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.util.ArrayList;

 import java.util.Collections;

 import java.util.List;

 import org.apache.maven.artifact.Artifact;

 import org.apache.maven.artifact.factory.ArtifactFactory;

 import org.apache.maven.artifact.metadata.ArtifactMetadataSource;

 import org.apache.maven.artifact.repository.ArtifactRepository;

 import org.apache.maven.artifact.resolver.ArtifactCollector;

 import org.apache.maven.artifact.resolver.filter.ArtifactFilter;

 import org.apache.maven.enforcer.rule.api.EnforcerRule;

 import org.apache.maven.enforcer.rule.api.EnforcerRuleException;

 import org.apache.maven.enforcer.rule.api.EnforcerRuleHelper;

 import org.apache.maven.plugin.logging.Log;

 import org.apache.maven.plugins.enforcer.utils.DependencyVersionMap;

 import org.apache.maven.project.MavenProject;

 import org.apache.maven.shared.dependency.tree.DependencyNode;

 import org.apache.maven.shared.dependency.tree.DependencyTreeBuilder;

 import org.apache.maven.shared.dependency.tree.DependencyTreeBuilderException;

 import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;

 import org.codehaus.plexus.component.repository.exception.ComponentLookupException;

 import org.codehaus.plexus.i18n.I18N;

 /**

  * @author <a href="mailto:rex@e-hoffman.org">Rex Hoffman</a>

  */

 public class DependencyConvergence

     implements EnforcerRule

 {

     private static Log log;

     private static I18N i18n;

     private boolean uniqueVersions; 

     public void setUniqueVersions( boolean uniqueVersions )

     {

         this.uniqueVersions = uniqueVersions;

     }

     /**

      * Uses the {@link EnforcerRuleHelper} to populate the values of the

      * {@link DependencyTreeBuilder#buildDependencyTree(MavenProject, ArtifactRepository, ArtifactFactory, ArtifactMetadataSource, ArtifactFilter, ArtifactCollector)}

      * factory method. <br/>

      * This method simply exists to hide all the ugly lookup that the {@link EnforcerRuleHelper} has to do.

      * 

      * @param helper

      * @return a Dependency Node which is the root of the project's dependency tree

      * @throws EnforcerRuleException

      */

     private DependencyNode getNode( EnforcerRuleHelper helper )

         throws EnforcerRuleException

     {

         try

         {

             MavenProject project = (MavenProject) helper.evaluate( "${project}" );

             DependencyTreeBuilder dependencyTreeBuilder =

                 (DependencyTreeBuilder) helper.getComponent( DependencyTreeBuilder.class );

             ArtifactRepository repository = (ArtifactRepository) helper.evaluate( "${localRepository}" );

             ArtifactFactory factory = (ArtifactFactory) helper.getComponent( ArtifactFactory.class );

             ArtifactMetadataSource metadataSource =

                 (ArtifactMetadataSource) helper.getComponent( ArtifactMetadataSource.class );

             ArtifactCollector collector = (ArtifactCollector) helper.getComponent( ArtifactCollector.class );

             ArtifactFilter filter = null; // we need to evaluate all scopes

             DependencyNode node =

                 dependencyTreeBuilder.buildDependencyTree( project, repository, factory, metadataSource, filter,

                                                            collector );

             return node;

         }

         catch ( ExpressionEvaluationException e )

         {

             throw new EnforcerRuleException( "Unable to lookup an expression " + e.getLocalizedMessage(), e );

         }

         catch ( ComponentLookupException e )

         {

             throw new EnforcerRuleException( "Unable to lookup a component " + e.getLocalizedMessage(), e );

         }

         catch ( DependencyTreeBuilderException e )

         {

             throw new EnforcerRuleException( "Could not build dependency tree " + e.getLocalizedMessage(), e );

         }

     }

     public void execute( EnforcerRuleHelper helper )

         throws EnforcerRuleException

     {

         if ( log == null )

         {

             log = helper.getLog();

         }

         try

         {

             if ( i18n == null )

             {

                 i18n = (I18N) helper.getComponent( I18N.class );

             }

             DependencyNode node = getNode( helper );

             DependencyVersionMap visitor = new DependencyVersionMap( log );

             visitor.setUniqueVersions( uniqueVersions );

             node.accept( visitor );

             List<CharSequence> errorMsgs = new ArrayList<CharSequence>();

             errorMsgs.addAll( getConvergenceErrorMsgs( visitor.getConflictedVersionNumbers() ) );

             for ( CharSequence errorMsg : errorMsgs )

             {

                 log.error( errorMsg );

             }

             if ( errorMsgs.size() > 0 )

             {

                 throw new EnforcerRuleException( "Failed while enforcing releasability the error(s) are " + errorMsgs );

             }

         }

         catch ( ComponentLookupException e )

         {

             throw new EnforcerRuleException( "Unable to lookup a component " + e.getLocalizedMessage(), e );

         }

         catch ( Exception e )

         {

             throw new EnforcerRuleException( e.getLocalizedMessage(), e );

         }

     }

     private String getFullArtifactName( Artifact artifact )

     {

         return artifact.getGroupId() + ":" + artifact.getArtifactId() + ":" + artifact.getVersion();

     }

     private StringBuilder buildTreeString( DependencyNode node )

     {

         List<String> loc = new ArrayList<String>();

         DependencyNode currentNode = node;

         while ( currentNode != null )

         {

             loc.add( getFullArtifactName( currentNode.getArtifact() ) );

             currentNode = currentNode.getParent();

         }

         Collections.reverse( loc );

         StringBuilder builder = new StringBuilder();

         for ( int i = 0; i < loc.size(); i++ )

         {

             for ( int j = 0; j < i; j++ )

             {

                 builder.append( "  " );

             }

             builder.append( "+-" + loc.get( i ) );

             builder.append( "\n" );

         }

         return builder;

     }

     private List<String> getConvergenceErrorMsgs( List<List<DependencyNode>> errors )

     {

         List<String> errorMsgs = new ArrayList<String>();

         for ( List<DependencyNode> nodeList : errors )

         {

             errorMsgs.add( buildConvergenceErrorMsg( nodeList ) );

         }

         return errorMsgs;

     }

     private String buildConvergenceErrorMsg( List<DependencyNode> nodeList )

     {

         StringBuilder builder = new StringBuilder();

         builder.append( "\nDependency convergence error for " + getFullArtifactName( nodeList.get( 0 ).getArtifact() )

             + " paths to dependency are:\n" );

         if ( nodeList.size() > 0 )

         {

             builder.append( buildTreeString( nodeList.get( 0 ) ) );

         }

         for ( DependencyNode node : nodeList.subList( 1, nodeList.size() ) )

         {

             builder.append( "and\n" );

             builder.append( buildTreeString( node ) );

         }

         return builder.toString();

     }

     /**

      * If your rule is cacheable, you must return a unique id when parameters or conditions change that would cause the

      * result to be different. Multiple cached results are stored based on their id. The easiest way to do this is to

      * return a hash computed from the values of your parameters. If your rule is not cacheable, then the result here is

      * not important, you may return anything.

      */

     public String getCacheId()

     {

         return "";

     }

     /**

      * This tells the system if the results are cacheable at all. Keep in mind that during forked builds and other

      * things, a given rule may be executed more than once for the same project. This means that even things that change

      * from project to project may still be cacheable in certain instances.

      */

     public boolean isCacheable()

     {

         return false;

     }

     /**

      * If the rule is cacheable and the same id is found in the cache, the stored results are passed to this method to

      * allow double checking of the results. Most of the time this can be done by generating unique ids, but sometimes

      * the results of objects returned by the helper need to be queried. You may for example, store certain objects in

      * your rule and then query them later.

      */

     public boolean isResultValid( EnforcerRule arg0 )

     {

         return false;

     }

 }