/**
    * Copyright 2014 Internet2
    *
    * Licensed under the Apache 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.apache.org/licenses/LICENSE-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 edu.internet2.middleware.grouper.scim;
  
  import edu.internet2.middleware.grouper.GroupFinder;
  import edu.internet2.middleware.grouper.GrouperSession;
  import edu.internet2.middleware.grouper.changeLog.ChangeLogConsumerBase;
  import edu.internet2.middleware.grouper.changeLog.ChangeLogEntry;
  import edu.internet2.middleware.grouper.changeLog.ChangeLogLabels;
  import edu.internet2.middleware.grouper.changeLog.ChangeLogProcessorMetadata;
  import edu.internet2.middleware.grouper.changeLog.ChangeLogType;
  import edu.internet2.middleware.grouper.util.GrouperUtil;
  import java.util.List;
  import org.apache.commons.lang.builder.ToStringBuilder;
  import org.apache.commons.lang.builder.ToStringStyle;
  import org.apache.commons.logging.Log;
  
  /**
   *
   * @author davel
   */
  public class ScimChangeLogConsumer extends ChangeLogConsumerBase {
  
  	protected static final Log log = GrouperUtil.getLog(ScimChangeLogConsumer.class);
  
  	private ScimEmitter scim;
  	private GrouperSession gs;
  	
  	/**
  	 * The change log consumer name from the processor metadata.
  	 */
  	private String name;
  
  	private void processGroupAdd(ScimChangeLogConsumer consumer, ChangeLogEntry changeLogEntry) {
  		scim.createGroup(GroupFinder.findByName(gs, changeLogEntry.retrieveValueForLabel(ChangeLogLabels.GROUP_ADD.name), true));
  	}
  
  	private void processGroupDelete(ScimChangeLogConsumer consumer, ChangeLogEntry changeLogEntry) {
  		scim.deleteGroup(GroupFinder.findByName(gs, changeLogEntry.retrieveValueForLabel(ChangeLogLabels.GROUP_DELETE.name), true));
  	}
  
  	private void processGroupUpdate(ScimChangeLogConsumer consumer, ChangeLogEntry changeLogEntry) {
  		scim.updateGroup(GroupFinder.findByName(gs,changeLogEntry.retrieveValueForLabel(ChangeLogLabels.GROUP_FIELD_UPDATE.name), true));
  	}
  
  	private void processMembershipAdd(ScimChangeLogConsumer consumer, ChangeLogEntry changeLogEntry) {
  		scim.updateGroup(GroupFinder.findByName(gs,changeLogEntry.retrieveValueForLabel(ChangeLogLabels.MEMBERSHIP_ADD.groupName), true));
  	}
  
  	private void processMembershipDelete(ScimChangeLogConsumer consumer, ChangeLogEntry changeLogEntry) {
  		scim.updateGroup(GroupFinder.findByName(gs,changeLogEntry.retrieveValueForLabel(ChangeLogLabels.MEMBERSHIP_DELETE.groupName), true));
  	}
  
  	/**
  	 * Maps change log entry category and action (change log type) to methods.
  	 */
  	enum ScimEventType {
  
  		/**
  		 * Process the add group change log entry type.
  		 */
  		group__addGroup {
  					public void process(ScimChangeLogConsumer consumer, ChangeLogEntry changeLogEntry) throws Exception {
  						consumer.processGroupAdd(consumer, changeLogEntry);
  					}
  				},
  		/**
  		 * Process the delete group change log entry type.
  		 */
  		group__deleteGroup {
  					public void process(ScimChangeLogConsumer consumer, ChangeLogEntry changeLogEntry) throws Exception {
  						consumer.processGroupDelete(consumer, changeLogEntry);
  					}
  				},
  		/**
  		 * Process the update group change log entry type.
  		 */
  		group__updateGroup {
  					public void process(ScimChangeLogConsumer consumer, ChangeLogEntry changeLogEntry) throws Exception {
  						consumer.processGroupUpdate(consumer, changeLogEntry);
  					}
  				},
  		/**
  		 * Process the add membership change log entry type.
  		 */
  		membership__addMembership {
 					public void process(ScimChangeLogConsumer consumer, ChangeLogEntry changeLogEntry) throws Exception {
 						consumer.processMembershipAdd(consumer, changeLogEntry);
 					}
 				},
 		/**
 		 * Process the delete membership change log entry type.
 		 */
 		membership__deleteMembership {
 					public void process(ScimChangeLogConsumer consumer, ChangeLogEntry changeLogEntry) throws Exception {
 						consumer.processMembershipDelete(consumer, changeLogEntry);
 					}
 				},
 		;
 		 /**
          * Process the change log entry.
          * 
          * @param consumer the scim change log consumer
          * @param changeLogEntry the change log entry
          * @throws Exception if any error occurs
          */
         public abstract void process(ScimChangeLogConsumer consumer, ChangeLogEntry changeLogEntry) throws Exception;
 
 	};
 
 	public ScimChangeLogConsumer() {
 		scim = new ScimEmitter();
 		gs = new GrouperSession();
 	}
 
 	@Override
 	public long processChangeLogEntries(List<ChangeLogEntry> changeLogEntryList, ChangeLogProcessorMetadata changeLogProcessorMetadata) {
 		long currentId = -1;
 
 		// initialize this consumer's name from the change log metadata
 		if (name == null) {
 			name = changeLogProcessorMetadata.getConsumerName();
 			log.trace("ScimChangeLog Consumer '" + name + "' - Setting name.");
 		}
 
 		for (ChangeLogEntry entry : changeLogEntryList) {
 			currentId = entry.getSequenceNumber();
 			// find the method to run via the enum
 			String enumKey = entry.getChangeLogType().getChangeLogCategory() + "__"
 					+ entry.getChangeLogType().getActionName();
 
 			ScimEventType scimEventType = ScimEventType.valueOf(enumKey);
 
 			if (scimEventType == null) {
 				log.debug("ScimChangeLog Consumer '" + name + "' - Change log entry '" + entry + "' Unsupported category and action.");
 			} else {
 				// process the change log event
 				log.info("ScimChangeLog Consumer '" + name + "' - Change log entry '" + toStringDeep(entry) + "'");
 				try{
 					scimEventType.process(this, entry);
 				}catch(Exception e){
 					log.warn("ScimChangeLog Consumer '"+ name +"' exception "+e.getMessage(),e);
 				}
 				log.info("ScimChangeLog Consumer '" + name + "' - Change log entry '" + entry + "'");
 			}
 
 		}
 		return currentId;
 	}
 
 	/**
 	 * Return a string representing an {ChangeLogEntry}.
 	 *
 	 * Returns all labels (attributes).
 	 *
 	 * Uses {
 	 *
 	 * @ToStringBuilder}.
 	 *
 	 * @param changeLogEntry the change log entry
 	 * @return the string representing the entire change log entry
 	 */
 	public static String toStringDeep(ChangeLogEntry changeLogEntry) {
 		ToStringBuilder toStringBuilder = new ToStringBuilder(changeLogEntry, ToStringStyle.SHORT_PREFIX_STYLE);
 		toStringBuilder.append("timestamp", changeLogEntry.getCreatedOn());
 		toStringBuilder.append("sequence", changeLogEntry.getSequenceNumber());
 		toStringBuilder.append("category", changeLogEntry.getChangeLogType().getChangeLogCategory());
 		toStringBuilder.append("actionname", changeLogEntry.getChangeLogType().getActionName());
 		toStringBuilder.append("contextId", changeLogEntry.getContextId());
 
 		ChangeLogType changeLogType = changeLogEntry.getChangeLogType();
 
 		for (String label : changeLogType.labels()) {
 			toStringBuilder.append(label, changeLogEntry.retrieveValueForLabel(label));
 		}
 
 		return toStringBuilder.toString();
 	}
 
 }