package org.codehaus.plexus.component.collections;
   
   /*
    * Copyright 2001-2006 Codehaus Foundation.
    *
    * 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.
   */
  
  import java.util.Collection;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import org.codehaus.plexus.MutablePlexusContainer;
  import org.codehaus.plexus.component.repository.ComponentDescriptor;
  import org.codehaus.plexus.component.repository.exception.ComponentLifecycleException;
  
  /**
   * @author Jason van Zyl FIXME: [jdcasey] We need to review the efficiency (in speed and memory) of this collection...
   */
  public class ComponentMap<T> extends AbstractComponentCollection<T> implements Map<String, T> {
      private Map<String, T> components;
  
      private Map<String, T> customAdditions = new LinkedHashMap<String, T>();
  
      public ComponentMap(
              MutablePlexusContainer container,
              Class<T> type,
              String role,
              List<String> roleHints,
              String hostComponent) {
          super(container, type, role, roleHints, hostComponent);
      }
  
      public int size() {
          return getComponentDescriptorMap().size();
      }
  
      public boolean isEmpty() {
          return getComponentDescriptorMap().isEmpty();
      }
  
      public boolean containsKey(Object key) {
          return getComponentDescriptorMap().containsKey(key);
      }
  
      public boolean containsValue(Object value) {
          return getMap().containsValue(value);
      }
  
      public T get(Object k) {
          return getMap().get(k);
      }
  
      public synchronized T put(String key, T value) {
          logger.warn("Custom "
                  + role
                  + " implementations should NOT be added directly to this Map. Instead, add them as Plexus components.");
  
          T prev = customAdditions.put(key, value);
          if (prev == null) {
              prev = getComponentMap().get(key);
          }
  
          return prev;
      }
  
      public synchronized void putAll(Map<? extends String, ? extends T> map) {
          logger.warn("Custom "
                  + role
                  + " implementations should NOT be added directly to this Map. Instead, add them as Plexus components.");
  
          customAdditions.putAll(map);
      }
  
      public Set<String> keySet() {
          return getMap().keySet();
      }
  
      public Collection<T> values() {
          return getMap().values();
      }
  
      public Set<Map.Entry<String, T>> entrySet() {
          return getMap().entrySet();
      }
  
      public boolean equals(Object o) {
         if (this == o) {
             return true;
         }
         if (!(o instanceof Map)) {
             return false;
         }
 
         Map<?, ?> object = (Map<?, ?>) o;
         return getMap().equals(object);
     }
 
     public int hashCode() {
         return getMap().hashCode();
     }
 
     public synchronized T remove(Object key) {
         logger.warn(
                 "Items in this Map should NOT be removed directly. If the matching entry is a component, it will NOT be removed.");
 
         if (key instanceof String) {
             if (customAdditions.containsKey(key)) {
                 return customAdditions.remove(key);
             }
         }
 
         return null;
     }
 
     private synchronized Map<String, T> getMap() {
         Map<String, T> result = getComponentMap();
 
         if (!customAdditions.isEmpty()) {
             result.putAll(customAdditions);
         }
 
         return result;
     }
 
     private synchronized Map<String, T> getComponentMap() {
         if ((components == null) || checkUpdate()) {
             Map<String, T> componentMap = new LinkedHashMap<String, T>();
 
             Map<String, ComponentDescriptor<T>> descriptorMap = getComponentDescriptorMap();
 
             if (roleHints != null) {
                 // we must follow the order given in roleHints
                 for (String roleHint : roleHints) {
                     ComponentDescriptor<T> componentDescriptor = descriptorMap.get(roleHint);
 
                     T component = lookup(componentDescriptor);
 
                     if (component != null) {
                         componentMap.put(roleHint, component);
                     }
                 }
             } else {
                 for (Entry<String, ComponentDescriptor<T>> entry : descriptorMap.entrySet()) {
                     String roleHint = entry.getKey();
 
                     ComponentDescriptor<T> componentDescriptor = entry.getValue();
 
                     T component = lookup(componentDescriptor);
 
                     if (component != null) {
                         componentMap.put(roleHint, component);
                     }
                 }
             }
             components = componentMap;
         }
 
         return components;
     }
 
     @Override
     protected boolean checkUpdate() {
         if (super.checkUpdate()) {
             components = null;
 
             return true;
         }
 
         return false;
     }
 
     protected void releaseAllCallback() {
         if (components != null) {
             try {
                 container.releaseAll(components);
             } catch (ComponentLifecycleException e) {
                 logger.debug("Error releasing components in active collection: " + e.getMessage(), e);
             }
 
             components = null;
         }
     }
 }