CollectionListManagerImpl.java

/**
 * Copyright 2008 The University of North Carolina at Chapel Hill
 *
 * Licensed 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 edu.unc.lib.dl.cdr.sword.server.managers;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.apache.abdera.Abdera;
import org.apache.abdera.i18n.iri.IRI;
import org.apache.abdera.model.Entry;
import org.apache.abdera.model.Feed;
import org.swordapp.server.AuthCredentials;
import org.swordapp.server.CollectionListManager;
import org.swordapp.server.SwordAuthException;
import org.swordapp.server.SwordConfiguration;
import org.swordapp.server.SwordError;
import org.swordapp.server.SwordServerException;

import edu.unc.lib.dl.acl.util.Permission;
import edu.unc.lib.dl.cdr.sword.server.SwordConfigurationImpl;
import edu.unc.lib.dl.fedora.PID;
import edu.unc.lib.dl.util.ErrorURIRegistry;

/**
 * 
 * @author bbpennel
 * 
 */
public class CollectionListManagerImpl extends AbstractFedoraManager implements CollectionListManager {

	private static final Abdera abdera = new Abdera();
	private int pageSize = 10;

	@Override
	public Feed listCollectionContents(IRI collectionIRI, AuthCredentials auth, SwordConfiguration config)
			throws SwordServerException, SwordAuthException, SwordError {

		SwordConfigurationImpl configImpl = (SwordConfigurationImpl) config;

		PID containerPID = null;

		String query = collectionIRI.getPath();
		// Remove path prefixing from url
		int index = query.indexOf(SwordConfigurationImpl.COLLECTION_PATH + "/");
		if (index == -1)
			throw new SwordServerException("No collection path was found for IRI " + collectionIRI);
		query = query.substring(index + SwordConfigurationImpl.COLLECTION_PATH.length() + 1);

		// Extract the PID
		String pidString = null;
		int startPage = 0;
		index = query.indexOf("/");
		if (index > 0) {
			pidString = query.substring(0, index);
			try {
				startPage = Integer.parseInt(query.substring(index + 1));
				if (startPage < 0)
					startPage = 0;
			} catch (NumberFormatException e) {
				throw new SwordError(ErrorURIRegistry.RETRIEVAL_EXCEPTION, 404, "Collection content page number was not valid.");
			}
		} else {
			pidString = query;
		}

		if (pidString == null || "".equals(pidString.trim())) {
			containerPID = this.collectionsPidObject;
		} else {
			containerPID = new PID(pidString);
		}

		// Verify access control
		if (!hasAccess(auth, containerPID, Permission.viewDescription, configImpl)) {
			throw new SwordError(ErrorURIRegistry.INSUFFICIENT_PRIVILEGES, 403,
					"Insufficient privileges to view the collection list for " + containerPID.getPid());
		}

		Feed feed = abdera.getFactory().newFeed();
		feed.setId(containerPID.getPid());
		// add in the next page link
		feed.addLink(configImpl.getSwordPath() + SwordConfigurationImpl.COLLECTION_PATH + "/" + containerPID.getPid()
				+ "/" + (startPage + 1), "next");

		try {
			this.getImmediateChildren(containerPID, startPage, feed, auth, configImpl);
		} catch (IOException e) {
			throw new SwordError(ErrorURIRegistry.RETRIEVAL_EXCEPTION, 500, "Failed to retrieve children for "
					+ containerPID.getPid(), e);
		}

		return feed;
	}

	protected List<Entry> getImmediateChildren(PID pid, int startPage, Feed feed, AuthCredentials auth,
			SwordConfigurationImpl config) throws IOException {
		String query = this.readFileAsString("immediateChildrenPaged.sparql");
		query = String.format(query, tripleStoreQueryService.getResourceIndexModelUri(), pid.getURI(), pageSize,
				startPage * pageSize);
		List<Entry> result = new ArrayList<Entry>();
		@SuppressWarnings({ "rawtypes", "unchecked" })
		List<Map> bindings = (List<Map>) ((Map) tripleStoreQueryService.sendSPARQL(query).get("results")).get("bindings");
		for (Map<?, ?> binding : bindings) {
			PID childPID = new PID((String) ((Map<?, ?>) binding.get("pid")).get("value"));
			String slug = (String) ((Map<?, ?>) binding.get("slug")).get("value");

			if (hasAccess(auth, childPID, Permission.viewDescription, config)) {
				Entry entry = feed.addEntry();
				entry.addLink(config.getSwordPath() + SwordConfigurationImpl.EDIT_MEDIA_PATH + "/" + childPID.getPid()
						+ ".atom", "edit");
				entry.addLink(config.getSwordPath() + SwordConfigurationImpl.EDIT_MEDIA_PATH + "/" + childPID.getPid(),
						"edit-media");
				entry.setId(childPID.getURI());
				entry.setTitle(slug);

				result.add(entry);
			}
		}
		return result;
	}

	public int getPageSize() {
		return pageSize;
	}

	public void setPageSize(int pageSize) {
		this.pageSize = pageSize;
	}
}