%{
#include <sys/cdefs.h>

#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>

#include <netinet/in.h>

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <netdb.h>

extern FILE *yyin;
extern FILE *yyout;
extern int yylineno;
extern int yy_flex_debug;

static size_t errors;
enum filter_dir {
GTW_IN,
GTW_OUT,
GTW_INOUT
};

#define GODROP 0
enum filter_action {
GTW_DROP = 0,
GTW_PASS,
};

struct mqtt_rule {
	char topic[128];
	char from[128];
	enum filter_action	action;
	enum filter_dir		dir;
	int	log;
	int	quick;
};

static size_t parsed_lines;
static size_t errors;
static size_t nrule;
%}

%union {
	int64_t number;
	char *string;
};

%token ACTION IN OUT FROM QUICK LOG SOCKET
%token TOPIC WORD WORD2
%token ANY FROM
%token SLASH HYPHEN
%type <number> ACTION QUICK LOG get_dir get_log get_quick
%type <string> get_from get_topic WORD SOCKET


%%

ruleset: /* empty */
	   | ruleset mqttrule
	   | ruleset comment
	   | ruleset error { errors++; }
	   ;

comment:	COMMENT '\n'
	   {
	   };
mqttrule	: get_log ACTION get_quick get_dir get_topic get_from
	   {
	   parsed_lines++;
	   struct mqtt_rule r;
	   memset(&r, 0, sizeof(r));
	   r.action = $2;
	   r.dir = $4;
	   if ($5)
		   strlcpy(r.topic, $5, sizeof r.topic);
	   if ($6)
		   strlcpy(r.from, $6, sizeof r.from);

		++nrule;
		if ($1==1) {
		printf("\t#%zu: %c %s %c %s <from> %s;\n", nrule, $3?'!':' ', r.action == GTW_DROP ? "Drop" : "pass", 
		r.dir==GTW_INOUT ? '=' : r.dir==GTW_IN ? '<' :'>',
		r.topic[0]!=0 ? r.topic :"*", r.from[0]!=0 ? r.from : "<all>");
		}
	   };

get_quick	: /*empty*/ {$$=0;}
			| QUICK {$$=1;}
			;
get_log		: /*empty*/ {$$=0;}
			| LOG {$$ = 1;}
			;

get_topic	:	ANY {$$=NULL;}
			|	WORD {$$=$1;}
			;

get_from	: /*empty*/ {$$=NULL;}
			| SOCKET {$$ = $1;}
			;

get_dir	:	/*empty*/ {$$=GTW_INOUT;}
		|	IN	{$$=GTW_IN;}
		|	OUT	{$$=GTW_OUT;}
		;
%%

void
yyerror(msg)
	char *msg;
{
	fprintf(stderr, "while parsing line %d: error occured \"%s\"\n",
	yylineno,
		msg);

	return;
}

int main( int argc, char **argv )
{
	++argv, --argc;  /* skip over program name */
	if ( argc > 0 )
		yyin = fopen( argv[0], "r" );
	else
		yyin = stdin;

	int devNull = open("/dev/null", O_WRONLY);
	int dup2Result = dup2(devNull, STDERR_FILENO);

	yyparse();
	printf("#%zu. R: %zu\tE: %zu\n", parsed_lines, nrule, errors);
}