/*
    * 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.plugin.internal;
  
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.maven.plugin.descriptor.MojoDescriptor;
  import org.apache.maven.plugin.descriptor.Parameter;
  import org.codehaus.plexus.component.configurator.ConfigurationListener;
  
  /**
   * A configuration listener to help validate the plugin configuration. For instance, check for required but missing
   * parameters.
   *
   */
  class ValidatingConfigurationListener implements ConfigurationListener {
      private final Object mojo;
  
      private final ConfigurationListener delegate;
  
      private final Map<String, Parameter> missingParameters;
  
      ValidatingConfigurationListener(Object mojo, MojoDescriptor mojoDescriptor, ConfigurationListener delegate) {
          this.mojo = mojo;
          this.delegate = delegate;
          this.missingParameters = new HashMap<>();
  
          if (mojoDescriptor.getParameters() != null) {
              for (Parameter param : mojoDescriptor.getParameters()) {
                  if (param.isRequired()) {
                      missingParameters.put(param.getName(), param);
                  }
              }
          }
      }
  
      public Collection<Parameter> getMissingParameters() {
          return missingParameters.values();
      }
  
      @Override
      public void notifyFieldChangeUsingSetter(String fieldName, Object value, Object target) {
          delegate.notifyFieldChangeUsingSetter(fieldName, value, target);
  
          if (mojo == target) {
              notify(fieldName, value);
          }
      }
  
      @Override
      public void notifyFieldChangeUsingReflection(String fieldName, Object value, Object target) {
          delegate.notifyFieldChangeUsingReflection(fieldName, value, target);
  
          if (mojo == target) {
              notify(fieldName, value);
          }
      }
  
      private void notify(String fieldName, Object value) {
          if (value != null) {
              missingParameters.remove(fieldName);
          }
      }
  }