/*
    * 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.repository.internal;
  
  import java.io.Reader;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Date;
  import java.util.Iterator;
  import java.util.LinkedHashMap;
  import java.util.Map;
  import java.util.jar.JarFile;
  import java.util.zip.ZipEntry;
  import org.apache.maven.repository.internal.PluginsMetadata.PluginInfo;
  import org.codehaus.plexus.util.ReaderFactory;
  import org.codehaus.plexus.util.xml.Xpp3Dom;
  import org.codehaus.plexus.util.xml.Xpp3DomBuilder;
  import org.eclipse.aether.RepositorySystemSession;
  import org.eclipse.aether.artifact.Artifact;
  import org.eclipse.aether.deployment.DeployRequest;
  import org.eclipse.aether.impl.MetadataGenerator;
  import org.eclipse.aether.installation.InstallRequest;
  import org.eclipse.aether.metadata.Metadata;
  import org.eclipse.aether.util.ConfigUtils;
  
  /**
   * Maven G level metadata generator.
   * <p>
   * Plugin metadata contains G level list of "prefix" to A mapping for plugins present under this G.
   */
  class PluginsMetadataGenerator implements MetadataGenerator {
      private static final String PLUGIN_DESCRIPTOR_LOCATION = "META-INF/maven/plugin.xml";
  
      private final Map<Object, PluginsMetadata> processedPlugins;
  
      private final Date timestamp;
  
      PluginsMetadataGenerator(RepositorySystemSession session, InstallRequest request) {
          this(session, request.getMetadata());
      }
  
      PluginsMetadataGenerator(RepositorySystemSession session, DeployRequest request) {
          this(session, request.getMetadata());
      }
  
      private PluginsMetadataGenerator(RepositorySystemSession session, Collection<? extends Metadata> metadatas) {
          this.processedPlugins = new LinkedHashMap<>();
          this.timestamp = (Date) ConfigUtils.getObject(session, new Date(), "maven.startTime");
  
          /*
           * NOTE: This should be considered a quirk to support interop with Maven's legacy ArtifactDeployer which
           * processes one artifact at a time and hence cannot associate the artifacts from the same project to use the
           * same version index. Allowing the caller to pass in metadata from a previous deployment allows to re-establish
           * the association between the artifacts of the same project.
           */
          for (Iterator<? extends Metadata> it = metadatas.iterator(); it.hasNext(); ) {
              Metadata metadata = it.next();
              if (metadata instanceof PluginsMetadata) {
                  it.remove();
                  PluginsMetadata pluginMetadata = (PluginsMetadata) metadata;
                  processedPlugins.put(pluginMetadata.getGroupId(), pluginMetadata);
              }
          }
      }
  
      @Override
      public Collection<? extends Metadata> prepare(Collection<? extends Artifact> artifacts) {
          return Collections.emptyList();
      }
  
      @Override
      public Artifact transformArtifact(Artifact artifact) {
          return artifact;
      }
  
      @Override
      public Collection<? extends Metadata> finish(Collection<? extends Artifact> artifacts) {
          LinkedHashMap<String, PluginsMetadata> plugins = new LinkedHashMap<>();
          for (Artifact artifact : artifacts) {
              PluginInfo pluginInfo = extractPluginInfo(artifact);
              if (pluginInfo != null) {
                 String key = pluginInfo.groupId;
                 if (processedPlugins.get(key) == null) {
                     PluginsMetadata pluginMetadata = plugins.get(key);
                     if (pluginMetadata == null) {
                         pluginMetadata = new PluginsMetadata(pluginInfo, timestamp);
                         plugins.put(key, pluginMetadata);
                     }
                 }
             }
         }
         return plugins.values();
     }
 
     private PluginInfo extractPluginInfo(Artifact artifact) {
         // sanity: jar, no classifier and file exists
         if (artifact != null
                 && "jar".equals(artifact.getExtension())
                 && "".equals(artifact.getClassifier())
                 && artifact.getFile() != null) {
             Path artifactPath = artifact.getFile().toPath();
             if (Files.isRegularFile(artifactPath)) {
                 try (JarFile artifactJar = new JarFile(artifactPath.toFile(), false)) {
                     ZipEntry pluginDescriptorEntry = artifactJar.getEntry(PLUGIN_DESCRIPTOR_LOCATION);
 
                     if (pluginDescriptorEntry != null) {
                         try (Reader reader =
                                 ReaderFactory.newXmlReader(artifactJar.getInputStream(pluginDescriptorEntry))) {
                             // Note: using DOM instead of use of
                             // org.apache.maven.plugin.descriptor.PluginDescriptor
                             // as it would pull in dependency on:
                             // - maven-plugin-api (for model)
                             // - Plexus Container (for model supporting classes and exceptions)
                             Xpp3Dom root = Xpp3DomBuilder.build(reader);
                             String groupId = root.getChild("groupId").getValue();
                             String artifactId = root.getChild("artifactId").getValue();
                             String goalPrefix = root.getChild("goalPrefix").getValue();
                             String name = root.getChild("name").getValue();
                             return new PluginInfo(groupId, artifactId, goalPrefix, name);
                         }
                     }
                 } catch (Exception e) {
                     // here we can have: IO. ZIP or Plexus Conf Ex: but we should not interfere with user intent
                 }
             }
         }
         return null;
     }
 }