/*
 * 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.sysml.runtime.instructions.mr;

import java.util.ArrayList;

import org.apache.sysml.runtime.DMLRuntimeException;
import org.apache.sysml.runtime.instructions.InstructionUtils;
import org.apache.sysml.runtime.matrix.data.LibMatrixReorg;
import org.apache.sysml.runtime.matrix.data.MatrixValue;
import org.apache.sysml.runtime.matrix.mapred.CachedValueMap;
import org.apache.sysml.runtime.matrix.mapred.IndexedMatrixValue;
import org.apache.sysml.runtime.matrix.operators.Operator;
import org.apache.sysml.runtime.util.UtilFunctions;


/**
 * Supported optcodes: rmempty.
 * 
 */
public class RemoveEmptyMRInstruction extends BinaryInstruction
{	
	
	
	private long    _len   = -1;
	private boolean _rmRows = true;
	
	
	public RemoveEmptyMRInstruction(Operator op, byte in1, byte in2, long len, boolean rmRows, byte out, String istr)
	{
		super(op, in1, in2, out, istr);
		instString = istr;
		
		_len = len;
		_rmRows = rmRows;
	}
	
	public boolean isRemoveRows()
	{
		return _rmRows;
	}
	
	public long getOutputLen()
	{
		return _len;
	}

	public static RemoveEmptyMRInstruction parseInstruction ( String str ) 
		throws DMLRuntimeException 
	{
		InstructionUtils.checkNumFields ( str, 5 );
		
		String[] parts = InstructionUtils.getInstructionParts(str);
		String opcode = parts[0];
		
		if(!opcode.equalsIgnoreCase("rmempty"))
			throw new DMLRuntimeException("Unknown opcode while parsing an RemoveEmptyMRInstruction: " + str);
		
		byte in1 = Byte.parseByte(parts[1]);
		byte in2 = Byte.parseByte(parts[2]);
		long rlen = UtilFunctions.toLong(Double.parseDouble(parts[3]));
		boolean rmRows = parts[4].equals("rows");
		byte out = Byte.parseByte(parts[5]);
		
		return new RemoveEmptyMRInstruction(null, in1, in2, rlen, rmRows, out, str);
	}
	
	@Override
	public void processInstruction(Class<? extends MatrixValue> valueClass,
			CachedValueMap cachedValues, IndexedMatrixValue tempValue,
			IndexedMatrixValue zeroInput, int blockRowFactor, int blockColFactor)
		throws DMLRuntimeException 
	{			
		//get input and offsets
		IndexedMatrixValue inData = cachedValues.getFirst(input1);
		IndexedMatrixValue inOffset = cachedValues.getFirst(input2);

		//execute remove empty operations
		ArrayList<IndexedMatrixValue> out = new ArrayList<IndexedMatrixValue>();
		LibMatrixReorg.rmempty(inData, inOffset, _rmRows, _len, blockRowFactor, blockColFactor, out);
		
		//put results into cache map
		for( IndexedMatrixValue imv : out )
			cachedValues.add(output, imv);
	}
}