/*

  * 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.flow.impl;

 import java.util.Iterator;

 import java.util.Map;

 import java.util.concurrent.ConcurrentHashMap;

 import javax.faces.context.ExternalContext;

 import javax.faces.context.FacesContext;

 import javax.faces.flow.Flow;

 import org.apache.myfaces.flow.util.FlowUtils;

 import org.apache.myfaces.spi.FacesFlowProvider;

 /**

  *

  * @author Leonardo Uribe

  */

 public class DefaultFacesFlowProvider extends FacesFlowProvider

 {

     private static final String FLOW_PREFIX = "oam.flow";

     static final String FLOW_SESSION_MAP_SUBKEY_PREFIX = FLOW_PREFIX + ".SCOPE";

     /**

      * Token separator.

      */

     static final char SEPARATOR_CHAR = '.';

     private final static String CURRENT_FLOW_SCOPE_MAP = "oam.flow.SCOPE_MAP";

     @Override

     public Iterator<Flow> getAnnotatedFlows(FacesContext facesContext)

     {

         //Without CDI there is no @FlowDefinition annotations to scan for

         return null;

     }

     @Override

     public void doAfterEnterFlow(FacesContext facesContext, Flow flow)

     {

         // Reset current flow scope map

         String mapKey = CURRENT_FLOW_SCOPE_MAP+SEPARATOR_CHAR+

             flow.getDefiningDocumentId()+SEPARATOR_CHAR+flow.getId();        

         facesContext.getAttributes().remove(mapKey);

     }

     @Override

     public void doBeforeExitFlow(FacesContext facesContext, Flow flow)

     {

         String flowMapKey = FlowUtils.getFlowMapKey(facesContext, flow);

         String fullToken = FLOW_SESSION_MAP_SUBKEY_PREFIX + SEPARATOR_CHAR + flowMapKey;

         String mapKey = CURRENT_FLOW_SCOPE_MAP+SEPARATOR_CHAR+

             flow.getDefiningDocumentId()+SEPARATOR_CHAR+flow.getId();

         Map<Object, Object> map = (Map<Object, Object>) facesContext.getAttributes().get(

             mapKey);

         if (map != null)

         {

             map.clear();

         }

         else

         {

             map = (Map<Object, Object>) facesContext.getExternalContext().

                 getSessionMap().get(fullToken);

             if (map != null)

             {

                 map.clear();

             }

         }

         // Remove the map from session

         facesContext.getExternalContext().getSessionMap().remove(fullToken);

         // Reset current flow scope map

         facesContext.getAttributes().remove(mapKey);

     }

     @Override

     public Map<Object, Object> getCurrentFlowScope(FacesContext facesContext)

     {

         Flow flow = facesContext.getApplication().getFlowHandler().getCurrentFlow(facesContext);

         Map<Object, Object> map = null;

         if (flow != null)

         {

             String mapKey = CURRENT_FLOW_SCOPE_MAP+SEPARATOR_CHAR+

                 flow.getDefiningDocumentId()+SEPARATOR_CHAR+flow.getId();

             map = (Map<Object, Object>) facesContext.getAttributes().get(mapKey);

             if (map == null)

             {

                 String flowMapKey = FlowUtils.getFlowMapKey(facesContext, flow);

                 //String fullToken = FLOW_SESSION_MAP_SUBKEY_PREFIX + SEPARATOR_CHAR + flowMapKey;

                 //map = createOrRestoreMap(facesContext, fullToken);

                 map = new FlowScopeMap(this, flowMapKey);

                 facesContext.getAttributes().put(mapKey, map);

             }

         }

         return map;

     }

     /**

      * Create a new subkey-wrapper of the session map with the given prefix.

      * This wrapper is used to implement the maps for the flash scope.

      * For more information see the SubKeyMap doc.

      */

     Map<Object, Object> createOrRestoreMap(FacesContext context, String prefix,

         boolean create)

     {

         ExternalContext external = context.getExternalContext();

         Map<String, Object> sessionMap = external.getSessionMap();

         Map<Object, Object> map = (Map<Object, Object>) sessionMap.get(prefix);

         if (map == null && create)

         {

             map = new ConcurrentHashMap<Object, Object>();

             sessionMap.put(prefix, map);

         }

         return map;

     }

 }