package uk.ac.ebi.intenz.webapp.controller.modification;
   
   import org.apache.log4j.Logger;
   import org.apache.struts.action.*;
   import org.apache.struts.taglib.html.Constants;
   import uk.ac.ebi.intenz.webapp.dtos.*;
   import uk.ac.ebi.intenz.webapp.utilities.ControlFlowToken;
   import uk.ac.ebi.intenz.webapp.utilities.EntryLockSingleton;
   
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import java.util.Map;
  
  /**
   * This class checks to see if the entry is still valid.
   * If its not it reloads it. 
   *
   * @author Michael Darsow
   * @version $Revision: 1.2 $ $Date: 2008/01/28 12:33:07 $
   */
  public class CurationAction extends Action {
  
    private static final Logger LOGGER =
  	  Logger.getLogger(CurationAction.class.getName());
    private final static String SEARCH_BY_ID_ACTION_FWD = "searchId";
  
    public ActionForward execute(ActionMapping mapping,
                                 ActionForm form,
                                 HttpServletRequest request,
                                 HttpServletResponse response) throws Exception {
      LOGGER.info("CurationAction");
      ActionMessages errors = new ActionMessages();
  //    EnzymeDTO enzymeDTO = (EnzymeDTO) request.getSession().getAttribute("enzymeDTO");
      EnzymeDTO enzymeDTO = (EnzymeDTO) form;
      if(enzymeDTO.getId() == null || enzymeDTO.getId().equals("")) return null; // new enzymes do not need token checking
      Long enzymeId = new Long(enzymeDTO.getId());
  
      // Check if the current entry is still valid.
      if (request.getParameter(Constants.TOKEN_KEY) != null && !ControlFlowToken.isValid(request)) {
        Map tokenHashtable = (Map) request.getSession().getAttribute("tokenHashtable");
        LOGGER.debug("Entry with ID " + enzymeId + " is being discarded ...");
        enzymeId = (Long) tokenHashtable.get(request.getParameter(Constants.TOKEN_KEY));
        LOGGER.debug("... entry with ID " + enzymeId + " will be loaded instead.");
  
        // Store a message to inform the user about the reload.
        errors.add(ActionMessages.GLOBAL_MESSAGE, new ActionMessage("errors.application.entry.reloaded.noec"));
        saveErrors(request, errors);
  
        // Set view where to forward to after the entry has been reloaded.
        ActionForward forward = mapping.findForward(SEARCH_BY_ID_ACTION_FWD);
        StringBuffer path = new StringBuffer(forward.getPath());
        boolean isQuery = (path.indexOf("?") > -1);
        if (isQuery) {
          path.append("&view=" + mapping.getInputForward().getPath() + "&reload=true&id=");
        } else {
          path.append("?view=" + mapping.getInputForward().getPath() + "&reload=true&id=");
        }
        path.append(enzymeId);
  
        return new ActionForward(path.toString());
      }
  
      return null;
    }
  
    /**
     * Keeps the token as it is to ensure that the entry can be reloaded if necessary.
     *
     * @param request Used to transfer the token parameter to the token attribute.
     * @throws NullPointerException if <code>request</code> is <code>null</code>
     */
    protected void keepToken(HttpServletRequest request) {
      if (request == null) throw new NullPointerException("Parameter 'request' must not be null.");
      if (request.getParameter(Constants.TOKEN_KEY) != null) request.setAttribute(Constants.TOKEN_KEY, request.getParameter(Constants.TOKEN_KEY));
    }
  }