/** @file Newport 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 response
*   eg
* 2. An acknowledgement (ie 'OK')
*   eg
*     sct_rva send "STT03E8"
*     OK
* 3. An error message
*   eg
*     sct_mc2 send "BGG"
*     ASCERR: 20 Begin not valid with motor off (during read finished)
*/
#include <ctype.h>
#include <errno.h>
#include <ascon.h>
#include <ascon.i>
#include <dynstring.h>

struct NewportProtocol_t {
  unsigned int magic;
  Ascon* parent;
  double last_line_time;
  double last_char_time;
  double inter_line_time;
  double inter_char_time;
};
typedef struct NewportProtocol_t NewportProtocol;

/** @brief Set line terminator before sending command
*/
int NewportWriteStart(Ascon *a) {
  NewportProtocol* private;
  double now;
  int i, len;
  char *text;
  private = (NewportProtocol*) a->private;
  assert(private->magic == 0xcafef00d);
  now = DoubleTime();
  if (now < private->last_line_time) {
    private->last_line_time = now;
  }
  private->last_char_time = now;
  /*
  if (now > private->last_line_time + private->inter_line_time) {
    return 1;
  }
  */
  len = GetDynStringLength(a->wrBuffer);
  text = GetCharArray(a->wrBuffer);
  if (len < 1 || text[len - 1] != '\r')
    DynStringConcat(a->wrBuffer, "\r");
  len = GetDynStringLength(a->wrBuffer);
  /* if there is only the terminator, do not send it */
  if (len <= 1) {
    a->state = AsconWriteDone;
    return 1;
  }
  a->wrPos = 0;
  a->state = AsconWriting;
  text = GetCharArray(a->wrBuffer);
  for (i = 0; i < len; ++i)
    if (islower(text[i]))
      text[i] = toupper(text[i]);
  return 1;
}

/** @brief Write the line one character at a time
*/
int NewportWriting(Ascon *a) {
  NewportProtocol* private;
  int ret;
  double now;
  private = (NewportProtocol*) a->private;
  assert(private->magic == 0xcafef00d);
  now = DoubleTime();
  if (now < private->last_char_time) {
    private->last_char_time = now;
  }
  if (now < private->last_char_time + private->inter_char_time) {
    return 1;
  }
  if (a->wrPos == 0)
    AsconReadGarbage(a->fd);
  ret = AsconWriteChars(a->fd, GetCharArray(a->wrBuffer) + a->wrPos, 1);
  if (ret < 0) {
    AsconError(a, "send failed:", errno);
    /*
     * Ooops: which state shall we go to after a write fail?
     * This seems to retry.
     */
  } else {
    private->last_char_time = now;
    a->wrPos += ret;
    if (a->wrPos >= GetDynStringLength(a->wrBuffer)) {
      private->last_line_time = now;
      a->state = AsconWriteDone;
    }
  }
  return 1;
}

/** @brief Map replies to OK, ASCERR: ..., value.
* You can not use the first character to sort replies from a Newport controller
*/
int NewportReading(Ascon *a) {
  int ret;
  char chr, ch[2];
  char* cp = NULL;

  ret = AsconReadChar(a->fd, &chr);
  while (ret > 0) {
    a->start = DoubleTime();

    DynStringConcatChar(a->rdBuffer, chr);

    ret = AsconReadChar(a->fd, &chr);
  }
  if (ret < 0) {
    AsconError(a, "AsconReadChar failed:", errno);
    return 0;
  } else {
  /* TODO: should always timeout and check for trailing CR */
    double now = DoubleTime();
    char *text = GetCharArray(a->rdBuffer);
    int len = GetDynStringLength(a->rdBuffer);
    double timeout;
    if (len  < 5) {
      if (a->timeout > 0.0)
        timeout = a->timeout;
      else
        timeout = 1.0;
    } else if (text[len - 1] == '\r') {
      timeout = 0.2;
    } else {
      timeout = 0.2;
    }
    if ((now - a->start) > timeout) {
      if (len < 5) {
        a->state = AsconTimeout;
        AsconError(a, "read timeout", 0);
      } else if (text[len - 1] != '\r') {
        AsconError(a, "missing terminator", 0);
      } else if (len > 5 && text[len - 6] != '\r') {
        AsconError(a, "format error", 0);
      } else {
        int i;
        for (i = 0; i < len - 1; ++i)
          if (text[i] == '\r')
            text[i] = ' ';
        text[len - 1] = '\0';
        a->state = AsconReadDone;
      }
    }
  }
  return 0;
}

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

  switch(a->state){
    case AsconWriteStart:
      ret = NewportWriteStart(a);
      return ret;
      break;
    case AsconWriting:
      ret = NewportWriting(a);
      return ret;
      break;
    case AsconReadStart:
      a->start = DoubleTime();
      ret = AsconStdHandler(a);
      return ret;
      break;
    case AsconReading:
      ret = NewportReading(a);
      return ret;
      break;
    default:
      ret = AsconStdHandler(a);
      return ret;
      break;
  }
  return 1;
}

void NewportKillPrivate(void *arg) {
  NewportProtocol *private = (NewportProtocol *) arg;
  assert(private->magic == 0xcafef00d);
  assert(private->parent->private == private);
  private->magic = 0;
  free(arg);
}

int NewportInit(Ascon *a, SConnection *con,
    int argc, char *argv[]) {
  NewportProtocol *private;
  int ret;
  ret = AsconStdInit(a, con, argc, argv);
  private = calloc(sizeof(NewportProtocol), 1);
  a->private = (void *) private;
  private->magic = 0xcafef00d;
  private->parent = a;
  private->inter_line_time = 0.100;
  private->inter_char_time = 0.010;
  a->killPrivate = NewportKillPrivate;
  return ret;
}

void AddNewportProtocoll(){
  AsconProtocol *prot = NULL;

  prot = calloc(sizeof(AsconProtocol), 1);
  prot->name = strdup("newport");
  prot->init = NewportInit;
  prot->handler = NewportProtHandler;
  AsconInsertProtocol(prot);
}