/* $Id: URLModelLoader.java 18282 2010-04-18 08:50:37Z tfmorris $
 *****************************************************************************
 * Copyright (c) 2009 Contributors - see below
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    tfmorris
 *****************************************************************************
 *
 * Some portions of this file was previously release using the BSD License:
 */

// Copyright (c) 2007-2008 The Regents of the University of California. All
// Rights Reserved. Permission to use, copy, modify, and distribute this
// software and its documentation without fee, and without a written
// agreement is hereby granted, provided that the above copyright notice
// and this paragraph appear in all copies. This software program and
// documentation are copyrighted by The Regents of the University of
// California. The software program and documentation are supplied "AS
// IS", without any accompanying services from The Regents. The Regents
// does not warrant that the operation of the program will be
// uninterrupted or error-free. The end-user understands that the program
// was developed for research purposes and is advised not to rely
// exclusively on the program for any reason. IN NO EVENT SHALL THE
// UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
// SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,
// ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
// THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY
// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
// PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
// CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,
// UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

package org.argouml.profile;

import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Collection;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

import org.argouml.model.Model;
import org.argouml.model.UmlException;
import org.argouml.model.XmiReader;
import org.xml.sax.InputSource;

/**
 * Abstract ProfileModelLoader which loads models from a URL.
 *
 * @author Tom Morris, Thomas Neustupny
 */
public class URLModelLoader implements ProfileModelLoader {

    /**
     * Load a profile from a URL.  If a profile with the same public ID has 
     * already been loaded, its contents are returned instead of loading the
     * new profile.
     * 
     * @param url the url/system id to load
     * @param publicId the publicId for which the model will be known - must be
     *                equal in different machines in order to be possible to
     *                load the model.  If a profile with this public ID has 
     *                already been loaded, it is returned instead.
     * @return a collection of top level elements in the profile (usually a
     *         single package stereotyped <<profile>>
     * @throws ProfileException if the XMIReader couldn't read the profile
     */
    public Collection loadModel(URL url, URL publicId) 
        throws ProfileException {
        if (url == null) {
            throw new ProfileException("Null profile URL");
        }
        
        Collection elements = 
            Model.getUmlFactory().getExtentPackages(publicId.toExternalForm());
        if (elements == null) {
            ZipInputStream zis = null;
            try {
                XmiReader xmiReader = Model.getXmiReader();
                if (url.getPath().toLowerCase().endsWith(".zip")) {
                    zis = new ZipInputStream(url.openStream());
                    ZipEntry entry = zis.getNextEntry();
                    // TODO: check if it's OK to just get the first zip entry
                    // since the zip file should contain only one xmi file - thn
                    if (entry != null) {
                        url = makeZipEntryUrl(url, entry.getName());
                    }
                    zis.close();
                }
                InputSource inputSource = new InputSource(url.toExternalForm());
                inputSource.setPublicId(publicId.toString());
                elements = xmiReader.parse(inputSource, true);
            } catch (UmlException e) {
                throw new ProfileException("Error loading profile XMI file ", e);
            } catch (IOException e) {
                throw new ProfileException("I/O error loading profile XMI ", e);
            }
        }
        return elements;
    }

    /**
     * Load a profile from a ProfileReference.
     * 
     * @param reference ProfileReference for desired profile
     * @return a collection of top level elements in the profile (usually a
     *         single package stereotyped <<profile>>
     * @throws ProfileException if the XMIReader couldn't read the profile
     */
    public Collection loadModel(final ProfileReference reference)
        throws ProfileException {
        return loadModel(reference.getPublicReference(), reference
                .getPublicReference());
    }

    private URL makeZipEntryUrl(URL url, String entryName)
        throws MalformedURLException {
        String entryURL = "jar:" + url + "!/" + entryName;
        return new URL(entryURL);
    }
}