/*
 * BEGIN_HEADER - DO NOT EDIT
 * 
 * The contents of this file are subject to the terms
 * of the Common Development and Distribution License
 * (the "License").  You may not use this file except
 * in compliance with the License.
 *
 * You can obtain a copy of the license at
 * https://open-jbi-components.dev.java.net/public/CDDLv1.0.html.
 * See the License for the specific language governing
 * permissions and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL
 * HEADER in each file and include the License file at
 * https://open-jbi-components.dev.java.net/public/CDDLv1.0.html.
 * If applicable add the following below this CDDL HEADER,
 * with the fields enclosed by brackets "[]" replaced with
 * your own identifying information: Portions Copyright
 * [year] [name of copyright owner]
 */

/*
 * @(#)Union.java 
 *
 * Copyright 2004-2007 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * END_HEADER - DO NOT EDIT
 */
package com.sun.jbi.engine.iep.core.derby;

import com.sun.jbi.engine.iep.core.runtime.operator.OperatorConstants;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Timestamp;

/**
 *
 * @author Bing Lu
 */
public class Union implements OperatorConstants {
    public static void operate(String outRName, String inRName, String colNames, Timestamp ts0, Timestamp ts1) throws Exception {
        Connection con = null;
        PreparedStatement s = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        try {
            con = DriverManager.getConnection("jdbc:default:connection");
            String[] cols = Util.getTokens(colNames, DELIM);

            String outputTableName = outRName;
            String inputTableName = inRName;
            
            StringBuffer sb = new StringBuffer();
            sb.append("SELECT DISTINCT ");
            for (String col : cols) {
                sb.append(col + ",");
            }
            sb.append(COL_TIMESTAMP + " FROM " + inputTableName + " r WHERE ");
            sb.append("r." + COL_TAG + " = '+' AND ");
            sb.append("? < r." + COL_TIMESTAMP + " AND r." + COL_TIMESTAMP + " <= ? AND ");
            sb.append("(SELECT COUNT(*) FROM " + inputTableName + " s WHERE ");
            for (String col : cols) {
                sb.append("s." + col + " = r." +  col + " AND ");
            }
            sb.append("s." + COL_TIMESTAMP + " < r." +  COL_TIMESTAMP + " AND ");
            sb.append("s." + COL_TAG + " = '+')");
            sb.append(" = "); // existing: + = -
            sb.append("(SELECT COUNT(*) FROM " + inputTableName + " s WHERE ");
            for (String col : cols) {
                sb.append("s." + col + " = r." +  col + " AND ");
            }
            sb.append("s." + COL_TIMESTAMP + " < r." +  COL_TIMESTAMP + " AND ");
            sb.append("s." + COL_TAG + " = '-') AND ");
            sb.append("(SELECT COUNT(*) FROM " + inputTableName + " s WHERE ");
            for (String col : cols) {
                sb.append("s." + col + " = r." +  col + " AND ");
            }
            sb.append("s." + COL_TIMESTAMP + " = r." +  COL_TIMESTAMP + " AND ");
            sb.append("s." + COL_TAG + " = '-')");
            sb.append(" < "); // new: - < +
            sb.append("(SELECT COUNT(*) FROM " + inputTableName + " s WHERE ");
            for (String col : cols) {
                sb.append("s." + col + " = r." +  col + " AND ");
            }
            sb.append("s." + COL_TIMESTAMP + " = r." +  COL_TIMESTAMP + " AND ");
            sb.append("s." + COL_TAG + " = '+')");
            sb.append(" ORDER BY " + COL_TIMESTAMP);
            String sqlStr = sb.toString();
            s = con.prepareStatement(sqlStr);
            s.setTimestamp(1, ts0);
            s.setTimestamp(2, ts1);
            rs = s.executeQuery();
            
            // For each (Name, Value, Timestamp) = (n, v, t)
            // INSERT INTO R (Name, Value, Timestamp, Tag) VALUES (n, v, t, '+')
            sb = new StringBuffer();
            sb.append("INSERT INTO " + outputTableName + " (");
            for (String col : cols) {
                sb.append(col + ", ");
            }
            sb.append(COL_TIMESTAMP + ", " + COL_TAG + ") VALUES (");
            for (int i = 0, I = cols.length; i < I; i++) {
                sb.append("?, ");
            }
            sb.append("?, '+')");
            sqlStr = sb.toString();
            ps = con.prepareStatement(sqlStr);
            int colTotal = cols.length + 1; // 1 for Timestamp
            while (rs.next()) {
                for (int i = 1; i <= colTotal; i++) {
                    ps.setObject(i, rs.getObject(i));
                }
                ps.addBatch();
            }
            ps.executeBatch();
        } catch (Exception e) {
            throw e;
        } finally {
            Util.close(rs);
            Util.close(s);
            Util.close(ps);
            Util.close(con);
        }
    }
    
}