/**

  * Copyright 2010 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.osedu.org/licenses/ECL-2.0

  *

  * 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.student.core.statement.naturallanguage.translators;

 import java.util.HashMap;

 import java.util.List;

 import java.util.Locale;

 import java.util.Map;

 import org.kuali.student.common.exceptions.DoesNotExistException;

 import org.kuali.student.common.exceptions.OperationFailedException;

 import org.kuali.student.core.statement.dto.ReqComponentInfo;

 import org.kuali.student.core.statement.entity.ReqComponent;

 import org.kuali.student.core.statement.entity.ReqComponentType;

 import org.kuali.student.core.statement.entity.ReqComponentTypeNLTemplate;

 import org.kuali.student.core.statement.naturallanguage.Context;

 import org.kuali.student.core.statement.naturallanguage.ContextRegistry;

 import org.kuali.student.core.statement.service.impl.StatementAssembler;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 /**

  * This class translates requirement components into a specific

  * natural language. This class is not thread safe.

  */

 public class ReqComponentTranslator {

     /** SLF4J logging framework */

         private final static Logger logger = LoggerFactory.getLogger(ReqComponentTranslator.class);

     private String language;

     private ContextRegistry<Context<ReqComponentInfo>> contextRegistry;

     private TemplateTranslator templateTranslator = new TemplateTranslator();

     /**

          * Constructs a new natural language translator in the

          * default language locale.

      */

     public ReqComponentTranslator() {

                 this.language = Locale.getDefault().getLanguage();

     }

         /**

          * Sets requirement component translation language.

          *

          * @param language Language translation

          */

     public void setLanguage(final String language) {

                 this.language = language;

         }

     /**

      * Sets the template context registry.

      *

      * @param contextRegistry Template context registry

      */

     public void setContextRegistry(final ContextRegistry<Context<ReqComponentInfo>> contextRegistry) {

             this.contextRegistry = contextRegistry;

     }

     /**

      * Translates an <code>reqComponent</code> for a specific

      * <code>nlUsageTypeKey</code> into natural language.

      * This method is not thread safe.

      *

      * @param reqComponent

      *            Requirement component to translate

      * @param nlUsageTypeKey

      *            Natural language usuage type key (context)

      * @return Natural language translation

      * @throws DoesNotExistException

      *             Natural language usuage type key does not exist

      * @throws OperationFailedException

      *             Translation failed

      */

     public String translate(final ReqComponent reqComponent, final String nlUsageTypeKey) throws DoesNotExistException, OperationFailedException {

             return translate(reqComponent, nlUsageTypeKey, this.language);

     }

     /**

      * Translates an <code>reqComponent</code> for a specific

      * <code>nlUsageTypeKey</code> into natural language.

      * This method is not thread safe.

      *

      * @param reqComponent

      *            Requirement component to translate

      * @param nlUsageTypeKey

      *            Natural language usuage type key (context)

      * @param language

      *            Translation language

      * @return

      * @throws DoesNotExistException

      *             Natural language usuage type key does not exist

      * @throws OperationFailedException

      *             Translation failed

      */

     public String translate(final ReqComponent reqComponent, final String nlUsageTypeKey, final String language) throws DoesNotExistException, OperationFailedException {

             if(reqComponent == null) {

                     throw new DoesNotExistException("ReqComponent cannot be null");

             }

             ReqComponentType reqComponentType = reqComponent.getRequiredComponentType();

             ReqComponentInfo reqComponentInfo = StatementAssembler.toReqComponentInfo(reqComponent);

             Map<String, Object> contextMap = buildContextMap(reqComponentInfo);

         ReqComponentTypeNLTemplate template = getTemplate(reqComponentType, nlUsageTypeKey, language);

         try {

                         String nl = this.templateTranslator.translate(contextMap, template.getTemplate());

                         if(logger.isInfoEnabled()) {

                             logger.info("nl="+nl);

                     }

                         return nl;

                 } catch (OperationFailedException e) {

                         String msg = "Generating template for requirement component failed: "+reqComponent;

                         logger.error(msg, e);

                         throw new OperationFailedException(msg);

                 }

     }

     /**

      * Builds a requirement component type context map.

      *

      * @param reqComponent Requirement component

      * @throws DoesNotExistException Requirement component context not found in registry

      * @throws OperationFailedException Creating context map failed

      */

     private Map<String, Object> buildContextMap(ReqComponentInfo reqComponent) throws DoesNotExistException, OperationFailedException {

         List<Context<ReqComponentInfo>> contextList = this.contextRegistry.get(reqComponent.getType());

         if(contextList == null || contextList.isEmpty()) {

                 throw new DoesNotExistException("Requirement component context not found in registry for requirement component type id: " + reqComponent.getType());

         }

         Map<String, Object> contextMap = new HashMap<String, Object>();

         for(Context<ReqComponentInfo> context : contextList) {

                     Map<String, Object> cm = context.createContextMap(reqComponent);

                     contextMap.putAll(cm);

             }

         if(logger.isInfoEnabled()) {

                         logger.info("contextMap="+contextMap);

                 }

         return contextMap;

     }

     /**

      * Gets the requirement component type template for the <code>nlUsageTypeKey</code>.

      *

      * @param reqComponentType

      *            Requirement component type

      * @param nlUsageTypeKey

      *            Natural language usuage type key (context)

      * @return Requirement component type template

      * @throws DoesNotExistException Template does not exist

      */

     private ReqComponentTypeNLTemplate getTemplate(ReqComponentType reqComponentType, String nlUsageTypeKey, String language) throws DoesNotExistException {

             List<ReqComponentTypeNLTemplate> templateList = reqComponentType.getNlUsageTemplates();

         for (ReqComponentTypeNLTemplate template : templateList) {

             if (nlUsageTypeKey.equals(template.getNlUsageTypeKey()) && language.equals(template.getLanguage())) {

                     if(logger.isInfoEnabled()) {

                                 logger.info("template="+template);

                         }

                 return template;

             }

         }

         throw new DoesNotExistException("Natural language usage type key '" + nlUsageTypeKey + "'" +

                         " and language code '" + language + "' for requirement component type " + reqComponentType.getId() + " template not found");

     }

 }