/**
    * Copyright 2005-2014 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.krad.messages.providers;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.core.api.exception.RiceRuntimeException;
  import org.kuali.rice.core.api.search.SearchOperator;
  import org.kuali.rice.krad.messages.Message;
  import org.kuali.rice.krad.messages.MessageProvider;
  import org.kuali.rice.krad.service.KRADServiceLocatorWeb;
  import org.kuali.rice.krad.service.LookupService;
  
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * Implementation of {@link MessageProvider} that stores messages in a database
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class DatabaseMessageProvider implements MessageProvider {
      private LookupService lookupService;
  
      /**
       * @see org.kuali.rice.krad.messages.MessageProvider#getMessage(java.lang.String, java.lang.String,
       * java.lang.String, java.lang.String)
       */
      public Message getMessage(String namespace, String component, String key, String locale) {
          Collection<Message> results = getMessageByCriteria(namespace, component, key, locale);
  
          if ((results != null) && !results.isEmpty()) {
              return results.iterator().next();
          }
  
          return null;
      }
  
      /**
       * @see org.kuali.rice.krad.messages.MessageProvider#getAllMessagesForComponent(java.lang.String,
       * java.lang.String, java.lang.String)
       */
      public Collection<Message> getAllMessagesForComponent(String namespace, String component, String locale) {
          return getMessageByCriteria(namespace, component, null, locale);
      }
  
      /**
       * Performs a query using the {@link LookupService} to retrieve messages that match the given
       * namespace, component, name, and locale. Not parameters maybe empty in which case they will not be added
       * to the criteria
       *
       * @param namespace namespace code to search for
       * @param component component code to search for
       * @param key key of the parameter to find
       * @param locale locale code to search for
       * @return Collection<Message> matching messages or empty collection if not are found
       */
      protected Collection<Message> getMessageByCriteria(String namespace, String component, String key, String locale) {
          Collection<Message> results = null;
  
          Map<String, String> criteria = new HashMap<String, String>();
  
          if (StringUtils.isNotBlank(namespace)) {
              criteria.put("namespaceCode", namespace);
          }
  
          if (StringUtils.isNotBlank(component)) {
              criteria.put("componentCode", component);
          }
  
          if (StringUtils.isNotBlank(key)) {
              criteria.put("key", key);
          }
  
          if (StringUtils.isNotBlank(locale)) {
              // build or condition that will match just the language as well
              String[] localeIdentifiers = StringUtils.split(locale, "-");
              if ((localeIdentifiers == null) || (localeIdentifiers.length != 2)) {
                  throw new RiceRuntimeException("Invalid locale code: " + (locale == null ? "Null" : locale));
              }
  
              String localeLanguage = localeIdentifiers[0];
              criteria.put("locale", locale + SearchOperator.OR.op() + localeLanguage);
          }
  
          results = getLookupService().findCollectionBySearch(Message.class, criteria);
 
         // filter out duplicate message results due to locale wildcard search (for example could have a match 
         // for en and en-US, in which case we want to take the record for the more specific locale
         Map<String, Message> uniqueMessages = new HashMap<String, Message>();
         for (Message message : results) {
             String messageKey = message.getNamespaceCode() + "|" + message.getComponentCode() + "|" + message.getKey();
             if (uniqueMessages.containsKey(messageKey)) {
                 Message duplicateMessage = uniqueMessages.get(messageKey);
                 // attempt to find the one that matches the locale exactly
                 if (message.getLocale().equals(locale)) {
                     // use current message, otherwise leave the previous message
                     uniqueMessages.put(messageKey, message);
                 }
             } else {
                 uniqueMessages.put(messageKey, message);
             }
         }
 
         return uniqueMessages.values();
     }
 
     public LookupService getLookupService() {
         if (lookupService == null) {
             lookupService = KRADServiceLocatorWeb.getLookupService();
         }
 
         return lookupService;
     }
 
     public void setLookupService(LookupService lookupService) {
         this.lookupService = lookupService;
     }
 }