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.taskdefs.optional.extension;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  import java.util.Stack;
  
  import org.apache.tools.ant.BuildException;
  import org.apache.tools.ant.Project;
  import org.apache.tools.ant.types.DataType;
  import org.apache.tools.ant.types.FileSet;
  import org.apache.tools.ant.types.Reference;
  
  /**
   * The Extension set lists a set of "Optional Packages" /
   * "Extensions".
   *
   * @ant.datatype name="extension-set"
   */
  public class ExtensionSet
      extends DataType {
      /**
       * ExtensionAdapter objects representing extensions.
       */
      private final List<ExtensionAdapter> extensions = new ArrayList<>();
  
      /**
       * Filesets specifying all the extensions wanted.
       */
      private final List<FileSet> extensionsFilesets = new ArrayList<>();
  
      /**
       * Adds an extension that this library requires.
       *
       * @param extensionAdapter an extension that this library requires.
       */
      public void addExtension(final ExtensionAdapter extensionAdapter) {
          if (isReference()) {
              throw noChildrenAllowed();
          }
          setChecked(false);
          extensions.add(extensionAdapter);
      }
  
      /**
       * Adds a set of files about which extensions data will be extracted.
       *
       * @param fileSet a set of files about which extensions data will be extracted.
       */
      public void addLibfileset(final LibFileSet fileSet) {
          if (isReference()) {
              throw noChildrenAllowed();
          }
          setChecked(false);
          extensionsFilesets.add(fileSet);
      }
  
      /**
       * Adds a set of files about which extensions data will be extracted.
       *
       * @param fileSet a set of files about which extensions data will be extracted.
       */
      public void addFileset(final FileSet fileSet) {
          if (isReference()) {
              throw noChildrenAllowed();
          }
          setChecked(false);
          extensionsFilesets.add(fileSet);
      }
  
      /**
       * Extract a set of Extension objects from the ExtensionSet.
       *
       * @param proj the project instance.
       * @return an array containing the Extensions from this set
       * @throws BuildException if an error occurs
       */
      public Extension[] toExtensions(final Project proj)
          throws BuildException {
          if (isReference()) {
              return getRef().toExtensions(proj);
          }
          dieOnCircularReference();
          final List<Extension> extensionsList = ExtensionUtil.toExtensions(extensions);
          ExtensionUtil.extractExtensions(proj, extensionsList, extensionsFilesets);
          return extensionsList.toArray(new Extension[0]);
      }
  
      /**
       * Makes this instance in effect a reference to another ExtensionSet
       * instance.
       *
       * <p>You must not set another attribute or nest elements inside
       * this element if you make it a reference.</p>
       *
       * @param reference the reference to which this instance is associated
       * @exception BuildException if this instance already has been configured.
       */
      @Override
      public void setRefid(final Reference reference)
          throws BuildException {
          if (!extensions.isEmpty() || !extensionsFilesets.isEmpty()) {
              throw tooManyAttributes();
          }
          super.setRefid(reference);
      }
  
      @Override
      protected synchronized void dieOnCircularReference(Stack<Object> stk, Project p)
          throws BuildException {
          if (isChecked()) {
              return;
          }
          if (isReference()) {
              super.dieOnCircularReference(stk, p);
          } else {
              for (ExtensionAdapter extensionAdapter : extensions) {
                  pushAndInvokeCircularReferenceCheck(extensionAdapter, stk, p);
              }
              for (FileSet fileSet : extensionsFilesets) {
                  pushAndInvokeCircularReferenceCheck(fileSet, stk, p);
              }
              setChecked(true);
          }
      }
  
      private ExtensionSet getRef() {
          return getCheckedRef(ExtensionSet.class);
      }
  
      /**
       * @see java.lang.Object#toString()
       * @return the extensions in a string.
       */
      @Override
      public String toString() {
          return "ExtensionSet" + Arrays.asList(toExtensions(getProject()));
      }
  }
  