/*
    * 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;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.io.File;
  import java.io.IOException;
  import java.nio.file.DirectoryNotEmptyException;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.nio.file.StandardCopyOption;
  import java.util.ArrayDeque;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Deque;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Objects;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  import org.apache.maven.api.model.Model;
  import org.apache.maven.api.services.Lookup;
  import org.apache.maven.eventspy.EventSpy;
  import org.apache.maven.execution.ExecutionEvent;
  import org.apache.maven.execution.MavenSession;
  import org.apache.maven.internal.impl.resolver.MavenWorkspaceReader;
  import org.apache.maven.project.MavenProject;
  import org.apache.maven.project.artifact.ProjectArtifact;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.repository.WorkspaceRepository;
  import org.eclipse.aether.util.artifact.ArtifactIdUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * An implementation of a workspace reader that knows how to search the Maven reactor for artifacts, either as packaged
   * jar if it has been built, or only compile output directory if packaging hasn't happened yet.
   *
   */
  @Named(ReactorReader.HINT)
  @SessionScoped
  class ReactorReader implements MavenWorkspaceReader {
      public static final String HINT = "reactor";
  
      public static final String PROJECT_LOCAL_REPO = "project-local-repo";
  
      private static final Collection<String> COMPILE_PHASE_TYPES = new HashSet<>(
              Arrays.asList("jar", "ejb-client", "war", "rar", "ejb3", "par", "sar", "wsr", "har", "app-client"));
  
      private static final Logger LOGGER = LoggerFactory.getLogger(ReactorReader.class);
  
      private final MavenSession session;
      private final WorkspaceRepository repository;
      // groupId -> (artifactId -> (version -> project)))
      private Map<String, Map<String, Map<String, MavenProject>>> projects;
      private Map<String, Map<String, Map<String, MavenProject>>> allProjects;
      private Path projectLocalRepository;
      // projectId -> Deque<lifecycle>
      private final Map<String, Deque<String>> lifecycles = new ConcurrentHashMap<>();
  
      @Inject
      ReactorReader(MavenSession session) {
          this.session = session;
          this.repository = new WorkspaceRepository("reactor", null);
      }
  
      //
      // Public API
      //
  
      public WorkspaceRepository getRepository() {
          return repository;
      }
  
     public File findArtifact(Artifact artifact) {
         MavenProject project = getProject(artifact);
 
         if (project != null) {
             File file = findArtifact(project, artifact, true);
             if (file == null && project != project.getExecutionProject()) {
                 file = findArtifact(project.getExecutionProject(), artifact, true);
             }
             return file;
         }
 
         // No project, but most certainly a dependency which has been built previously
         File packagedArtifactFile = findInProjectLocalRepository(artifact);
         if (packagedArtifactFile != null && packagedArtifactFile.exists()) {
             return packagedArtifactFile;
         }
 
         return null;
     }
 
     public List<String> findVersions(Artifact artifact) {
         List<String> versions = getProjects()
                 .getOrDefault(artifact.getGroupId(), Collections.emptyMap())
                 .getOrDefault(artifact.getArtifactId(), Collections.emptyMap())
                 .values()
                 .stream()
                 .map(MavenProject::getVersion)
                 .collect(Collectors.collectingAndThen(Collectors.toList(), Collections::unmodifiableList));
         if (!versions.isEmpty()) {
             return versions;
         }
         return getAllProjects()
                 .getOrDefault(artifact.getGroupId(), Collections.emptyMap())
                 .getOrDefault(artifact.getArtifactId(), Collections.emptyMap())
                 .values()
                 .stream()
                 .filter(p -> Objects.nonNull(findArtifact(p, artifact, false)))
                 .map(MavenProject::getVersion)
                 .collect(Collectors.collectingAndThen(Collectors.toList(), Collections::unmodifiableList));
     }
 
     @Override
     public Model findModel(Artifact artifact) {
         MavenProject project = getProject(artifact);
         return project == null ? null : project.getModel().getDelegate();
     }
 
     //
     // Implementation
     //
 
     private File findArtifact(MavenProject project, Artifact artifact, boolean checkUptodate) {
         // POMs are always returned from the file system
         if ("pom".equals(artifact.getExtension())) {
             return project.getFile();
         }
 
         // Get the matching artifact from the project
         Artifact projectArtifact = findMatchingArtifact(project, artifact);
         if (projectArtifact != null) {
             // If the artifact has been associated to a file, use it
             File packagedArtifactFile = projectArtifact.getFile();
             if (packagedArtifactFile != null && packagedArtifactFile.exists()) {
                 return packagedArtifactFile;
             }
         }
 
         // Check in the project local repository
         File packagedArtifactFile = findInProjectLocalRepository(artifact);
         if (packagedArtifactFile != null
                 && packagedArtifactFile.exists()
                 && (!checkUptodate || isPackagedArtifactUpToDate(project, packagedArtifactFile))) {
             return packagedArtifactFile;
         }
 
         if (!hasBeenPackagedDuringThisSession(project)) {
             // fallback to loose class files only if artifacts haven't been packaged yet
             // and only for plain old jars. Not war files, not ear files, not anything else.
             return determineBuildOutputDirectoryForArtifact(project, artifact);
         }
 
         // The fall-through indicates that the artifact cannot be found;
         // for instance if package produced nothing or classifier problems.
         return null;
     }
 
     private File determineBuildOutputDirectoryForArtifact(final MavenProject project, final Artifact artifact) {
         if (isTestArtifact(artifact)) {
             if (project.hasLifecyclePhase("test-compile")) {
                 return new File(project.getBuild().getTestOutputDirectory());
             }
         } else {
             String type = artifact.getProperty("type", "");
             File outputDirectory = new File(project.getBuild().getOutputDirectory());
 
             // Check if the project is being built during this session, and if we can expect any output.
             // There is no need to check if the build has created any outputs, see MNG-2222.
             boolean projectCompiledDuringThisSession =
                     project.hasLifecyclePhase("compile") && COMPILE_PHASE_TYPES.contains(type);
 
             // Check if the project is part of the session (not filtered by -pl, -rf, etc). If so, we check
             // if a possible earlier Maven invocation produced some output for that project which we can use.
             boolean projectHasOutputFromPreviousSession =
                     !session.getProjects().contains(project) && outputDirectory.exists();
 
             if (projectHasOutputFromPreviousSession || projectCompiledDuringThisSession) {
                 return outputDirectory;
             }
         }
 
         // The fall-through indicates that the artifact cannot be found;
         // for instance if package produced nothing or classifier problems.
         return null;
     }
 
     private boolean isPackagedArtifactUpToDate(MavenProject project, File packagedArtifactFile) {
         Path outputDirectory = Paths.get(project.getBuild().getOutputDirectory());
         if (!outputDirectory.toFile().exists()) {
             return true;
         }
 
         try (Stream<Path> outputFiles = Files.walk(outputDirectory)) {
             // Not using File#lastModified() to avoid a Linux JDK8 milliseconds precision bug: JDK-8177809.
             long artifactLastModified =
                     Files.getLastModifiedTime(packagedArtifactFile.toPath()).toMillis();
 
             if (session.getProjectBuildingRequest().getBuildStartTime() != null) {
                 long buildStartTime =
                         session.getProjectBuildingRequest().getBuildStartTime().getTime();
                 if (artifactLastModified > buildStartTime) {
                     return true;
                 }
             }
 
             for (Path outputFile : (Iterable<Path>) outputFiles::iterator) {
                 if (Files.isDirectory(outputFile)) {
                     continue;
                 }
 
                 long outputFileLastModified =
                         Files.getLastModifiedTime(outputFile).toMillis();
                 if (outputFileLastModified > artifactLastModified) {
                     LOGGER.warn(
                             "File '{}' is more recent than the packaged artifact for '{}', "
                                     + "please run a full `mvn package` build",
                             relativizeOutputFile(outputFile),
                             project.getArtifactId());
                     return true;
                 }
             }
 
             return true;
         } catch (IOException e) {
             LOGGER.warn(
                     "An I/O error occurred while checking if the packaged artifact is up-to-date "
                             + "against the build output directory. "
                             + "Continuing with the assumption that it is up-to-date.",
                     e);
             return true;
         }
     }
 
     private boolean hasBeenPackagedDuringThisSession(MavenProject project) {
         boolean packaged = false;
         for (String phase : getLifecycles(project)) {
             switch (phase) {
                 case "clean":
                     packaged = false;
                     break;
                 case "package":
                 case "install":
                 case "deploy":
                     packaged = true;
                     break;
                 default:
                     break;
             }
         }
         return packaged;
     }
 
     private Path relativizeOutputFile(final Path outputFile) {
         Path rootDirectory = session.getRequest().getRootDirectory();
         return rootDirectory.relativize(outputFile);
     }
 
     /**
      * Tries to resolve the specified artifact from the artifacts of the given project.
      *
      * @param project The project to try to resolve the artifact from, must not be <code>null</code>.
      * @param requestedArtifact The artifact to resolve, must not be <code>null</code>.
      * @return The matching artifact from the project or <code>null</code> if not found. Note that this
      */
     private Artifact findMatchingArtifact(MavenProject project, Artifact requestedArtifact) {
         String requestedRepositoryConflictId = ArtifactIdUtils.toVersionlessId(requestedArtifact);
         return getProjectArtifacts(project)
                 .filter(artifact ->
                         Objects.equals(requestedRepositoryConflictId, ArtifactIdUtils.toVersionlessId(artifact)))
                 .findFirst()
                 .orElse(null);
     }
 
     /**
      * Determines whether the specified artifact refers to test classes.
      *
      * @param artifact The artifact to check, must not be {@code null}.
      * @return {@code true} if the artifact refers to test classes, {@code false} otherwise.
      */
     private static boolean isTestArtifact(Artifact artifact) {
         return ("test-jar".equals(artifact.getProperty("type", "")))
                 || ("jar".equals(artifact.getExtension()) && "tests".equals(artifact.getClassifier()));
     }
 
     private File findInProjectLocalRepository(Artifact artifact) {
         Path target = getArtifactPath(artifact);
         return Files.isRegularFile(target) ? target.toFile() : null;
     }
 
     /**
      * We are interested in project success events, in which case we call
      * the {@link #installIntoProjectLocalRepository(MavenProject)} method.
      * The mojo started event is also captured to determine the lifecycle
      * phases the project has been through.
      *
      * @param event the execution event
      */
     private void processEvent(ExecutionEvent event) {
         MavenProject project = event.getProject();
         switch (event.getType()) {
             case MojoStarted:
                 String phase = event.getMojoExecution().getLifecyclePhase();
                 if (phase != null) {
                     Deque<String> phases = getLifecycles(project);
                     if (!Objects.equals(phase, phases.peekLast())) {
                         phases.addLast(phase);
                         if ("clean".equals(phase)) {
                             cleanProjectLocalRepository(project);
                         }
                     }
                 }
                 break;
             case ProjectSucceeded:
             case ForkedProjectSucceeded:
                 installIntoProjectLocalRepository(project);
                 break;
             default:
                 break;
         }
     }
 
     private Deque<String> getLifecycles(MavenProject project) {
         return lifecycles.computeIfAbsent(project.getId(), k -> new ArrayDeque<>());
     }
 
     /**
      * Copy packaged and attached artifacts from this project to the
      * project local repository.
      * This allows a subsequent build to resume while still being able
      * to locate attached artifacts.
      *
      * @param project the project to copy artifacts from
      */
     private void installIntoProjectLocalRepository(MavenProject project) {
         if ("pom".equals(project.getPackaging())
                         && !"clean".equals(getLifecycles(project).peekLast())
                 || hasBeenPackagedDuringThisSession(project)) {
             getProjectArtifacts(project).filter(this::isRegularFile).forEach(this::installIntoProjectLocalRepository);
         }
     }
 
     private void cleanProjectLocalRepository(MavenProject project) {
         try {
             Path artifactPath = getProjectLocalRepo()
                     .resolve(project.getGroupId())
                     .resolve(project.getArtifactId())
                     .resolve(project.getVersion());
             if (Files.isDirectory(artifactPath)) {
                 try (Stream<Path> paths = Files.list(artifactPath)) {
                     for (Path path : (Iterable<Path>) paths::iterator) {
                         Files.delete(path);
                     }
                 }
                 try {
                     Files.delete(artifactPath);
                     Files.delete(artifactPath.getParent());
                     Files.delete(artifactPath.getParent().getParent());
                 } catch (DirectoryNotEmptyException e) {
                     // ignore
                 }
             }
         } catch (IOException e) {
             LOGGER.error("Error while cleaning project local repository", e);
         }
     }
 
     /**
      * Retrieve a stream of the project's artifacts
      */
     private Stream<Artifact> getProjectArtifacts(MavenProject project) {
         Stream<org.apache.maven.artifact.Artifact> artifacts = Stream.concat(
                 Stream.concat(
                         // pom artifact
                         Stream.of(new ProjectArtifact(project)),
                         // main project artifact if not a pom
                         "pom".equals(project.getPackaging()) ? Stream.empty() : Stream.of(project.getArtifact())),
                 // attached artifacts
                 project.getAttachedArtifacts().stream());
         return artifacts.map(RepositoryUtils::toArtifact);
     }
 
     private boolean isRegularFile(Artifact artifact) {
         return artifact.getFile() != null && artifact.getFile().isFile();
     }
 
     private void installIntoProjectLocalRepository(Artifact artifact) {
         String extension = artifact.getExtension();
         String classifier = artifact.getClassifier();
 
         Path target = getArtifactPath(
                 artifact.getGroupId(), artifact.getArtifactId(), artifact.getVersion(), classifier, extension);
         try {
             LOGGER.info("Copying {} to project local repository", artifact);
             Files.createDirectories(target.getParent());
             Files.copy(
                     artifact.getPath(),
                     target,
                     StandardCopyOption.REPLACE_EXISTING,
                     StandardCopyOption.COPY_ATTRIBUTES);
         } catch (IOException e) {
             LOGGER.error("Error while copying artifact to project local repository", e);
         }
     }
 
     private Path getArtifactPath(Artifact artifact) {
         String groupId = artifact.getGroupId();
         String artifactId = artifact.getArtifactId();
         String version = artifact.getBaseVersion();
         String classifier = artifact.getClassifier();
         String extension = artifact.getExtension();
         return getArtifactPath(groupId, artifactId, version, classifier, extension);
     }
 
     private Path getArtifactPath(
             String groupId, String artifactId, String version, String classifier, String extension) {
         Path repo = getProjectLocalRepo();
         return repo.resolve(groupId)
                 .resolve(artifactId)
                 .resolve(version)
                 .resolve(artifactId
                         + "-" + version
                         + (classifier != null && !classifier.isEmpty() ? "-" + classifier : "")
                         + "." + extension);
     }
 
     private Path getProjectLocalRepo() {
         if (projectLocalRepository == null) {
             Path root = session.getRequest().getRootDirectory();
             List<MavenProject> projects = session.getProjects();
             if (projects != null) {
                 projectLocalRepository = projects.stream()
                         .filter(project -> Objects.equals(root.toFile(), project.getBasedir()))
                         .findFirst()
                         .map(project -> project.getBuild().getDirectory())
                         .map(Paths::get)
                         .orElseGet(() -> root.resolve("target"))
                         .resolve(PROJECT_LOCAL_REPO);
             } else {
                 return root.resolve("target").resolve(PROJECT_LOCAL_REPO);
             }
         }
         return projectLocalRepository;
     }
 
     private MavenProject getProject(Artifact artifact) {
         return getAllProjects()
                 .getOrDefault(artifact.getGroupId(), Collections.emptyMap())
                 .getOrDefault(artifact.getArtifactId(), Collections.emptyMap())
                 .getOrDefault(artifact.getBaseVersion(), null);
     }
 
     // groupId -> (artifactId -> (version -> project)))
     private Map<String, Map<String, Map<String, MavenProject>>> getAllProjects() {
         // compute the projects mapping
         if (allProjects == null) {
             List<MavenProject> allProjects = session.getAllProjects();
             if (allProjects != null) {
                 Map<String, Map<String, Map<String, MavenProject>>> map = new HashMap<>();
                 allProjects.forEach(project -> map.computeIfAbsent(project.getGroupId(), k -> new HashMap<>())
                         .computeIfAbsent(project.getArtifactId(), k -> new HashMap<>())
                         .put(project.getVersion(), project));
                 this.allProjects = map;
             } else {
                 return Collections.emptyMap();
             }
         }
         return allProjects;
     }
 
     private Map<String, Map<String, Map<String, MavenProject>>> getProjects() {
         // compute the projects mapping
         if (projects == null) {
             List<MavenProject> projects = session.getProjects();
             if (projects != null) {
                 Map<String, Map<String, Map<String, MavenProject>>> map = new HashMap<>();
                 projects.forEach(project -> map.computeIfAbsent(project.getGroupId(), k -> new HashMap<>())
                         .computeIfAbsent(project.getArtifactId(), k -> new HashMap<>())
                         .put(project.getVersion(), project));
                 this.projects = map;
             } else {
                 return Collections.emptyMap();
             }
         }
         return projects;
     }
 
     /**
      * Singleton class used to receive events by implementing the EventSpy.
      * It simply forwards all {@code ExecutionEvent}s to the {@code ReactorReader}.
      */
     @Named
     @Singleton
     @SuppressWarnings("unused")
     static class ReactorReaderSpy implements EventSpy {
 
         private final Lookup lookup;
 
         @Inject
         ReactorReaderSpy(Lookup lookup) {
             this.lookup = lookup;
         }
 
         @Override
         public void init(Context context) throws Exception {}
 
         @Override
         public void onEvent(Object event) throws Exception {
             if (event instanceof ExecutionEvent) {
                 ReactorReader reactorReader = lookup.lookup(ReactorReader.class);
                 reactorReader.processEvent((ExecutionEvent) event);
             }
         }
 
         @Override
         public void close() throws Exception {}
     }
 }