/**

  * 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.kew.engine.node.service.impl;

 import java.util.List;

 import org.apache.log4j.Logger;

 import org.kuali.rice.kew.engine.node.Branch;

 import org.kuali.rice.kew.engine.node.BranchState;

 import org.kuali.rice.kew.engine.node.dao.BranchDAO;

 import org.kuali.rice.kew.engine.node.service.BranchService;

 public class BranchServiceImpl implements BranchService {

     private static final Logger LOG = Logger.getLogger(BranchServiceImpl.class);

     private BranchDAO branchDAO;

     public void save(Branch branch){

         getBranchDAO().save(branch);

     }

      public BranchDAO getBranchDAO() {

         return branchDAO;

     }

     public void setBranchDAO(BranchDAO branchDAO) {

         this.branchDAO = branchDAO;

     }

     public void deleteBranchStates(List statesToBeDeleted){

         getBranchDAO().deleteBranchStates(statesToBeDeleted);

     }

     /**

      * Walks up the Branch/scope hierarchy trying to find a variable with the specified name

      * @param branch the lowermost branch at which to start the search

      * @param name name of the variable to search for

      * @return a BranchState object in the first Branch/scope in which the variable was found

      */

     private BranchState resolveScopedVariable(Branch branch, String name) {

         Branch b = branch;

         while (b != null) {

             for (BranchState bs: b.getBranchState()) {

                 LOG.debug(bs);

             }

             LOG.debug("Resolving variable: '" + name + "' in scope (branch): '" + branch.getName() + "' (" + branch.getBranchId() + ")");

             BranchState bs = b.getBranchState(name);

             if (bs != null) {

                 return bs;    

             }

             b = b.getParentBranch();

         }

         return null;

     }

     public String getScopedVariableValue(Branch branch, String name) {

         BranchState bs = resolveScopedVariable(branch, name);

         if (bs != null) return bs.getValue();

         return null;

     }

     public String setScopedVariableValue(Branch branch, String name, String value) {

         LOG.debug("Setting scoped variable value: " + name + " " + value);

         BranchState bs = resolveScopedVariable(branch, name);

         String oldValue = null;

         if (bs == null) {

             LOG.debug("Defining new variable named '" + name + "' at scope '" + branch + "'");

             // create new variable at initial search scope

             bs = new BranchState();

             bs.setKey(name);

             bs.setValue(value);

             bs.setBranch(branch);

             branch.addBranchState(bs);

         } else {

             oldValue = bs.getValue();

             LOG.debug("Replacing old value of variable '" + name + "' (" + oldValue + ") at scope '" + branch + "' with new value: " + value);

             bs.setValue(value);

         }

         // now save the Branch whose state we just modified

         save(bs.getBranch());

         return oldValue;

     }

 }