/*
 * 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.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.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.RelationshipDirection;
import org.apache.chemistry.opencmis.commons.impl.Constants;
import org.apache.chemistry.opencmis.commons.impl.UrlBuilder;
import org.apache.chemistry.opencmis.commons.impl.dataobjects.ObjectListImpl;
import org.apache.chemistry.opencmis.commons.spi.RelationshipService;

/**
 * Relationship Service AtomPub client.
 */
public class RelationshipServiceImpl extends AbstractAtomPubService implements RelationshipService {

    /**
     * Constructor.
     */
    public RelationshipServiceImpl(BindingSession session) {
        setSession(session);
    }

    @Override
    public ObjectList getObjectRelationships(String repositoryId, String objectId, Boolean includeSubRelationshipTypes,
            RelationshipDirection relationshipDirection, String typeId, String filter, Boolean includeAllowableActions,
            BigInteger maxItems, BigInteger skipCount, ExtensionsData extension) {
        ObjectListImpl result = new ObjectListImpl();

        // find the link
        String link = loadLink(repositoryId, objectId, Constants.REL_RELATIONSHIPS, Constants.MEDIATYPE_FEED);

        if (link == null) {
            throwLinkException(repositoryId, objectId, Constants.REL_RELATIONSHIPS, Constants.MEDIATYPE_FEED);
        }

        UrlBuilder url = new UrlBuilder(link);
        url.addParameter(Constants.PARAM_SUB_RELATIONSHIP_TYPES, includeSubRelationshipTypes);
        url.addParameter(Constants.PARAM_RELATIONSHIP_DIRECTION, relationshipDirection);
        url.addParameter(Constants.PARAM_TYPE_ID, typeId);
        url.addParameter(Constants.PARAM_FILTER, filter);
        url.addParameter(Constants.PARAM_ALLOWABLE_ACTIONS, includeAllowableActions);
        url.addParameter(Constants.PARAM_MAX_ITEMS, maxItems);
        url.addParameter(Constants.PARAM_SKIP_COUNT, skipCount);

        // read and parse
        Response resp = read(url);
        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 children
        if (!feed.getEntries().isEmpty()) {
            result.setObjects(new ArrayList<ObjectData>(feed.getEntries().size()));

            for (AtomEntry entry : feed.getEntries()) {
                ObjectData relationship = null;

                lockLinks();
                try {
                    // clean up cache
                    removeLinks(repositoryId, entry.getId());

                    // walk through the entry
                    for (AtomElement element : entry.getElements()) {
                        if (element.getObject() instanceof AtomLink) {
                            addLink(repositoryId, entry.getId(), (AtomLink) element.getObject());
                        } else if (element.getObject() instanceof ObjectData) {
                            relationship = (ObjectData) element.getObject();
                        }
                    }
                } finally {
                    unlockLinks();
                }

                if (relationship != null) {
                    result.getObjects().add(relationship);
                }
            }

        }

        return result;
    }
}