content: /*
   * 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.client.bindings.spi.atompub;
  
  import java.io.OutputStream;
  import java.math.BigInteger;
  import java.util.ArrayList;
  
  import org.apache.chemistry.opencmis.client.bindings.spi.BindingSession;
  import org.apache.chemistry.opencmis.client.bindings.spi.atompub.objects.AtomElement;
  import org.apache.chemistry.opencmis.client.bindings.spi.atompub.objects.AtomEntry;
  import org.apache.chemistry.opencmis.client.bindings.spi.atompub.objects.AtomFeed;
  import org.apache.chemistry.opencmis.client.bindings.spi.atompub.objects.AtomLink;
  import org.apache.chemistry.opencmis.client.bindings.spi.http.Output;
  import org.apache.chemistry.opencmis.client.bindings.spi.http.Response;
  import org.apache.chemistry.opencmis.commons.data.ExtensionsData;
  import org.apache.chemistry.opencmis.commons.data.ObjectData;
  import org.apache.chemistry.opencmis.commons.data.ObjectList;
  import org.apache.chemistry.opencmis.commons.enums.CmisVersion;
  import org.apache.chemistry.opencmis.commons.enums.IncludeRelationships;
  import org.apache.chemistry.opencmis.commons.exceptions.CmisObjectNotFoundException;
  import org.apache.chemistry.opencmis.commons.impl.Constants;
  import org.apache.chemistry.opencmis.commons.impl.UrlBuilder;
  import org.apache.chemistry.opencmis.commons.impl.XMLConverter;
  import org.apache.chemistry.opencmis.commons.impl.XMLUtils;
  import org.apache.chemistry.opencmis.commons.impl.dataobjects.ObjectListImpl;
  import org.apache.chemistry.opencmis.commons.impl.dataobjects.QueryTypeImpl;
  import org.apache.chemistry.opencmis.commons.spi.DiscoveryService;
  import org.apache.chemistry.opencmis.commons.spi.ExtendedHolder;
  import org.apache.chemistry.opencmis.commons.spi.Holder;
  import org.xmlpull.v1.XmlSerializer;
  
  /**
   * Discovery Service AtomPub client.
   */
  public class DiscoveryServiceImpl extends AbstractAtomPubService implements DiscoveryService {
  
      /**
       * Constructor.
       */
      public DiscoveryServiceImpl(BindingSession session) {
          setSession(session);
      }
  
      @Override
      public ObjectList getContentChanges(String repositoryId, Holder<String> changeLogToken, Boolean includeProperties,
              String filter, Boolean includePolicyIds, Boolean includeACL, BigInteger maxItems, ExtensionsData extension) {
          ObjectListImpl result = new ObjectListImpl();
  
          // find the link
          String link = null;
          UrlBuilder url = null;
  
          // if the application doesn't know the change log token but the link to
          // the next Atom feed
          if (changeLogToken instanceof ExtendedHolder && changeLogToken.getValue() == null) {
              link = (String) ((ExtendedHolder<String>) changeLogToken).getExtraValue(Constants.REP_REL_CHANGES);
              if (link != null) {
                  url = new UrlBuilder(link);
              }
          }
  
          // if the application didn't provide a link to next Atom feed
          if (link == null) {
              link = loadRepositoryLink(repositoryId, Constants.REP_REL_CHANGES);
              if (link != null) {
                  url = new UrlBuilder(link);
                  url.addParameter(Constants.PARAM_CHANGE_LOG_TOKEN,
                          (changeLogToken == null ? null : changeLogToken.getValue()));
                  url.addParameter(Constants.PARAM_PROPERTIES, includeProperties);
                  url.addParameter(Constants.PARAM_FILTER, filter);
                  url.addParameter(Constants.PARAM_POLICY_IDS, includePolicyIds);
                  url.addParameter(Constants.PARAM_ACL, includeACL);
                  url.addParameter(Constants.PARAM_MAX_ITEMS, maxItems);
              }
          }
  
          if (link == null) {
              throw new CmisObjectNotFoundException("Unknown repository or content changes not supported!");
          }
  
          // read and parse
          Response resp = read(url);
          AtomFeed feed = parse(resp.getStream(), AtomFeed.class);
          String lastChangeLogToken = null;
  
          // handle top level
          String nextLink = null;
          for (AtomElement element : feed.getElements()) {
              if (element.getObject() instanceof AtomLink) {
                  if (isNextLink(element)) {
                      result.setHasMoreItems(Boolean.TRUE);
                      nextLink = ((AtomLink) element.getObject()).getHref();
                  }
              } else if (isInt(NAME_NUM_ITEMS, element)) {
                  result.setNumItems((BigInteger) element.getObject());
              } else if (isStr("changeLogToken", element)) {
                  lastChangeLogToken = (String) element.getObject();
              }
          }
  
          // get the changes
          if (!feed.getEntries().isEmpty()) {
              result.setObjects(new ArrayList<ObjectData>(feed.getEntries().size()));
  
              for (AtomEntry entry : feed.getEntries()) {
                  ObjectData hit = null;
  
                  // walk through the entry
                  for (AtomElement element : entry.getElements()) {
                      if (element.getObject() instanceof ObjectData) {
                          hit = (ObjectData) element.getObject();
                      }
                  }
  
                  if (hit != null) {
                      result.getObjects().add(hit);
                  }
              }
          }
  
          if (changeLogToken != null) {
              // the AtomPub binding cannot return a new change log token,
              // but an OpenCMIS server uses a proprietary tag
              changeLogToken.setValue(lastChangeLogToken);
  
              // but we can provide the link to the next Atom feed
              if (changeLogToken instanceof ExtendedHolder && nextLink != null) {
                  ((ExtendedHolder<String>) changeLogToken).setExtraValue(Constants.REP_REL_CHANGES, nextLink);
              }
          }
  
          return result;
      }
  
      @Override
      public ObjectList query(String repositoryId, String statement, Boolean searchAllVersions,
              Boolean includeAllowableActions, IncludeRelationships includeRelationships, String renditionFilter,
              BigInteger maxItems, BigInteger skipCount, ExtensionsData extension) {
          ObjectListImpl result = new ObjectListImpl();
  
          // find the link
          String link = loadCollection(repositoryId, Constants.COLLECTION_QUERY);
  
          if (link == null) {
              throw new CmisObjectNotFoundException("Unknown repository or query not supported!");
          }
  
          UrlBuilder url = new UrlBuilder(link);
  
          // compile query request
          final QueryTypeImpl query = new QueryTypeImpl();
          query.setStatement(statement);
          query.setSearchAllVersions(searchAllVersions);
          query.setIncludeAllowableActions(includeAllowableActions);
          query.setIncludeRelationships(includeRelationships);
          query.setRenditionFilter(renditionFilter);
          query.setMaxItems(maxItems);
          query.setSkipCount(skipCount);
  
          final CmisVersion cmisVersion = getCmisVersion(repositoryId);
  
          // post the query and parse results
          Response resp = post(url, Constants.MEDIATYPE_QUERY, new Output() {
              @Override
              public void write(OutputStream out) throws Exception {
                  XmlSerializer writer = XMLUtils.createWriter(out);
                  XMLUtils.startXmlDocument(writer);
                  XMLConverter.writeQuery(writer, cmisVersion, query);
                  XMLUtils.endXmlDocument(writer);
              }
          });
          AtomFeed feed = parse(resp.getStream(), AtomFeed.class);
  
          // handle top level
          for (AtomElement element : feed.getElements()) {
              if (element.getObject() instanceof AtomLink) {
                  if (isNextLink(element)) {
                      result.setHasMoreItems(Boolean.TRUE);
                  }
              } else if (isInt(NAME_NUM_ITEMS, element)) {
                  result.setNumItems((BigInteger) element.getObject());
              }
          }
  
          // get the result set
          if (!feed.getEntries().isEmpty()) {
              result.setObjects(new ArrayList<ObjectData>(feed.getEntries().size()));
  
              for (AtomEntry entry : feed.getEntries()) {
                  ObjectData hit = null;
  
                  // walk through the entry
                  for (AtomElement element : entry.getElements()) {
                      if (element.getObject() instanceof ObjectData) {
                          hit = (ObjectData) element.getObject();
                      }
                  }
  
                  if (hit != null) {
                      result.getObjects().add(hit);
                  }
              }
          }
  
          return result;
      }
  }
  