package org.apache.cornerstone.blocks.datasource;

import java.util.Iterator;
import java.util.Map;
import java.util.HashMap;

import org.apache.avalon.AbstractLoggable;
import org.apache.avalon.ComponentManagerException;
import org.apache.avalon.ComponentNotFoundException;
import org.apache.avalon.configuration.Configurable;
import org.apache.avalon.configuration.Configuration;
import org.apache.avalon.Initializable;
import org.apache.avalon.Disposable;
import org.apache.avalon.Component;
import org.apache.avalon.util.datasource.DataSourceComponent;
import org.apache.phoenix.Block;

import org.apache.cornerstone.services.datasource.DataSourceSelector;

/**
 *
 * @author <a href="mailto:colus@isoft.co.kr">Eung-ju Park</a>
 */
public class DefaultDataSourceSelector
    extends AbstractLoggable
    implements DataSourceSelector, Block, Configurable, Initializable, Disposable
{

    private Configuration m_configuration;

    /** data sources */
    private Map m_dataSources;

    public void configure( final Configuration configuration )
    {
        m_configuration = configuration;
    }

    public void init()
        throws Exception
    {
        m_dataSources = new HashMap();

        final Configuration[] dataSourceConfs = m_configuration.getChild( "data-sources" ).getChildren( "data-source" );
        for ( int i = 0; i < dataSourceConfs.length; i++ )
        {
            final Configuration dataSourceConf = dataSourceConfs[ i ];

            final String name = dataSourceConf.getAttribute( "name" );
            final String clazz = dataSourceConf.getAttribute( "type" );
            final String driver = dataSourceConf.getChild( "driver" ).getValue();

            //load jdbc driver for data source
            Class.forName( driver );
            //create data source
            final DataSourceComponent component = (DataSourceComponent)Class.forName( clazz ).newInstance();
            setupLogger( component, name );
            component.configure( dataSourceConf );
            m_dataSources.put( name, component );
            getLogger().info( "DataSource " + name + " registered" );
        }
    }

    public void dispose()
        throws Exception
    {
        final Iterator keys = m_dataSources.keySet().iterator();
        while ( keys.hasNext() )
        {
            final Component component = (Component)m_dataSources.get( keys.next() );
            if ( component instanceof Disposable )
            {
                ((Disposable)component).dispose();
            }
        }
        m_dataSources.clear();
        m_dataSources = null;
    }

    /**
     *
     * @param name
     * @return
     */
    public Component select( final Object hint )
        throws ComponentManagerException
    {
        final Component component = (Component)m_dataSources.get( hint );

        if ( null == component )
        {
            throw new ComponentNotFoundException( "Unable to provide implementation for "
                                                  + hint.toString() );
        }

        return component;
    }

    public void release( final Component component )
    {
        //do nothing
    }

    public DataSourceComponent selectDataSource( final Object hint )
        throws ComponentManagerException
    {
        return (DataSourceComponent)select( hint );
    }

}