/* 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;
/* index to generate, C1,C2 .. */
int cred_count = 0;

int sz_overhead = 0;

char *compose_cred_list();
int get_next_cred_idx();

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

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

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

%%
/* 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);
                 sprintf(tmp,"isMember(%s,%s,['%s'])",$3,$1,abac_yyfptr);
               } else {
                 sz=strlen($3)+strlen($1)+sz_overhead;
                 tmp=(char *)abac_xmalloc(sz);
                 if (cred_count==0) { 
                     sprintf(tmp,"isMember(X,%s,['%s']):-%s",
                                        $1, abac_yyfptr, $3);
                     } else {
                     char *tmp_cred_list=compose_cred_list();
                     sprintf(tmp,"isMember(X,%s,L):-%s, appendL([['%s'],%s],L)",
                                        $1, $3, abac_yyfptr, tmp_cred_list);
                     free(tmp_cred_list);
                     cred_count=0;
                 }
               }
               $$=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 : term
             { $$=$1; }
      | term AND right
             { 
               int sz=strlen($1)+strlen($3)+2;
               char *tmp=(char *)abac_xmalloc(sz);
               sprintf(tmp,"%s,%s",$1,$3);
               $$=tmp; 
               free($1);free($3);
             }

term : keypart DOT IDEN DOT IDEN
             { 
               int sz=strlen($1)+strlen($3)+strlen($5)+sz_overhead;
               char *tmp=(char *)abac_xmalloc(sz);
               int fst=get_next_cred_idx();
               int snd=get_next_cred_idx();
               sprintf(tmp,"isMember(Y,role(%s,%s),C%d),isMember(X,role(Y,%s),C%d)",$1,$3,fst,$5,snd);
               $$=tmp; 
               free($1);free($3);free($5);
             }
      | keypart DOT IDEN
             { 
               int sz=strlen($1)+strlen($3)+sz_overhead;
               int fst=get_next_cred_idx();
               char *tmp=(char *)abac_xmalloc(sz);
               sprintf(tmp,"isMember(X,role(%s,%s),C%d)", $1, $3, fst);
               $$=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);
}

int get_next_cred_idx()
{
    printf("ZZZ count it once..%d\n", cred_count);
    cred_count++;
    return cred_count;
}

int get_curr_cred_idx()
{
    return cred_count;
}

/* remember to free the returned string */
char *compose_cred_list()
{
    int i=cred_count;;
    if(cred_count==0) return "";

    char *clist=(char *)abac_xmalloc(sizeof(char)*(cred_count)*3);
    strcpy(clist,"C1");
    if (cred_count==1) return clist;

    i=1;
    while(i!=cred_count) {
        i++;
        sprintf(clist,"%s,C%d",clist,i);
    }
    return clist;
}