/**
    * 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.validation;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.log4j.Logger;
  import org.kuali.rice.core.api.exception.RiceIllegalArgumentException;
  import org.kuali.rice.kew.api.extension.ExtensionDefinition;
  import org.kuali.rice.kew.api.extension.ExtensionRepositoryService;
  import org.kuali.rice.kew.api.extension.ExtensionUtils;
  import org.kuali.rice.kew.api.validation.RuleValidationContext;
  import org.kuali.rice.kew.api.validation.ValidationResults;
  import org.kuali.rice.kew.framework.validation.RuleValidationAttributeExporterService;
  import org.kuali.rice.kew.rule.RuleValidationAttribute;
  import org.springframework.beans.factory.annotation.Required;
  
  /**
   * RuleValidationAttributeExporterService reference impl.  Delegates to the ExtensionRepositoryService
   * to load the custom RuleValidationAttribute.
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class RuleValidationAttributeExporterServiceImpl implements RuleValidationAttributeExporterService {
      private static final Logger LOG = Logger.getLogger(RuleValidationAttributeExporterServiceImpl.class);
  
      private ExtensionRepositoryService extensionRepositoryService;
  
      @Required
      public void setExtensionRepositoryService(ExtensionRepositoryService extensionRepositoryService) {
          this.extensionRepositoryService = extensionRepositoryService;
      }
      private ExtensionRepositoryService getExtensionRepositoryService() {
          return this.extensionRepositoryService;
      }
  
      @Override
      public ValidationResults validate(String attributeName, RuleValidationContext validationContext) {
          if (StringUtils.isBlank(attributeName)) {
              throw new RiceIllegalArgumentException("attribute name was null or blank");
          }
          RuleValidationAttribute attr = loadAttribute(attributeName);
          return attr.validate(validationContext);
      }
  
      /**
       * Loads RuleValidationAttribute implementation class via {@link ExtensionRepositoryService}
       * @param attributeName the RuleValidationAttribute name
       * @return instance of the RuleValidationAttribute implementation class
       * @throws RiceIllegalArgumentException if specified attribute name cannot be found or loaded
       */
      protected RuleValidationAttribute loadAttribute(String attributeName) {
          ExtensionDefinition extensionDefinition = getExtensionRepositoryService().getExtensionByName(attributeName);
          if (extensionDefinition == null) {
              throw new RiceIllegalArgumentException("Failed to locate a RuleValidationAttribute with the given name: " + attributeName);
          }
          RuleValidationAttribute attribute = ExtensionUtils.loadExtension(extensionDefinition);
          if (attribute == null) {
              throw new RiceIllegalArgumentException("Failed to load RuleValidationAttribute for: " + extensionDefinition);
          }
          return attribute;
      }
  }