/**
  *
  *                      OOAS Compiler
  *
  *       Copyright 2015, AIT Austrian Institute of Technology.
  * This code is based on the C# Version of the OOAS Compiler, which is
  * copyright 2015 by the Institute of Software Technology, Graz University
  * of Technology with portions copyright by the AIT Austrian Institute of
  * Technology. All rights reserved.
  *
  * SEE THE "LICENSE" FILE FOR THE TERMS UNDER WHICH THIS FILE IS PROVIDED.
  *
  * If you modify the file please update the list of contributors below to in-
  * clude your name. Please also stick to the coding convention of using TABs
  * to do the basic (block-level) indentation and spaces for anything after
  * that. (Enable the display of special chars and it should be pretty obvious
  * what this means.) Also, remove all trailing whitespace.
  *
  * Contributors:
  *               Willibald Krenn (AIT)
  *               Stephan Zimmerer (AIT)
  *               Markus Demetz (AIT)
  *               Christoph Czurda (AIT)
  *
  */


package org.momut.ooas.ast.statements;

import java.util.LinkedList;

import org.momut.ooas.ast.IAstVisitor;
import org.momut.ooas.ast.IScope;
import org.momut.ooas.ast.expressions.Expression;
import org.momut.ooas.ast.identifiers.Identifier;
import org.momut.ooas.parser.SymbolTable;

///////////////////////////////////////////////
///  Assignment
///
public final class Assignment extends Statement implements IScope
{
	private final LinkedList<Expression> m_places;
	private final LinkedList<Expression> m_values;
	private Expression m_nondetExpression;
	private IScope m_parentScope;
	private final SymbolTable m_symbols; // needed for nondeterminsitic assignment (we most likely will have new variables)

	public LinkedList<Expression> places() { return m_places; }
	public LinkedList<Expression> values() { return m_values; }
	public Expression nondetExpression() { return m_nondetExpression; }
	public SymbolTable symbols() { return m_symbols; }

	public Assignment(Expression place, Expression value, Expression nondetExpression, int aline, int apos)
	{
		super (StatementKind.Assignment, aline, apos);
		m_places = new LinkedList<Expression>();
		m_values = new LinkedList<Expression>();
		if (place != null)
			m_places.addFirst(place);
		if (value != null)
			m_values.addFirst(value);
		m_nondetExpression = nondetExpression;
		m_symbols = new SymbolTable();
	}

	public Assignment(Assignment toCopy)
	{
		super (toCopy);
		m_places = new LinkedList<Expression>(toCopy.m_places);
		m_values = new LinkedList<Expression>(toCopy.m_values);
		m_nondetExpression = toCopy.m_nondetExpression;
		m_symbols = new SymbolTable(toCopy.symbols());
	}

	@Override
	public /*override*/ Statement Clone()
	{
		return new Assignment(this);
	}

	public void AddPlace(Expression aPlace)
	{
		m_places.addLast(aPlace);
	}

	public void AddValue(Expression aValue)
	{
		m_values.addLast(aValue);
	}

	public void SetNondetExpression(Expression anExpr)
	{
		m_nondetExpression = anExpr;
	}

	@Override
	public /*override*/ void Accept(IAstVisitor visitor)
	{
		visitor.visit(this);
	}

	@Override
	public Identifier ResolveIdentifier(String aName)
	{
		if (m_symbols.Defined(aName))
			return m_symbols.Get(aName);
		else
			return null;
	}

	@Override
	public IScope GetParentScope()
	{
		return m_parentScope;
	}

	@Override
	public void SetParentScope(IScope parentScope)
	{
		m_parentScope = parentScope;
	}

	@Override
	public void AddIdentifier(Identifier anIdentifier, Object tag)
	{
		m_symbols.AddIdentifier(anIdentifier);
	}
}