#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <termios.h>
#include "definitions.h"
#include "rs232.h"
/*
Compumotor_command function that passed the command to the compumotor for 
intrepretation.  The argruements are

  file_descriptor = device opened by rs232_openport function that describes 
                    the serial device where the compumotor is found.
  command = pointer to the string containing the command that will be passed 
            to the compumotor command.  The command should not have the 
	    terminating ":".  This will be appended to the string in the 
	    function automatically.
  responce = array of string pointers that will contain the reply from the
             compumotor.  If response==NULL, response_buffer_length==0, or 
	     number_of_terminators==0 then no reply is expected.
  response_buffer_length = length of the reply buffer string.  This is the 
                           maximum size of the reply buffer any string beyond 
			   this will not be read in. 
  number_of_terminators = number of "\n" (carrage returns) expected from the 
                          reply of the compumotor.  This is to allow for 
                          reading of multiple line replies from the compumotor.

Initial version of this software was written by Robert C. Berrington.
Please contact for questions regarding the code at rberring@uwyo.edu.
*/
int compumotor_command(int file_descriptor,
		       char *command,
		       char **response,
		       int response_buffer_length,
		       int number_of_terminators) {
  char c='\0';
  int i;
  int j;
  int max_attempts=1;
  int status=FAILURE;
  size_t bytes_read;
  unsigned int sleep_s=1; /* seconds to sleep */
  char *command_with_terminator=NULL;
  /*
    Test to make sure the arguements passed into the
    compumotor_command function are correct
  */
  if (command == NULL) {
    fprintf(stderr,
	    "'command' buffer pointer passed was NULL.  No command sent.\n");
    fflush(stderr);
    return NULL_ARGUEMENT;
  }
  if ((response_buffer_length>0) && (response==NULL)) {
    fprintf(stderr,
	    "'response' buffer pointer passed was NULL with positive expected buffer length!\n");
    fflush(stderr);
    return NULL_ARGUEMENT;
  }
  if (number_of_terminators==0) {
    fprintf(stderr,
	    "*WARNING* expected number of terminators was %d! No reply expected\n",
	    number_of_terminators);
    fflush(stderr);
  }
  /* 
     Allocate the memory required for the string that will include the
     terminator sequence for the compumotor command.  This is the will
     be the string that will actually be sent to the compumotor
  */
  if ((command_with_terminator = calloc(strlen(command)+2, sizeof(char)))==NULL) {
    fprintf(stderr, "*ERROR* failed to allocate command buffer!");
    fflush(stderr);
    return FAILURE;
  }

  strcpy(command_with_terminator, command);
  strcat(command_with_terminator, ":\0"); /* Append end of command sequence */

#ifdef DEBUG
  /* Just to show that we got this far. */
  printf("The command '%s' was received.\n", command_with_terminator);
#endif
  
  status = rs232_putline(file_descriptor,command_with_terminator);
  free(command_with_terminator);

  if (status != SUCCESS) {
    return status;
  }
/* 
   Get the response, if one is expected. 
*/
  if (   (response != NULL) 
      || (response_buffer_length != 0) 
      || (number_of_terminators != 0)) {
    for (j=0; j<number_of_terminators; j++) {
      for (i=0; i<max_attempts; i++) {
	c = '\0';
	while (c != '*') {
	  status = rs232_getchar(file_descriptor, &c);
	  
	  if (status != SUCCESS) {
	    response[0] = '\0';
	    fprintf(stderr,
		    "*ERROR* Failed while waiting for '*'.\n");
	    fflush(stderr);
	    return status;
	  }
	}
	/* Read in the Compumotor response. */
	status = rs232_getline(file_descriptor,
			       response[j],
			       response_buffer_length,
			       &(bytes_read));
	if (status == SUCCESS) {
	  break;		/* Exit the for() loop. */
	}
	sleep(sleep_s);
      }
      
      if (i >= max_attempts) {
	if (status != SUCCESS) {
	  fprintf(stderr,
		  "Failed at attempt to discard unread characters");
	  fflush(stderr);
	  return FAILURE;
	}
      } 
    }
  }
  return SUCCESS;
} /* function compumotor_command */