package com.quantum.adapters;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Basically this Factory is a Singleton that is used to return the proper adapter
 * @author root
 */
public class AdapterFactory {
	
	static class ComparatorImpl implements Comparator {

		public int compare(Object arg0, Object arg1) {
			DatabaseAdapter adapter0 = (DatabaseAdapter) arg0;
			DatabaseAdapter adapter1 = (DatabaseAdapter) arg1;
			
			if (adapter0 == null && adapter0 != null) {
				return -1;
			} else if (adapter0 != null && adapter1 == null) {
				return 1;
			} else if (adapter0 == null && adapter1 == null) {
				return 0;
			} else {
				return adapter0.getDisplayName().compareTo(adapter1.getDisplayName());
			}
		}
	}
	
	public static final String GENERIC = "GENERIC"; //$NON-NLS-1$
	public static final String HSQLDB = "HSQLDB"; //$NON-NLS-1$
    public static final String ORACLE = "ORACLE"; //$NON-NLS-1$
    public static final String POSTGRES = "POSTGRES"; //$NON-NLS-1$
    public static final String MYSQL = "MYSQL"; //$NON-NLS-1$
    public static final String DB2 = "DB2"; //$NON-NLS-1$
    public static final String DB2AS400 = "DB2AS400"; //$NON-NLS-1$
	public static final String ADABASD = "ADABASD"; //$NON-NLS-1$
    public static final String INFORMIX = "INFORMIX"; //$NON-NLS-1$
	public static final String REDBRICK = "REDBRICK"; //$NON-NLS-1$
	public static final String POINTBASE = "POINTBASE"; //$NON-NLS-1$
    public static final String SYBASE = "SYBASE"; //$NON-NLS-1$

	private static final Map DRIVER_MAP = Collections.synchronizedMap(new HashMap());
	
	static {
		DRIVER_MAP.put("com.ddtek.jdbc.informix.InformixDriver", AdapterFactory.INFORMIX);
		DRIVER_MAP.put("com.ddtek.jdbc.db2.DB2Driver", AdapterFactory.DB2);
		DRIVER_MAP.put("com.ddtek.jdbc.oracle.OracleDriver", AdapterFactory.ORACLE);
		DRIVER_MAP.put("com.ddtek.jdbc.sqlserver.SQLServerDriver", AdapterFactory.GENERIC);
		DRIVER_MAP.put("com.ddtek.jdbc.sybase.SybaseDriver", AdapterFactory.SYBASE);
		DRIVER_MAP.put("com.ibm.as400.access.AS400JDBCDriver", AdapterFactory.DB2AS400);
		DRIVER_MAP.put("COM.ibm.db2.jdbc.app.DB2Driver", AdapterFactory.DB2);
		DRIVER_MAP.put("COM.ibm.db2.jdbc.net.DB2Driver", AdapterFactory.DB2);
		DRIVER_MAP.put("com.inet.ora.OraDriver", AdapterFactory.ORACLE);
		DRIVER_MAP.put("com.inet.drda.DRDADriver", AdapterFactory.DB2);
		DRIVER_MAP.put("com.inet.syb.SybDriver", AdapterFactory.SYBASE);
		DRIVER_MAP.put("com.inet.tds.TdsDriver", AdapterFactory.GENERIC);
		DRIVER_MAP.put("com.informix.jdbc.IfxDriver", AdapterFactory.INFORMIX);
		DRIVER_MAP.put("com.microsoft.jdbc.sqlserver.SQLServerDriver", AdapterFactory.GENERIC);
		DRIVER_MAP.put("com.mysql.jdbc.Driver", AdapterFactory.MYSQL);
		DRIVER_MAP.put("com.pointbase.jdbc.jdbcUniversalDriver", AdapterFactory.POINTBASE);
		DRIVER_MAP.put("com.sybase.jdbcx.SybDriver", AdapterFactory.SYBASE);
		DRIVER_MAP.put("oracle.jdbc.driver.OracleDriver", AdapterFactory.ORACLE);
		DRIVER_MAP.put("org.gjt.mm.mysql.Driver", AdapterFactory.MYSQL);
		DRIVER_MAP.put("org.hsqldb.jdbcDriver", AdapterFactory.HSQLDB);
		DRIVER_MAP.put("org.postgresql.Driver", AdapterFactory.POSTGRES);
		DRIVER_MAP.put("weblogic.jdbc.informix.InformixDriver", AdapterFactory.INFORMIX);
		DRIVER_MAP.put("weblogic.jdbc.sqlserver.SybaseDriver", AdapterFactory.SYBASE);
	}
	
    private static AdapterFactory instance;
    
    private Map adapters = Collections.synchronizedMap(new HashMap());
    
    private AdapterFactory() {
    	addAdapter(new GenericAdapter(GENERIC));
    	addAdapter(new GenericAdapter(HSQLDB));
    	addAdapter(new OracleAdapter());
    	addAdapter(new DB2Adapter());
    	addAdapter(new DB2AS400Adapter());
    	addAdapter(new PostgresAdapter());
    	addAdapter(new GenericAdapter(MYSQL));
    	addAdapter(new AdabasDAdapter());
    	addAdapter(new GenericAdapter(INFORMIX));
    	addAdapter(new RedBrickAdapter());
    	addAdapter(new GenericAdapter(SYBASE));
    	addAdapter(new GenericAdapter(POINTBASE));
    }
    private void addAdapter(DatabaseAdapter adapter) {
    	this.adapters.put(adapter.getType(), adapter);
    }
    
    public static synchronized AdapterFactory getInstance() {
    	if (instance == null) {
    		instance = new AdapterFactory();
    	}
    	return instance;
    }

    public DatabaseAdapter getAdapter(String type){
    	DatabaseAdapter result = (DatabaseAdapter) this.adapters.get(type);
    	if (result == null) {
    		result = (DatabaseAdapter) this.adapters.get(GENERIC);
    	}
    	return result == null ? null : result;
    }
    
    public DatabaseAdapter[] getDriverList() {
        List list = new ArrayList(this.adapters.values());
        Collections.sort(list, new ComparatorImpl());
    	return (DatabaseAdapter[]) list.toArray(new DatabaseAdapter[list.size()]);
    }
    
    /**
     * 
     * @param driverClassName
     * @return the adapter type, or null if the adapter type is not known
     */
    public String getAdapterType(String driverClassName) {
    	return (String) DRIVER_MAP.get(driverClassName);
    }
}