/** @file Oxford protocol handler for script-context based controllers.
*
* If you 'send' commands to a oxford controller using this protocol you
* will get one of three possible responses,
* 1. A value
*   eg
* 2. An acknowledgement (ie 'OK')
*   eg
*     sct_mc2 send "MOG"
*     OK
* 3. An error message
*   eg
*     sct_mc2 send "BGG"
*     ASCERR: 20 Begin not valid with motor off (during read finished)
*/
#include <errno.h>
#include <ascon.h>
#include <ascon.i>
#include <dynstring.h>

/** @brief Set line terminator before sending command
*/
int OxfordWriteStart(Ascon *a) {
  DynStringConcat(a->wrBuffer,"\r");
  a->state = AsconWriting;
  a->wrPos = 0;
  return 1;
}

/** @brief Map oxford replies to OK, ASCERR:..., value.
* You can use the first character to sort replies from a oxford controller
* into four categories
* First character is,
* 'SPACE' This is followed by a value
* '?' Error, use 'TC 1' to get  error code and message.
* ':' Command received, in response to commands which don't request data.
* '1-9' First digit of error-code followed by error message. (in response to 'TC 1')
*/
int OxfordReading(Ascon *a) {
  int ret;
  char chr, ch[2];
  char* cp = NULL;

  ret = AsconReadChar(a->fd, &chr);
  while (ret > 0) {
    if (chr != '\r') {
      DynStringConcatChar(a->rdBuffer, chr);
      ret = AsconReadChar(a->fd, &chr);
    }
    else {
      cp = GetCharArray(a->rdBuffer);
      chr = *cp;
      if (*cp == '?') { /* command was in error */
	a->state = AsconIdle;
#if 0
        AsconError(a, GetCharArray(a->rdBuffer), 0);
#else
        DynStringInsert(a->rdBuffer, "ASCERR:", 0);
#endif
	return 0;
      }
      else if (GetDynStringLength(a->rdBuffer) == 1) { /* command was successful */
	DynStringReplace(a->rdBuffer, "OK", 0);
	a->state = AsconReadDone;
	return 1;
      }
      else {
        a->state = AsconReadDone;
	return 1;
      }
    }
  }
  return 1;
}

/** brief Oxford protocol handler.
* This handler formats commands (ie adds cr line terminator) and
* sorts replies into standard responses of
* <value>
* OK
* ASCERR:...
*/
int OxfordProtHandler(Ascon *a) {
  int ret;

  switch(a->state){
    case AsconWriteStart:
      ret = OxfordWriteStart(a);
      return ret;
      break;
    case AsconReading:
      ret = OxfordReading(a);
      return ret;
      break;
    default:
      ret = AsconStdHandler(a);
      return ret;
  }
  return 1;
}

void AddOxfordProtocoll(){
	AsconProtocol *prot = NULL;
	
	prot = calloc(sizeof(AsconProtocol), 1);
	prot->name = strdup("oxford");
	prot->init = AsconStdInit;
	prot->handler = OxfordProtHandler;
	AsconInsertProtocol(prot);
}