/***************************************************************************************************
 **
 **  Original work Copyright (C) 2013 Ingo Berg
 **  Modified work Copyright 2014 Roman Telezhynskyi <dismine(at)gmail.com>
 **
 **  Permission is hereby granted, free of charge, to any person obtaining a copy of this
 **  software and associated documentation files (the "Software"), to deal in the Software
 **  without restriction, including without limitation the rights to use, copy, modify,
 **  merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 **  permit persons to whom the Software is furnished to do so, subject to the following conditions:
 **
 **  The above copyright notice and this permission notice shall be included in all copies or
 **  substantial portions of the Software.
 **
 **  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
 **  NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 **  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
 **  DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 **  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 **
 ******************************************************************************************************/

#ifndef QMUPARSERTOKEN_H
#define QMUPARSERTOKEN_H

#include <cassert>
#include <string>
#include <stack>
#include <memory>
#include <QtGlobal>

#include "qmuparsererror.h"
#include "qmuparsercallback.h"

/** @file
    @brief This file contains the parser token definition.
*/

namespace qmu
{
  /** @brief Encapsulation of the data for a single formula token. 

    Formula token implementation. Part of the Math Parser Package.
    Formula tokens can be either one of the following:
    <ul>
      <li>value</li>
      <li>variable</li>
      <li>function with numerical arguments</li>
      <li>functions with a string as argument</li>
      <li>prefix operators</li>
      <li>infix operators</li>
	    <li>binary operator</li>
    </ul>

   @author (C) 2004-2013 Ingo Berg 
  */
  template<typename TBase, typename TString>
  class QmuParserToken
  {
  private:

      ECmdCode  m_iCode;  ///< Type of the token; The token type is a constant of type #ECmdCode.
      ETypeCode m_iType;
      void  *m_pTok;      ///< Stores Token pointer; not applicable for all tokens
      int  m_iIdx;        ///< An otional index to an external buffer storing the token data
      TString m_strTok;   ///< Token string
      TString m_strVal;   ///< Value for string variables
      qreal m_fVal;  ///< the value
      std::auto_ptr<QmuParserCallback> m_pCallback;

  public:

      //---------------------------------------------------------------------------
      /** @brief Constructor (default).
        
          Sets token to an neutral state of type cmUNKNOWN.
          @throw nothrow
          @sa ECmdCode
      */
      QmuParserToken()
        :m_iCode(cmUNKNOWN)
        ,m_iType(tpVOID)
        ,m_pTok(0)
        ,m_iIdx(-1)
        ,m_strTok()
        ,m_pCallback()
      {}

      //------------------------------------------------------------------------------
      /** @brief Create token from another one.
      
          Implemented by calling Assign(...)
          @throw nothrow
          @post m_iType==cmUNKNOWN
          @sa #Assign
      */
      QmuParserToken(const QmuParserToken &a_Tok)
      {
        Assign(a_Tok);
      }
      
      //------------------------------------------------------------------------------
      /** @brief Assignement operator. 
      
          Copy token state from another token and return this.
          Implemented by calling Assign(...).
          @throw nothrow
      */
      QmuParserToken& operator=(const QmuParserToken &a_Tok)
      {
        Assign(a_Tok);
        return *this;
      }

      //------------------------------------------------------------------------------
      /** @brief Copy token information from argument.
      
          @throw nothrow
      */
      void Assign(const QmuParserToken &a_Tok)
      {
        m_iCode = a_Tok.m_iCode;
        m_pTok = a_Tok.m_pTok;
        m_strTok = a_Tok.m_strTok;
        m_iIdx = a_Tok.m_iIdx;
        m_strVal = a_Tok.m_strVal;
        m_iType = a_Tok.m_iType;
        m_fVal = a_Tok.m_fVal;
        // create new callback object if a_Tok has one 
        m_pCallback.reset(a_Tok.m_pCallback.get() ? a_Tok.m_pCallback->Clone() : 0);
      }

      //------------------------------------------------------------------------------
      /** @brief Assign a token type. 

        Token may not be of type value, variable or function. Those have seperate set functions. 

        \pre [assert] a_iType!=cmVAR
        \pre [assert] a_iType!=cmVAL
        \pre [assert] a_iType!=cmFUNC
        @post m_fVal = 0
        @post m_pTok = 0
      */
      QmuParserToken& Set(ECmdCode a_iType, const TString &a_strTok=TString())
      {
        // The following types cant be set this way, they have special Set functions
        assert(a_iType!=cmVAR);
        assert(a_iType!=cmVAL);
        assert(a_iType!=cmFUNC);

        m_iCode = a_iType;
        m_iType = tpVOID;
        m_pTok = 0;
        m_strTok = a_strTok;
        m_iIdx = -1;

        return *this;
      }

      //------------------------------------------------------------------------------
      /** @brief Set Callback type. */
      QmuParserToken& Set(const QmuParserCallback &a_pCallback, const TString &a_sTok)
      {
        assert(a_pCallback.GetAddr());

        m_iCode = a_pCallback.GetCode();
        m_iType = tpVOID;
        m_strTok = a_sTok;
        m_pCallback.reset(new QmuParserCallback(a_pCallback));

        m_pTok = 0;
        m_iIdx = -1;
        
        return *this;
      }

      //------------------------------------------------------------------------------
      /** @brief Make this token a value token. 
      
          Member variables not necessary for value tokens will be invalidated.
          @throw nothrow
      */
      QmuParserToken& SetVal(TBase a_fVal, const TString &a_strTok=TString())
      {
        m_iCode = cmVAL;
        m_iType = tpDBL;
        m_fVal = a_fVal;
        m_strTok = a_strTok;
        m_iIdx = -1;
        
        m_pTok = 0;
        m_pCallback.reset(0);

        return *this;
      }

      //------------------------------------------------------------------------------
      /** @brief make this token a variable token. 
      
          Member variables not necessary for variable tokens will be invalidated.
          @throw nothrow
      */
      QmuParserToken& SetVar(TBase *a_pVar, const TString &a_strTok)
      {
        m_iCode = cmVAR;
        m_iType = tpDBL;
        m_strTok = a_strTok;
        m_iIdx = -1;
        m_pTok = (void*)a_pVar;
        m_pCallback.reset(0);
        return *this;
      }

      //------------------------------------------------------------------------------
      /** @brief Make this token a variable token. 
      
          Member variables not necessary for variable tokens will be invalidated.
          @throw nothrow
      */
      QmuParserToken& SetString(const TString &a_strTok, std::size_t a_iSize)
      {
        m_iCode = cmSTRING;
        m_iType = tpSTR;
        m_strTok = a_strTok;
        m_iIdx = static_cast<int>(a_iSize);

        m_pTok = 0;
        m_pCallback.reset(0);
        return *this;
      }

      //------------------------------------------------------------------------------
      /** @brief Set an index associated with the token related data. 
      
          In cmSTRFUNC - This is the index to a string table in the main parser.
		  * @param a_iIdx The index the string function result will take in the bytecode parser.
          @throw exception_type if #a_iIdx<0 or #m_iType!=cmSTRING
      */
      void SetIdx(int a_iIdx)
      {
        if (m_iCode!=cmSTRING || a_iIdx<0)
            throw QmuParserError(ecINTERNAL_ERROR);
        
        m_iIdx = a_iIdx;
      }

      //------------------------------------------------------------------------------
      /** @brief Return Index associated with the token related data. 
      
          In cmSTRFUNC - This is the index to a string table in the main parser.

          @throw exception_type if #m_iIdx<0 or #m_iType!=cmSTRING
		  * @return The index the result will take in the Bytecode calculatin array (#m_iIdx).
      */
      int GetIdx() const
      {
        if (m_iIdx<0 || m_iCode!=cmSTRING )
          throw QmuParserError(ecINTERNAL_ERROR);

        return m_iIdx;
      }

      //------------------------------------------------------------------------------
      /** @brief Return the token type.
      
		  * @return #m_iType
          @throw nothrow
      */
      ECmdCode GetCode() const
      {
        if (m_pCallback.get())
        {
          return m_pCallback->GetCode();
        }
        else
        {
          return m_iCode;
        }
      }

      //------------------------------------------------------------------------------
      ETypeCode GetType() const
      {
        if (m_pCallback.get())
        {
          return m_pCallback->GetType();
        }
        else
        {
          return m_iType;
        }
      }
      
      //------------------------------------------------------------------------------
      int GetPri() const
      {
        if ( !m_pCallback.get())
            throw QmuParserError(ecINTERNAL_ERROR);
            
        if ( m_pCallback->GetCode()!=cmOPRT_BIN && m_pCallback->GetCode()!=cmOPRT_INFIX)
            throw QmuParserError(ecINTERNAL_ERROR);

        return m_pCallback->GetPri();
      }

      //------------------------------------------------------------------------------
      EOprtAssociativity GetAssociativity() const
      {
        if (m_pCallback.get()==NULL || m_pCallback->GetCode()!=cmOPRT_BIN)
            throw QmuParserError(ecINTERNAL_ERROR);

        return m_pCallback->GetAssociativity();
      }

      //------------------------------------------------------------------------------
      /** @brief Return the address of the callback function assoziated with
                 function and operator tokens.

		  * @return The pointer stored in #m_pTok.
          @throw exception_type if token type is non of:
                 <ul>
                   <li>cmFUNC</li>
                   <li>cmSTRFUNC</li>
                   <li>cmPOSTOP</li>
                   <li>cmINFIXOP</li>
                   <li>cmOPRT_BIN</li>
                 </ul>
          @sa ECmdCode
      */
      generic_fun_type GetFuncAddr() const
      {
        return (m_pCallback.get()) ? (generic_fun_type)m_pCallback->GetAddr() : 0;
      }

      //------------------------------------------------------------------------------
      /** \biref Get value of the token.
        
          Only applicable to variable and value tokens.
          @throw exception_type if token is no value/variable token.
      */
      TBase GetVal() const
      {
        switch (m_iCode)
        {
          case cmVAL:  return m_fVal;
          case cmVAR:  return *((TBase*)m_pTok);
          default:     throw QmuParserError(ecVAL_EXPECTED);
        }
      }

      //------------------------------------------------------------------------------
      /** @brief Get address of a variable token.

        Valid only if m_iType==CmdVar.
        @throw exception_type if token is no variable token.
      */
      TBase* GetVar() const
      {
        if (m_iCode!=cmVAR)
            throw QmuParserError(ecINTERNAL_ERROR);

        return (TBase*)m_pTok;
      }

      //------------------------------------------------------------------------------
      /** @brief Return the number of function arguments. 

        Valid only if m_iType==CmdFUNC.
      */
      int GetArgCount() const
      {
        assert(m_pCallback.get());

        if (!m_pCallback->GetAddr())
            throw QmuParserError(ecINTERNAL_ERROR);

        return m_pCallback->GetArgc();
      }

      //------------------------------------------------------------------------------
      /** @brief Return the token identifier. 
          
          If #m_iType is cmSTRING the token identifier is the value of the string argument
          for a string function.
		  * @return #m_strTok
          @throw nothrow
          @sa m_strTok
      */
      const TString& GetAsString() const
      {
        return m_strTok;
      }
  };
} // namespace qmu

#endif