package org.codehaus.plexus.container.initialization;
   
   /*
    * 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.ArrayList;
  import java.util.List;
  
  import org.codehaus.plexus.PlexusConstants;
  import org.codehaus.plexus.component.composition.CycleDetectedInComponentGraphException;
  import org.codehaus.plexus.component.repository.ComponentDescriptor;
  import org.codehaus.plexus.component.repository.exception.ComponentLookupException;
  import org.codehaus.plexus.configuration.source.ChainedConfigurationSource;
  import org.codehaus.plexus.configuration.source.ConfigurationSource;
  
  /**
   * @author Jason van Zyl
   * @author cstamas
   */
  public class InitializeUserConfigurationSourcePhase extends AbstractCoreComponentInitializationPhase {
      public void initializeCoreComponent(ContainerInitializationContext context)
              throws ContainerInitializationException {
          ConfigurationSource existingConfigurationSource = context.getContainer().getConfigurationSource();
  
          try {
              // is the user overriding the ConfigurationSource (role-hint: default) or only extending it?
              if (context.getContainer().hasComponent(ConfigurationSource.class, PlexusConstants.PLEXUS_DEFAULT_HINT)) {
                  // overriding
  
                  ConfigurationSource cs = context.getContainer().lookup(ConfigurationSource.class);
  
                  // swap the user provided configuration source with current one
                  context.getContainer().setConfigurationSource(cs);
              } else {
                  // extending
                  List<ConfigurationSource> userConfigurationSources =
                          context.getContainer().lookupList(ConfigurationSource.class);
  
                  if (userConfigurationSources.size() > 0) {
                      List<ConfigurationSource> configurationSources =
                              new ArrayList<ConfigurationSource>(userConfigurationSources.size() + 1);
  
                      // adding user provied ones to be able to interfere
                      configurationSources.addAll(userConfigurationSources);
  
                      // at the end adding the container source, to make sure config will be returned
                      // from plexus.xml if no user interference is given
                      configurationSources.add(existingConfigurationSource);
  
                      ConfigurationSource configurationSource = new ChainedConfigurationSource(configurationSources);
  
                      context.getContainer().setConfigurationSource(configurationSource);
                  }
  
                  // register the default source, either the chained or the existing one as default
                  ComponentDescriptor<ConfigurationSource> cd = new ComponentDescriptor<ConfigurationSource>();
  
                  cd.setRole(ConfigurationSource.ROLE);
  
                  cd.setRoleHint(PlexusConstants.PLEXUS_DEFAULT_HINT);
  
                  cd.setImplementationClass(
                          context.getContainer().getConfigurationSource().getClass());
  
                  try {
                      context.getContainer().addComponentDescriptor(cd);
                  } catch (CycleDetectedInComponentGraphException cre) {
                      throw new ContainerInitializationException("Error setting up configuration source.", cre);
                  }
              }
  
          } catch (ComponentLookupException e) {
              throw new ContainerInitializationException("Error setting up user configuration source.", e);
          }
      }
  }