/*
    * 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.plugins.dependency;
  
  import java.io.File;
  import java.io.IOException;
  import java.util.Enumeration;
  import java.util.List;
  import java.util.jar.JarEntry;
  import java.util.jar.JarFile;
  
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.MojoFailureException;
  import org.apache.maven.plugins.annotations.Component;
  import org.apache.maven.plugins.annotations.Mojo;
  import org.apache.maven.plugins.annotations.Parameter;
  import org.apache.maven.plugins.dependency.utils.ParamArtifact;
  import org.apache.maven.plugins.dependency.utils.ResolverUtil;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.resolution.ArtifactResolutionException;
  import org.eclipse.aether.resolution.DependencyResolutionException;
  
  /**
   * Retrieves and lists all classes contained in the specified artifact from the specified remote repositories.
   *
   * @since 3.1.3
   */
  @Mojo(name = "list-classes", requiresProject = false, threadSafe = true)
  public class ListClassesMojo extends AbstractMojo {
  
      @Component
      private ResolverUtil resolverUtil;
  
      private ParamArtifact paramArtifact = new ParamArtifact();
  
      /**
       * The group ID of the artifact to download. Ignored if {@code artifact} is used.
       *
       * @since 3.1.3
       */
      @Parameter(property = "groupId")
      public void setGroupId(String groupId) {
          paramArtifact.setGroupId(groupId);
      }
  
      /**
       * The artifact ID of the artifact to download. Ignored if {@code artifact} is used.
       *
       * @since 3.1.3
       */
      @Parameter(property = "artifactId")
      public void setArtifactId(String artifactId) {
          paramArtifact.setArtifactId(artifactId);
      }
  
      /**
       * The version of the artifact to download. Ignored if {@code artifact} is used.
       *
       * @since 3.1.3
       */
      @Parameter(property = "version")
      public void setVersion(String version) {
          paramArtifact.setVersion(version);
      }
  
      /**
       * The classifier of the artifact to download. Ignored if {@code artifact} is used.
       *
       * @since 3.1.3
       */
      @Parameter(property = "classifier")
      public void setClassifier(String classifier) {
          paramArtifact.setClassifier(classifier);
      }
  
      /**
       * The packaging of the artifact to download. Ignored if {@code artifact} is used.
       *
       * @since 3.1.3
       */
      @Parameter(property = "packaging", defaultValue = "jar")
      public void setPackaging(String packaging) {
         paramArtifact.setPackaging(packaging);
     }
 
     /**
      * A string of the form {@code groupId:artifactId:version[:packaging[:classifier]]}.
      *
      * @since 3.1.3
      */
     @Parameter(property = "artifact")
     public void setArtifact(String artifact) {
         paramArtifact.setArtifact(artifact);
     }
 
     /**
      * Repositories in the format {@code id::[layout::]url} or just URLs. That is,
      * <code>
      * central::default::https://repo.maven.apache.org/maven2,myrepo::https://repo.acme.com,https://repo.acme2.com
      * </code>
      *
      * @since 3.1.3
      */
     @Parameter(property = "remoteRepositories")
     private List<String> remoteRepositories;
 
     /**
      * Download transitively, retrieving the specified artifact and all of its dependencies.
      *
      * @since 3.1.3
      */
     @Parameter(property = "transitive", defaultValue = "false")
     private boolean transitive = false;
 
     /**
      * Skip plugin execution completely.
      *
      * @since 3.6.0
      */
     @Parameter(property = "mdep.skip", defaultValue = "false")
     private boolean skip;
 
     @Override
     public void execute() throws MojoExecutionException, MojoFailureException {
         if (skip) {
             getLog().info("Skipping plugin execution");
             return;
         }
 
         if (!paramArtifact.isDataSet()) {
             throw new MojoExecutionException("You must specify an artifact OR GAV separately, "
                     + "e.g. -Dartifact=org.apache.maven.plugins:maven-downloader-plugin:1.0 OR "
                     + "-DgroupId=org.apache.maven.plugins -DartifactId=maven-downloader-plugin -Dversion=1.0");
         }
 
         Artifact artifact = resolverUtil.createArtifactFromParams(paramArtifact);
 
         try {
             if (transitive) {
                 List<Artifact> artifacts =
                         resolverUtil.resolveDependencies(artifact, resolverUtil.remoteRepositories(remoteRepositories));
 
                 for (Artifact a : artifacts) {
                     printClassesFromArtifactResult(a.getFile());
                 }
             } else {
                 Artifact a =
                         resolverUtil.resolveArtifact(artifact, resolverUtil.remoteRepositories(remoteRepositories));
                 printClassesFromArtifactResult(a.getFile());
             }
         } catch (IOException | ArtifactResolutionException | DependencyResolutionException e) {
             throw new MojoExecutionException("Couldn't download artifact: " + e.getMessage(), e);
         }
     }
 
     private void printClassesFromArtifactResult(File file) throws IOException {
         // open jar file in try-with-resources statement to guarantee the file closes after use regardless of errors
         try (JarFile jarFile = new JarFile(file)) {
             Enumeration<JarEntry> entries = jarFile.entries();
 
             while (entries.hasMoreElements()) {
                 JarEntry entry = entries.nextElement();
                 String entryName = entry.getName();
 
                 // filter out files that do not end in .class
                 if (!entryName.endsWith(".class")) {
                     continue;
                 }
 
                 // remove .class from the end and change format to use periods instead of forward slashes
                 String className =
                         entryName.substring(0, entryName.length() - 6).replace('/', '.');
                 getLog().info(className);
             }
         }
     }
 }