#include <errno.h>
#include <tcl.h>
#include <json-c/json.h>
#include "ascon.h"
#include "ascon.i"
#include "script.h"

/*
 * protocol for SECoP
 *
 * Markus Zolliker June 2017
 */

/*----------------------------------------------------------------------------*/
int SecopProtHandler(Ascon *a) {
  int ret;
  char *result;
  char *space;
  char *json;
  Tcl_Obj *tcllist[3], *tclobj;
  int l;
  struct json_object *jobj;

  switch (a->state) {
  case AsconWriting:
    /* do not skip garbage (might be a message!) */
    l = GetDynStringLength(a->wrBuffer) - a->wrPos;
    ret = AsconWriteChars(a->fd, GetCharArray(a->wrBuffer) + a->wrPos, l);
    if (ret < 0) {
      AsconError(a, "ASC4", errno); /* sets state to AsconFailed */
    } else {
      a->wrPos += ret;
      if (a->wrPos >= GetDynStringLength(a->wrBuffer)) {
        a->state = AsconWriteDone;
      }
    }
    return 1;
  case AsconWriteStart:
    if (GetDynStringLength(a->wrBuffer) == 0) {
      /* do not send empty message */
      a->state = AsconWriteDone;
      return 1;
    }
    break;
  }
  ret = AsconStdHandler(a);
  switch (a->state) {
  case AsconReading:
    if (ret) {
      if (a->timeout < 1) {
        /* extend timeout to 1 sec during a message */
        a->start = DoubleTime() + 1 - a->timeout;
      }
    }
    break;
  case AsconReadDone:
    result = GetCharArray(a->rdBuffer);
    space = strchr(result, ' ');
    if (space) {
      json = strchr(space+1, ' ');
      if (json) {
        json++;
        jobj = json_tokener_parse(json);
        if (jobj) {
          tcllist[0] = Tcl_NewStringObj(result, space - result);
          tcllist[1] = Tcl_NewStringObj(space + 1, json - space - 2);
          tcllist[2] = json2tcl(jobj);
          tclobj = Tcl_NewListObj(3, tcllist);
          DynStringCopy(a->rdBuffer, Tcl_GetString(tclobj));
          json_object_put(jobj); /* free jobj */
        }
      }
    }
  }
  return ret;
}

/*----------------------------------------------------------------------------*/
void AddSecopProtocol() {
  static AsconProtocol secopprot;
  secopprot.name = "SECoP";
  secopprot.handler = SecopProtHandler;
  secopprot.init = AsconStdInit;
  AsconInsertProtocol(&secopprot);
}