package org.geoserver.config;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.logging.Level;

import org.geoserver.catalog.Catalog;
import org.geoserver.catalog.MetadataMap;
import org.geoserver.catalog.event.CatalogListener;
import org.geoserver.catalog.impl.CatalogImpl;
import org.geoserver.config.impl.CoverageAccessInfoImpl;
import org.geoserver.config.impl.GeoServerInfoImpl;
import org.geoserver.config.util.LegacyConfigurationImporter;
import org.geoserver.config.util.XStreamPersister;
import org.geoserver.config.util.XStreamServiceLoader;
import org.geoserver.platform.GeoServerExtensions;
import org.geoserver.platform.GeoServerResourceLoader;

/**
 * Default GeoServerLoader which loads and persists configuration from the classic GeoServer data 
 * directory structure.
 *  
 * @author Justin Deoliveira, OpenGeo
 *
 */
public class DefaultGeoServerLoader extends GeoServerLoader {
    
    ConfigurationListener listener;
    GeoServerPersister persister; 

    public DefaultGeoServerLoader(GeoServerResourceLoader resourceLoader) {
        super(resourceLoader);
    }
    
    protected void loadCatalog(Catalog catalog, XStreamPersister xp) throws Exception {
        catalog.setResourceLoader(resourceLoader);

        readCatalog(catalog, xp);
        
        if ( !legacy ) {
            //add the listener which will persist changes
            catalog.addListener( new GeoServerPersister( resourceLoader, xp ) );
        }
    }
    
    protected void loadGeoServer(final GeoServer geoServer, XStreamPersister xp) throws Exception {
        if(listener == null) { 
            // add event listener which persists changes
            final List<XStreamServiceLoader> loaders = 
                GeoServerExtensions.extensions( XStreamServiceLoader.class );
            listener = new ServicePersister(loaders, geoServer);
            geoServer.addListener(listener);
        }
        
        try {
            if (this.persister != null) {
                // avoid having the persister write down new config files while we read the config,
                // otherwise it'll dump it back in xml files
                geoserver.removeListener(persister);
            } else {
                // lazy creation of the persister at the first need
                this.persister = new GeoServerPersister(resourceLoader, xp);
            }
            readConfiguration(geoServer, xp);
        } finally {
            // attach back the persister
            geoserver.addListener(persister);
        }
    }
    
    @Override
    protected void initializeStyles(Catalog catalog, XStreamPersister xp) throws IOException {
        //add a persister temporarily in case the styles don't exist on disk
        GeoServerPersister p = new GeoServerPersister(resourceLoader, xp);
        catalog.addListener(p);
        
        super.initializeStyles(catalog, xp);
        
        catalog.removeListener(p);
    }

}