// TnzBase includes

#include "tgrammar.h"

#include "tparser.h"

#include "tunit.h"

#include "texpression.h"

using namespace TSyntax;

//**********************************************************************************

//    TExpression::Imp  definition

//**********************************************************************************

class TExpression::Imp

{

public:

	const Grammar *m_grammar; //!< (not owned) The expression's grammar

	TDoubleParam *m_param;	//!< (not owned) The expression's owner

	Calculator *m_calculator; //!< (owned) Expression calculator object

	std::string m_text; //!< Text content

	std::string m_error;			//!< Description of an error in the expression's text

	std::pair<int, int=""> m_errorPos; //!< Position of the error in the expression's text</int,>

	bool m_isValid,		 //!< Whether the expression is valid

		m_hasBeenParsed; //!< Whether the expression has already been parsed

public:

	Imp() : m_grammar(0), m_param(0), m_calculator(0), m_errorPos(0, -1), m_isValid(false), m_hasBeenParsed(true) {}

	~Imp() { delete m_calculator; }

};

//**********************************************************************************

//    TExpression  implementation

//**********************************************************************************

TExpression::TExpression()

	: m_imp(new Imp())

{

}

//--------------------------------------------------------------------------

TExpression::~TExpression()

{

	delete m_imp;

}

//--------------------------------------------------------------------------

TExpression::TExpression(const TExpression &src)

	: m_imp(new Imp())

{

	m_imp->m_grammar = src.m_imp->m_grammar;

	m_imp->m_param = src.m_imp->m_param;

	m_imp->m_text = src.m_imp->m_text;

	m_imp->m_calculator = 0;

	m_imp->m_isValid = src.m_imp->m_isValid;

	m_imp->m_error = src.m_imp->m_error;

	m_imp->m_errorPos = src.m_imp->m_errorPos;

	m_imp->m_hasBeenParsed = false;

}

//--------------------------------------------------------------------------

TExpression &TExpression::operator=(TExpression copy)

{

	std::swap(copy.m_imp, m_imp);

	return *this;

}

//--------------------------------------------------------------------------

void TExpression::setGrammar(const TSyntax::Grammar *grammar)

{

	m_imp->m_grammar = grammar;

	m_imp->m_hasBeenParsed = false;

}

//--------------------------------------------------------------------------

const TSyntax::Grammar *TExpression::getGrammar() const

{

	return m_imp->m_grammar;

}

//--------------------------------------------------------------------------

void TExpression::setText(string text)

{

	if (m_imp->m_text != text) {

		m_imp->m_text = text;

		delete m_imp->m_calculator;

		m_imp->m_calculator = 0;

		m_imp->m_isValid = false;

		m_imp->m_hasBeenParsed = false;

		m_imp->m_error = "";

		m_imp->m_errorPos = std::make_pair(0, -1);

	}

}

//--------------------------------------------------------------------------

string TExpression::getText() const

{

	return m_imp->m_text;

}

//--------------------------------------------------------------------------

// note: unit is used by the CycleNode node only

TSyntax::Calculator *TExpression::getCalculator()

{

	if (!m_imp->m_hasBeenParsed)

		parse();

	if (m_imp->m_isValid && m_imp->m_calculator)

		return m_imp->m_calculator;

	else

		return 0;

}

//--------------------------------------------------------------------------

bool TExpression::isValid()

{

	if (!m_imp->m_hasBeenParsed)

		parse();

	return m_imp->m_isValid;

}

//--------------------------------------------------------------------------

string TExpression::getError() const

{

	return m_imp->m_error;

}

//--------------------------------------------------------------------------

std::pair<int, int=""> TExpression::getErrorPos() const</int,>

{

	return m_imp->m_errorPos;

}

//--------------------------------------------------------------------------

void TExpression::accept(TSyntax::CalculatorNodeVisitor &visitor)

{

	if (!m_imp->m_hasBeenParsed)

		parse();

	if (m_imp->m_isValid && m_imp->m_calculator)

		m_imp->m_calculator->accept(visitor);

}

//--------------------------------------------------------------------------

void TExpression::parse()

{

	delete m_imp->m_calculator;

	m_imp->m_calculator = 0;

	m_imp->m_errorPos = std::make_pair(0, -1);

	m_imp->m_error = std::string();

	if (!m_imp->m_grammar) {

		m_imp->m_error = "No grammar defined";

		m_imp->m_isValid = false;

	} else {

		Parser parser(m_imp->m_grammar);

		m_imp->m_calculator = parser.parse(m_imp->m_text);

		if (m_imp->m_calculator)

			m_imp->m_calculator->setOwnerParameter(m_imp->m_param);

		m_imp->m_isValid = parser.isValid();

		if (!m_imp->m_isValid) {

			m_imp->m_error = parser.getError();

			m_imp->m_errorPos = parser.getErrorPos();

		}

	}

	m_imp->m_hasBeenParsed = true;

}

//--------------------------------------------------------------------------

void TExpression::setOwnerParameter(TDoubleParam *param)

{

	m_imp->m_param = param;

	if (m_imp->m_calculator)

		m_imp->m_calculator->setOwnerParameter(param);

}

//--------------------------------------------------------------------------

TDoubleParam *TExpression::getOwnerParameter() const

{

	return m_imp->m_param;

}

//--------------------------------------------------------------------------

bool TExpression::isCycling() const

{

	// TODO: this is a quick&dirty implementation to be replaced with a more "semantic" one

	return getText().find("cycle") != string::npos;

}