// 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=""></int,>

      m_errorPos;  //!< Position of the error in the expression's text

  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() {}

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

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(std::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);

  }

}

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

std::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;

}

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

std::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") != std::string::npos;

}