/*
 * Copyright (c) 2008, SQL Power Group Inc.
 *
 * This file is part of SQL Power Library.
 *
 * SQL Power Library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * SQL Power Library 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>. 
 */

package ca.sqlpower.sql.jdbcwrapper;

import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Types;

import org.apache.log4j.Logger;

import ca.sqlpower.sql.CachedRowSet;

/**
 * Extends the base SQL Server database meta data decorator by providing a more accurate
 * method of retrieving schema names on SQL Server 2008.
 */
public class SQLServer2008DatabaseMetaDataDecorator extends SQLServerDatabaseMetaDataDecorator {
	
	private static final Logger logger = Logger.getLogger(SQLServer2008DatabaseMetaDataDecorator.class);

    public SQLServer2008DatabaseMetaDataDecorator(DatabaseMetaData delegate, ConnectionDecorator connectionDecorator) {
        super(delegate, connectionDecorator);
    }

    /**
     * Works around a user-reported bug in the SQL Server JDBC driver 2.0. Note
     * this is a different workaround than the one for SQL Server 2000 and 2005!
     * Microsoft has been busy. See <a
     * href="http://www.sqlpower.ca/forum/posts/list/0/1788.page">the post</a>
     * for details.
     * <p>
     * Note: the query changed just before the 0.9.13 release. See
     * <a href="http://www.sqlpower.ca/forum/posts/list/15/2271.page">the new post</a>
     * for reasons.
     */
    @Override
    public ResultSet getSchemas() throws SQLException {
        Statement stmt = null;
        ResultSet rs = null;
        try {
            stmt = getConnection().createStatement();
            String sql = 
                "SELECT DISTINCT" +
                "\n  w.schema_name AS TABLE_SCHEM," +
                "\n  w.catalog_name AS TABLE_CAT" +
                "\nFROM sys.schemas u" +
                "\nJOIN sys.objects v ON u.schema_id = v.schema_id" +
                "\nJOIN INFORMATION_SCHEMA.SCHEMATA w ON w.schema_name = u.name" +
                "\nORDER BY table_schem";
            rs = stmt.executeQuery(sql);
            CachedRowSet crs = new CachedRowSet();
            crs.populate(rs);
            return crs;
            
        } finally {
            if (rs != null) rs.close();
            if (stmt != null) stmt.close();
        }
    }
    
    @Override
    public ResultSet getColumns(String catalog, String schemaPattern,
    		String tableNamePattern, String columnNamePattern)
    		throws SQLException {
    	ResultSet rs = null;
    	CachedRowSet crs = new CachedRowSet();
    	try {
    		rs = super.getColumns(catalog, schemaPattern, tableNamePattern,
    				columnNamePattern);
    		crs.populate(rs);
    	} finally {
    		if (rs != null) {
    			try {
    				rs.close();
    			} catch (SQLException e) {
    				logger.error(e);
    			}
    		}
    	}
    	while (crs.next()) {
    		if (crs.getInt(5) == -9) {
    			if (crs.getString(6).equalsIgnoreCase("date")) {
    				crs.updateInt(5, Types.DATE);
    			} else if (crs.getString(6).equalsIgnoreCase("time")) {
    				crs.updateInt(5, Types.TIME);
    			}
    		}
    	}
    	crs.beforeFirst();
    	return crs;
    }
    
}