/**
    * Copyright 2005-2011 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.kuali.rice.krms.framework.engine;
  
  import java.util.Collection;
  
  import org.kuali.rice.krms.api.engine.ExecutionEnvironment;
  import org.kuali.rice.krms.api.engine.ResultEvent;
  import org.kuali.rice.krms.api.engine.Term;
  import org.kuali.rice.krms.api.engine.TermResolutionException;
  import org.kuali.rice.krms.framework.engine.result.BasicResult;
  
  public class CollectionOfComparablesTermBasedProposition<T> extends ComparableTermBasedProposition<T> {
  	private static final ResultLogger LOG = ResultLogger.getInstance();
  
  	private CollectionOperator collectionOper;
  	private Term term;
  
  	public CollectionOfComparablesTermBasedProposition(CollectionOperator collectionOper, ComparisonOperator compareOper, Term term, T expectedValue) {
  		super(compareOper, term, expectedValue);
  		this.term = term;
  		this.collectionOper = collectionOper;
  	}
  
  	/**
  	 * @see org.kuali.rice.krms.framework.engine.ComparableTermBasedProposition#evaluate(org.kuali.rice.krms.api.engine.ExecutionEnvironment)
  	 * @throws TermResolutionException if there is a problem resolving a {@link Term}
  	 */
  	@Override
  	public PropositionResult evaluate(ExecutionEnvironment environment) {
  		boolean collatedResult = collectionOper.getInitialCollatedResult();
  
  		Collection<? extends Comparable<T>> termValue;
  
  		termValue = environment.resolveTerm(term, this);
  
  		if (termValue != null) {
  			for (Comparable<T> item : termValue) {
  				collatedResult = collectionOper.reduce(compare(item), collatedResult);
  				if (collectionOper.shortCircuit(collatedResult)) break;
  			}
  		}
  
  		// TODO: log this appropriately
  		if (LOG.isEnabled(environment)) {
  			LOG.logResult(new BasicResult(ResultEvent.PropositionEvaluated, this, environment, collatedResult));
  		}
  
  		return new PropositionResult(collatedResult);
  	}
  
  	public String toString() {
  		StringBuilder sb = new StringBuilder();
  		sb.append(collectionOper.toString());
  		sb.append(" "+super.toString());
  		return sb.toString();
  	}
  }