/**
 * Copyright (c) 2002-2012 "Neo Technology,"
 * Network Engine for Objects in Lund AB [http://neotechnology.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.neo4j.backup;

import java.net.URI;

import org.neo4j.helpers.Args;
import org.neo4j.helpers.Service;
import org.neo4j.kernel.logging.Logging;

/**
 * <p>
 * This class provides a basic interface for backup sources to implement their
 * own resolution algorithms. The backup tool in general expects a location to
 * backup from but the format of it is in general specific to the source
 * database, while the OnlineBackup class expects a valid socket to connect to
 * and perform the backup. For that reason each implementation is expected to
 * provide a translator from its specific addressing scheme to a valid
 * <i>host:port</i> combination.
 * </p>
 * <p>
 * The prime consumer of this API is the HA component, where a set of cluster
 * members can be passed as targets to backup but only one will be used. It is
 * expected therefore that a {@link Service} implementation will be present on
 * the classpath that will properly communicate with the cluster and find the
 * master.
 * </p>
 * <p>
 * The URI is strictly expected to have a scheme component, matching the name of
 * the service implementation used to resolve it. The same holds for the default
 * case, with a scheme name of "single". The scheme specific fragment after that
 * will be the responsibility of the plugin to resolve to a valid host. In any
 * case, the resolve method is expected to return a valid URI, with a scheme
 * which is the same as the one passed to it (ie the service's name).
 * </p>
 */
public abstract class BackupExtensionService extends Service
{
    public BackupExtensionService( String name )
    {
        super( name );
    }

    /**
     * The source specific target to valid backup host translation method.
     * 
     * @param from The URI as passed in the command line
     * @param arguments all arguments to the backup command
     * @return A URI where the scheme is the service's name and there exist host
     *         and port parts that point to a backup source.
     */
    public abstract URI resolve( URI from, Args arguments, Logging logging );
}