/*
    * 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.commons.jexl3.jexl342;
  
  import org.apache.commons.jexl3.JexlEngine;
  import org.apache.commons.jexl3.JexlException;
  import org.apache.commons.jexl3.introspection.JexlPropertySet;
  
  /**
   * Wraps a reference or optional property set executor.
   */
  public class ReferenceSetExecutor implements JexlPropertySet {
      /** The reference handler. */
      private final ReferenceUberspect.ReferenceHandler handler;
      /** The previous setter we did delegate to. */
      private final JexlPropertySet setter;
  
      /**
       * Creates an instance.
       * @param referenceHandler the reference handler
       * @param jexlSet the property setter
       */
      public ReferenceSetExecutor(final ReferenceUberspect.ReferenceHandler referenceHandler, final JexlPropertySet jexlSet) {
          if (referenceHandler == null || jexlSet == null) {
              throw new IllegalArgumentException("handler and setter cant be null");
          }
          this.handler = referenceHandler;
          this.setter = jexlSet;
      }
  
      /**
       * Dereference an expected optional or reference .
       * @param opt the reference
       * @return the reference value, TRY_FAILED if null
       */
      protected Object getReference(final Object opt) {
          return handler.callGet(opt);
      }
  
      @Override
      public Object invoke(final Object opt, final Object arg) throws Exception {
          final Object obj = getReference(opt);
          return setter.invoke(obj, arg);
      }
  
      @Override
      public boolean isCacheable() {
          return setter.isCacheable();
      }
  
      @Override
      public boolean tryFailed(final Object rval) {
          return setter.tryFailed(rval);
      }
  
      @Override
      public Object tryInvoke(final Object opt, final Object key, final Object arg) throws JexlException.TryFailed {
          final Object obj = getReference(opt);
          return obj == opt? JexlEngine.TRY_FAILED : obj == null ? null : setter.tryInvoke(key, obj, arg);
      }
  }