/*
    * Copyright (C) 2007 the original author or authors.
    *
    * 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.
   */
  
  package org.codehaus.plexus.maven.plugin;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import org.codehaus.plexus.component.repository.cdc.ComponentDescriptor;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Support for {@link ComponentDescriptorExtractor} implementations.
   *
   * @version $Id$
   */
  public abstract class ComponentDescriptorExtractorSupport
      implements ComponentDescriptorExtractor
  {
      protected final Logger log = LoggerFactory.getLogger(getClass());
  
      protected Map getDefaultsByRole(final ComponentDescriptor[] roleDefaults) {
          Map defaultsByRole = new HashMap();
  
          if (roleDefaults != null) {
              for (int i = 0; i < roleDefaults.length; i++) {
                  String role = roleDefaults[i].getRole();
  
                  if (role == null) {
                      throw new IllegalArgumentException("Invalid role defaults; found null role in: " + roleDefaults[i]);
                  }
  
                  defaultsByRole.put(role, roleDefaults[i]);
              }
          }
  
          return defaultsByRole;
      }
  
      protected void applyDefaults(final ComponentDescriptor descriptor, final Map defaultsByRole) {
          assert descriptor != null;
          assert defaultsByRole != null;
  
          if (defaultsByRole.containsKey(descriptor.getRole())) {
              ComponentDescriptor defaults = (ComponentDescriptor) defaultsByRole.get(descriptor.getRole());
  
              if (descriptor.getInstantiationStrategy() == null) {
                  descriptor.setInstantiationStrategy(defaults.getInstantiationStrategy());
              }
          }
      }
  }