/*
    * 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.Collections;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import java.util.function.Function;
  import java.util.stream.Collectors;
  
  import org.apache.maven.artifact.ArtifactUtils;
  import org.apache.maven.execution.MavenSession;
  import org.apache.maven.project.MavenProject;
  
  /**
   * <p>
   * A list of project segments, ordered so that all ProjectSegments from first TaskSegment come before any
   * subsequent TaskSegments.
   * </p>
   * <strong>Note:</strong> This interface is part of work in progress and can be changed or removed without notice.
   *
   * @since 3.0
   */
  public class ProjectBuildList implements Iterable<ProjectSegment> {
      private final List<ProjectSegment> items;
  
      public ProjectBuildList(List<ProjectSegment> items) {
          this.items = Collections.unmodifiableList(items);
      }
  
      // TODO Optimize; or maybe just rewrite the whole way aggregating mojos are being run.
      /**
       * Returns aProjectBuildList that contains only items for the specified taskSegment
       * @param taskSegment the requested task segment
       * @return a project build list for the supplied task segment
       */
      public ProjectBuildList getByTaskSegment(TaskSegment taskSegment) {
          return new ProjectBuildList(
                  items.stream().filter(pb -> taskSegment == pb.getTaskSegment()).collect(Collectors.toList()));
      }
  
      public Map<MavenProject, ProjectSegment> selectSegment(TaskSegment taskSegment) {
          return items.stream()
                  .filter(pb -> taskSegment == pb.getTaskSegment())
                  .collect(Collectors.toMap(ProjectSegment::getProject, Function.identity()));
      }
  
      /**
       * Finds the first ProjectSegment matching the supplied project
       * @param mavenProject the requested project
       * @return The projectSegment or null.
       */
      public ProjectSegment findByMavenProject(MavenProject mavenProject) {
          return items.stream()
                  .filter(pb -> mavenProject.equals(pb.getProject()))
                  .findFirst()
                  .orElse(null);
      }
  
      @Override
      public Iterator<ProjectSegment> iterator() {
          return items.iterator();
      }
  
      public void closeAll() {
          for (ProjectSegment item : items) {
              MavenSession sessionForThisModule = item.getSession();
              sessionForThisModule.setCurrentProject(null);
          }
      }
  
      public int size() {
          return items.size();
      }
  
      public ProjectSegment get(int index) {
          return items.get(index);
      }
  
      public Set<String> getReactorProjectKeys() {
         Set<String> projectKeys = new HashSet<>(items.size() * 2);
         for (ProjectSegment projectBuild : items) {
             MavenProject project = projectBuild.getProject();
             String key = ArtifactUtils.key(project.getGroupId(), project.getArtifactId(), project.getVersion());
             projectKeys.add(key);
         }
         return projectKeys;
     }
 
     public boolean isEmpty() {
         return items.isEmpty();
     }
 
     /**
      * @return a set of all the projects managed by the build
      */
     public Set<MavenProject> getProjects() {
         return items.stream().map(ProjectSegment::getProject).collect(Collectors.toSet());
     }
 }