package org.eclipse.aether.util.graph.transformer;
   
   /*
    * 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.Collection;
  import java.util.HashSet;
  import java.util.Set;
  
  import org.eclipse.aether.RepositoryException;
  import org.eclipse.aether.util.artifact.JavaScopes;
  import org.eclipse.aether.util.graph.transformer.ConflictResolver.ConflictContext;
  import org.eclipse.aether.util.graph.transformer.ConflictResolver.ConflictItem;
  import org.eclipse.aether.util.graph.transformer.ConflictResolver.ScopeSelector;
  
  /**
   * A scope selector for use with {@link ConflictResolver} that supports the scopes from {@link JavaScopes}. In general,
   * this selector picks the widest scope present among conflicting dependencies where e.g. "compile" is wider than
   * "runtime" which is wider than "test". If however a direct dependency is involved, its scope is selected.
   */
  public final class JavaScopeSelector
      extends ScopeSelector
  {
  
      /**
       * Creates a new instance of this scope selector.
       */
      public JavaScopeSelector()
      {
      }
  
      @Override
      public void selectScope( ConflictContext context )
          throws RepositoryException
      {
          String scope = context.getWinner().getDependency().getScope();
          if ( !JavaScopes.SYSTEM.equals( scope ) )
          {
              scope = chooseEffectiveScope( context.getItems() );
          }
          context.setScope( scope );
      }
  
      private String chooseEffectiveScope( Collection<ConflictItem> items )
      {
          Set<String> scopes = new HashSet<>();
          for ( ConflictItem item : items )
          {
              if ( item.getDepth() <= 1 )
              {
                  return item.getDependency().getScope();
              }
              scopes.addAll( item.getScopes() );
          }
          return chooseEffectiveScope( scopes );
      }
  
      private String chooseEffectiveScope( Set<String> scopes )
      {
          if ( scopes.size() > 1 )
          {
              scopes.remove( JavaScopes.SYSTEM );
          }
  
          String effectiveScope = "";
  
          if ( scopes.size() == 1 )
          {
              effectiveScope = scopes.iterator().next();
          }
          else if ( scopes.contains( JavaScopes.COMPILE ) )
          {
              effectiveScope = JavaScopes.COMPILE;
          }
          else if ( scopes.contains( JavaScopes.RUNTIME ) )
          {
              effectiveScope = JavaScopes.RUNTIME;
          }
          else if ( scopes.contains( JavaScopes.PROVIDED ) )
          {
              effectiveScope = JavaScopes.PROVIDED;
          }
          else if ( scopes.contains( JavaScopes.TEST ) )
         {
             effectiveScope = JavaScopes.TEST;
         }
 
         return effectiveScope;
     }
 
 }