/*

   Derby - Class org.apache.derby.impl.sql.execute.rts.RealNestedLoopJoinStatistics

   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to you under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */

package org.apache.derby.impl.sql.execute.rts;

import org.apache.derby.iapi.sql.execute.ResultSetStatistics;
import org.apache.derby.iapi.services.io.StoredFormatIds;

import org.apache.derby.iapi.services.i18n.MessageService;
import org.apache.derby.iapi.reference.SQLState;

import org.apache.derby.iapi.services.io.FormatableHashtable;
import org.apache.derby.iapi.sql.execute.xplain.XPLAINVisitor;
import org.apache.derby.impl.sql.execute.xplain.XPLAINUtil;

import java.io.ObjectOutput;
import java.io.ObjectInput;
import java.io.IOException;

/**
  ResultSetStatistics implemenation for NestedLoopJoinResultSet.


*/
public class RealNestedLoopJoinStatistics 
	extends RealJoinResultSetStatistics
{

	/* Leave these fields public for object inspectors */
	public boolean oneRowRightSide;
	public ResultSetStatistics leftResultSetStatistics;
	public ResultSetStatistics rightResultSetStatistics;

	/* KLUDGE - Prior to 2.5, all joins were nested loop in the join node.  
	 * "Make" this a HashJoin if the right child is a HashScan.
	 */
	protected String nodeName ;
	public String resultSetName;

	// CONSTRUCTORS

	/**
	 * 
	 *
	 */
    public	RealNestedLoopJoinStatistics(
								int numOpens,
								int rowsSeen,
								int rowsFiltered,
								long constructorTime,
								long openTime,
								long nextTime,
								long closeTime,
								int resultSetNumber,
								int rowsSeenLeft,
								int rowsSeenRight,
								int rowsReturned,
								long restrictionTime,
								boolean oneRowRightSide,
								double optimizerEstimatedRowCount,
								double optimizerEstimatedCost,
								String userSuppliedOptimizerOverrides,
								ResultSetStatistics leftResultSetStatistics,
								ResultSetStatistics rightResultSetStatistics
								)
	{
		super(
			numOpens,
			rowsSeen,
			rowsFiltered,
			constructorTime,
			openTime,
			nextTime,
			closeTime,
			resultSetNumber,
			rowsSeenLeft,
			rowsSeenRight,
			rowsReturned,
			restrictionTime,
			optimizerEstimatedRowCount,
			optimizerEstimatedCost,
			userSuppliedOptimizerOverrides
			);
		this.oneRowRightSide = oneRowRightSide;
		this.leftResultSetStatistics = leftResultSetStatistics;
		this.rightResultSetStatistics = rightResultSetStatistics;

		setNames();
	}

	// ResultSetStatistics methods

	/**
	 * Return the statement execution plan as a String.
	 *
	 * @param depth	Indentation level.
	 *
	 * @return String	The statement execution plan as a String.
	 */
	public String getStatementExecutionPlanText(int depth)
	{
		initFormatInfo(depth);

		String header = "";
		if (userSuppliedOptimizerOverrides != null)
		{ 
			header = 
				indent + MessageService.getTextMessage(SQLState.RTS_USER_SUPPLIED_OPTIMIZER_OVERRIDES_FOR_JOIN,
						userSuppliedOptimizerOverrides);
			header = header + "\n";
		}
		
		return
		header +
			indent + resultSetName + ":\n" +
			indent + MessageService.getTextMessage(SQLState.RTS_NUM_OPENS) +
				" = " + numOpens + "\n" + 
			indent + MessageService.getTextMessage(
												SQLState.RTS_ROWS_SEEN_LEFT) +
				" = " + rowsSeenLeft + "\n" +
			indent + MessageService.getTextMessage(
												SQLState.RTS_ROWS_SEEN_RIGHT) +
				" = " + rowsSeenRight + "\n" +
			indent + MessageService.getTextMessage(
												SQLState.RTS_ROWS_FILTERED) +
				" = " + rowsFiltered + "\n" +
			indent + MessageService.getTextMessage(
												SQLState.RTS_ROWS_RETURNED) +
				" = " + rowsReturned + "\n" +
			dumpTimeStats(indent, subIndent) + "\n" +
			dumpEstimatedCosts(subIndent) + "\n" +
			indent + MessageService.getTextMessage(
												SQLState.RTS_LEFT_RS) +
				":\n" +
			leftResultSetStatistics.getStatementExecutionPlanText(sourceDepth) +
				"\n" +
			indent + MessageService.getTextMessage(SQLState.RTS_RIGHT_RS) +
				":\n" +
			rightResultSetStatistics.getStatementExecutionPlanText(sourceDepth) + "\n";
	}


	/**
	 * Return information on the scan nodes from the statement execution 
	 * plan as a String.
	 *
	 * @param depth	Indentation level.
	 * @param tableName if not NULL then print information for this table only
	 *
	 * @return String	The information on the scan nodes from the 
	 *					statement execution plan as a String.
	 */
	public String getScanStatisticsText(String tableName, int depth)
	{
		return  leftResultSetStatistics.getScanStatisticsText(tableName, depth)
			+ rightResultSetStatistics.getScanStatisticsText(tableName, depth);
	}



	// Class implementation
	
	public String toString()
	{
		return getStatementExecutionPlanText(0);
	}

	public java.util.Vector getChildren()
	{
		java.util.Vector children = new java.util.Vector();
	    children.addElement(leftResultSetStatistics);
		children.addElement(rightResultSetStatistics);
	    return children;
	}

	/**
     * Format for display, a name for this node.
	 *
	 */
	public String getNodeName()
	{
		return nodeName;
	}

	protected void setNames()
	{
		if (nodeName == null)
		{
			if (oneRowRightSide)
			{
				nodeName = MessageService.getTextMessage(
										SQLState.RTS_NESTED_LOOP_EXISTS_JOIN);
				resultSetName = MessageService.getTextMessage(
									SQLState.RTS_NESTED_LOOP_EXISTS_JOIN_RS);
			}
			else
			{
				nodeName = MessageService.getTextMessage(
										SQLState.RTS_NESTED_LOOP_JOIN);
				resultSetName = MessageService.getTextMessage(
									SQLState.RTS_NESTED_LOOP_JOIN_RS);
			}
		}
	}
	
    // -----------------------------------------------------
    // XPLAINable Implementation
    // -----------------------------------------------------
    
      public void accept(XPLAINVisitor visitor) {
          int noChildren = 0;
          if(this.leftResultSetStatistics!=null) noChildren++;
          if(this.rightResultSetStatistics!=null) noChildren++;
          
          //inform the visitor
          visitor.setNumberOfChildren(noChildren);

          // pre-order, depth-first traversal
          // me first
          visitor.visit(this);
          // then first my left child
          if(leftResultSetStatistics!=null){
              leftResultSetStatistics.accept(visitor);
          }
          // then first my right child
          if(rightResultSetStatistics!=null){
              rightResultSetStatistics.accept(visitor);
          }
          
          
      }
    public String getRSXplainType() { return XPLAINUtil.OP_JOIN_NL; }
    public String getRSXplainDetails()
    {
        String op_details = "("+this.resultSetNumber + ")";
        // check to see if this NL Join is part of an Exist clause
        if (this.oneRowRightSide) op_details+= ", EXISTS JOIN";
        return op_details;
    }
}