/* bison grammar rules for process old rt0 statements */
/*
   isi.employee <- ted
   ted.friend <- mike
   usc.employee <- isi.employee
   usc.playground <- usc.employee.friend
   query,
      usc.playground <- ?Z
      isi.playground <- mike
*/

%{
/* C declarations */
#include <stdio.h>
#include <string.h>
#include <abac_stack.h>

extern char *abac_cn_with_sha(char*);

FILE *abac_yyin = NULL;
FILE *abac_yyout = NULL;
char *abac_yap_clause = NULL;
char *abac_yyfptr = NULL;
char *tmp_cred_list = NULL;

int sz_overhead = 0;

%}
/* Bison declarations */
%union {
int  number;
char *string;   /* For returning char strings */
}
%type <string> keypart rolepart left right stmt

%token <string> IDEN       /* keyname or rolename */

%token  <operator>  DERIVE    "<-"
%token  <operator>  DOT       "."

%%
/* Grammar rules */

input:      /* empty */
             { }
        | stmt 
             { fprintf (abac_yyout,"stmt (%s)\n", $1);
               abac_yap_clause = $1;
             }
 
stmt : left DERIVE right
             { int sz;
               char *ptr=strstr($3,"role(");
               char *tmp;
               if(ptr==NULL) {
                 sz=strlen($3)+strlen($1)+sz_overhead;
                 tmp=(char *)abac_xmalloc(sz);
                 printf("before.. (%s)\n", $3);
                 sprintf(tmp,"isMember(%s,%s,['%s'])",$3,$1,abac_yyfptr);
                 printf("after.. (%s)\n", tmp);
               } else {
                 sz=strlen($3)+strlen($1)+sz_overhead;
                 tmp=(char *)abac_xmalloc(sz);
                 if (tmp_cred_list==NULL) { 
                     sprintf(tmp,"isMember(X,%s,['%s']):-%s",
                                        $1, abac_yyfptr, $3);
                     } else {
                     sprintf(tmp,"isMember(X,%s,['%s',%s]):-%s",
                                        $1, abac_yyfptr, tmp_cred_list, $3);
                     free(tmp_cred_list);
                     tmp_cred_list=NULL;
                 }
               }
               $$=tmp;
               free($3);free($1);
             }

left : keypart DOT rolepart
             { 
               int sz=strlen($1)+strlen($3)+sz_overhead;
               char *tmp=(char *)abac_xmalloc(sz);
               sprintf(tmp,"role(%s,%s)", $1, $3);
               $$=tmp; 
               free($3);free($1);
             }
/* isi */
keypart : IDEN 
             { 
             char *cn=abac_cn_with_sha($1);
             $$=strdup(cn);
             }

/* friend */
rolepart : IDEN
             { $$=strdup($1); }

right : keypart DOT IDEN DOT IDEN
             { 
               int sz=strlen($1)+strlen($3)+strlen($5)+sz_overhead;
               char *tmp=(char *)abac_xmalloc(sz);
               sprintf(tmp,"isMember(Y,role(%s,%s),[C1]),isMember(X,role(Y,%s),[C2])",$1,$3,$5);
               tmp_cred_list = strdup("C1,C2");
               $$=tmp; 
               free($1);free($3);free($5);
             }
      | keypart DOT IDEN
             { 
               int sz=strlen($1)+strlen($3)+sz_overhead;
               char *tmp=(char *)abac_xmalloc(sz);
               sprintf(tmp,"isMember(X,role(%s,%s),[C1])", $1, $3);
               tmp_cred_list = strdup("C1");
               $$=tmp; 
               free($1);free($3);
             }
      | keypart
             { 
             $$=$1;
             }

%%
#include "abac_rt0.h"

/* Additional C code */
int yywrap()
{
     /* exit when done lexing the current input */
     return 1;
} 

int yyerror (char *s)
{
     fprintf (abac_yyout,"yyerror: %s\n", s);
}

/* setting defaults */
void abac_yyinit()
{
    abac_yyin=abac_get_yyin();
    abac_yyout=abac_get_yyout();
    abac_yyfptr = abac_get_yyfptr();
    sz_overhead = strlen(abac_yyfptr)+2000;
} 

char *abac_get_yap_clause()
{
    return abac_yap_clause;
}

char *abac_free_yap_clause()
{
    if (abac_yap_clause != NULL)
        free(abac_yap_clause);
}