/**
 * 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.kernel.ha;

import static org.neo4j.kernel.impl.nioneo.xa.NeoStoreXaDataSource.LOGICAL_LOG_DEFAULT_NAME;

import java.io.File;
import java.io.FileFilter;
import java.io.IOException;

import org.neo4j.com.RequestContext;
import org.neo4j.com.Response;
import org.neo4j.com.ServerUtil;
import org.neo4j.com.ToFileStoreWriter;
import org.neo4j.graphdb.factory.GraphDatabaseFactory;
import org.neo4j.graphdb.factory.GraphDatabaseSetting;
import org.neo4j.graphdb.factory.GraphDatabaseSettings;
import org.neo4j.kernel.GraphDatabaseAPI;
import org.neo4j.kernel.InternalAbstractGraphDatabase;
import org.neo4j.kernel.configuration.Config;
import org.neo4j.kernel.ha.HaSettings;
import org.neo4j.kernel.ha.Master;
import org.neo4j.kernel.impl.nioneo.store.NeoStore;
import org.neo4j.kernel.impl.transaction.xaframework.XaLogicalLog;
import org.neo4j.kernel.impl.util.FileUtils;
import org.neo4j.kernel.impl.util.StringLogger;

public class SlaveStoreWriter
{
    public static final String COPY_FROM_MASTER_TEMP = "temp-copy";
    private final Config config;

    public SlaveStoreWriter( Config config )
    {
        this.config = config;
    }

    public void copyStore( Master master ) throws IOException
    {
        // Clear up the current temp directory if there
        File storeDir = new File( config.get( InternalAbstractGraphDatabase.Configuration.store_dir ) );
        File tempStore = new File( storeDir, COPY_FROM_MASTER_TEMP );
        if ( !tempStore.mkdir() )
        {
            FileUtils.deleteRecursively( tempStore );
            tempStore.mkdir();
        }

        // Get the response, deserialise to disk
        Response response = master.copyStore( new RequestContext( 0,
                config.get( HaSettings.server_id ), 0, new RequestContext.Tx[0], 0,
                0 ), new ToFileStoreWriter( tempStore ) );
        long highestLogVersion = XaLogicalLog.getHighestHistoryLogVersion( tempStore, LOGICAL_LOG_DEFAULT_NAME );
        if ( highestLogVersion > -1 )
        {
            NeoStore.setVersion( tempStore, highestLogVersion + 1 );
        }
        GraphDatabaseAPI copiedDb = (GraphDatabaseAPI) new GraphDatabaseFactory().newEmbeddedDatabaseBuilder(
                tempStore.getAbsolutePath() ).setConfig(
                GraphDatabaseSettings.keep_logical_logs, GraphDatabaseSetting.TRUE ).setConfig(
                GraphDatabaseSettings.allow_store_upgrade,
                config.get( GraphDatabaseSettings.allow_store_upgrade ).toString() ).

                newGraphDatabase();

        // Apply pending transactions
        try
        {
            ServerUtil.applyReceivedTransactions( response, copiedDb.getXaDataSourceManager(),
                    ServerUtil.txHandlerForFullCopy() );
        }
        finally
        {
            copiedDb.shutdown();
            response.close();
        }

        // All is well, move to the real store directory
        for ( File candidate : tempStore.listFiles( new FileFilter()
        {
            @Override
            public boolean accept( File file )
            {
                // Skip log files and tx files from temporary database
                return !file.getName().equals( StringLogger.DEFAULT_NAME ) && !("active_tx_log tm_tx_log.1 tm_tx_log" +
                        ".2").contains( file.getName() );
            }
        } ) )
        {
            FileUtils.moveFileToDirectory( candidate, storeDir );
        }
    }
}