/*
 * JBoss, Home of Professional Open Source.
 * See the COPYRIGHT.txt file distributed with this work for information
 * regarding copyright ownership.  Some portions may be licensed
 * to Red Hat, Inc. under one or more contributor license agreements.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA.
 */

package org.teiid.query.processor.relational;

import static org.teiid.query.analysis.AnalysisRecord.*;

import java.util.ArrayList;
import java.util.List;

import org.teiid.client.plan.PlanNode;
import org.teiid.common.buffer.BlockedException;
import org.teiid.common.buffer.TupleBatch;
import org.teiid.common.buffer.TupleBuffer;
import org.teiid.common.buffer.TupleSource;
import org.teiid.core.TeiidComponentException;
import org.teiid.core.TeiidProcessingException;
import org.teiid.query.processor.BatchIterator;
import org.teiid.query.processor.relational.SortUtility.Mode;
import org.teiid.query.sql.lang.OrderByItem;


public class SortNode extends RelationalNode {

	private List<OrderByItem> items;
    private Mode mode = Mode.SORT;

    private SortUtility sortUtility;
    private int phase = SORT;
    private TupleBuffer output;
    private TupleSource outputTs;
    private boolean usingOutput;
    
    private int rowLimit = -1;

    private static final int SORT = 2;
    private static final int OUTPUT = 3;

	public SortNode(int nodeID) {
		super(nodeID);
	}

    public void reset() {
        super.reset();
        sortUtility = null;
        phase = SORT;
        output = null;
        outputTs = null;
        usingOutput = false;
        rowLimit = -1;
    }

	public void setSortElements(List<OrderByItem> items) {
		this.items = items;
	}
	
	public List<OrderByItem> getSortElements() {
		return this.items;
	}
	
	public Mode getMode() {
		return mode;
	}

	public void setMode(Mode mode) {
		this.mode = mode;
	}

	public TupleBatch nextBatchDirect()
		throws BlockedException, TeiidComponentException, TeiidProcessingException {
        if(this.phase == SORT) {
            sortPhase();
        }

        return outputPhase();
    }

    private void sortPhase() throws BlockedException, TeiidComponentException, TeiidProcessingException {
    	if (this.sortUtility == null) {
    		TupleSource ts = null;
    		TupleBuffer working = null;
    		if (!getChildren()[0].hasBuffer(true)) {
    			ts = new BatchIterator(getChildren()[0]);
    		} else {
    			working = getChildren()[0].getBuffer(-1);
    		}
	        this.sortUtility = new SortUtility(ts, items, this.mode, getBufferManager(),
                    getConnectionID(), getChildren()[0].getElements());
	        if (ts == null) {
	        	this.sortUtility.setWorkingBuffer(working);
	        }
		}
		this.output = this.sortUtility.sort();
		if (this.outputTs == null) {
			this.outputTs = this.output.createIndexedTupleSource();
		}
    	if (rowLimit >= 0) {
			this.output.truncateTo(rowLimit);
			if (!this.output.isFinal() && this.output.getRowCount() == rowLimit) {
				this.output.close();
			}
		}
        this.phase = OUTPUT;
    }

    private TupleBatch outputPhase() throws BlockedException, TeiidComponentException, TeiidProcessingException {
		if (!this.output.isFinal()) {
			this.phase = SORT;
		} else if (!usingOutput) {
			this.output.setForwardOnly(true);
		}
		List<?> tuple = null;
		try {
			while ((tuple = this.outputTs.nextTuple()) != null) {
				//resize to remove unrelated columns
				if (this.getElements().size() < tuple.size()) {
					tuple = new ArrayList<Object>(tuple.subList(0, this.getElements().size()));
				}
				addBatchRow(tuple);
				if (this.isBatchFull()) {
					return pullBatch();
				}
			}
		} catch (BlockedException e) {
			if (this.hasPendingRows()) {
				return this.pullBatch();
			}
			throw e;
		}
		this.terminateBatches();
		return this.pullBatch();
    }

    public void closeDirect() {
        if(this.output != null) {
        	if (!usingOutput) {
        		this.output.remove();
        	}
        	this.output = null;
        }
        if (this.sortUtility != null) {
        	this.sortUtility.remove();
        	this.sortUtility = null;
        }
        this.outputTs = null;
    }

	protected void getNodeString(StringBuffer str) {
		super.getNodeString(str);
		str.append("[").append(mode).append("] "); //$NON-NLS-1$ //$NON-NLS-2$
		if (this.mode != Mode.DUP_REMOVE) {
			str.append(this.items);
		}
	}

	protected void copyTo(SortNode target){
		super.copyTo(target);
		target.items = items;
		target.mode = mode;
	}

	public Object clone(){
		SortNode clonedNode = new SortNode(super.getID());
		this.copyTo(clonedNode);

		return clonedNode;
	}
    
    public PlanNode getDescriptionProperties() {
    	PlanNode props = super.getDescriptionProperties();
        
        if(this.mode != Mode.DUP_REMOVE && this.items != null) {
            props.addProperty(PROP_SORT_COLS, this.items.toString());
        }
        
        props.addProperty(PROP_SORT_MODE, this.mode.toString());
        
        return props;
    }
    
    @Override
    public TupleBuffer getBuffer(int maxRows) throws BlockedException, TeiidComponentException, TeiidProcessingException {
    	this.rowLimit = maxRows;
    	//TODO: push limiting into the sort logic
    	if (this.output == null) {
    		sortPhase();
    	}
    	usingOutput = true;
    	TupleBuffer result = this.output;
    	if (this.output.isFinal()) {
    		this.output = null;
    		close();
    	}
    	return result;
    }
    
    @Override
    public boolean hasBuffer(boolean requireFinal) {
    	if (this.getElements().size() == this.getChildren()[0].getElements().size()) {
    		return !requireFinal || mode != Mode.DUP_REMOVE;
    	}
    	return false;
    }
    
}
