/*
 *  eXist Open Source Native XML Database
 *  Copyright (C) 2001-04 The eXist Project
 *  http://exist-db.org
 *  
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *  
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 *  
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *  
 *  $Id$
 */
package org.exist.storage;

import org.exist.EXistException;
import org.exist.collections.IndexInfo;
import org.exist.dom.persistent.DefaultDocumentSet;
import org.exist.dom.persistent.DocumentImpl;
import org.exist.dom.persistent.MutableDocumentSet;
import org.exist.security.PermissionDeniedException;
import org.exist.storage.lock.Lock.LockMode;
import org.exist.storage.serializers.Serializer;
import org.exist.storage.txn.TransactionManager;
import org.exist.storage.txn.Txn;
import org.exist.test.TestConstants;
import org.exist.util.DatabaseConfigurationException;
import org.exist.util.LockException;
import org.exist.xmldb.XmldbURI;
import org.exist.xquery.XPathException;
import org.exist.xupdate.Modification;
import org.exist.xupdate.XUpdateProcessor;
import org.xml.sax.InputSource;
import org.junit.Test;
import org.xml.sax.SAXException;

import javax.xml.parsers.ParserConfigurationException;

import static org.junit.Assert.assertNotNull;

import java.io.IOException;
import java.io.StringReader;
import java.util.Optional;

public class RemoveTest extends AbstractUpdateTest {
    
    @Test
    public void update() throws EXistException, DatabaseConfigurationException, LockException, SAXException, PermissionDeniedException, IOException, ParserConfigurationException, XPathException {
        BrokerPool.FORCE_CORRUPTION = true;
        final BrokerPool pool = startDb();
        final TransactionManager mgr = pool.getTransactionManager();

        try(final DBBroker broker = pool.get(Optional.of(pool.getSecurityManager().getSystemSubject()))) {
            final IndexInfo info = init(broker, mgr);
            assertNotNull(info);
            final MutableDocumentSet docs = new DefaultDocumentSet();
            docs.add(info.getDocument());
            final XUpdateProcessor proc = new XUpdateProcessor(broker, docs);
            assertNotNull(proc);
            
            try(final Txn transaction = mgr.beginTransaction()) {

                // append some new element to records
                for (int i = 1; i <= 50; i++) {
                    final String xupdate =
                            "<xu:modifications version=\"1.0\" xmlns:xu=\"http://www.xmldb.org/xupdate\">" +
                                    "   <xu:append select=\"/products\">" +
                                    "       <product>" +
                                    "           <xu:attribute name=\"id\"><xu:value-of select=\"count(/products/product) + 1\"/></xu:attribute>" +
                                    "           <description>Product " + i + "</description>" +
                                    "           <price>" + (i * 2.5) + "</price>" +
                                    "           <stock>" + (i * 10) + "</stock>" +
                                    "       </product>" +
                                    "   </xu:append>" +
                                    "</xu:modifications>";
                    proc.setBroker(broker);
                    proc.setDocumentSet(docs);
                    final Modification modifications[] = proc.parse(new InputSource(new StringReader(xupdate)));
                    assertNotNull(modifications);
                    modifications[0].process(transaction);
                    proc.reset();
                }

                mgr.commit(transaction);
            }
            
            final Serializer serializer = broker.getSerializer();
            serializer.reset();
            
            DocumentImpl doc = null;
            try {
                doc = broker.getXMLResource(TestConstants.TEST_COLLECTION_URI2.append(TestConstants.TEST_XML_URI), LockMode.READ_LOCK);
                assertNotNull("Document '" + XmldbURI.ROOT_COLLECTION + "/test/test2/test.xml' should not be null", doc);
                final String data = serializer.serialize(doc);
            } finally {
                if(doc != null) {
                    doc.getUpdateLock().release(LockMode.READ_LOCK);
                }
            }
            
            // the following transaction will not be committed and thus undone during recovery
            final Txn transaction = mgr.beginTransaction();

            // remove elements
            for (int i = 1; i <= 25; i++) {
                final String xupdate =
                    "<xu:modifications version=\"1.0\" xmlns:xu=\"http://www.xmldb.org/xupdate\">" +
                    "   <xu:remove select=\"/products/product[last()]\"/>" +
                    "</xu:modifications>";
                proc.setBroker(broker);
                proc.setDocumentSet(docs);
                final Modification modifications[] = proc.parse(new InputSource(new StringReader(xupdate)));
                assertNotNull(modifications);
                modifications[0].process(transaction);
                proc.reset();
            }
            
//DO NOT COMMIT TRANSACTION
            pool.getJournalManager().get().flush(true, false);
	    }
    }
}