#include <stdio.h>

#define MAXNAME 128
#define MAXOPTS 20
#define MAXLINE 80

#include "scr_def.h"

#define NONE 2
#define BACKUP 3
#define DONE 4

#define CLEAR_STR "\f"

#define ANS_X 0
#define ANS_Y 23

#define ESC 0x1b
#define CNTRL_E 0x05

#define TRUE 1
#define FALSE 0

#ifdef DEBUG
#define DBG(x) printf x
#else
#define DBG(x)
#endif

main(argc,argv)
int argc;
char *argv[];
{
int stat;
char *dirname, fname[MAXNAME], *getenv();
char mname[MAXNAME];
FILE *mfile;
void domenu();
void bldfname();

scr_init();
if ((dirname = getenv("MENUS")) == NULL){
   dirname = "menus/";
   }
if (argc > 1){
   strcpy(fname,argv[1]);
   }
else strcpy(fname,"main");
bldfname(mname,dirname,fname);
DBG(("effective menu name = /%s/\n",mname));

while ((stat=strncmp(fname,"exit",4))!= 0){
   if((mfile = fopen(mname,"r")) == NULL){
      fprintf(stderr,"%s: Can't find menu %s.\n",argv[0],mname);
      scr_end();
      exit(1);
      }
   domenu(mfile,fname);
   fclose(mfile);    
   bldfname(mname,dirname,fname);
   } /* end while */
scr_end();
exit(0);
}   

void domenu(file,nxbuf)
FILE *file;
char *nxbuf;
{
char options[MAXOPTS+1];
char backup[MAXNAME+1];
char buf[MAXLINE+1];
char dflt,sel, get_sel();
void do_sel();

scr_cls();
fscanf(file,"%[^|]%*c%[^|]%*c%c%*c%s",options,backup,&dflt,nxbuf);
DBG(("options set to /%s/\n",options));
while (strncmp(fgets(buf,MAXLINE,file),"END",3)) scr_put(buf);
sprintf(buf,"ENTER selects %c\n",dflt);
scr_put(buf);
sel=get_sel(options);
if (sel == NONE) sel = dflt;
if (sel == BACKUP) strncpy(nxbuf,backup,MAXNAME);
else if (sel == DONE) strcpy(nxbuf,"exit");
else do_sel(file,sel,nxbuf);
DBG(("next menu set to %s\n",nxbuf));
}

char get_sel(opts)
char *opts;
{
char buf[MAXLINE+1];

do {
   scr_mv_xy(ANS_X, ANS_Y);
   scr_eol();
   scr_mv_xy(ANS_X, ANS_Y);
   scr_put("Selection...");
   if (opts[0] == 'Y') scr_put("ESC backs up...");
   if (opts[1] == 'Y') scr_put("CNTRL_E exits...");
   scr_get(buf);
   } while  (! in_set(buf[0],opts)); 
if (buf[0] == '\n') return NONE;
if (buf[0] == ESC) return BACKUP;
if (buf[0] == CNTRL_E) return DONE;
return buf[0];
}

int in_set(ch,opts)
char ch, *opts;
{
int i;

if (ch == '\n') return TRUE;
if ((ch == ESC) && (opts[0] == 'Y')) return TRUE;
if ((ch == CNTRL_E) && (opts[1] == 'Y')) return TRUE;
for (i=2; opts[i]; i++){
   if (ch == opts[i]) return TRUE;
   }
return FALSE;
}


void bldfname(buf,dir,file)
char *buf, *dir, *file;
{
buf[0] = '\0';
strncat(buf,dir,MAXNAME);
strncat(buf,file,MAXNAME-strlen(dir));
} 

void do_sel(file,sel,next)
FILE *file;
char sel, *next;
{
char l_sel,l_next[MAXLINE+1];
char action[MAXLINE+1], atype;
int args;

for (;;){
   if ((args=fscanf(file,"%c%c%*c%[^|]%*c%[^\n]%*c",
                    &l_sel,&atype,&l_next[0],&action[0])) ==EOF){
      fprintf(stderr,"Error in menu specification, can't find %c\n",sel);
      return;
      }
   if (sel == l_sel) {
      DBG(("\nmatches = %d",args));
      DBG(("\naction = %s",action));
      DBG(("\nlsel,atype = %c %c ", l_sel, atype));
      if (atype == 'P') system(action);
      else strcpy(next,action);
      if ((l_next[0] != ' ') && (atype != 'M')) strcpy(next,l_next);
      return;
      }
   } 
}