/**
    * Copyright 2005-2012 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.List;
  
  import org.kuali.rice.krms.api.engine.ExecutionEnvironment;
  import org.kuali.rice.krms.api.engine.ResultEvent;
  import org.kuali.rice.krms.framework.engine.result.BasicResult;
  
  /**
   * A {@link org.kuali.rice.krms.framework.engine.Rule} that executes a {@link org.kuali.rice.krms.framework.engine.Action} when the {@link Proposition} is true.
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class BasicRule implements Rule {
  	private static final ResultLogger LOG = ResultLogger.getInstance();
  
  	private String name;
  	private Proposition proposition;
  	private List<Action> actions;
  
      /**
       *
       * @param name Rule name
       * @param proposition cannot be null
       * @param actions Rule Actions
       * @throws IllegalArgumentException if the Proposition is null
       */
      public BasicRule(String name, Proposition proposition, List<Action> actions) {
  		if (proposition == null) {
  			throw new IllegalArgumentException("Proposition cannot be null.");
  		}
  		this.name = name;
  		this.proposition = proposition;
  		this.actions = actions;
  	}
  
      /**
       *
       * @param proposition cannot be null
       * @param actions Rule Actions
       * @throws IllegalArgumentException if the Proposition is null
       */
  	public BasicRule(Proposition proposition, List<Action> actions) {
  		this(null, proposition, actions);
  	}
  	
  	@Override
  	public boolean evaluate(ExecutionEnvironment environment) {
  		boolean result = proposition.evaluate(environment).getResult();
  		if (actions != null) {
  			for (Action action : actions) {
  				if (shouldExecuteAction(result)) {
  					action.execute(environment);
  				}
  			}
  		}
  		if (LOG.isEnabled(environment)){
  			LOG.logResult(new BasicResult(ResultEvent.RuleEvaluated, this, environment, result));
  		}
  		return result;
  	}
  
      /**
       * overridden
       * @param ruleExecutionResult the result of the engines evaluation method.
       * @return should the action execute
       */
  	protected boolean shouldExecuteAction(boolean ruleExecutionResult) {
  		return ruleExecutionResult;
  	}
  
      /**
       *
       * @return name Rule name
       */
  	public String getName() {
  		return name;
  	}
  	
      @Override
  	public String toString(){
  		return name;
  	}
  }