package org.apache.maven.shared.dependency.graph.internal;
   
   /*
    * 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.List;
  
  import org.apache.maven.artifact.Artifact;
  import org.apache.maven.shared.dependency.graph.DependencyNode;
  import org.apache.maven.shared.dependency.graph.traversal.DependencyNodeVisitor;
  
  /**
   * Default implementation of a DependencyNode.
   */
  public class DefaultDependencyNode implements DependencyNode
  {
      private final Artifact artifact;
  
      private final DependencyNode parent;
  
      private final String premanagedVersion;
  
      private final String premanagedScope;
  
      private final String versionConstraint;
  
      private List<DependencyNode> children;
  
      private Boolean optional;
  
      /**
       * Constructs the DefaultDependencyNode.
       *
       * @param parent            Parent node, may be {@code null}.
       * @param artifact          Artifact associated with this dependency.
       * @param premanagedVersion the premanaged version, may be {@code null}.
       * @param premanagedScope   the premanaged scope, may be {@code null}.
       * @param versionConstraint the version constraint, may be {@code null.}
       */
      public DefaultDependencyNode( DependencyNode parent, Artifact artifact, String premanagedVersion,
                                    String premanagedScope, String versionConstraint )
      {
          this.parent = parent;
          this.artifact = artifact;
          this.premanagedVersion = premanagedVersion;
          this.premanagedScope = premanagedScope;
          this.versionConstraint = versionConstraint;
      }
  
      public DefaultDependencyNode( DependencyNode parent, Artifact artifact, String premanagedVersion,
                                    String premanagedScope, String versionConstraint, Boolean optional )
      {
          this.parent = parent;
          this.artifact = artifact;
          this.premanagedVersion = premanagedVersion;
          this.premanagedScope = premanagedScope;
          this.versionConstraint = versionConstraint;
          this.optional = optional;
      }
  
      /**
       * Applies the specified dependency node visitor to this dependency node and its children.
       * 
       * @param visitor the dependency node visitor to use
       * @return the visitor result of ending the visit to this node
       * @since 1.1
       */
      @Override
      public boolean accept( DependencyNodeVisitor visitor )
      {
          if ( visitor.visit( this ) )
          {
              for ( DependencyNode child : getChildren() )
              {
                  if ( !child.accept( visitor ) )
                  {
                      break;
                  }
              }
          }
  
          return visitor.endVisit( this );
      }
 
     /**
      * @return Artifact for this DependencyNode.
      */
     @Override
     public Artifact getArtifact()
     {
         return artifact;
     }
 
     /**
      *
      * @param children  List of DependencyNode to set as child nodes.
      */
     public void setChildren( List<DependencyNode> children )
     {
         this.children = children;
     }
 
     /**
      * @return List of child nodes for this DependencyNode.
      */
     @Override
     public List<DependencyNode> getChildren()
     {
         return children;
     }
 
     /**
      * @return Parent of this DependencyNode.
      */
     @Override
     public DependencyNode getParent()
     {
         return parent;
     }
 
     @Override
     public String getPremanagedVersion()
     {
         return premanagedVersion;
     }
 
     @Override
     public String getPremanagedScope()
     {
         return premanagedScope;
     }
 
     @Override
     public String getVersionConstraint()
     {
         return versionConstraint;
     }
 
     @Override
     public Boolean getOptional()
     {
         return optional;
     }
 
     /**
      * @return Stringified representation of this DependencyNode.
      */
     @Override
     public String toNodeString()
     {
         StringBuffer buffer = new StringBuffer();
 
         buffer.append( artifact );
 
         ItemAppender appender = new ItemAppender( buffer, " (", "; ", ")" );
 
         if ( getPremanagedVersion() != null )
         {
             appender.append( "version managed from ", getPremanagedVersion() );
         }
 
         if ( getPremanagedScope() != null )
         {
             appender.append( "scope managed from ", getPremanagedScope() );
         }
 
         if ( getVersionConstraint() != null )
         {
             appender.append( "version selected from constraint ", getVersionConstraint() );
         }
 
 
         appender.flush();
         if ( optional != null && optional )
         {
             buffer.append( " (optional) " );
         }
 
         return buffer.toString();
     }
 
     /**
      * Utility class to concatenate a number of parameters with separator tokens.
      */
     private static class ItemAppender
     {
         private StringBuffer buffer;
 
         private String startToken;
 
         private String separatorToken;
 
         private String endToken;
 
         private boolean appended;
 
         public ItemAppender( StringBuffer buffer, String startToken, String separatorToken, String endToken )
         {
             this.buffer = buffer;
             this.startToken = startToken;
             this.separatorToken = separatorToken;
             this.endToken = endToken;
 
             appended = false;
         }
 
         public ItemAppender append( String item1, String item2 )
         {
             appendToken();
 
             buffer.append( item1 ).append( item2 );
 
             return this;
         }
 
         public void flush()
         {
             if ( appended )
             {
                 buffer.append( endToken );
 
                 appended = false;
             }
         }
 
         private void appendToken()
         {
             buffer.append( appended ? separatorToken : startToken );
 
             appended = true;
         }
     }
 }