/**
    * 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.kew.rule;
  
  import org.kuali.rice.core.api.exception.RiceIllegalStateException;
  import org.kuali.rice.kew.api.KewApiServiceLocator;
  import org.kuali.rice.kew.engine.RouteContext;
  import org.kuali.rice.kew.engine.node.NodeState;
  import org.kuali.rice.kew.engine.node.RouteNode;
  import org.kuali.rice.kew.engine.node.RouteNodeInstance;
  import org.kuali.rice.kew.routeheader.DocumentRouteHeaderValue;
  import org.kuali.rice.kew.api.KewApiConstants;
  import org.kuali.rice.kew.util.Utilities;
  
  import java.sql.Timestamp;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  
  
  /**
   * Rule selector that select a rule based on configured rule name 
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class NamedRuleSelector implements RuleSelector {
      /**
       * The route node config param consulted to determine the rule name to select
       */
      public static final String RULE_NAME_CFG_KEY = "ruleName";
  
      /**
       * @return the name of the rule that should be selected
       */
      protected String getName(RouteContext context, DocumentRouteHeaderValue routeHeader,
              RouteNodeInstance nodeInstance, String selectionCriterion, Timestamp effectiveDate) {
          String ruleName = null;
          RouteNode routeNodeDef = nodeInstance.getRouteNode();
          // first check to see if there is a rule name configured on the node instance
          NodeState ns = nodeInstance.getNodeState(KewApiConstants.RULE_NAME_NODE_STATE_KEY);
          if (ns != null) {
              ruleName = ns.getValue();
          } else {
              // otherwise check the node def
              Map<String, String> routeNodeConfig = Utilities.getKeyValueCollectionAsMap(routeNodeDef.getConfigParams());
              ruleName = routeNodeConfig.get(RULE_NAME_CFG_KEY);
          }
          return ruleName;
      }
  
      public List<Rule> selectRules(RouteContext context, DocumentRouteHeaderValue routeHeader,
              RouteNodeInstance nodeInstance, String selectionCriterion, Timestamp effectiveDate) {
  
          String ruleName = getName(context, routeHeader, nodeInstance, selectionCriterion, effectiveDate);
  
          if (ruleName == null) {
              throw new RiceIllegalStateException("No 'ruleName' configuration parameter present on route node definition: " + nodeInstance.getRouteNode());
          }
  
          org.kuali.rice.kew.api.rule.Rule ruleDef = KewApiServiceLocator.getRuleService().getRuleByName(ruleName);
          if (ruleDef == null) {
              throw new RiceIllegalStateException("No rule found with name '" + ruleName + "'");
          }
  
          List<Rule> rules = new ArrayList<Rule>(1);
          rules.add(new RuleImpl(ruleDef));
          return rules;
      }
  }