/*
 * 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 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 {

    /**
     * Get object relationships.
     */
    public static class GetObjectRelationships extends AbstractAtomPubServiceCall {
        public void serve(CallContext context, CmisService service, String repositoryId, HttpServletRequest request,
                HttpServletResponse response) throws Exception {
            assert context != null;
            assert service != null;
            assert repositoryId != null;
            assert request != null;
            assert response != null;

            // 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
            if (stopBeforeService(service)) {
                return;
            }

            ObjectList relationships = service.getObjectRelationships(repositoryId, objectId,
                    includeSubRelationshipTypes, relationshipDirection, typeId, filter, includeAllowableActions,
                    maxItems, skipCount, null);

            if (stopAfterService(service)) {
                return;
            }

            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(), getNamespaces(service));
            feed.startFeed(true);

            // write basic Atom feed elements
            feed.writeFeedElements(objectInfo.getId(), objectInfo.getAtomId(), objectInfo.getCreatedBy(),
                    objectInfo.getName(), objectInfo.getLastModificationDate(), null, relationships.getNumItems());

            // write links
            UrlBuilder baseUrl = compileBaseUrl(request, repositoryId);

            feed.writeServiceLink(baseUrl.toString(), repositoryId);

            UrlBuilder selfLink = compileUrlBuilder(baseUrl, RESOURCE_RELATIONSHIPS, objectInfo.getId());
            selfLink.addParameter(Constants.PARAM_SUB_RELATIONSHIP_TYPES, includeSubRelationshipTypes);
            selfLink.addParameter(Constants.PARAM_RELATIONSHIP_DIRECTION, relationshipDirection);
            selfLink.addParameter(Constants.PARAM_TYPE_ID, typeId);
            selfLink.addParameter(Constants.PARAM_FILTER, filter);
            selfLink.addParameter(Constants.PARAM_ALLOWABLE_ACTIONS, includeAllowableActions);
            selfLink.addParameter(Constants.PARAM_MAX_ITEMS, maxItems);
            selfLink.addParameter(Constants.PARAM_SKIP_COUNT, skipCount);
            feed.writeSelfLink(selfLink.toString(), 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(), 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,
                        context.getCmisVersion());
            }

            // write extensions
            feed.writeExtensions(relationships);

            // we are done
            feed.endFeed();
            feed.endDocument();
        }
    }
}