/*
 * 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.runtime.controlprogram.context;

import org.apache.sysds.api.DMLScript;
import org.apache.sysds.common.Types.ExecMode;
import org.apache.sysds.hops.OptimizerUtils;
import org.apache.sysds.runtime.controlprogram.LocalVariableMap;
import org.apache.sysds.runtime.controlprogram.Program;

public class ExecutionContextFactory 
{
	public static ExecutionContext createContext() {
		return createContext( null );
	}
	
	public static ExecutionContext createContext(Program prog) {
		return createContext(true, prog);
	}
	
	public static ExecutionContext createContext(LocalVariableMap vars, Program prog) {
		ExecutionContext ec = createContext(false, prog);
		ec.setVariables(vars);
		return ec;
	}

	public static ExecutionContext createContext(boolean allocateVars, Program prog) {
		return createContext(allocateVars, DMLScript.LINEAGE, prog );
	}
	
	public static ExecutionContext createContext(boolean allocateVars, boolean allocateLineage, Program prog)
	{
		ExecutionContext ec = null;
		
		switch( DMLScript.getGlobalExecMode() )
		{
			case SINGLE_NODE:
				//NOTE: even in case of forced singlenode operations, users might still 
				//want to run remote parfor which requires the correct execution context
				if( OptimizerUtils.getDefaultExecutionMode()==ExecMode.HYBRID
					&& !(prog!=null && prog.getDMLProg()!=null && prog.getDMLProg().containsRemoteParfor()))
					ec = new ExecutionContext(allocateVars, allocateLineage, prog);
				else
					ec = new SparkExecutionContext(allocateVars, allocateLineage, prog);
				break;
				
			case SPARK:
			case HYBRID:
				ec = new SparkExecutionContext(allocateVars, allocateLineage, prog);
				break;
		}
		
		return ec;
	}
}
