/*
    * 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 static org.apache.chemistry.opencmis.commons.impl.Converter.convert;
  
  import java.io.OutputStream;
  import java.util.ArrayList;
  import java.util.List;
  
  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.HttpUtils;
  import org.apache.chemistry.opencmis.commons.PropertyIds;
  import org.apache.chemistry.opencmis.commons.data.ExtensionsData;
  import org.apache.chemistry.opencmis.commons.data.ObjectData;
  import org.apache.chemistry.opencmis.commons.exceptions.CmisInvalidArgumentException;
  import org.apache.chemistry.opencmis.commons.impl.Constants;
  import org.apache.chemistry.opencmis.commons.impl.UrlBuilder;
  import org.apache.chemistry.opencmis.commons.impl.jaxb.CmisObjectType;
  import org.apache.chemistry.opencmis.commons.impl.jaxb.CmisProperty;
  import org.apache.chemistry.opencmis.commons.impl.jaxb.CmisPropertyId;
  import org.apache.chemistry.opencmis.commons.spi.PolicyService;
  
  /**
   * Policy Service AtomPub client.
   */
  public class PolicyServiceImpl extends AbstractAtomPubService implements PolicyService {
  
      /**
       * Constructor.
       */
      public PolicyServiceImpl(BindingSession session) {
          setSession(session);
      }
  
      public void applyPolicy(String repositoryId, String policyId, String objectId, ExtensionsData extension) {
          // find the link
          String link = loadLink(repositoryId, objectId, Constants.REL_POLICIES, Constants.MEDIATYPE_FEED);
  
          if (link == null) {
              throwLinkException(repositoryId, objectId, Constants.REL_POLICIES, Constants.MEDIATYPE_FEED);
          }
  
          UrlBuilder url = new UrlBuilder(link);
  
          // set up object and writer
          final AtomEntryWriter entryWriter = new AtomEntryWriter(createIdObject(objectId));
  
          // post applyPolicy request
          post(url, Constants.MEDIATYPE_ENTRY, new HttpUtils.Output() {
              public void write(OutputStream out) throws Exception {
                  entryWriter.write(out);
              }
          });
      }
  
      public List<ObjectData> getAppliedPolicies(String repositoryId, String objectId, String filter,
              ExtensionsData extension) {
          List<ObjectData> result = new ArrayList<ObjectData>();
  
          // find the link
          String link = loadLink(repositoryId, objectId, Constants.REL_POLICIES, Constants.MEDIATYPE_FEED);
  
          if (link == null) {
              throwLinkException(repositoryId, objectId, Constants.REL_POLICIES, Constants.MEDIATYPE_FEED);
          }
  
          UrlBuilder url = new UrlBuilder(link);
          url.addParameter(Constants.PARAM_FILTER, filter);
  
          // read and parse
          HttpUtils.Response resp = read(url);
          AtomFeed feed = parse(resp.getStream(), AtomFeed.class);
  
          // get the policies
          if (!feed.getEntries().isEmpty()) {
              for (AtomEntry entry : feed.getEntries()) {
                  ObjectData policy = null;
  
                 // walk through the entry
                 for (AtomElement element : entry.getElements()) {
                     if (element.getObject() instanceof CmisObjectType) {
                         policy = convert((CmisObjectType) element.getObject());
                     }
                 }
 
                 if (policy != null) {
                     result.add(policy);
                 }
             }
         }
 
         return result;
     }
 
     public void removePolicy(String repositoryId, String policyId, String objectId, ExtensionsData extension) {
         // we need a policy id
         if (policyId == null) {
             throw new CmisInvalidArgumentException("Policy id must be set!");
         }
 
         // find the link
         String link = loadLink(repositoryId, objectId, Constants.REL_POLICIES, Constants.MEDIATYPE_FEED);
 
         if (link == null) {
             throwLinkException(repositoryId, objectId, Constants.REL_POLICIES, Constants.MEDIATYPE_FEED);
         }
 
         UrlBuilder url = new UrlBuilder(link);
         url.addParameter(Constants.PARAM_FILTER, PropertyIds.OBJECT_ID);
 
         // read and parse
         HttpUtils.Response resp = read(url);
         AtomFeed feed = parse(resp.getStream(), AtomFeed.class);
 
         // find the policy
         String policyLink = null;
         boolean found = false;
 
         if (!feed.getEntries().isEmpty()) {
             for (AtomEntry entry : feed.getEntries()) {
                 // walk through the entry
                 for (AtomElement element : entry.getElements()) {
                     if (element.getObject() instanceof AtomLink) {
                         AtomLink atomLink = (AtomLink) element.getObject();
                         if (Constants.REL_SELF.equals(atomLink.getRel())) {
                             policyLink = atomLink.getHref();
                         }
                     } else if (element.getObject() instanceof CmisObjectType) {
                         String id = findIdProperty((CmisObjectType) element.getObject());
                         if (policyId.equals(id)) {
                             found = true;
                         }
                     }
                 }
 
                 if (found) {
                     break;
                 }
             }
         }
 
         // if found, delete it
         if (found && (policyLink != null)) {
             delete(new UrlBuilder(policyLink));
         }
     }
 
     /**
      * Finds the id property within a CMIS object.
      */
     private static String findIdProperty(CmisObjectType object) {
         if ((object == null) || (object.getProperties() == null)) {
             return null;
         }
 
         for (CmisProperty property : object.getProperties().getProperty()) {
             if (PropertyIds.OBJECT_ID.equals(property.getPropertyDefinitionId())
                     && (property instanceof CmisPropertyId)) {
                 List<String> values = ((CmisPropertyId) property).getValue();
                 if (values.size() == 1) {
                     return values.get(0);
                 }
             }
         }
 
         return null;
     }
 }