/* Copyright 2010 ESRI
* 
* All rights reserved under the copyright laws of the United States
* and applicable international laws, treaties, and conventions.
* 
* You may freely redistribute and use this sample code, with or
* without modification, provided you include the original copyright
* notice and use restrictions.
* 
* See the use restrictions.
* 
*/
package com.esri.arcgis.sample.mapinformation;

import com.esri.adf.web.data.WebMap;
import com.esri.adf.web.data.geometry.WebExtent;
import com.esri.adf.web.faces.component.MapControl;
import com.esri.adf.web.faces.renderkit.xml.ajax.AJAXUtil;
import com.esri.adf.web.util.XMLUtil;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.faces.component.UIComponent;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;
import javax.faces.event.PhaseEvent;
import javax.faces.event.PhaseId;
import javax.faces.event.PhaseListener;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

public class MapInformationPhaseListener implements PhaseListener {
  private static Logger logger = Logger.getLogger(com.esri.arcgis.sample.mapinformation.MapInformationPhaseListener.class.getName());

  //This PhaseListener must be executed in the JSF's Restore View phase
  public PhaseId getPhaseId() {
    return PhaseId.APPLY_REQUEST_VALUES;
  }

  //No processing
  public void beforePhase(PhaseEvent phaseEvent) {
    //do nothing
  }

  //Process functionality based on request parameters
  public void afterPhase(PhaseEvent phaseEvent) {
    FacesContext facesContext = phaseEvent.getFacesContext();
    ExternalContext externalContext = facesContext.getExternalContext();
    Map params = externalContext.getRequestParameterMap();

    //verify if request is to be processed by this PhaseListener
    if (! "mapinformation".equals(params.get("mapinformation")))
      return;

    try {
      Document doc = XMLUtil.newDocument();

      //get Form from view
      String formId = (String) params.get("formId");
      UIComponent form = facesContext.getViewRoot().findComponent(formId);

      if (form == null)
        XMLUtil.createElement(doc, "error", "Unable to find form (" + formId + ") in FacesContext", null);
      else {
        //get MapControl
        String mapId = (String) params.get("mapId");
        MapControl mapControl = (MapControl) form.findComponent(mapId);

        if (mapControl == null) {
          XMLUtil.createElement(doc, "error", "Unable to find MapControl (" + mapId + ") in form (" + formId + ").", null);
        }
        else {
          WebMap map = mapControl.getWebMap();
          WebExtent extent = map.getCurrentExtent();

          //populate response document
          Element responseElement = XMLUtil.createElement(doc, "response", null, null);
          XMLUtil.createElement("minx", Double.toString(extent.getMinX()), responseElement);
          XMLUtil.createElement("miny", Double.toString(extent.getMinY()), responseElement);
          XMLUtil.createElement("maxx", Double.toString(extent.getMaxX()), responseElement);
          XMLUtil.createElement("maxy", Double.toString(extent.getMaxY()), responseElement);
          XMLUtil.createElement("map-scale", Double.toString(map.getMapScale()), responseElement);
        }
      }

      AJAXUtil.writeResponse(facesContext, doc);
      facesContext.responseComplete();
    }
    catch (Exception e) {
      logger.log(Level.SEVERE, "Error in rendering AJAX response.", e);
    }
  }
}