/*
 * 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.parser;

import java.util.ArrayList;


public class IfStatement extends Statement
{
	private ConditionalPredicate _predicate;
	private ArrayList<StatementBlock> _ifBody;
	private ArrayList<StatementBlock> _elseBody;
	
	@Override
	public Statement rewriteStatement(String prefix) {
		throw new LanguageException(this.printErrorLocation() + "should not call rewriteStatement for IfStatement");
	}
	
	public IfStatement(){
		 _predicate = null;
		 _ifBody = new ArrayList<>();
		 _elseBody = new ArrayList<>();
	}
	
	public void setConditionalPredicate(ConditionalPredicate pred){
		_predicate = pred;
	}
	
	
	public void addStatementBlockIfBody(StatementBlock sb){
		_ifBody.add(sb);
	}
	
	public void addStatementBlockElseBody(StatementBlock sb){
		_elseBody.add(sb);
	}
	
	public ConditionalPredicate getConditionalPredicate(){
		return _predicate;
	}
	
	public ArrayList<StatementBlock> getIfBody(){
		return _ifBody;
	}
	
	public ArrayList<StatementBlock> getElseBody(){
		return _elseBody;
	}
	
	public void setIfBody(ArrayList<StatementBlock> body){
		_ifBody = body;
	}
	
	public void setElseBody(ArrayList<StatementBlock> body){
		_elseBody = body;
	}
	
	
	@Override
	public boolean controlStatement() {
		return true;
	}
	
	@Override
	public void initializeforwardLV(VariableSet activeIn) {
		throw new LanguageException(this.printErrorLocation() + "should never call initializeforwardLV for IfStatement");
	}

	@Override
	public VariableSet initializebackwardLV(VariableSet lo) {
		throw new LanguageException(this.printErrorLocation() + "should never call initializeforwardLV for IfStatement");
	}

	public void mergeStatementBlocksIfBody(){
		_ifBody = StatementBlock.mergeStatementBlocks(_ifBody);
	}
	
	public void mergeStatementBlocksElseBody(){
		if (!_elseBody.isEmpty())
			_elseBody = StatementBlock.mergeStatementBlocks(_elseBody);
	}

	@Override
	public String toString(){
		StringBuilder sb = new StringBuilder();
		sb.append("if ( ");
		sb.append(_predicate.toString());
		sb.append(") { \n");
		for (StatementBlock block : _ifBody){
			sb.append(block.toString());
		}
		sb.append("}\n");
		if (!_elseBody.isEmpty()){
			sb.append(" else { \n");
			for (StatementBlock block : _elseBody){
				sb.append(block.toString());
			}
			sb.append("}\n");
		}
		return sb.toString();
	}

	@Override
	public VariableSet variablesRead() {
		LOG.warn("WARNING: line " + this.getBeginLine() + ", column " + this.getBeginColumn() + " --  should not call variablesRead from IfStatement ");
		return null;
	}

	@Override
	public VariableSet variablesUpdated() {
		LOG.warn("WARNING: line " + this.getBeginLine() + ", column " + this.getBeginColumn() + " --  should not call variablesUpdated from IfStatement ");
		return null;
	}
}