/*
    * Copyright 2005-2008 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(name, 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;
      }
      
  }