/*
    * Copyright 2011 FatWire Corporation. All Rights Reserved.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *    http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.fatwire.gst.foundation.controller.annotation;
  
  import static COM.FutureTense.Interfaces.Utilities.goodString;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  
  import COM.FutureTense.Util.ftErrors;
  import COM.FutureTense.Util.ftMessage;
  
  import com.fatwire.gst.foundation.CSRuntimeException;
  import com.fatwire.gst.foundation.controller.AbstractController;
  import com.fatwire.gst.foundation.facade.RenderUtils;
  import com.fatwire.gst.foundation.facade.runtag.render.LogDep;
  
  /**
   * The Controller delegates the business logic to an annotated method. In this
   * method the special logic for the request is executed. Method selection is
   * done via the {@literal @}IcsVariable annotation. This works of the premise that a special
   * name/value pair on the ics scope set before this controller is executed, is
   * enough to determine the selection for the business logic method.
   * 
   * @author Dolf Dijkstra
   * @since Apr 15, 2011
   * @see IcsVariable
   */
  public abstract class AnnotationController extends AbstractController {
  
      /*
       * (non-Javadoc)
       * 
       * @see com.fatwire.gst.foundation.controller.AbstractController#doExecute()
       */
      @Override
      protected void doExecute() {
  
          // record seid and eid and any other deps required
          RenderUtils.recordBaseCompositionalDependencies(ics);
          final ControllerMappingResolver resolver = new ControllerMappingResolver();
          final Object target = getTarget();
          final Method m = resolver.findControllerMethod(ics, target);
          if (m == null) {
              executeDefault();
          } else {
              invokeControllerMethod(m, target);
          }
      }
  
      /**
       * @param m
       * @param target
       */
      protected void invokeControllerMethod(final Method m, final Object target) {
          try {
              m.invoke(target, new Object[] { ics });
          } catch (final IllegalArgumentException e) {
              handleException(e);
          } catch (final IllegalAccessException e) {
              handleException(e);
          } catch (final InvocationTargetException e) {
              handleException(e);
          }
  
      }
  
      /**
       * @return this
       */
      protected Object getTarget() {
          return this;
      }
  
      /**
       * Default operation to execute if no matching annotated method can be
       * found.
       */
      abstract void executeDefault();
  
      @Override
      protected void handleException(final Exception e) {
          if (e instanceof CSRuntimeException) {
              handleCSRuntimeException((CSRuntimeException) e);
          } else {
             sendError(500, e);
         }
     }
 
     /**
      * This method transforms errno values into http status codes and sets them
      * using the X-Fatwire-Status header.
      * <p/>
      * Only some errnos are handled by this base class.
      * <p/>
      * More info coming soon
      * 
      * @param e exception
      */
     protected void handleCSRuntimeException(final CSRuntimeException e) {
         switch (e.getErrno()) {
             case 400:
             case ftErrors.badparams:
                 sendError(400, e);
                 break;
             case 404:
             case ftErrors.pagenotfound:
                 sendError(404, e);
                 break;
             case 403:
             case ftErrors.noprivs:
                 sendError(403, e);
                 break;
             default:
                 sendError(500, e);
                 break;
         }
     }
 
     /**
      * Record compositional dependencies that are required for the controller
      */
     protected void recordCompositionalDependencies() {
         if (ics.isCacheable(ics.GetVar(ftMessage.PageName))) {
             if (goodString(ics.GetVar("seid"))) {
                 LogDep.logDep(ics, "SiteEntry", ics.GetVar("seid"));
             }
             if (goodString(ics.GetVar("eid"))) {
                 LogDep.logDep(ics, "CSElement", ics.GetVar("eid"));
             }
         }
     }
 
 }