/*
* 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.jclouds.openstack.v2_0.domain;
import com.google.common.base.Optional;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Multimap;
import org.jclouds.collect.IterableWithMarker;
import org.jclouds.javax.annotation.Nullable;
import org.jclouds.openstack.v2_0.options.PaginationOptions;
import java.util.Iterator;
import static org.jclouds.http.utils.Queries.queryParser;
/**
* Base class for a paginated collection in OpenStack.
*
* @see <a
* href="http://docs.openstack.org/api/openstack-identity-service/2.0/content/Paginated_Collections-d1e325.html">
* docs</a>
*/
public class PaginatedCollection<T> extends IterableWithMarker<T> {
private final Iterable<T> resources;
private final Iterable<Link> links;
private final Integer totalEntries;
protected PaginatedCollection(@Nullable Iterable<T> resources, @Nullable Iterable<Link> links,
@Nullable Integer totalEntries) {
this.resources = resources != null ? resources : ImmutableSet.<T> of();
this.links = links != null ? links : ImmutableSet.<Link> of();
this.totalEntries = totalEntries;
}
protected PaginatedCollection(Iterable<T> resources, Iterable<Link> links) {
this(resources, links, null);
}
@Override
public Iterator<T> iterator() {
return resources.iterator();
}
/**
* links that relate to this collection
*/
public Iterable<Link> getLinks() {
return links;
}
/**
* @return The total number of entries in this collection, if that information is present.
*/
public Optional<Integer> getTotalEntries() {
return Optional.fromNullable(totalEntries);
}
public PaginationOptions nextPaginationOptions() {
return PaginationOptions.class.cast(nextMarker().get());
}
@Override
public Optional<Object> nextMarker() {
for (Link link : getLinks()) {
if (Link.Relation.NEXT == link.getRelation()) {
return Optional.of(toPaginationOptions(link));
}
}
return Optional.absent();
}
private Object toPaginationOptions(Link link) {
Multimap<String, String> queryParams = queryParser().apply(link.getHref().getRawQuery());
PaginationOptions paginationOptions = PaginationOptions.Builder.queryParameters(queryParams);
return paginationOptions;
}
}