/*
    * 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.
   */
  package org.apache.maven.internal.impl;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.util.List;
  
  import org.apache.maven.api.Node;
  import org.apache.maven.api.annotations.Nonnull;
  import org.apache.maven.api.services.DependencyCollector;
  import org.apache.maven.api.services.DependencyCollectorException;
  import org.apache.maven.api.services.DependencyCollectorRequest;
  import org.apache.maven.api.services.DependencyCollectorResult;
  import org.eclipse.aether.DefaultRepositorySystemSession;
  import org.eclipse.aether.RepositorySystem;
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.collection.CollectRequest;
  import org.eclipse.aether.collection.CollectResult;
  import org.eclipse.aether.collection.DependencyCollectionException;
  import org.eclipse.aether.graph.Dependency;
  import org.eclipse.aether.util.graph.manager.DependencyManagerUtils;
  import org.eclipse.aether.util.graph.transformer.ConflictResolver;
  
  import static org.apache.maven.internal.impl.Utils.cast;
  import static org.apache.maven.internal.impl.Utils.nonNull;
  
  @Named
  @Singleton
  public class DefaultDependencyCollector implements DependencyCollector {
  
      private final RepositorySystem repositorySystem;
  
      @Inject
      DefaultDependencyCollector(@Nonnull RepositorySystem repositorySystem) {
          this.repositorySystem = repositorySystem;
      }
  
      @Nonnull
      @Override
      public DependencyCollectorResult collect(@Nonnull DependencyCollectorRequest request)
              throws DependencyCollectorException, IllegalArgumentException {
          nonNull(request, "request can not be null");
          DefaultSession session =
                  cast(DefaultSession.class, request.getSession(), "request.session should be a " + DefaultSession.class);
  
          Artifact rootArtifact =
                  request.getRootArtifact().map(session::toArtifact).orElse(null);
          Dependency root = request.getRoot().map(session::toDependency).orElse(null);
          CollectRequest collectRequest = new CollectRequest()
                  .setRootArtifact(rootArtifact)
                  .setRoot(root)
                  .setDependencies(session.toDependencies(request.getDependencies()))
                  .setManagedDependencies(session.toDependencies(request.getManagedDependencies()))
                  .setRepositories(session.toRepositories(session.getRemoteRepositories()));
  
          RepositorySystemSession systemSession = session.getSession();
          if (request.getVerbose()) {
              systemSession = new DefaultRepositorySystemSession(systemSession)
                      .setConfigProperty(ConflictResolver.CONFIG_PROP_VERBOSE, true)
                      .setConfigProperty(DependencyManagerUtils.CONFIG_PROP_VERBOSE, true);
          }
  
          try {
              final CollectResult result = repositorySystem.collectDependencies(systemSession, collectRequest);
              return new DependencyCollectorResult() {
                  @Override
                  public List<Exception> getExceptions() {
                      return result.getExceptions();
                  }
  
                  @Override
                  public Node getRoot() {
                      return session.getNode(result.getRoot(), request.getVerbose());
                  }
              };
          } catch (DependencyCollectionException e) {
              throw new DependencyCollectorException("Unable to collect dependencies", e);
          }
      }
 }