/*

  * 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.onami.factoryannotation;

 import java.lang.annotation.Annotation;

 import java.util.HashMap;

 import java.util.Map;

 import com.google.inject.Key;

 import com.google.inject.TypeLiteral;

 class ProvisionCacheIdentityProviderFacade<T, A extends Annotation>

     implements FactoryAnnotationProvider<T, A>

 {

     private final Map<Key<T>, T> provisionCache = new HashMap<Key<T>, T>();

     private final FactoryAnnotationProvider<T, A> factoryAnnotationProvider;

     private final TypeLiteral<T> typeLiteral;

     public ProvisionCacheIdentityProviderFacade( final FactoryAnnotationProvider<T, A> factoryAnnotationProvider,

                                                  final TypeLiteral<T> typeLiteral )

     {

         this.factoryAnnotationProvider = factoryAnnotationProvider;

         this.typeLiteral = typeLiteral;

     }

     public Class<T> getInjectionType()

     {

         return factoryAnnotationProvider.getInjectionType();

     }

     public T buildValue( A annotation )

     {

         final Key<T> key = buildCacheKey( typeLiteral, annotation );

         if ( provisionCache.containsKey( key ) )

         {

             return provisionCache.get( key );

         }

         final T value = factoryAnnotationProvider.buildValue( annotation );

         provisionCache.put( key, value );

         return value;

     }

     private Key<T> buildCacheKey( final TypeLiteral<T> typeLiteral, final A annotation )

     {

         return Key.get( typeLiteral, annotation );

     }

 }