%{
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include "y.tab.h"
    
    void yyerror(char *);

    extern YYSTYPE yylval;
    extern FILE *yyin;
    int yylineno;
    int _DEBUG;
    
%}
%%
[//]*                                                                           { ; }
-?[0-9]+                                                                        { yylval.num = atoi(yytext); return INTEGER; }
\'[ -~]\'                                                                       { yylval.character = yytext[1]; return CHAR; }
[-()<>=+*/:;,%{}\[\]]                                                           { return  *yytext; }
"if"                                                                            { return IF; }
"else"                                                                          { return ELSE; }
"printf"                                                                        { return PRINTF; }
"string"                                                                        { return KEYWORD_S; }
"while"                                                                         { return WHILE; }
"int"                                                                           { return KEYWORD_I; }
"def"                                                                           { return DEF;}
"call"                                                                          { return CALL; }
"char"                                                                          { return KEYWORD_C; }
"++"                                                                            { return INCREASE; }
"--"                                                                            { return DECREASE; }
\"(\\.|[^"\\])*\"                                                               { yytext++; yytext[strlen(yytext)-1] = 0; yylval.str = strdup(yytext); return STRING; }
[a-zA-Z0-9_]+                                                                   { yylval.str = strdup(yytext); return VARNAME; }
-?[0-9]*\.[0-9]+                                                                { yylval.Double = atof(yytext); return DOUBLEVAR; }
"\n"                                                                            { yylineno++; }
[ ?\t\n\r]                                                                      
.               printf("invalid character on line %d, '%s'\n", yylineno, yytext);
<<EOF>>         { exit(0); }
%%

int yywrap(void) {

    return 1;

}

int main(int argc, char* argv[]) 
{
    FILE *fh;
    if (argc > 1) 
    {
        if (strcmp(argv[1],"help") == 0 || strcmp(argv[1],"-help") == 0
            || strcmp(argv[1],"--help") == 0 || strcmp(argv[1],"h") == 0 
            || strcmp(argv[1],"-h") == 0) 
        {
            printf("[ HELP ] put a file/path as the first flag.\n");
            printf("[ HELP ] -h, -help, --help, help, h: Prints this.\n");
            printf("[ HELP ] -d, d, -debug, debug: Enter REPL mode.\n");
        } 
        else if (strcmp(argv[1],"-debug") == 0 || strcmp(argv[1],"-d") == 0
            || strcmp(argv[1],"d") == 0 || strcmp(argv[1],"debug") == 0) 
        {
            _DEBUG = 1;
            printf(">>> ");
            yyparse();  
        } 
        else if (fh = fopen(argv[1], "r"))
        {
            yyin = fh;
            yyparse();
            fclose(fh);
        } 
        else
        {
            printf("[ ERROR ] please enter a correct command. try --help\n");
            fclose(fh);
        }
    } else
        printf("[ ERROR ] missing input file. Try --help?\n");
    return 0;
}