trunk/src/modules/lenyadoc/java/src/org/apache/lenya/cms/cocoon/source/LenyaDocSourceFactory.java

/*
 * 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.lenya.cms.cocoon.source;

import java.io.IOException;
import java.net.MalformedURLException;
import java.util.Map;

import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.context.Context;
import org.apache.avalon.framework.context.ContextException;
import org.apache.avalon.framework.context.Contextualizable;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.Serviceable;
import org.apache.avalon.framework.thread.ThreadSafe;
import org.apache.cocoon.components.ContextHelper;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Request;
import org.apache.excalibur.source.Source;
import org.apache.excalibur.source.SourceException;
import org.apache.excalibur.source.SourceFactory;
import org.apache.lenya.cms.publication.Document;
import org.apache.lenya.cms.publication.DocumentBuildException;
import org.apache.lenya.cms.publication.DocumentFactory;
import org.apache.lenya.cms.publication.DocumentUtil;
import org.apache.lenya.cms.publication.Publication;
import org.apache.lenya.cms.publication.PublicationException;
import org.apache.lenya.cms.publication.PublicationUtil;
import org.apache.lenya.cms.publication.URLInformation;
import org.apache.lenya.cms.repository.RepositoryException;
import org.apache.lenya.cms.repository.RepositoryUtil;
import org.apache.lenya.cms.repository.Session;
import org.apache.lenya.util.ServletHelper;

/**
 * A factory for the "lenyadoc" scheme (virtual protocol), which is used to resolve any
 * src="lenyadoc:<...>" attributes in sitemaps.
 * 
 * <code>lenyadoc://<publication>/<area>/<language>/<uuid></code>
 * <code>lenyadoc:/<language>/<uuid></code>
 * 
 * If we want to request the meta data for a document
 * instead of the document itself, we need to use
 * 
 * <code>lenyadoc:meta:/<language>/<uuid></code>
 * <code>lenyadoc:meta://<publication>/<area>/<language>/<uuid></code>
 * 
 * @version $Id:$
 */
public class LenyaDocSourceFactory extends AbstractLogEnabled implements SourceFactory, ThreadSafe,
        Contextualizable, Serviceable, Configurable {

    protected static final String SCHEME = "lenyadoc";

    private Context context;
    private ServiceManager manager;

    /**
     * Used for resolving the object model.
     * @see org.apache.avalon.framework.context.Contextualizable#contextualize(org.apache.avalon.framework.context.Context)
     */
    public void contextualize(Context context) throws ContextException {
        this.context = context;
    }

    /**
     * @see org.apache.avalon.framework.service.Serviceable#service(org.apache.avalon.framework.service.ServiceManager)
     */
    public void service(ServiceManager manager) throws ServiceException {
        this.manager = manager;
    }

    /**
     * @see org.apache.avalon.framework.configuration.Configurable#configure(org.apache.avalon.framework.configuration.Configuration)
     */
    public void configure(Configuration configuration) throws ConfigurationException {
    }

    /**
     * @see org.apache.excalibur.source.SourceFactory#getSource(java.lang.String, java.util.Map)
     */
    public Source getSource(String location, Map parameters) throws MalformedURLException,
            IOException, SourceException {
        String scheme = null;
        String area = null;
        String language = null;
        String uuid = null;
        Publication pub;

        // Parse the url
        int start = 0;
        int end;

        // Scheme
        end = location.indexOf(':', start);
        if (end == -1) {
            throw new MalformedURLException("Malformed lenyadoc: URI: can not find scheme part ["
                    + location + "]");
        }
        scheme = location.substring(start, end);
        if (!SCHEME.equals(scheme)) {
            throw new MalformedURLException("Malformed lenyadoc: URI: unknown scheme [" + location
                    + "]");
        }

        Map objectModel = ContextHelper.getObjectModel(this.context);
        Request request = ObjectModelHelper.getRequest(objectModel);
        DocumentFactory factory = DocumentUtil.getDocumentFactory(this.manager, request);

        start = end + 1;
        
        // Absolute vs. relative
        if (location.startsWith("//", start)) {
            // Absolute: get publication id
            start += 2;
            end = location.indexOf('/', start);
            if (end == -1) {
                throw new MalformedURLException("Malformed lenyadoc: URI: publication part not found ["
                        + location + "]");
            }
            String publicationId = location.substring(start, end);
            try {
                pub = factory.getPublication(publicationId);
            } catch (PublicationException e) {
                throw new MalformedURLException("Malformed lenyadoc: Publication [" + publicationId
                        + "] does not exist or could not be initialized");
            }
            if (pub == null || !pub.exists()) {
                throw new SourceException("The publication [" + publicationId + "] does not exist!");
            }

            // Area
            start = end + 1;
            end = location.indexOf('/', start);
            if (end == -1) {
                throw new MalformedURLException("Malformed lenyadoc: URI: cannot find area ["
                        + location + "]");
            }
            area = location.substring(start, end);

        } else if (location.startsWith("/", start)) {
            end += 1;
            // Relative: get publication id and area from page envelope
            try {
                pub = PublicationUtil.getPublication(this.manager, objectModel);
            } catch (PublicationException e) {
                throw new SourceException("Error getting publication id / area from page envelope ["
                        + location + "]");
            }
            if (pub != null && pub.exists()) {
                String url = ServletHelper.getWebappURI(request);
                area = new URLInformation(url).getArea();
            } else {
                throw new SourceException("Error getting publication id / area from page envelope ["
                        + location + "]");
            }
        } else {
            throw new MalformedURLException("Malformed lenyadoc: URI [" + location + "]");
        }

        // Language
        start = end + 1;
        end = location.indexOf('/', start);
        if (end == -1) {
            throw new MalformedURLException("Malformed lenyadoc: URI: cannot find language ["
                    + location + "]");
        }
        language = location.substring(start, end);

        // UUID
        start = end + 1;
        uuid = location.substring(start);

        Session session;
        try {
            session = RepositoryUtil.getSession(this.manager, request);
        } catch (RepositoryException e1) {
            throw new RuntimeException(e1);
        }

        if (getLogger().isDebugEnabled()) {
            getLogger().debug("Creating repository source for URI [" + location + "]");
        }
        Document document;
        try {
            document = factory.get(pub, area, uuid, language);
        } catch (DocumentBuildException e) {
            throw new MalformedURLException("Malformed lenyadoc: Document [" + uuid + ":"
                    + language + "] could not be created.");
        }

        String lenyaURL = document.getSourceURI();

        if (getLogger().isDebugEnabled()) {
            getLogger().debug("Mapping 'lenyadoc:' URL [" + location + "] to 'lenya:' URL ["
                    + lenyaURL + "]");
            getLogger().debug("Creating repository source for URI [" + lenyaURL + "]");
        }

        return new RepositorySource(manager, lenyaURL, session, getLogger());
    }

    /**
     * @see org.apache.excalibur.source.SourceFactory#release(org.apache.excalibur.source.Source)
     */
    public void release(Source source) {
        // Source will be released by delegated source factory.
    }
}