package org.eclipse.aether.resolution;
   
   /*
    * 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.eclipse.aether.RepositorySystem;
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.RequestTrace;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.graph.DependencyNode;
  import org.eclipse.aether.repository.RemoteRepository;
  
  /**
   * A request to resolve an artifact.
   * 
   * @see RepositorySystem#resolveArtifacts(RepositorySystemSession, java.util.Collection)
   * @see Artifact#getFile()
   */
  public final class ArtifactRequest
  {
  
      private Artifact artifact;
  
      private DependencyNode node;
  
      private List<RemoteRepository> repositories = Collections.emptyList();
  
      private String context = "";
  
      private RequestTrace trace;
  
      /**
       * Creates an uninitialized request.
       */
      public ArtifactRequest()
      {
          // enables default constructor
      }
  
      /**
       * Creates a request with the specified properties.
       * 
       * @param artifact The artifact to resolve, may be {@code null}.
       * @param repositories The repositories to resolve the artifact from, may be {@code null}.
       * @param context The context in which this request is made, may be {@code null}.
       */
      public ArtifactRequest( Artifact artifact, List<RemoteRepository> repositories, String context )
      {
          setArtifact( artifact );
          setRepositories( repositories );
          setRequestContext( context );
      }
  
      /**
       * Creates a request from the specified dependency node.
       * 
       * @param node The dependency node to resolve, may be {@code null}.
       */
      public ArtifactRequest( DependencyNode node )
      {
          setDependencyNode( node );
          setRepositories( node.getRepositories() );
          setRequestContext( node.getRequestContext() );
      }
  
      /**
       * Gets the artifact to resolve.
       * 
       * @return The artifact to resolve or {@code null}.
       */
      public Artifact getArtifact()
      {
          return artifact;
      }
  
      /**
       * Sets the artifact to resolve.
       * 
       * @param artifact The artifact to resolve, may be {@code null}.
      * @return This request for chaining, never {@code null}.
      */
     public ArtifactRequest setArtifact( Artifact artifact )
     {
         this.artifact = artifact;
         return this;
     }
 
     /**
      * Gets the dependency node (if any) for which to resolve the artifact.
      * 
      * @return The dependency node to resolve or {@code null} if unknown.
      */
     public DependencyNode getDependencyNode()
     {
         return node;
     }
 
     /**
      * Sets the dependency node to resolve.
      * 
      * @param node The dependency node to resolve, may be {@code null}.
      * @return This request for chaining, never {@code null}.
      */
     public ArtifactRequest setDependencyNode( DependencyNode node )
     {
         this.node = node;
         if ( node != null )
         {
             setArtifact( node.getDependency().getArtifact() );
         }
         return this;
     }
 
     /**
      * Gets the repositories to resolve the artifact from.
      * 
      * @return The repositories, never {@code null}.
      */
     public List<RemoteRepository> getRepositories()
     {
         return repositories;
     }
 
     /**
      * Sets the repositories to resolve the artifact from.
      * 
      * @param repositories The repositories, may be {@code null}.
      * @return This request for chaining, never {@code null}.
      */
     public ArtifactRequest setRepositories( List<RemoteRepository> repositories )
     {
         if ( repositories == null )
         {
             this.repositories = Collections.emptyList();
         }
         else
         {
             this.repositories = repositories;
         }
         return this;
     }
 
     /**
      * Adds the specified repository for the resolution.
      * 
      * @param repository The repository to add, may be {@code null}.
      * @return This request for chaining, never {@code null}.
      */
     public ArtifactRequest addRepository( RemoteRepository repository )
     {
         if ( repository != null )
         {
             if ( this.repositories.isEmpty() )
             {
                 this.repositories = new ArrayList<RemoteRepository>();
             }
             this.repositories.add( repository );
         }
         return this;
     }
 
     /**
      * Gets the context in which this request is made.
      * 
      * @return The context, never {@code null}.
      */
     public String getRequestContext()
     {
         return context;
     }
 
     /**
      * Sets the context in which this request is made.
      * 
      * @param context The context, may be {@code null}.
      * @return This request for chaining, never {@code null}.
      */
     public ArtifactRequest setRequestContext( String context )
     {
         this.context = ( context != null ) ? context : "";
         return this;
     }
 
     /**
      * Gets the trace information that describes the higher level request/operation in which this request is issued.
      * 
      * @return The trace information about the higher level operation or {@code null} if none.
      */
     public RequestTrace getTrace()
     {
         return trace;
     }
 
     /**
      * Sets the trace information that describes the higher level request/operation in which this request is issued.
      * 
      * @param trace The trace information about the higher level operation, may be {@code null}.
      * @return This request for chaining, never {@code null}.
      */
     public ArtifactRequest setTrace( RequestTrace trace )
     {
         this.trace = trace;
         return this;
     }
 
     @Override
     public String toString()
     {
         return getArtifact() + " < " + getRepositories();
     }
 
 }