/*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you 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 org.apache.myfaces.config;

 import java.util.Collection;

 import java.util.HashMap;

 import java.util.LinkedList;

 import javax.faces.event.ComponentSystemEvent;

 import javax.faces.event.PostAddToViewEvent;

 import javax.faces.event.PostValidateEvent;

 import javax.faces.event.PreRenderComponentEvent;

 import javax.faces.event.PreRenderViewEvent;

 import javax.faces.event.PreValidateEvent;

 /**

  * The NamedEventManager class is used to keep map a short name to ComponentSystemEvent classes

  * annotated with @NamedEvent.

  */

 public class NamedEventManager

 {

     //private static final NamedEventManager instance = new NamedEventManager();

     private HashMap<String, Collection<Class<? extends ComponentSystemEvent>>> events;

     public NamedEventManager ()

     {

         events = new HashMap<String, Collection<Class<? extends ComponentSystemEvent>>>();

         // Special spec-defined values.

         addNamedEvent ("postAddToView", PostAddToViewEvent.class);

         addNamedEvent ("preRenderView", PreRenderViewEvent.class);

         addNamedEvent ("preRenderComponent", PreRenderComponentEvent.class);

         addNamedEvent ("preValidate", PreValidateEvent.class);

         addNamedEvent ("postValidate", PostValidateEvent.class);

     }

     //public static NamedEventManager getInstance ()

     //{

     //    return instance;

     //}

     /**

      * Registers a named event.

      * 

      * @param shortName a String containing the short name for the event, from the @NamedEvent.shortName()

      *        attribute.

      * @param cls the event class to register.

      */

     public void addNamedEvent (String shortName, Class<? extends ComponentSystemEvent> cls)

     {

         String key = shortName;

         Collection<Class<? extends ComponentSystemEvent>> eventList;

         // Per the spec, if the short name is missing, generate one.

         if (shortName == null)

         {

             key = getFixedName (cls);

         }

         eventList = events.get (key);

         if (eventList == null)

         {

             // First event registered to this short name.

             eventList = new LinkedList<Class<? extends ComponentSystemEvent>>();

             events.put (key, eventList);

         }

         eventList.add (cls);

     }

     /**

      * Retrieves a collection of system event classes based on their short name.

      * 

      * @param shortName the short name to look up.

      * @return a Collection of Class objects containing the system event classes registered to

      *         the given short name.

      */

     public Collection<Class<? extends ComponentSystemEvent>> getNamedEvent (String shortName)

     {

         return events.get (shortName);

     }

     /**

      * Retrieves the short name for an event class, according to spec rules.

      * 

      * @param cls the class to find the short name for.

      * @return a String containing the short name for the given class.

      */

     private String getFixedName (Class<? extends ComponentSystemEvent> cls)

     {

         StringBuilder result = new StringBuilder();

         String className;

         // Get the unqualified class name.

         className = cls.getSimpleName();

         // Strip the trailing "event" off the class name if present.

         if (className.toLowerCase().endsWith ("event"))

         {

             className = className.substring (0, result.length() - 5);

         }

         // Prepend the package name.

         if (cls.getPackage() != null)

         {

             result.append (cls.getPackage().getName());

             result.append ('.');

         }

         result.append (className);

         return result.toString();

     }

 }