/*
 * 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.sysds.lops;

import java.util.HashSet;

 
import org.apache.sysds.lops.LopProperties.ExecType;
import org.apache.sysds.runtime.instructions.InstructionUtils;
import org.apache.sysds.common.Types.DataType;
import org.apache.sysds.common.Types.ValueType;

public class SortKeys extends Lop 
{
	
	public static final String OPCODE = "qsort"; //quantile sort 
	
	public enum OperationTypes { 
		WithWeights, 
		WithoutWeights,
		Indexes,
	}
	
	private OperationTypes operation;
	
	public OperationTypes getOpType() {
		return operation;
	}

	public SortKeys(Lop input, OperationTypes op, DataType dt, ValueType vt, ExecType et) {
		super(Lop.Type.SortKeys, dt, vt);
		init(input, null, op, et);
	}
	
	public SortKeys(Lop input, boolean desc, OperationTypes op, DataType dt, ValueType vt, ExecType et) {
		super(Lop.Type.SortKeys, dt, vt);
		init(input, null, op, et);
	}

	public SortKeys(Lop input1, Lop input2, OperationTypes op, DataType dt, ValueType vt, ExecType et) {
		super(Lop.Type.SortKeys, dt, vt);		
		init(input1, input2, op, et);
	}
	
	private void init(Lop input1, Lop input2, OperationTypes op, ExecType et) {
		addInput(input1);
		input1.addOutput(this);
		
		operation = op;
		
		// SortKeys can accept a optional second input only when executing in CP
		// Example: sorting with weights inside CP
		if ( input2 != null ) {
			addInput(input2);
			input2.addOutput(this);
		}
		lps.setProperties( inputs, et);
	}


	@Override
	public String toString() {
		return "Operation: SortKeys (" + operation + ")";
	}

	@Override
	public String getInstructions(String input, String output) {
		return InstructionUtils.concatOperands(
			getExecType().name(),
			OPCODE,
			getInputs().get(0).prepInputOperand(input),
			prepOutputOperand(output));
	}
	
	@Override
	public String getInstructions(String input1, String input2, String output) {
		return InstructionUtils.concatOperands(
			getExecType().name(),
			OPCODE,
			getInputs().get(0).prepInputOperand(input1),
			getInputs().get(1).prepInputOperand(input2),
			prepOutputOperand(output));
	}
	
	// This method is invoked in two cases:
	// 1) SortKeys (both weighted and unweighted) executes in MR
	// 2) Unweighted SortKeys executes in CP
	public static SortKeys constructSortByValueLop(Lop input1, OperationTypes op, 
			DataType dt, ValueType vt, ExecType et) {
		
		for (Lop lop  : input1.getOutputs()) {
			if ( lop.type == Lop.Type.SortKeys ) {
				return (SortKeys)lop;
			}
		}
		
		SortKeys retVal = new SortKeys(input1, op, dt, vt, et);
		retVal.setAllPositions(input1.getFilename(), input1.getBeginLine(), input1.getBeginColumn(), input1.getEndLine(), input1.getEndColumn());
		return retVal;
	}

	// This method is invoked ONLY for the case of Weighted SortKeys executing in CP
	public static SortKeys constructSortByValueLop(Lop input1, Lop input2, OperationTypes op, 
			DataType dt, ValueType vt, ExecType et) {
		
		HashSet<Lop> set1 = new HashSet<>();
		set1.addAll(input1.getOutputs());
		// find intersection of input1.getOutputs() and input2.getOutputs();
		set1.retainAll(input2.getOutputs());
		
		for (Lop lop  : set1) {
			if ( lop.type == Lop.Type.SortKeys ) {
				return (SortKeys)lop;
			}
		}
		
		SortKeys retVal = new SortKeys(input1, input2, op, dt, vt, et);
		retVal.setAllPositions(input1.getFilename(), input1.getBeginLine(), input1.getBeginColumn(), input1.getEndLine(), input1.getEndColumn());
		return retVal;
	}


}