#include "kermit.h"

/*
 *      receive - routines for receiving data
 */

/*
 *      r e c s w
 */

recsw()
{
  state = 'R';                          /* receive is the start state */
  n = 0;                                /* initialize message number */
  numtry = 0;                           /* say no tries yet */

  while(TRUE) switch(state)             /* do this for as long as necessary */
   {
    case 'D':   state = rdata(); break; /* data receive state */

    case 'F':   state = rfile(); break; /* file receive state */

    case 'R':   state = rinit(); break; /* send initiate state */

    case 'C':   return(TRUE);           /* complete state */

    case 'A':   return(FALSE);          /* unknown state, abort */
    }
  }
    
/*
 *       r i n i t
 */
  
rinit()
{
  int len, num;

  if (numtry++ > MAXTRY) return('A');   /* abort if to many tries */
  switch(rpack(&len,&num,packet))       /* get a packet */
  {
   case 'S':                            /* send-init */
    {
     rpar(packet);                      /* get the init data */
     spar(packet);                      /* fill up packet with init info */
     spack('Y',n,6,packet);             /* ACK with my parameters */
     oldtry = numtry;                   /* save old try count */
     numtry = 0;                        /* and start a new counter */
     n = (n+1)%64;                      /* bump packet number */
     return('F');                       /* enter file-send state */
    }
   case FALSE:  return (state);         /* we didn't receive a packet */
   default:     return('A');            /* unknown type, abort */
  }
}

/*
 *      r f i l e
 */

rfile()
{
 int num, len;

 if (numtry++ > MAXTRY) return('A');    /* abort if too many tries */
 switch(rpack(&len,&num,packet))        /* get packet */
  {
   case 'S':                            /* send-init */
    {
     if (oldtry++ > MAXTRY)
     return('A');                       /* if too many tries, abort */
     if (num == n-1)                    /* check packet number */
      {
       spar(packet);                    /* get the init params */
       spack('Y',num,6,packet);         /* it's right, ACK it */
       numtry = 0;                      /* reset try counter */
       return(state);
      }
     else return('A');                  /* sorry, wrong number */
    }

   case 'Z':                            /* end-of-file */
    {
     if (oldtry++ > MAXTRY) return('A');
     if (num == n-1)                    /* acknowledge good packet */
      {
       spack('Y',num,0,0);
       numtry = 0;
       return(state);
      }
     else return('A');                  /* or abort on bad one */
    }

   case 'F':                            /* file-header */
    {
     if (num != n) return('A');
     if (!getfil(packet))
      {
       fprintf(stderr,"Could not create %s\n");
       return('A');
      }
     else
       if (!host) printf("Receiving %s\n",packet);
     spack('Y',n,0,0);                  /* acknowledge */
     oldtry = numtry;
     numtry = 0;
     n = (n+1)%64;
     return('D');                       /* switch to data state */
    }
   case 'B':                            /* break transmission */
    {
     if (num != n) return ('A');
     spack('Y',n,0,0);                  /* say OK */
     return('C');                       /* and go to complete state */
    }
   case FALSE: return(state);
   default: return ('A');
  }
}

/*
 *      r d a t a
 */

rdata()
{
 int num, len;

 if (numtry++ > MAXTRY) return('A');    /* abort if too many tries */
 switch(rpack(&len,&num,packet))        /* get packet */
  {
   case 'D':                            /* data */
    {
     if (num != n)                      /* right packet? */
      {                                 /* no */
       if (oldtry++ > MAXTRY) return('A'); /* if too many tries */
       if (num == n-1)                  /* check packet number */
        {
         spar(packet);                  /* get the init params */
         spack('Y',num,6,packet);       /* ACK it */
         numtry = 0;                    /* reset try counter */
         return(state);
        }
       else return('A');                /* sorry wrong number */
      }
                                        /* data with right packet number */
     bufemp(packet,fd,len);             /* write out the packet */
     spack('Y',n,0,0);                  /* right packet, acknowledge */
     oldtry = numtry;
     numtry = 0;
     n = (n+1)%64;
     return('D');                       /* remain in data state */
    }
   case 'F':                            /* file-send */
    {
     if (oldtry++ > MAXTRY) return('A');
     if (num == n-1)                    /* acknowledge good packet */
      {
       spack('Y',num,0,0);
       numtry = 0;
       return(state);
      }
     else return('A');                  /* or abort on bad one */
    }

   case 'Z':                            /* end-of-file */
    {
     if (num != n) return('A');
     spack('Y',n,0,0);                  /* say OK */
     close(fd);                         /* close up the file */
     n = (n+1)%64;
     return('F');                       /* and go to file state */
    }
   case FALSE:  return(state);

   default:     return('A');
  }
}