/*
    * 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.resolver.internal.ant.tasks;
  
  import org.apache.tools.ant.BuildException;
  import org.apache.tools.ant.ComponentHelper;
  import org.apache.tools.ant.Project;
  import org.apache.tools.ant.Task;
  import org.apache.tools.ant.types.Reference;
  
  /**
   */
  public abstract class RefTask extends Task {
  
      private Reference ref;
  
      public boolean isReference() {
          return ref != null;
      }
  
      public void setRefid(final Reference ref) {
          this.ref = ref;
      }
  
      protected void checkAttributesAllowed() {
          if (isReference()) {
              throw tooManyAttributes();
          }
      }
  
      protected void checkChildrenAllowed() {
          if (isReference()) {
              throw noChildrenAllowed();
          }
      }
  
      protected BuildException tooManyAttributes() {
          return new BuildException("You must not specify more than one " + "attribute when using refid");
      }
  
      protected BuildException noChildrenAllowed() {
          return new BuildException("You must not specify nested elements " + "when using refid");
      }
  
      protected String getDataTypeName() {
          return ComponentHelper.getElementName(getProject(), this, true);
      }
  
      protected Object getCheckedRef() {
          return getCheckedRef(getClass(), getDataTypeName(), getProject());
      }
  
      protected Object getCheckedRef(final Class<?> requiredClass, final String dataTypeName, final Project project) {
          if (project == null) {
              throw new BuildException("No Project specified");
          }
          Object o = ref.getReferencedObject(project);
          if (!(requiredClass.isAssignableFrom(o.getClass()))) {
              log("Class " + o.getClass() + " is not a subclass of " + requiredClass, Project.MSG_VERBOSE);
              String msg = ref.getRefId() + " doesn't denote a " + dataTypeName;
              throw new BuildException(msg);
          }
          return o;
      }
  }