/*
  OpenMQTTGateway  - ESP8266 or Arduino program for home automation

   Act as a wifi or ethernet gateway between your RF/infrared IR signal  and a MQTT broker
   Send and receiving command by MQTT

  This gateway enables to:
 - receive MQTT data from a topic and send RF signal corresponding to the received MQTT data with an RFM69 module
 - publish MQTT data to a different topic related to received signal from an RFM69 module

    Copyright: (c)Felix Rusu LowPowerLab.com
    Library and code by Felix Rusu - felix@lowpowerlab.com
    Modification of the code nanohab from bbx10 https://github.com/bbx10/nanohab
    Copyright: (c)Florian ROBERT

    This file is part of OpenMQTTGateway.

    OpenMQTTGateway 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.

    OpenMQTTGateway 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 ZgatewayRFM69

#include <RFM69.h>                //https://www.github.com/lowpowerlab/rfm69
#include <SPI.h>
#include <EEPROM.h>

char RadioConfig[128];

// vvvvvvvvv Global Configuration vvvvvvvvvvv

struct _GLOBAL_CONFIG {
  uint32_t    checksum;
  char        rfmapname[32];
  char        encryptkey[16+1];
  uint8_t     networkid;
  uint8_t     nodeid;
  uint8_t     powerlevel; // bits 0..4 power leve, bit 7 RFM69HCW 1=true
  uint8_t     rfmfrequency;
};

#define GC_POWER_LEVEL    (pGC->powerlevel & 0x1F)
#define GC_IS_RFM69HCW  ((pGC->powerlevel & 0x80) != 0)
#define SELECTED_FREQ(f)  ((pGC->rfmfrequency==f)?"selected":"")

struct _GLOBAL_CONFIG *pGC;

// vvvvvvvvv Global Configuration vvvvvvvvvvv
uint32_t gc_checksum() {
  uint8_t *p = (uint8_t *)pGC;
  uint32_t checksum = 0;
  p += sizeof(pGC->checksum);
  for (size_t i = 0; i < (sizeof(*pGC) - 4); i++) {
    checksum += *p++;
  }
  return checksum;
}

#if defined(ESP8266) || defined(ESP32)
void eeprom_setup() {
  EEPROM.begin(4096);
  pGC = (struct _GLOBAL_CONFIG *)EEPROM.getDataPtr();
  // if checksum bad init GC else use GC values
  if (gc_checksum() != pGC->checksum) {
    trc("Factory reset");
    memset(pGC, 0, sizeof(*pGC));
    strcpy_P(pGC->encryptkey, ENCRYPTKEY);
    strcpy_P(pGC->rfmapname, RFM69AP_NAME);
    pGC->networkid = NETWORKID;
    pGC->nodeid = NODEID;
    pGC->powerlevel = ((IS_RFM69HCW)?0x80:0x00) | POWER_LEVEL;
    pGC->rfmfrequency = FREQUENCY;
    pGC->checksum = gc_checksum();
    EEPROM.commit();
  }
}
#endif

RFM69 radio;

void setupRFM69(void) {
  #if defined(ESP8266) || defined(ESP32)
    eeprom_setup();
  #endif
  int freq;
  static const char PROGMEM JSONtemplate[] =
    R"({"msgType":"config","freq":%d,"rfm69hcw":%d,"netid":%d,"power":%d})";
  char payload[128];

  radio = RFM69(RFM69_CS, RFM69_IRQ, GC_IS_RFM69HCW, RFM69_IRQN);

  // Initialize radio
  if (!radio.initialize(pGC->rfmfrequency, pGC->nodeid, pGC->networkid))
  {
    trc(F("ZgatewayRFM69 initialization failed"));
    }

  if (GC_IS_RFM69HCW) {
    radio.setHighPower();    // Only for RFM69HCW & HW!
  }
  radio.setPowerLevel(GC_POWER_LEVEL); // power output ranges from 0 (5dBm) to 31 (20dBm)

  if (pGC->encryptkey[0] != '\0') radio.encrypt(pGC->encryptkey);

  trc(F("ZgatewayRFM69 Listening and transmitting at"));
  switch (pGC->rfmfrequency) {
    case RF69_433MHZ:
      freq = 433;
      break;
    case RF69_868MHZ:
      freq = 868;
      break;
    case RF69_915MHZ:
      freq = 915;
      break;
    case RF69_315MHZ:
      freq = 315;
      break;
    default:
      freq = -1;
      break;
  }
  trc(String(freq));

  size_t len = snprintf_P(RadioConfig, sizeof(RadioConfig), JSONtemplate,
      freq, GC_IS_RFM69HCW, pGC->networkid, GC_POWER_LEVEL);
  if (len >= sizeof(RadioConfig)) {
    trc("\n\n*** RFM69 config truncated ***\n");
  }
}

#ifdef subjectRFM69toMQTTrssi
void publishRSSI(int16_t rssi) {
  // Send the value of the rssi to MQTT
  char buff[sizeof(subjectRFM69toMQTTrssi)+4];
  sprintf(buff, "%s/%d", subjectRFM69toMQTTrssi, radio.SENDERID);
  char buff_rssi[5];
  sprintf(buff_rssi, "%d", radio.RSSI);
  boolean result = client.publish(buff, buff_rssi);
}
#else
#define publishRSSI(input)
#endif

boolean RFM69toMQTT(void) {
  //check if something was received (could be an interrupt from the radio)
  if (radio.receiveDone())
  {
    uint8_t data[RF69_MAX_DATA_LEN+1]; // For the null character
    uint8_t SENDERID = radio.SENDERID;
    uint8_t DATALEN = radio.DATALEN;
    uint16_t RSSI = radio.RSSI;

    //save packet because it may be overwritten
    memcpy(data, (void *)radio.DATA, DATALEN);
    data[DATALEN] = '\0';  // Terminate the string

    // Ack as soon as possible
    //check if sender wanted an ACK
    if (radio.ACKRequested())
    {
      radio.sendACK();
    }
    //updateClients(senderId, rssi, (const char *)data);

    trc(F("Data received"));
    trc((const char *)data);

    char buff[sizeof(subjectRFM69toMQTT)+4];
    sprintf(buff, "%s/%d", subjectRFM69toMQTT, SENDERID);
    client.publish(buff,(char *)data);

    publishRSSI(RSSI);

    return true;

  } else {
    return false;
  }
}

boolean MQTTtoRFM69(char * topicOri, char * datacallback) {
  int loops;
  uint32_t startMillis;
  static uint32_t deltaMillis = 0;

  bool good_topic = true;
  for (int i=0; i<strlen(subjectMQTTtoRFM69); i++) {
    if (topicOri[i] != subjectMQTTtoRFM69[i])
      good_topic = false;
  }
  if (!good_topic) {
     Serial.println("Wrong topic");
    return false;
  }
  trc(F("MQTTtoRFM69"));

  char data[RF69_MAX_DATA_LEN+1];
  memcpy(data, (void *)datacallback, RF69_MAX_DATA_LEN);
  data[RF69_MAX_DATA_LEN] = '\0';

  //We look into the subject to see if a special RF protocol is defined
  String topic = topicOri;
  int valueRCV = defaultRFM69ReceiverId; //default receiver id value
  int pos = topic.lastIndexOf(RFM69receiverKey);
  if (pos != -1){
    pos = pos + +strlen(RFM69receiverKey);
    valueRCV = (topic.substring(pos,pos + 3)).toInt();
    trc(F("RFM69 receiver ID:"));
    trc(String(valueRCV));
  }
  loops = 10;
  startMillis = millis();
  while (loops--) {
    if(radio.sendWithRetry(valueRCV, data, strlen(data))) {
      deltaMillis = millis() - startMillis;
      Serial.print(" OK ");
      Serial.println(deltaMillis);

      // Acknowledgement to the GTWRF topic
      char buff[sizeof(subjectGTWRFM69toMQTT)+4];
      sprintf(buff, "%s/%d", subjectGTWRFM69toMQTT, radio.SENDERID);
      boolean result = client.publish(buff, data);
      if (result)trc(F("Ack published"));

      publishRSSI(radio.RSSI);

      return true;
    }
    else {
      Serial.print("!");
    }
    delay(50);
  }
  if (loops <= 0) {
    deltaMillis = 0;
    trc(F("RFM69 sending failed"));
    return false;
  }
}
#endif