/*

	 _____  __ _____________ _______  ______ ___________
	/     \|  |  \____ \__  \\_  __ \/  ___// __ \_  __ \
   |  Y Y  \  |  /  |_> > __ \|  | \/\___ \\  ___/|  | \/
   |__|_|  /____/|   __(____  /__|  /____  >\___  >__|
		 \/      |__|       \/           \/     \/
   Copyright (C) 2004 - 2022 Ingo Berg

	Redistribution and use in source and binary forms, with or without modification, are permitted
	provided that the following conditions are met:

	  * Redistributions of source code must retain the above copyright notice, this list of
		conditions and the following disclaimer.
	  * Redistributions in binary form must reproduce the above copyright notice, this list of
		conditions and the following disclaimer in the documentation and/or other materials provided
		with the distribution.

	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
	IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
	FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
	CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
	IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
	OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef MU_PARSER_TOKEN_READER_H
#define MU_PARSER_TOKEN_READER_H

#include <cstdio>
#include <cstring>
#include <list>
#include <map>
#include <memory>
#include <stack>
#include <string>

#include "muParserDef.h"
#include "muParserToken.h"

/** \file
	\brief This file contains the parser token reader definition.
*/


namespace mu
{
	// Forward declaration
	class ParserBase;

	/** \brief Token reader for the ParserBase class. */
	class API_EXPORT_CXX ParserTokenReader final
	{
	private:

		typedef ParserToken<value_type, string_type> token_type;

	public:

		ParserTokenReader(ParserBase* a_pParent);
		ParserTokenReader* Clone(ParserBase* a_pParent) const;

		void AddValIdent(identfun_type a_pCallback);
		void SetVarCreator(facfun_type a_pFactory, void* pUserData);
		void SetFormula(const string_type& a_strFormula);
		void SetArgSep(char_type cArgSep);

		/** \brief Check whether a variable factory is installed. 
		 
			Variable factories automatically create new variables when a unknown variable is found in an expression.
		*/
		bool HasVarCreator() const
		{
			return m_pFactory != nullptr;
		}

		int GetPos() const;
		const string_type& GetExpr() const;
		varmap_type& GetUsedVar();
		char_type GetArgSep() const;

		void IgnoreUndefVar(bool bIgnore);
		void ReInit();
		token_type ReadNextToken();

	private:

		/** \brief Syntax codes.

			The syntax codes control the syntax check done during the first time parsing of
			the expression string. They are flags that indicate which tokens are allowed next
			if certain tokens are identified.
		*/
		enum ESynCodes
		{
			noBO = 1 << 0,			///< to avoid i.e. "cos(7)(" 
			noBC = 1 << 1,			///< to avoid i.e. "sin)" or "()"
			noVAL = 1 << 2,			///< to avoid i.e. "tan 2" or "sin(8)3.14"
			noVAR = 1 << 3,			///< to avoid i.e. "sin a" or "sin(8)a"
			noARG_SEP = 1 << 4,		///< to avoid i.e. ",," or "+," ...
			noFUN = 1 << 5,			///< to avoid i.e. "sqrt cos" or "(1)sin"	
			noOPT = 1 << 6,			///< to avoid i.e. "(+)"
			noPOSTOP = 1 << 7,		///< to avoid i.e. "(5!!)" "sin!"
			noINFIXOP = 1 << 8,		///< to avoid i.e. "++4" "!!4"
			noEND = 1 << 9,			///< to avoid unexpected end of formula
			noSTR = 1 << 10,		///< to block numeric arguments on string functions
			noASSIGN = 1 << 11,		///< to block assignment to constant i.e. "4=7"
			noIF = 1 << 12,
			noELSE = 1 << 13,
			sfSTART_OF_LINE = noOPT | noBC | noPOSTOP | noASSIGN | noIF | noELSE | noARG_SEP,
			noANY = ~0				///< All of he above flags set
		};

		ParserTokenReader(const ParserTokenReader& a_Reader);
		ParserTokenReader& operator=(const ParserTokenReader& a_Reader);
		void Assign(const ParserTokenReader& a_Reader);

		void SetParent(ParserBase* a_pParent);
		int ExtractToken(const char_type* a_szCharSet, string_type& a_strTok, std::size_t a_iPos) const;
		int ExtractOperatorToken(string_type& a_sTok, std::size_t a_iPos) const;

		bool IsBuiltIn(token_type& a_Tok);
		bool IsArgSep(token_type& a_Tok);
		bool IsEOF(token_type& a_Tok);
		bool IsInfixOpTok(token_type& a_Tok);
		bool IsFunTok(token_type& a_Tok);
		bool IsPostOpTok(token_type& a_Tok);
		bool IsOprt(token_type& a_Tok);
		bool IsValTok(token_type& a_Tok);
		bool IsVarTok(token_type& a_Tok);
		bool IsStrVarTok(token_type& a_Tok);
		bool IsUndefVarTok(token_type& a_Tok);
		bool IsString(token_type& a_Tok);
		void Error(EErrorCodes a_iErrc, int a_iPos = -1, const string_type& a_sTok = string_type()) const;

		token_type& SaveBeforeReturn(const token_type& tok);

		ParserBase* m_pParser;
		string_type m_strFormula;
		int  m_iPos;
		int  m_iSynFlags;
		bool m_bIgnoreUndefVar;

		const funmap_type* m_pFunDef;
		const funmap_type* m_pPostOprtDef;
		const funmap_type* m_pInfixOprtDef;
		const funmap_type* m_pOprtDef;
		const valmap_type* m_pConstDef;
		const strmap_type* m_pStrVarDef;

		varmap_type* m_pVarDef;  ///< The only non const pointer to parser internals
		facfun_type m_pFactory;
		void* m_pFactoryData;
		std::list<identfun_type> m_vIdentFun; ///< Value token identification function
		varmap_type m_UsedVar;
		value_type m_fZero;      ///< Dummy value of zero, referenced by undefined variables
		
		std::stack<int> m_bracketStack;

		token_type m_lastTok;
		char_type m_cArgSep;     ///< The character used for separating function arguments
	};
} // namespace mu

#endif