/**
    * Copyright 2005-2015 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.kcb.service.impl;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Set;
  import java.util.Map.Entry;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.log4j.Logger;
  import org.kuali.rice.core.api.exception.RiceIllegalArgumentException;
  import org.kuali.rice.kcb.bo.MessageDelivery;
  import org.kuali.rice.kcb.deliverer.MessageDeliverer;
  import org.kuali.rice.kcb.deliverer.impl.AOLInstantMessageDeliverer;
  import org.kuali.rice.kcb.deliverer.impl.EmailMessageDeliverer;
  import org.kuali.rice.kcb.deliverer.impl.MockMessageDeliverer;
  import org.kuali.rice.kcb.deliverer.impl.SMSMessageDeliverer;
  import org.kuali.rice.kcb.service.MessageDelivererRegistryService;
  
  /**
   * MessageDelivererRegistryService implementation - for now we use a HashMap to do this registration, in the future we'll use resource loading.
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class MessageDelivererRegistryServiceImpl implements MessageDelivererRegistryService {
      private static Logger LOG = Logger.getLogger(MessageDelivererRegistryServiceImpl.class);
  
      // holds information about the registered deliverer types
      private HashMap<String, Class<? extends MessageDeliverer>> messageDelivererTypes;
  
      /**
       * Constructs an instance of the MessageDelivererRegistryServiceImpl class and sets up the 
       * registered MessageDeliverers in the system. These are the hardcoded message deliverers 
       * that we support out of the box.
       * 
       * TODO: we'll need to implement a plugin registry discovery mechanism long term.
       */
      public MessageDelivererRegistryServiceImpl() {
          EmailMessageDeliverer email = new EmailMessageDeliverer();
          SMSMessageDeliverer sms = new SMSMessageDeliverer();
          AOLInstantMessageDeliverer aim = new AOLInstantMessageDeliverer();
          MockMessageDeliverer mock = new MockMessageDeliverer();
  
          messageDelivererTypes = new HashMap<String, Class<? extends MessageDeliverer>>(4);
          messageDelivererTypes.put(email.getName().toLowerCase(), email.getClass());
          messageDelivererTypes.put(sms.getName().toLowerCase(), sms.getClass());
          messageDelivererTypes.put(aim.getName().toLowerCase(), aim.getClass());
          messageDelivererTypes.put(mock.getName().toLowerCase(), mock.getClass());
      }
  
      /**
       * @see org.kuali.rice.kcb.service.MessageDelivererRegistryService#getAllDelivererTypes()
       */
      public Collection<String> getAllDelivererTypes() {
          Collection<MessageDeliverer> deliverers = getAllDeliverers();
          Set<String> types = new HashSet<String>(deliverers.size());
          for (MessageDeliverer deliverer: deliverers) {
              types.add(deliverer.getName().toLowerCase());
          }
          return types;
      }
  
      /**
       * Implements by constructing instances of each registered class and adding to an ArrayList that
       * gets passed back to the calling method.
       * @see MessageDelivererRegistryService#getAllDelivererTypes()
       */
      public Collection<MessageDeliverer> getAllDeliverers() {
          ArrayList<MessageDeliverer>  delivererTypes = new ArrayList<MessageDeliverer>();
  
          Set<Entry<String, Class<? extends MessageDeliverer>>> registeredTypes = messageDelivererTypes.entrySet();
  
          // iterate over each type and add an instance of each to the returning ArrayList
          for(Entry<String, Class<? extends MessageDeliverer>> entry: registeredTypes ) {
              try {
                  delivererTypes.add(entry.getValue().newInstance());
              } catch (InstantiationException e) {
                  LOG.error(e.getStackTrace());
              } catch (IllegalAccessException e) {
                  LOG.error(e.getStackTrace());
              }
          }
  
          return delivererTypes;
     }
 
     /**
      * Implements by calling getDelivererByName for the delivery type name within the messageDelivery object.
      * @see MessageDelivererRegistryService#getDeliverer(MessageDelivery)
      */
     public MessageDeliverer getDeliverer(MessageDelivery messageDelivery) {
         if (messageDelivery == null) {
             throw new RiceIllegalArgumentException("messageDelivery is null");
         }
 
         MessageDeliverer nmd = getDelivererByName(messageDelivery.getDelivererTypeName());
         if (nmd == null) {
             LOG.error("The message deliverer type ('" + messageDelivery.getDelivererTypeName() + "') " +
                       "associated with message delivery id='" + messageDelivery.getId() + "' was not found in the message deliverer registry.  This deliverer " +
                       "plugin is not in the system.");
         }
         return nmd;
     }
 
     /**
      * Implements by doing a key lookup in the hashmap that acts as the deliverer plugin registry.  The deliverer name is the key in the hashmap for 
      * all registered deliverers.
      * @see MessageDelivererRegistryService#getDelivererByName(String)
      */
     public MessageDeliverer getDelivererByName(String messageDelivererName) {
         if (StringUtils.isBlank(messageDelivererName)) {
             throw new RiceIllegalArgumentException("messageDelivererName is null or blank");
         }
 
         Class<? extends MessageDeliverer> clazz = messageDelivererTypes.get(messageDelivererName.toLowerCase());
 
         if(clazz == null) {
             LOG.error("The message deliverer type ('" + messageDelivererName + "') " +
                       " was not found in the message deliverer registry.  This deliverer " +
                       "plugin is not in the system.");
             return null;
         }
 
         MessageDeliverer messageDeliverer = null;
         try {
             messageDeliverer = clazz.newInstance();
         } catch (InstantiationException e) {
             LOG.error(e.getStackTrace());
         } catch (IllegalAccessException e) {
             LOG.error(e.getStackTrace());
         }
 
         return messageDeliverer;
     }
 }