/*
    * 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.lifecycle.internal;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import javax.inject.Named;
  import javax.inject.Singleton;
  import org.apache.maven.execution.MavenSession;
  import org.apache.maven.lifecycle.internal.builder.BuilderCommon;
  import org.apache.maven.project.MavenProject;
  
  /**
   * <strong>NOTE:</strong> This class is not part of any public api and can be changed or deleted without prior notice.
   *
   * @since 3.0
   * @author Kristian Rosenvold
   */
  @Named
  @Singleton
  public class BuildListCalculator {
      public ProjectBuildList calculateProjectBuilds(MavenSession session, List<TaskSegment> taskSegments) {
          List<ProjectSegment> projectBuilds = new ArrayList<>();
  
          MavenProject rootProject = session.getTopLevelProject();
  
          for (TaskSegment taskSegment : taskSegments) {
              List<MavenProject> projects;
  
              if (taskSegment.isAggregating()) {
                  projects = Collections.singletonList(rootProject);
              } else {
                  projects = session.getProjects();
              }
              for (MavenProject project : projects) {
                  ClassLoader tccl = Thread.currentThread().getContextClassLoader();
                  MavenProject currentProject = session.getCurrentProject();
                  try {
                      BuilderCommon.attachToThread(project); // Not totally sure if this is needed for anything
                      session.setCurrentProject(project);
                      projectBuilds.add(new ProjectSegment(project, taskSegment, session));
                  } finally {
                      session.setCurrentProject(currentProject);
                      Thread.currentThread().setContextClassLoader(tccl);
                  }
              }
          }
          return new ProjectBuildList(projectBuilds);
      }
  }