/**

  * 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.xml;

 import org.jdom.Element;

 import org.jdom.Namespace;

 import org.kuali.rice.core.api.util.xml.XmlException;

 import org.kuali.rice.core.api.util.xml.XmlHelper;

 import org.kuali.rice.kew.rule.RuleBaseValues;

 import org.kuali.rice.kew.rule.RuleExtensionBo;

 import org.kuali.rice.kew.rule.RuleExtensionValue;

 import org.kuali.rice.kew.rule.bo.RuleAttribute;

 import org.kuali.rice.kew.rule.bo.RuleTemplateBo;

 import org.kuali.rice.kew.rule.bo.RuleTemplateAttributeBo;

 import org.kuali.rice.kew.service.KEWServiceLocator;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.Iterator;

 import java.util.List;

 /**

  * Parses {@link org.kuali.rice.kew.rule.RuleExtensionBo}s from XML.

  *

  * @see org.kuali.rice.kew.rule.RuleExtensionBo

  * @see RuleExtensionValue

  *

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class RuleExtensionXmlParser {

     private static final Namespace NAMESPACE = Namespace.getNamespace("", "ns:workflow/Rule");

     private static final String RULE_EXTENSION = "ruleExtension";

     private static final String ATTRIBUTE = "attribute";

     private static final String RULE_TEMPLATE = "ruleTemplate";

     private static final String RULE_EXTENSION_VALUES = "ruleExtensionValues";

     private static final String RULE_EXTENSION_VALUE = "ruleExtensionValue";

     private static final String KEY = "key";

     private static final String VALUE = "value";

     public List parseRuleExtensions(Element element, RuleBaseValues rule) throws XmlException {

         List ruleExtensions = new ArrayList();

         Collection<Element> ruleElements = XmlHelper.findElements(element, RULE_EXTENSION);

         for (Iterator iterator = ruleElements.iterator(); iterator.hasNext();) {

             ruleExtensions.add(parseRuleExtension((Element) iterator.next(), rule));

         }

         return ruleExtensions;

     }

     private RuleExtensionBo parseRuleExtension(Element element, RuleBaseValues rule) throws XmlException {

         String attributeName = element.getChildText(ATTRIBUTE, NAMESPACE);

         String templateName = element.getChildText(RULE_TEMPLATE, NAMESPACE);

         Element valuesElement = element.getChild(RULE_EXTENSION_VALUES, NAMESPACE);

         if (attributeName == null) {

             throw new XmlException("Rule extension must have a valid attribute.");

         }

         if (templateName == null) {

             throw new XmlException("Rule extension must have a valid rule template.");

         }

         RuleAttribute ruleAttribute = KEWServiceLocator.getRuleAttributeService().findByName(attributeName);

         if (ruleAttribute == null) {

             throw new XmlException("Could not locate attribute for the given name '" + attributeName + "'");

         }

         RuleTemplateBo ruleTemplate = KEWServiceLocator.getRuleTemplateService().findByRuleTemplateName(templateName);

         if (ruleTemplate == null) {

             throw new XmlException("Could not locate rule template for the given name '" + templateName + "'");

         }

         RuleExtensionBo extension = new RuleExtensionBo();

         extension.setRuleBaseValues(rule);

         boolean attributeFound = false;

         for (Iterator iter = ruleTemplate.getActiveRuleTemplateAttributes().iterator(); iter.hasNext();) {

             RuleTemplateAttributeBo templateAttribute = (RuleTemplateAttributeBo) iter.next();

             if (templateAttribute.getRuleAttributeId().equals(ruleAttribute.getId())) {

                 extension.setRuleTemplateAttribute(templateAttribute);

                 extension.setRuleTemplateAttributeId(templateAttribute.getId());

                 attributeFound = true;

                 break;

             }

         }

         if (!attributeFound) {

             // TODO: need test case for this

             throw new XmlException("Attribute '" + attributeName + "' not found on template '" + ruleTemplate.getName() + "'");

         }

         extension.setExtensionValues(parseRuleExtensionValues(valuesElement, extension));

         return extension;

     }

     private List parseRuleExtensionValues(Element element, RuleExtensionBo ruleExtension) throws XmlException {

         List values = new ArrayList();

         if (element == null) {

             return values;

         }

         Collection<Element> valueElements = XmlHelper.findElements(element, RULE_EXTENSION_VALUE);

         for (Iterator iterator = valueElements.iterator(); iterator.hasNext();) {

             Element valueElement = (Element) iterator.next();

             values.add(parseRuleExtensionValue(valueElement, ruleExtension));

         }

         return values;

     }

     private RuleExtensionValue parseRuleExtensionValue(Element element, RuleExtensionBo ruleExtension) throws XmlException {

         String key = element.getChildText(KEY, NAMESPACE);

         String value = element.getChildText(VALUE, NAMESPACE);

         if (org.apache.commons.lang.StringUtils.isEmpty(key)) {

             throw new XmlException("RuleExtensionValue must have a non-empty key.");

         }

         if (value == null) {

             throw new XmlException("RuleExtensionValue must have a non-null value.");

         }

         RuleExtensionValue extensionValue = new RuleExtensionValue(key, value);

         extensionValue.setExtension(ruleExtension);

         return extensionValue;

     }

 }