package org.apache.maven.plugins.enforcer;
   
   /*
    * 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.
   */
  
  import java.io.FileNotFoundException;
  import java.io.FileReader;
  import java.io.IOException;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import org.apache.maven.enforcer.rule.api.EnforcerRuleException;
  import org.apache.maven.enforcer.rule.api.EnforcerRuleHelper;
  import org.apache.maven.model.Dependency;
  import org.apache.maven.model.Model;
  import org.apache.maven.model.Profile;
  import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
  import org.apache.maven.project.MavenProject;
  import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
  import org.codehaus.plexus.util.IOUtil;
  import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
  
  /**
   * Since Maven 3 'dependencies.dependency.(groupId:artifactId:type:classifier)' must be unique. Early versions of Maven
   * 3 already warn, this rule can force to break a build for this reason.
   * 
   * @author Robert Scholte
   * @since 1.3
   */
  public class BanDuplicatePomDependencyVersions
      extends AbstractNonCacheableEnforcerRule
  {
  
      public void execute( EnforcerRuleHelper helper )
          throws EnforcerRuleException
      {
          // get the project
          MavenProject project;
          try
          {
              project = (MavenProject) helper.evaluate( "${project}" );
          }
          catch ( ExpressionEvaluationException eee )
          {
              throw new EnforcerRuleException( "Unable to retrieve the MavenProject: ", eee );
          }
  
          // re-read model, because M3 uses optimized model
          MavenXpp3Reader modelReader = new MavenXpp3Reader();
          FileReader pomReader = null;
          Model model;
          try
          {
              pomReader = new FileReader( project.getFile() );
  
              model = modelReader.read( pomReader );
          }
          catch ( FileNotFoundException e )
          {
              throw new EnforcerRuleException( "Unable to retrieve the MavenProject: ", e );
          }
          catch ( IOException e )
          {
              throw new EnforcerRuleException( "Unable to retrieve the MavenProject: ", e );
          }
          catch ( XmlPullParserException e )
          {
              throw new EnforcerRuleException( "Unable to retrieve the MavenProject: ", e );
          }
          finally
          {
              IOUtil.close( pomReader );
          }
  
          // @todo reuse ModelValidator when possible
  
          // Object modelValidator = null;
          // try
          // {
          // modelValidator = helper.getComponent( "org.apache.maven.model.validation.ModelValidator" );
         // }
         // catch ( ComponentLookupException e1 )
         // {
         // // noop
         // }
 
         // if( modelValidator == null )
         // {
         maven2Validation( helper, model );
         // }
         // else
         // {
         // }
     }
 
     private void maven2Validation( EnforcerRuleHelper helper, Model model )
         throws EnforcerRuleException
     {
         List<Dependency> dependencies = model.getDependencies();
         Map<String, Integer> duplicateDependencies = validateDependencies( dependencies );
 
         int duplicates = duplicateDependencies.size();
 
         StringBuilder summary = new StringBuilder();
         messageBuilder( duplicateDependencies, "dependencies.dependency", summary );
 
         if ( model.getDependencyManagement() != null )
         {
             List<Dependency> managementDependencies = model.getDependencies();
             Map<String, Integer> duplicateManagementDependencies = validateDependencies( managementDependencies );
             duplicates += duplicateManagementDependencies.size();
 
             messageBuilder( duplicateManagementDependencies, "dependencyManagement.dependencies.dependency", summary );
         }
 
         List<Profile> profiles = model.getProfiles();
         for ( Profile profile : profiles )
         {
             List<Dependency> profileDependencies = profile.getDependencies();
 
             Map<String, Integer> duplicateProfileDependencies = validateDependencies( profileDependencies );
 
             duplicates += duplicateProfileDependencies.size();
 
             messageBuilder( duplicateProfileDependencies, "profiles.profile[" + profile.getId()
                 + "].dependencies.dependency", summary );
 
             if ( model.getDependencyManagement() != null )
             {
                 List<Dependency> profileManagementDependencies = profile.getDependencies();
 
                 Map<String, Integer> duplicateProfileManagementDependencies =
                     validateDependencies( profileManagementDependencies );
 
                 duplicates += duplicateProfileManagementDependencies.size();
 
                 messageBuilder( duplicateProfileManagementDependencies, "profiles.profile[" + profile.getId()
                     + "].dependencyManagement.dependencies.dependency", summary );
             }
         }
 
         if ( summary.length() > 0 )
         {
             StringBuilder message = new StringBuilder();
             message.append( "Found " )
                 .append( duplicates )
                 .append( " duplicate dependency " );
             message.append( duplicateDependencies.size() == 1 ? "declaration" : "declarations" )
                 .append( " in this project:\n" );
             message.append( summary );
             throw new EnforcerRuleException( message.toString() );
         }
     }
 
     private void messageBuilder( Map<String, Integer> duplicateDependencies, String prefix, StringBuilder message )
     {
         if ( !duplicateDependencies.isEmpty() )
         {
             for ( Map.Entry<String, Integer> entry : duplicateDependencies.entrySet() )
             {
                 message.append( " - " )
                     .append( prefix )
                     .append( '[' )
                     .append( entry.getKey() )
                     .append( "] ( " )
                     .append( entry.getValue() )
                     .append( " times )\n" );
             }
         }
     }
 
     private Map<String, Integer> validateDependencies( List<Dependency> dependencies )
         throws EnforcerRuleException
     {
         Map<String, Integer> duplicateDeps = new HashMap<String, Integer>();
         Set<String> deps = new HashSet<String>();
         for ( Dependency dependency : dependencies )
         {
             String key = dependency.getManagementKey();
 
             if ( deps.contains( key ) )
             {
                 int times = 1;
                 if ( duplicateDeps.containsKey( key ) )
                 {
                     times = duplicateDeps.get( key );
                 }
                 duplicateDeps.put( key, times + 1 );
             }
             else
             {
                 deps.add( key );
             }
         }
         return duplicateDeps;
     }
 
 }