/*
  xsns_64_hrxl.ino - MaxBotix HRXL serial interface

  Copyright (C) 2021  Jon Little

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifdef USE_HRXL
/*********************************************************************************************\
 * MaxBotix HRXL-MaxSonar ultrasonic range finders
 * Source: https://www.maxbotix.com/documents/HRXL-MaxSonar-WR_Datasheet.pdf
 *
 * Hardware Serial will be selected if GPIO1 = [HRXL Rx]
\*********************************************************************************************/

#define XSNS_64                  64

#define HRXL_READ_TIMEOUT        400 // us; enough for 6 bytes@9600bps

#include <TasmotaSerial.h>
TasmotaSerial *HRXLSerial = nullptr;

uint32_t hrxl_distance_mm = 0;  // distance, mm

/*********************************************************************************************/

void HRXLInit(void) {
  if (PinUsed(GPIO_HRXL_RX)) {
    HRXLSerial = new TasmotaSerial(Pin(GPIO_HRXL_RX), -1, 1);
    if (HRXLSerial->begin(9600)) {
      if (HRXLSerial->hardwareSerial()) {
        ClaimSerial();
      }
      HRXLSerial->setTimeout(HRXL_READ_TIMEOUT);
    }
  }
}

void HRXLEverySecond(void) {
  int num_read = 0;
  int sum = 0;
  while (HRXLSerial->available() > 5) {
    if (HRXLSerial->read() != 'R') {
      continue;
    }
    int d = HRXLSerial->parseInt();
    if (d >= 30 && d <= 5000) {
      sum += d;
      num_read++;
    }
  }
  if (num_read > 1) {
    hrxl_distance_mm = int(sum / num_read);  // mm
  }
}

void HRXLShow(bool json) {
   char types[5] = "HRXL";
   float distance = (float)hrxl_distance_mm / 10;  // cm
   if (json) {
      ResponseAppend_P(PSTR(",\"%s\":{\"" D_JSON_DISTANCE "\":%1_f}"), types, &distance);
#ifdef USE_WEBSERVER
   } else {
      WSContentSend_PD(HTTP_SNS_F_DISTANCE_CM, types, &distance);
#endif  // USE_WEBSERVER
   }
}

/*********************************************************************************************\
 * Interface
\*********************************************************************************************/

bool Xsns64(uint32_t function) {
  if (FUNC_INIT == function) {
    HRXLInit();
  }
  else if (HRXLSerial) {
    switch (function) {
      case FUNC_EVERY_SECOND:
         HRXLEverySecond();
         break;
      case FUNC_JSON_APPEND:
         HRXLShow(1);
         break;
#ifdef USE_WEBSERVER
      case FUNC_WEB_SENSOR:
         HRXLShow(0);
         break;
#endif  // USE_WEBSERVER
    }
  }
  return false;
}

#endif  // USE_HRXL