/*
  xsns_90-hrg15.ino - Hydreon RG-15 support for Tasmota

  Copyright (c) 2021  Wouter Breukink

  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_HRG15
/*********************************************************************************************\
 * Hydreon RG-15
 * See https://rainsensors.com/products/rg-15/
 * https://rainsensors.com/rg-9-15-protocol/
 *
 * Rule for Domoticz Rain sensor index 418:
 * on tele-rg-15#flowrate do var1 %value% endon
 * on tele-rg-15#event do backlog var2 %value%; mult1 100; event sendrain endon
 * on event#sendrain do dzsend1 418,%var1%;%var2% endon
\*********************************************************************************************/

#define XSNS_90 90

#define RG15_NAME          "RG15"
#define RG15_BAUDRATE      9600
#define RG15_READ_TIMEOUT  500
#define RG15_EVENT_TIMEOUT 60
#define RG15_BUFFER_SIZE   150

#include <TasmotaSerial.h>

#ifdef USE_WEBSERVER
const char HTTP_RG15[] PROGMEM =
  // {s} = <tr><th>, {m} = </th><td>, {e} = </td></tr>
   "{s}" RG15_NAME " " D_JSON_ACTIVE "{m}%2_f " D_UNIT_MILLIMETER "{e}"
   "{s}" RG15_NAME " " D_JSON_EVENT "{m}%2_f " D_UNIT_MILLIMETER "{e}"
   "{s}" RG15_NAME " " D_JSON_TOTAL "{m}%2_f " D_UNIT_MILLIMETER "{e}"
   "{s}" RG15_NAME " " D_JSON_FLOWRATE "{m}%2_f " D_UNIT_MILLIMETER "/" D_UNIT_HOUR "{e}";
#endif  // USE_WEBSERVER

TasmotaSerial *HydreonSerial = nullptr;

struct RG15 {
  float acc = NAN;
  float event = NAN;
  float total = NAN;
  float rate = NAN;
  uint16_t time = RG15_EVENT_TIMEOUT;
  uint8_t init_step;
} Rg15;

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

bool Rg15ReadLine(char* buffer) {
  // All lines are terminated with a carriage return (\r or 13) followed by a new line (\n or 10)
  uint32_t i = 0;
  uint32_t cmillis = millis();
  while (HydreonSerial->available() ) {
    char c = HydreonSerial->read();
    if (c == 10) { break; }                  // New line ends the message

    if ((c >= 32) && (c < 127)) {            // Accept only valid characters
      buffer[i++] = c;
      if (i == RG15_BUFFER_SIZE -1) { break; }  // Overflow
    }

    if ((millis() - cmillis) > RG15_READ_TIMEOUT) {
      AddLog(LOG_LEVEL_DEBUG, PSTR("HRG: Timeout"));
      return false;
    }
  }
  buffer[i] = '\0';

  AddLog(LOG_LEVEL_DEBUG_MORE, PSTR("HRG: Read '%s'"), buffer);

  return true;
}

bool Rg15Parse(char* buffer, const char* item, float* result) {
  char* start = strstr(buffer, item);
  if (start != nullptr) {
    char* end = strstr(start, " mm");        // Metric (mm or mmph)
    if (end == nullptr) {
      end = strstr(start, " i");             // Imperial (in or iph)
    }
    if (end != nullptr) {
      char tmp = end[0];
      end[0] = '\0';
      *result = CharToFloat(start + strlen(item));
      end[0] = tmp;
      return true;
    }
  }
  return false;
}

bool Rg15Process(char* buffer) {
  // Process payloads like:
  // Acc  0.01 mm, EventAcc  2.07 mm, TotalAcc 54.85 mm, RInt  2.89 mmph
  // Acc 0.001 in, EventAcc 0.002 in, TotalAcc 0.003 in, RInt 0.004 iph
  // Acc 0.001 mm, EventAcc 0.002 mm, TotalAcc 0.003 mm, RInt 0.004 mmph, XTBTips 0, XTBAcc 0.01 mm, XTBEventAcc 0.02 mm, XTBTotalAcc 0.03 mm

  // check for the expected data elements
  // Acc should be a position 0 but note if missing we don't want to mistake it for EventAcc
  if (strstr(buffer, "Acc")==buffer && strstr(buffer, "EventAcc") != nullptr && strstr(buffer, "TotalAcc") != nullptr && strstr(buffer, "RInt") != nullptr) {
    Rg15.acc = NAN;
    Rg15.event = NAN;
    Rg15.total = NAN;
    Rg15.rate = NAN;

    float tmp;

    if (Rg15Parse(buffer, "Acc", &tmp)) {
      Rg15.acc=tmp;
    } else {
      AddLog(LOG_LEVEL_DEBUG_MORE, PSTR("HRG: Unable to parse 'Acc' from accumulation data"));
    }
    if (Rg15Parse(buffer, "EventAcc", &tmp)) {
      Rg15.event=tmp;
    } else {
      AddLog(LOG_LEVEL_DEBUG_MORE, PSTR("HRG: Unable to parse 'EventAcc' from accumulation data"));
    }
    if (Rg15Parse(buffer, "TotalAcc", &tmp)) {
      Rg15.total=tmp;
    } else {
      AddLog(LOG_LEVEL_DEBUG_MORE, PSTR("HRG: Unable to parse 'TotalAcc' from accumulation data"));
    }
    if (Rg15Parse(buffer, "RInt", &tmp)) {
      Rg15.rate=tmp;
    } else {
      AddLog(LOG_LEVEL_DEBUG_MORE, PSTR("HRG: Unable to parse 'RInt' from accumulation data"));
    }

    if (Rg15.acc > 0.0f) {
      Rg15.time = RG15_EVENT_TIMEOUT;        // We have some data, so the rain event is on-going
    }
    return true;
  }
  return false;
}

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

void Rg15Init(void) {
  if (PinUsed(GPIO_HRG15_RX) && PinUsed(GPIO_HRG15_TX)) {
    // Max size message:
    // Acc 0.001 mm, EventAcc 0.002 mm, TotalAcc 0.003 mm, RInt 0.004 mmph, XTBTips 0, XTBAcc 0.01 mm, XTBEventAcc 0.02 mm, XTBTotalAcc 0.03 mm
    HydreonSerial = new TasmotaSerial(Pin(GPIO_HRG15_RX), Pin(GPIO_HRG15_TX), 2, 0, RG15_BUFFER_SIZE);
    if (HydreonSerial) {
      if (HydreonSerial->begin(RG15_BAUDRATE)) {
        if (HydreonSerial->hardwareSerial()) { ClaimSerial(); }
#ifdef ESP32
        AddLog(LOG_LEVEL_DEBUG, PSTR("HRG: Serial UART%d"), HydreonSerial->getUart());
#endif
        Rg15.init_step = 5;                  // Perform RG-15 init
      }
    }
  }
}

void Rg15Poll(void) {
  bool publish = false;

  if (!HydreonSerial->available()) {
    if (Rg15.time) {                         // Check if the rain event has timed out, reset rate to 0
      Rg15.time--;
      if (!Rg15.time) {
        AddLog(LOG_LEVEL_DEBUG_MORE, PSTR("HRG: Rg15Poll - rain event has timed out, reset acc & rate to 0 "));
        Rg15.acc = 0;
        Rg15.rate = 0;
        publish = true;
      }
    }
  } else {
    char rg15_buffer[RG15_BUFFER_SIZE];      // Read what's available
    while (HydreonSerial->available()) {
      Rg15ReadLine(rg15_buffer);
      if (Rg15Process(rg15_buffer)) {        // Do NOT use "publish = Rg15Process(rg15_buffer)"
        publish = true;
      }
    }
  }

  if (publish && !TasmotaGlobal.global_state.mqtt_down) {
    MqttPublishSensor();
  }

//       Units: I = Imperial (in)          or M = Metric (mm)
//  Resolution: H = High (0.001)           or L = Low (0.01)
//        Mode: P = Request mode (Polling) or C = Continuous mode - report any change
//     Request: R = Read available data once
  char init_commands[] = "R CLM  ";          // Indexed by Rg15.init_step

  if (Rg15.init_step) {
    Rg15.init_step--;

    char cmnd = init_commands[Rg15.init_step];
    if (cmnd != ' ') {
      HydreonSerial->println(cmnd);
    }
  }
}

void Rg15Show(bool json) {
  if (json) {
    // if the parsing wasn't completely successful then skip the update
    if( !isnan(Rg15.acc) && !isnan(Rg15.event) && !isnan(Rg15.total) && !isnan(Rg15.rate) ) {
      ResponseAppend_P(PSTR(",\"" RG15_NAME "\":{"));
      ResponseAppend_P(PSTR("\"%s\":%2_f,"), D_JSON_ACTIVE, &Rg15.acc);
      ResponseAppend_P(PSTR("\"%s\":%2_f,"), D_JSON_EVENT, &Rg15.event);
      ResponseAppend_P(PSTR("\"%s\":%2_f,"), D_JSON_TOTAL, &Rg15.total);
      ResponseAppend_P(PSTR("\"%s\":%2_f"), D_JSON_FLOWRATE, &Rg15.rate);
      ResponseAppend_P(PSTR("}"));
    }
#ifdef USE_WEBSERVER
  } else {
    WSContentSend_PD(HTTP_RG15, &Rg15.acc, &Rg15.event, &Rg15.total, &Rg15.rate);
#endif  // USE_WEBSERVER
  }
}

/*********************************************************************************************\
 * Commands
\*********************************************************************************************/

bool Rg15Command(void) {
  bool serviced = true;

  if (XdrvMailbox.data_len == 1) {
    char send = XdrvMailbox.data[0] & 0xDF;  // Make uppercase
    HydreonSerial->flush();                  // Flush receive buffer
    HydreonSerial->println(send);

    if ('K' == send) {                       // Restart RG-15 reading DIP switches
      Rg15.init_step = 5;                    // Perform RG-15 init
    }

    ResponseCmndIdxChar(XdrvMailbox.data);
  }

  return serviced;
}

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

bool Xsns90(uint32_t function) {
  bool result = false;

  if (FUNC_INIT == function) {
    Rg15Init();
  }
  else if (HydreonSerial) {
    switch (function) {
      case FUNC_EVERY_SECOND:
        if((TasmotaGlobal.uptime % 60) == 0) {  // every minute
          ExecuteCommand("Sensor90 R", SRC_SENSOR);
        }
        Rg15Poll();
        break;
      case FUNC_COMMAND_SENSOR:
        if (XSNS_90 == XdrvMailbox.index) {
          result = Rg15Command();
        }
        break;
      case FUNC_JSON_APPEND:
        Rg15Show(1);
        break;
#ifdef USE_WEBSERVER
      case FUNC_WEB_SENSOR:
        Rg15Show(0);
        break;
#endif // USE_WEBSERVER
    }
  }
  return result;
}

#endif // USE_HRG15