/**
    * Copyright 2005-2011 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.kuali.rice.core.impl.cache;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.kuali.rice.core.api.cache.CacheManagerRegistry;
  import org.kuali.rice.core.api.exception.RiceIllegalArgumentException;
  import org.springframework.beans.factory.NamedBean;
  import org.springframework.cache.CacheManager;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.CopyOnWriteArrayList;
  
  /**
   * A simple class that holds a global registry to the cache managers.
   */
  public final class CacheManagerRegistryImpl implements CacheManagerRegistry {
      private static final String GET_NAME = "getName";
      private static final Log LOG = LogFactory.getLog(CacheManagerRegistryImpl.class);
      private static final String GET_NAME_MSG = "unable to get the getName method on the cache manager";
  
      private static final List<CacheManager> CACHE_MANAGERS = new CopyOnWriteArrayList<CacheManager>();
      private static final Map<String, CacheManager> CACHE_MANAGER_MAP = new ConcurrentHashMap<String, CacheManager> ();
  
      public void setCacheManager(CacheManager c) {
          if (c == null) {
              throw new IllegalArgumentException("c is null");
          }
  
          CACHE_MANAGERS.add(c);
  
          //keep map as well
          for (String cacheName : c.getCacheNames()) {
              CACHE_MANAGER_MAP.put(cacheName, c);
          }
      }
  
      @Override
      public List<CacheManager> getCacheManagers() {
          return Collections.unmodifiableList(CACHE_MANAGERS);
      }
  
      @Override
      public CacheManager getCacheManager(String name) {
          for (CacheManager cm : getCacheManagers()) {
              if (name.equals(getCacheManagerName(cm))) {
                  return cm;
              }
          }
          return null;
      }
  
      @Override
      public String getCacheManagerName(CacheManager cm) {
          if (cm instanceof NamedBean) {
              return ((NamedBean) cm).getBeanName();
          }
  
          String v = "Unnamed CacheManager " + cm.hashCode();
          try {
              final Method nameMethod = cm.getClass().getMethod(GET_NAME, new Class[] {});
              if (nameMethod != null && nameMethod.getReturnType() == String.class) {
                  v = (String) nameMethod.invoke(cm, new Object[] {});
              }
          } catch (NoSuchMethodException e) {
              LOG.warn(GET_NAME_MSG, e);
          } catch (InvocationTargetException e) {
              LOG.warn(GET_NAME_MSG, e);
          } catch (IllegalAccessException e) {
              LOG.warn(GET_NAME_MSG, e);
          }
  
          return v;
      }
  
      @Override
      public CacheManager getCacheManagerByCacheName(String cacheName) {
          CacheManager cm = CACHE_MANAGER_MAP.get(cacheName);
          if (cm != null) {
             return cm;
         }
         throw new RiceIllegalArgumentException("Cache not found : " + cacheName);
     }
 }