentation and all <i>Web Map Server</i> specific logic.
 * So all cals for <i>Web Map Server</i> data should be performed by
 * this class.<br/>
 * You can think about it as a special kind of proxy class which during
 * realisation of user calls creates necessary objects, doing calculatiion
 * downloading and processing proper data becouse it knows how, when and
 * what to do to return data to user.
 * </p>
 * @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: 1.18 $
 */
public class RemoteOGC
{

  private URL server = null;
  private URL proxy = null;
  protected String SRS = null;
  protected String version = "1.0.0";
  protected OGCCapabilities capabilities = null;
  private RemoteConnection remoteConnection = null;
  private final static boolean DEBUG=true;
  //private OGCWebService[] services = null;
  //private OGCWebMapService webMap = null;

  /**
   * Creates a new <code>RemoteOGC</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 RemoteOGC(URL server, URL proxy)
  {
    this.server = server;
    this.proxy = proxy;
    // Trigger GETCAPABILITIES to get SRS and version.
		capabilities=null;
  }

  /**
   * Creates a new <code>RemoteOGC</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 RemoteOGC(URL server)
  {
    this.server = server;
    this.proxy = null;
    // Trigger GETCAPABILITIES to get SRS and version.
		capabilities=null;
  }

  /**
   * Creates a new <code>RemoteOGC</code> instance.  This constructor will
   * 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 RemoteOGC(URL server, URL proxy, String SRS, String version)
  {
    this.server = server;
    this.proxy = proxy;
    this.SRS = SRS;
    this.version = version;
  }

  /**
   * Creates a new <code>RemoteOGC</code> instance.  This constructor will
   * 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 RemoteOGC(URL server, String SRS, String version)
  {
    this.server = server;
    this.proxy = null;
    this.SRS = SRS;
    this.version = version;
  }

  protected void initConnection()
  {
    if(proxy!=null)
      remoteConnection = new RemoteConnection(server.toString(), proxy.toString());
    else
      remoteConnection = new RemoteConnection(server.toString(), null);
  }

  /**
   * <code>getURL</code> method builds a URL based on the proxy, the OGC
   * service URL, and the parameters for the service.  The URL will look
   * something like
   * http://proxy.org?service=http://service?request=getcapabilities
   *
   * @return a <code>URL</code> of proxy service with the OGC service and
   * params as a parameter.
   * @param params an array of (name1,value1,name2,value2,...) params to build
   * into a URL.
   */
  public URL getURL(String[] params)
  {
    URL newURL;
    // Build server URL
    StringBuffer serverURL =
      new StringBuffer(server.toString()+"?");
    if(this.SRS!=null) serverURL.append("SRS="+this.SRS);
    else serverURL.append("SRS=EPSG:4326");
    serverURL.append("&WMTVER="+this.version);
    for (int i=0;i<params.length;i+=2) {
      if(params[i]==null||params[i+1]==null) continue;
      serverURL.append("&" + params[i] + "=" + params[i+1]);
//       serverURL.append("&" + URLEncoder.encode(params[i])
//                        + "=" + URLEncoder.encode(params[i+1]));
    }
    try {
      if (this.proxy != null) {
        newURL = new URL(this.proxy + "?ProxyURL=" + serverURL.toString());
//         newURL = new URL(this.proxy + "?ProxyURL=" +
//                          URLEncoder.encode(serverURL.toString()));
      } else {
        newURL = new URL(serverURL.toString());
      }
      if(DEBUG)System.out.println("RemoteOGC: URL to query "+ newURL.toString());
    } catch(java.net.MalformedURLException e) {
      System.out.println("RemoteOGC: Malformed URL");
      return null;
    }
    return newURL;
  }

  public byte[] getImageData(String[] params)
  {
    URL url = this.getURL(params);
    byte[] data = null;
    try {
      if (remoteConnection == null) {
        initConnection();
      } // end of if (remoteConnection == null)
      
      int res = remoteConnection.sendRequest(url);
      data = remoteConnection.getByteData();
    } catch (IOException e) {
      data = null;
    } // end of try-catch
    return data;
  }

  public InputStream getImageStream(String[] params)
  {
    URL url = this.getURL(params);
    InputStream instr = null;
    try {
      if (remoteConnection == null) {
        initConnection();
      } // end of if (remoteConnection == null)
      
      int res = remoteConnection.sendRequest(url);
      instr = remoteConnection.getInputStream();
    } catch (IOException e) {
			try{
				initConnection();
				int res = remoteConnection.sendRequest(url);;
				instr = remoteConnection.getInputStream();
			}catch(IOException ex) {
				instr=null;
			}
    } // end of try-catch
    return instr;
  }

  /* ********* <code>WebMapService</code> proxy methods START ***********  */

  /**
   * <code>getAvailableFormats</code> method returns <code>ArrayList</code>
   * with <code>String</code> representation of formats supported by remote
   * <b>Web Map Server</b>
   *
   * @return an <code>ArrayList</code> value
   * @exception IOException if an error occurs
   */
  public ArrayList getAvailableFormats(String service_type)
    throws IOException {
    
    if(capabilities == null)
      getCapabilities();
		if(capabilities == null) return null;
    return capabilities.getAvailableFormats(service_type);
    
  }

  /* ********* <code>WebMapService</code> proxy methods END ***********  */

  /**
   * <code>getCapabilities</code> method is first method which
   * should be called after object creating. This is done automatically
   * during first call for data from remote <b>WMS</b>.<br/>
   * This method connecting to remote <b>WMS</b>, sending request,
   * receiving capabilities data, performing syntax and structure checking
   * and creating objects reprezenting services on remote <b>WMS</b>.
   * Becouse of long time needed to perform all this actions. This should
   * be done in separated <code>Thread</code>. This is "future feature".
   * And on every step should be called function from objects similiar
   * to <code>JobProgresHandler</code>.<br/>
   * So please be patient after call to this method.
   *
   * @return an <code>OGCCapabilities</code> value
   * @exception IOException if an error occurs
   */
  protected OGCCapabilities getCapabilities()
    throws IOException
  {
    int query_result = -1;
    /* First try to read capabilities from disk (DTD still will be
       downloaded from the net) */
    if(capabilities == null)
      try {
        String h = (new URL(server.toString())).getHost();
        if(h == null || h.equals(""))
          h = "_CAP_";
        File ian = new File(h+"_capabilities.xml");
        if(ian.exists()){
          prln("Try to read from local disk: "+h+"_capabilities.xml");
          capabilities = new OGCCapabilities(new FileInputStream(h+"_capabilities.xml"));
          prln("Capabilities version: "+capabilities.getCapabilitiesVersion());
        }
        //services = capabilities.getAvailableServices();
        //for(int i = 0; i < services.length; i++) {
        //  prln(""+(i+1)+".  "+services[i].toString());
        //  if(services[i] instanceof OGCWebMapService) {
        //    webMap = (OGCWebMapService)services[i];
        //  }
        //}
      } catch(Exception e) {
        capabilities = null;
        prln("Caught exception -- trying for network");
      }

    /* If there isn't capabilities on local disk download it from the net */
    if(capabilities == null) {
      if(remoteConnection == null)
        initConnection();
      try {
        query_result =
          remoteConnection.sendQuery(OGCCapabilities.capabilitiesQuery(version));
      } catch(MalformedURLException mue) {
        query_result = -1;
        mue.printStackTrace();
      } catch(Exception e) {
        prln("Help - unexpected exception "+e+" in send Query");
				prln("server "+server.toString());
        e.printStackTrace();
      }
        
      prln("Content result="+query_result);
      switch(query_result) {
        case RemoteConnection.RESPONSE_ERROR :
          break;  
        case RemoteConnection.CONTENT_BASIC_XML :
        case RemoteConnection.CONTENT_CAPABILITIES :
        case RemoteConnection.CONTENT_UNKNOWN :
        case RemoteConnection.CONTENT_HTML : /* apache returns this for
									HEAD requests on xml files - Ian*/
          try {
            /* Create capabilities objecr and parse data */
            capabilities = new
              OGCCapabilities(remoteConnection.getInputStream());
            prln("Capabilities version: "+capabilities.getCapabilitiesVersion());
            /* Get all services instances from capabilities */
            //services = capabilities.getAvailableServices();
            //for(int i = 0; i < services.length; i++) {
            //  prln(""+(i+1)+".  "+services[i].toString());
            //  if(services[i] instanceof OGCWebMapService) {
            //    /* WebMap service found. */
            //    webMap = (OGCWebMapService)services[i];
            //  }
            //}

            /* Save capabilities to disk for future use */
            /* !!! Creating names should be changed, there can be many WMS on one
               virtual host on the net !!! */
            String host = (new URL(server.toString())).getHost();
            if(host == null || host.equals(""))
              host = "_CAP_";
            FileOutputStream fos =
              new FileOutputStream(host+"_capabilities.xml");
            capabilities.printCapabilitiesXML(fos);
            fos.close();
          } catch(Exception e) {
            capabilities = null;
            e.printStackTrace();
          }
          break;
        case RemoteConnection.CONTENT_GML :
          break;
        case RemoteConnection.CONTENT_SE :
          break;
        default :
          /* It should never happen!! */
      }
    }
    return capabilities;
  }
  
  /*
    public static void main(String argc[])
    throws Exception
    {
    URL u = new URL("file:sample.xml");
    for(int i = 0; i < argc.length; i++) {
    if(argc[i].equals("-u")) {
    u = new URL(argc[i+1]);
    i++;
    }
    }

    RemoteOGC remote = new RemoteOGC(u, null);
    remote.getCapabilities();
    }
  */

  protected static void prln(String str) {
    System.err.println(str);
  }

  protected static void pr(String str) {
    System.err.print(str);
  }
  
}
/*
 * Changes in file:
 *
 * $Log: RemoteOGC.java,v $
 * Revision 1.18  2001/12/21 11:46:47  ianturton
 * added some code to getImageStream to handle the connection timing out.
 *
 * Revision 1.17  2001/12/20 15:27:23  ianturton
 * various fixes and small mods to make WMSExample actually run. Can now
 * display an image if you remember to choose gif or jpg as output. Still
 * crashes if you zoom in.
 *
 * Revision 1.16  2001/11/21 13:48:19  kobit
 * Added support for creating ImageLayer with InputStream as image data source and full support for downaloding map data from WMS with jprotocols package
 *
 * Revision 1.15  2001/11/20 17:01:45  kobit
 * Added byte[] getContentData() support
 *
 * Revision 1.14  2001/11/19 10:03:33  kobit
 * *** empty log message ***
 *
 * Revision 1.13  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 1.12  2001/10/29 15:32:33  ianturton
 * added default SRS EPSG:4326 and some checking to skip null or empty
 * parameters
 *
 * Revision 1.11  2001/10/24 09:42:24  kobit
 * Some minor changes for working according to new design
 *
 *
 */