/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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 org.apache.chemistry.opencmis.server.impl.atompub;
  
  import static org.apache.chemistry.opencmis.server.impl.atompub.AtomPubUtils.RESOURCE_RELATIONSHIPS;
  import static org.apache.chemistry.opencmis.server.impl.atompub.AtomPubUtils.compileBaseUrl;
  import static org.apache.chemistry.opencmis.server.impl.atompub.AtomPubUtils.compileUrl;
  import static org.apache.chemistry.opencmis.server.impl.atompub.AtomPubUtils.compileUrlBuilder;
  import static org.apache.chemistry.opencmis.server.impl.atompub.AtomPubUtils.writeObjectEntry;
  import static org.apache.chemistry.opencmis.server.shared.HttpUtils.getBigIntegerParameter;
  import static org.apache.chemistry.opencmis.server.shared.HttpUtils.getBooleanParameter;
  import static org.apache.chemistry.opencmis.server.shared.HttpUtils.getEnumParameter;
  import static org.apache.chemistry.opencmis.server.shared.HttpUtils.getStringParameter;
  
  import java.math.BigInteger;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.chemistry.opencmis.commons.data.ObjectData;
  import org.apache.chemistry.opencmis.commons.data.ObjectList;
  import org.apache.chemistry.opencmis.commons.enums.RelationshipDirection;
  import org.apache.chemistry.opencmis.commons.exceptions.CmisRuntimeException;
  import org.apache.chemistry.opencmis.commons.impl.Constants;
  import org.apache.chemistry.opencmis.commons.impl.UrlBuilder;
  import org.apache.chemistry.opencmis.commons.server.CallContext;
  import org.apache.chemistry.opencmis.commons.server.CmisService;
  import org.apache.chemistry.opencmis.commons.server.ObjectInfo;
  
  /**
   * Relationship Service operations.
   */
  public class RelationshipService {
  
      private RelationshipService() {
      }
  
      /**
       * Get object relationships.
       */
      public static void getObjectRelationships(CallContext context, CmisService service, String repositoryId,
              HttpServletRequest request, HttpServletResponse response) throws Exception {
          // get parameters
          String objectId = getStringParameter(request, Constants.PARAM_ID);
          Boolean includeSubRelationshipTypes = getBooleanParameter(request, Constants.PARAM_SUB_RELATIONSHIP_TYPES);
          RelationshipDirection relationshipDirection = getEnumParameter(request, Constants.PARAM_RELATIONSHIP_DIRECTION,
                  RelationshipDirection.class);
          String typeId = getStringParameter(request, Constants.PARAM_TYPE_ID);
          String filter = getStringParameter(request, Constants.PARAM_FILTER);
          Boolean includeAllowableActions = getBooleanParameter(request, Constants.PARAM_ALLOWABLE_ACTIONS);
          BigInteger maxItems = getBigIntegerParameter(request, Constants.PARAM_MAX_ITEMS);
          BigInteger skipCount = getBigIntegerParameter(request, Constants.PARAM_SKIP_COUNT);
  
          // execute
          ObjectList relationships = service.getObjectRelationships(repositoryId, objectId, includeSubRelationshipTypes,
                  relationshipDirection, typeId, filter, includeAllowableActions, maxItems, skipCount, null);
  
          if (relationships == null) {
              throw new CmisRuntimeException("Relationships are null!");
          }
  
          ObjectInfo objectInfo = service.getObjectInfo(repositoryId, objectId);
          if (objectInfo == null) {
              throw new CmisRuntimeException("Object Info is missing!");
          }
  
          // set headers
          response.setStatus(HttpServletResponse.SC_OK);
          response.setContentType(Constants.MEDIATYPE_FEED);
  
          // write XML
          AtomFeed feed = new AtomFeed();
          feed.startDocument(response.getOutputStream());
          feed.startFeed(true);
  
          // write basic Atom feed elements
          feed.writeFeedElements(objectInfo.getId(), objectInfo.getCreatedBy(), objectInfo.getName(),
                  objectInfo.getLastModificationDate(), null, relationships.getNumItems());
  
          // write links
          UrlBuilder baseUrl = compileBaseUrl(request, repositoryId);
  
          feed.writeServiceLink(baseUrl.toString(), repositoryId);
 
         feed.writeSelfLink(compileUrl(baseUrl, RESOURCE_RELATIONSHIPS, objectInfo.getId()), null);
 
         UrlBuilder pagingUrl = new UrlBuilder(compileUrlBuilder(baseUrl, RESOURCE_RELATIONSHIPS, objectInfo.getId()));
         pagingUrl.addParameter(Constants.PARAM_SUB_RELATIONSHIP_TYPES, includeSubRelationshipTypes);
         pagingUrl.addParameter(Constants.PARAM_RELATIONSHIP_DIRECTION, relationshipDirection);
         pagingUrl.addParameter(Constants.PARAM_TYPE_ID, typeId);
         pagingUrl.addParameter(Constants.PARAM_FILTER, filter);
         pagingUrl.addParameter(Constants.PARAM_ALLOWABLE_ACTIONS, includeAllowableActions);
         feed.writePagingLinks(pagingUrl, maxItems, skipCount, relationships.getNumItems(),
                 relationships.hasMoreItems(), AtomPubUtils.PAGE_SIZE);
 
         // write entries
         AtomEntry entry = new AtomEntry(feed.getWriter());
         for (ObjectData object : relationships.getObjects()) {
             if (object == null) {
                 continue;
             }
             writeObjectEntry(service, entry, object, null, repositoryId, null, null, baseUrl, false);
         }
 
         // we are done
         feed.endFeed();
         feed.endDocument();
     }
 }