/*
 * 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.jackrabbit.core.fs.db;

import org.apache.jackrabbit.core.fs.FileSystemException;
import org.apache.jackrabbit.core.util.db.ConnectionHelper;
import org.apache.jackrabbit.core.util.db.DerbyConnectionHelper;
import java.sql.SQLException;

import javax.sql.DataSource;

/**
 * <code>DerbyFileSystem</code> is a JDBC-based <code>FileSystem</code>
 * implementation for Jackrabbit that persists file system entries in an
 * embedded Derby database.
 * <p>
 * It is configured through the following properties:
 * <ul>
 * <li><code>url</code>: the database url of the form
 * <code>"jdbc:derby:[db];[attributes]"</code></li>
 * <li><code>schemaObjectPrefix</code>: prefix to be prepended to schema objects</li>
 * <li><code>driver</code>: the FQN name of the JDBC driver class
 * (default: <code>"org.apache.derby.jdbc.EmbeddedDriver"</code>)</li>
 * <li><code>schema</code>: type of schema to be used
 * (default: <code>"derby"</code>)</li>
 * <li><code>user</code>: the database user (default: <code>null</code>)</li>
 * <li><code>password</code>: the user's password (default: <code>null</code>)</li>
 * <li><code>shutdownOnClose</code>: if <code>true</code> (the default) the
 * database is shutdown when the last connection is closed;
 * set this to <code>false</code> when using a standalone database</li>
 * </ul>
 * See also {@link DbFileSystem}.
 * <p>
 * The following is a fragment from a sample configuration:
 * <pre>
 *   <FileSystem class="org.apache.jackrabbit.core.fs.db.DerbyFileSystem">
 *       <param name="url" value="jdbc:derby:${rep.home}/db;create=true"/>
 *       <param name="schemaObjectPrefix" value="rep_"/>
 *  </FileSystem>
 * </pre>
 */
public class DerbyFileSystem extends DbFileSystem {

    /**
     * Flag indicating whether this derby database should be shutdown on close.
     */
    protected boolean shutdownOnClose;

    /**
     * Creates a new <code>DerbyFileSystem</code> instance.
     */
    public DerbyFileSystem() {
        // preset some attributes to reasonable defaults
        schema = "derby";
        driver = "org.apache.derby.jdbc.EmbeddedDriver";
        shutdownOnClose = true;
        initialized = false;
    }

    //----------------------------------------------------< setters & getters >

    public boolean getShutdownOnClose() {
        return shutdownOnClose;
    }

    public void setShutdownOnClose(boolean shutdownOnClose) {
        this.shutdownOnClose = shutdownOnClose;
    }

    //-----------------------------------------------< DbFileSystem overrides >

    /**
     * {@inheritDoc}
     */
    @Override
    protected ConnectionHelper createConnectionHelper(DataSource dataSrc) throws Exception {
        return new DerbyConnectionHelper(dataSrc, false);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void close() throws FileSystemException {
        super.close();
        if (shutdownOnClose) {
            try {
                ((DerbyConnectionHelper) conHelper).shutDown(driver);
            } catch (SQLException e) {
                throw new FileSystemException("failed to shutdown Derby", e);
            }
        }
    }
}