#include "stdafx.h"
#pragma warning(disable:4786)
#include <string>
#include <map>
#include "CParser.h"
using namespace std;

#define	Getc(s)			getc(s)
#define	Ungetc(c)		{ungetc(c,IP_Input); ugetflag=1;}



// Adds a character to the string value
void CParser::PushString(char c)
{
	yylval.s += c;
}
//------------------------------------------------------------------------
void CParser::Load_tokenentry(string str,int index)
{
	IP_Token_table[str]=index;
	IP_revToken_table[index]=str;
}
void CParser::IP_init_token_table()
{
	Load_tokenentry("STRING1",STRING1);
	Load_tokenentry("IDENTIFIER",IDENTIFIER);
	Load_tokenentry("INTEGER1",INTEGER1);

	Load_tokenentry("Variables",VARIABLES);
	Load_tokenentry("Terms",TERMS);
}
//------------------------------------------------------------------------

void CParser::pr_tokentable()
{
	
	typedef map<string,int>::const_iterator CI;
	const char* buf;

	printf( "Symbol Table ---------------------------------------------\n");

	for(CI p=IP_Token_table.begin(); p!=IP_Token_table.end(); ++p){
		buf = p->first.c_str();
		printf(" key:%s", buf);
		printf(" val:%d\n", p->second);;
	}
}
//------------------------------------------------------------------------

int	CParser::yyparse()
{
	int tok;
	if(prflag)fprintf(IP_List,"%5d ",(int)IP_LineNumber);
	/*
	*	Go parse things!
	*/
	parsestate pState = P_START;
	while ((tok=yylex())!=0){
		switch (pState)
		{
		case P_START:
			switch (tok)
			{
			case VARIABLES:
				pState = P_VARIABLES;
				break;
			case TERMS:
				pState = P_TERMS_KEY;
				break;
			}
			break;
		case P_VARIABLES:
			switch(tok)
			{
			case IDENTIFIER:
				printf("Variable %s",yylval.s.c_str());
				break;
			case TERMS:
				pState = P_TERMS_KEY;
				break;
			}
			break;
		case P_TERMS_KEY:
			switch(tok)
			{
			case STRING1:
				printf("Term Key %s",yylval.s.c_str());
				break;
			case INTEGER1:
				printf("Term Key %d",yylval.i);
				break;
			case (int)'>':
				pState = P_TERMS_VALUE;
				break;
			case VARIABLES:
				pState = P_VARIABLES;
				break;
			}
			break;
		case P_TERMS_VALUE:
			if (tok == INTEGER1)
			{
				printf("Term Value %d",yylval.i);
				pState = P_TERMS_KEY;
			}
			break;
		}
		printf("\n");
	}
	return 0;

}
//------------------------------------------------------------------------

/*
 *	Parse Initfile:
 *
 *	  This builds the context tree and then calls the real parser.
 *	It is passed two file streams, the first is where the input comes
 *	from; the second is where error messages get printed.
 */
void CParser::InitParse(FILE *inp,FILE *err,FILE *lst)

{

	/*
	*	Set up the file state to something useful.
	*/
	IP_Input = inp;
	IP_Error = err;
	IP_List  = lst;

	IP_LineNumber = 1;
	ugetflag=0;
	/*
	*	Define both the enabled token and keyword strings.
	*/
	IP_init_token_table();
}
//------------------------------------------------------------------------

/*
 *	yyerror:
 *
 *	  Standard error reporter, it prints out the passed string
 *	preceeded by the current filename and line number.
 */
void CParser::yyerror(char *ers)

{
  fprintf(IP_Error,"line %d: %s\n",IP_LineNumber,ers);
}
//------------------------------------------------------------------------

int CParser::IP_MatchToken(string &tok)
{
	int retval;
	if(	IP_Token_table.find(tok) != IP_Token_table.end()){
		retval = (IP_Token_table[tok]);
	}else{
		retval = (0);
	}
	return retval;
} 

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

/*
 *	yylex:
 *
 */
int CParser::yylex()
{
	//Locals
	int c;
	lexstate s;
	/*
	*	Keep on sucking up characters until we find something which
	*	explicitly forces us out of this function.
	*/
	yytext = "";
	yylval.s = "";
	yylval.i = 0;
	for (s = L_START; 1;){
		c = Getc(IP_Input);
		yytext = yytext + (char)c;
		if(!ugetflag) { 
			if(c != EOF)if(prflag)fprintf(IP_List,"%c",c);
		}else ugetflag = 0;
		switch (s){
		  //Starting state, look for something resembling a token.
			case L_START:
				yytext = (char)c;
				if (isdigit(c)){
				  s = L_INT;
				}else if (isalpha(c) || c == '\\' ){
						s = L_IDENT;
				}else if (isspace(c)){
							if (c == '\n'){
								IP_LineNumber += 1;
								if(prflag)
									fprintf(IP_List,"%5d ",(int)IP_LineNumber);
								s = L_START;
								yytext = "";
							}
				}else if (c == '/'){
							yytext = "";
							s = L_COMMENT;
				}else if (c == '"'){
							s = L_STRING;
				}else if (c == EOF){
							return ('\0');
				}else{
							s = L_START;
							yytext = "";
							return (c);
				}
			break;

			case L_COMMENT:
				if (c == '/') 
					s = L_LINE_COMMENT;
				else	if(c == '*')
							s = L_TEXT_COMMENT;
						else{
								Ungetc(c);
								return('/');	/* its the division operator not a comment */
							}
			break;
			case L_LINE_COMMENT:
				if ( c == '\n'){
					s = L_START;
					Ungetc(c);
				}
				yytext = "";
			break;
			case L_TEXT_COMMENT:
				if ( c == '\n'){
					IP_LineNumber += 1;
				}else if (c == '*')
							s = L_END_TEXT_COMMENT;
				yytext = "";
			break;
			case L_END_TEXT_COMMENT:
				if (c == '/'){
					s = L_START;
				}else{
					s = L_TEXT_COMMENT;
				}
				yytext = "";
			break;

		  /*
		   *	Suck up the integer digits.
		   */
			case L_INT:
				if (isdigit(c)){
				  break;
				}else {
					Ungetc(c);
					yylval.s = yytext.substr(0,yytext.size()-1);
					yylval.i = atoi(yylval.s.c_str());
					return (INTEGER1);
				}
			break;

		  /*
		   *	Grab an identifier, see if the current context enables
		   *	it with a specific token value.
		   */
			
			case L_IDENT:
			   if (isalpha(c) || isdigit(c) || c == '_')
				  break;
				Ungetc(c);
				yytext = yytext.substr(0,yytext.size()-1);
				yylval.s = yytext;
				if (c = IP_MatchToken(yytext)){
					return (c);
				}else{
					return (IDENTIFIER);
				}

		   /*
		   *	Suck up string characters but once resolved they should
		   *	be deposited in the string bucket because they can be
		   *	arbitrarily long.
		   */
			case L_STRING2:
				s = L_STRING;
				if(c == '"'){
					PushString((char)c);
				}else{
					if(c == '\\'){
						PushString((char)c);
					}else{
						PushString((char)'\\');
						PushString((char)c);
					}
				}
			break;
			case L_STRING:
				if (c == '\n')
				  IP_LineNumber += 1;
				else if (c == '\r')
						;
					 else	if (c == '"' || c == EOF){
								return (STRING1);
							} else	if(c=='\\'){
										s = L_STRING2;
										//PushString((char)c);
									}else
										PushString((char)c);
			break;
			default: printf("***Fatal Error*** Wrong case label in yylex\n");
		}
	}
}