/*_############################################################################
  _## 
  _##  SNMP4J-Agent 3 - SubRequestIteratorSupport.java  
  _## 
  _##  Copyright (C) 2005-2025  Frank Fock (SNMP4J.org)
  _##  
  _##  Licensed 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.snmp4j.agent.request;

import java.util.*;

/**
 * This support class allows to implement a <code>SubRequestIterator</code> instance based on an <code>Iterator</code>
 * that iterates on {@link SubRequest} instances.
 *
 * @param <S> the {@link SubRequest} type returned by this iterator.
 * @author Frank Fock
 * @version 3.1.0
 */
public class SubRequestIteratorSupport<S extends SubRequest<?>> implements SubRequestIterator<S> {

    private Iterator<?> subRequests;

    /**
     * Creates a <code>SubRequestIterator</code> that decorates an
     * <code>Iterator</code>.
     *
     * @param subRequests
     *         an <code>Iterator</code> on {@link SubRequest} instances or instances of other objects if {@link
     *         #mapToSubRequest(Object element)} is implemented (overwritten) accordingly.
     */
    public SubRequestIteratorSupport(Iterator<?> subRequests) {
        this.subRequests = subRequests;
    }

    public boolean hasNext() {
        return subRequests.hasNext();
    }

    public S next() {
        return mapToSubRequest(subRequests.next());
    }

    public void remove() {
        throw new UnsupportedOperationException();
    }

    /**
     * Returns the <code>SubRequest</code> contained or represented by the supplied object (element of the iterator).
     * The default implementation simply casts the supplied object to <code>SubRequest</code>.
     *
     * @param element
     *         an Object from which a <code>SubRequest</code> can be deduced.
     *
     * @return a <code>SubRequest</code> instance.
     */
    @SuppressWarnings("unchecked")
    protected S mapToSubRequest(Object element) {
        return (S) element;
    }
}
