content: /*
   *  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
   *
   *      https://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.tools.ant.types.resources;
  
  import java.util.Iterator;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Stack;
  import java.util.stream.Stream;
  
  import org.apache.tools.ant.BuildException;
  import org.apache.tools.ant.Project;
  import org.apache.tools.ant.types.ArchiveFileSet;
  import org.apache.tools.ant.types.DataType;
  import org.apache.tools.ant.types.Reference;
  import org.apache.tools.ant.types.Resource;
  import org.apache.tools.ant.types.ResourceCollection;
  import org.apache.tools.ant.types.TarFileSet;
  import org.apache.tools.ant.types.ZipFileSet;
  
  /**
   * A resource collection that treats all nested resources as archives
   * and returns the contents of the archives as its content.
   *
   * @since Ant 1.8.0
   */
  public class Archives extends DataType
      implements ResourceCollection, Cloneable {
  
      private Union zips = new Union();
      private Union tars = new Union();
  
      /**
       * Wrapper to identify nested resource collections as ZIP
       * archives.
       *
       * @return Union
       */
      public Union createZips() {
          if (isReference()) {
              throw noChildrenAllowed();
          }
          setChecked(false);
          return zips;
      }
  
      /**
       * Wrapper to identify nested resource collections as ZIP
       * archives.
       *
       * @return Union
       */
      public Union createTars() {
          if (isReference()) {
              throw noChildrenAllowed();
          }
          setChecked(false);
          return tars;
      }
  
      /**
       * Sums the sizes of nested archives.
       *
       * @return int
       */
      @Override
      public int size() {
          if (isReference()) {
              return getRef().size();
          }
          dieOnCircularReference();
          return streamArchives().mapToInt(ArchiveFileSet::size).sum();
      }
  
      /**
       * Merges the nested collections.
       *
       * @return Iterator&lt;Resource&gt;
       */
      public Iterator<Resource> iterator() {
          if (isReference()) {
              return getRef().iterator();
          }
          dieOnCircularReference();
          return streamArchives().flatMap(ResourceCollection::stream)
              .map(Resource.class::cast).iterator();
      }
  
      /**
       * @return false
       */
      public boolean isFilesystemOnly() {
          if (isReference()) {
              return getRef().isFilesystemOnly();
          }
          dieOnCircularReference();
          // TODO check each archive in turn?
          return false;
      }
  
      /**
       * Overrides the base version.
       *
       * @param r the Reference to set.
       */
      @Override
      public void setRefid(final Reference r) {
          if (!zips.getResourceCollections().isEmpty() || !tars.getResourceCollections().isEmpty()) {
              throw tooManyAttributes();
          }
          super.setRefid(r);
      }
  
      /**
       * Implement clone.  The nested resource collections are cloned as
       * well.
       *
       * @return a cloned instance.
       */
      @Override
      public Object clone() {
          try {
              final Archives a = (Archives) super.clone();
              a.zips = (Union) zips.clone();
              a.tars = (Union) tars.clone();
              return a;
          } catch (final CloneNotSupportedException e) {
              throw new BuildException(e);
          }
      }
  
      // TODO this is a pretty expensive operation and so the result
      // should be cached.
      /**
       * Turns all nested resources into corresponding ArchiveFileSets
       * and returns an iterator over the collected archives.
       *
       * @return Iterator&lt;ArchiveFileSet&gt;
       */
      protected Iterator<ArchiveFileSet> grabArchives() {
          return streamArchives().iterator();
      }
  
      // TODO this is a pretty expensive operation and so the result
      // should be cached.
      private Stream<ArchiveFileSet> streamArchives() {
          final List<ArchiveFileSet> l = new LinkedList<>();
          for (final Resource r : zips) {
              l.add(configureArchive(new ZipFileSet(), r));
          }
          for (final Resource r : tars) {
              l.add(configureArchive(new TarFileSet(), r));
          }
          return l.stream();
      }
  
      /**
       * Configures the archivefileset based on this type's settings,
       * set the source.
       *
       * @param afs ArchiveFileSet
       * @param src Resource
       * @return ArchiveFileSet
       */
      protected ArchiveFileSet configureArchive(final ArchiveFileSet afs,
                                                final Resource src) {
          afs.setProject(getProject());
          afs.setSrcResource(src);
          return afs;
      }
  
      /**
       * Overrides the version of DataType to recurse on all DataType
       * child elements that may have been added.
       *
       * @param stk the stack of data types to use (recursively).
       * @param p   the project to use to dereference the references.
       * @throws BuildException on error.
       */
      @Override
      protected synchronized void dieOnCircularReference(final Stack<Object> stk, final Project p)
          throws BuildException {
          if (isChecked()) {
              return;
          }
          if (isReference()) {
              super.dieOnCircularReference(stk, p);
          } else {
              pushAndInvokeCircularReferenceCheck(zips, stk, p);
              pushAndInvokeCircularReferenceCheck(tars, stk, p);
              setChecked(true);
          }
      }
  
      private Archives getRef() {
          return getCheckedRef(Archives.class);
      }
  
  }
  