StaticJsonDocument<48> doc;

doc["temperature"] = 45;
doc["humidity"] = 12.3;
doc["pressure"] = 1234;

serializeJson(doc, output);

#define TINY_GSM_MODEM_SIM800      // Modem is SIM800
#define TINY_GSM_RX_BUFFER   1024  // Set RX buffer to 1Kb
#include <Wire.h>
#include <ArduinoJson.h>
#include <TinyGsmClient.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>

const char apn[]      = "data.mono"; // APN https://docs.monogoto.io/getting-started/initial-configuration#device-configuration
const char gprsUser[] = ""; // GPRS User
const char gprsPass[] = ""; // GPRS Password

// SIM card PIN (leave empty, if not defined)
const char simPIN[]   = ""; 

// Server details
// The server variable can be just a domain name or it can have a subdomain. It depends on the service you are using
const char server[] = "industrial.api.ubidots.com";
const char resource[] = "/api/v1.6/devices/lilygo"; // resource path "/api/v1.6/devices/<device label>"
const int  port = 80;// server port number

// Keep this API Key value to be compatible with the PHP code provided in the project page. 
// If you change the apiKeyValue value, the PHP file /post-data.php also needs to have the same key 
String token = "<Ubidots account Token>";
StaticJsonDocument<48> doc;  //Reserve space for JSON object
#define MODEM_RST            5
#define MODEM_PWKEY          4
#define MODEM_POWER_ON       23
#define MODEM_TX             27
#define MODEM_RX             26
#define I2C_SDA              21
#define I2C_SCL              22
#define I2C_SDA_2            18
#define I2C_SCL_2            19
       

// Set serial for debug console (to Serial Monitor, default speed 115200)
#define SerialMon Serial
// Set serial for AT commands (to SIM800 module)
#define SerialAT Serial1

// Configure TinyGSM library
// Define the serial console for debug prints, if needed
//#define DUMP_AT_COMMANDS

#ifdef DUMP_AT_COMMANDS
  #include <StreamDebugger.h>
  StreamDebugger debugger(SerialAT, SerialMon);
  TinyGsm modem(debugger);
#else
  TinyGsm modem(SerialAT);
#endif

// I2C for SIM800 (to keep it running when powered from battery)
TwoWire I2CPower = TwoWire(0); 
TwoWire I2CBME = TwoWire(1);
Adafruit_BME280 bme; 

// TinyGSM Client for Internet connection
TinyGsmClient client(modem);

#define uS_TO_S_FACTOR 1000000UL   /* Conversion factor for micro seconds to seconds */
#define TIME_TO_SLEEP  3600        /* Time ESP32 will go to sleep (in seconds) 3600 seconds = 1 hour */

#define IP5306_ADDR          0x75
#define IP5306_REG_SYS_CTL0  0x00

bool setPowerBoostKeepOn(int en){
  I2CPower.beginTransmission(IP5306_ADDR);
  I2CPower.write(IP5306_REG_SYS_CTL0);
  if (en) {
    I2CPower.write(0x37); // Set bit1: 1 enable 0 disable boost keep on
  } else {
    I2CPower.write(0x35); // 0x37 is default reg value
  }
  return I2CPower.endTransmission() == 0;
}

void setup() {
  // Set serial monitor debugging window baud rate to 115200
  SerialMon.begin(115200);

  // Start I2C communication
  uint32_t frq = 400000;
  I2CPower.begin(I2C_SDA, I2C_SCL, frq);
  I2CBME.begin(I2C_SDA_2, I2C_SCL_2, frq);

 
  // Keep power when running from battery
  bool isOk = setPowerBoostKeepOn(1);
  SerialMon.println(String("IP5306 KeepOn ") + (isOk ? "OK" : "FAIL"));

  // Set modem reset, enable, power pins
  pinMode(MODEM_PWKEY, OUTPUT);
  pinMode(MODEM_RST, OUTPUT);
  pinMode(MODEM_POWER_ON, OUTPUT);
  digitalWrite(MODEM_PWKEY, LOW);
  digitalWrite(MODEM_RST, HIGH);
  digitalWrite(MODEM_POWER_ON, HIGH);

  // Set GSM module baud rate and UART pins
  SerialAT.begin(115200, SERIAL_8N1, MODEM_RX, MODEM_TX);
  delay(3000);

  // Restart SIM800 module, it takes quite some time
  // To skip it, call init() instead of restart()
  SerialMon.println("Initializing modem...");
  modem.restart();
  // use modem.init() if you don't need the complete restart

  // Unlock your SIM card with a PIN if needed
  if (strlen(simPIN) && modem.getSimStatus() != 3 ) {
    modem.simUnlock(simPIN);
  }

  if (!bme.begin(0x76, &I2CBME)) {
    Serial.println("Could not find a valid BME280 sensor, check wiring!");
    while (1);
  }
  
  // You might need to change the BME280 I2C address, in our case it's 0x76
  // Configure the wake up source as timer wake up  
  //esp_sleep_enable_timer_wakeup(TIME_TO_SLEEP * uS_TO_S_FACTOR);
}

void loop() {

  String json;  
  //Build JSON Object
  doc["humidity"] = bme.readHumidity();
  doc["temperature"] = bme.readTemperature();
  doc["pressure"] = bme.readPressure()/100;
  
  //Serialize your JSON Object
  serializeJson(doc, json);
  SerialMon.print("Connecting to APN: ");
  SerialMon.print(apn);
  if (!modem.gprsConnect(apn, gprsUser, gprsPass)) {
    SerialMon.println(" fail");
  }
  else {
    SerialMon.println(" OK");
    
    SerialMon.print("Connecting to ");
    SerialMon.print(server);
    if (!client.connect(server, port)) {
      SerialMon.println(" fail");
    }
    else {
      SerialMon.println(" OK");
    
      // Making an HTTP POST request
      SerialMon.println("Performing HTTP POST request...");
    
      client.print(String("POST ") + resource + " HTTP/1.1\r\n");
      client.print(String("Host: ") + server + "\r\n");
      client.println("User-Agent: ESP32");
      client.println("Connection: close");
      client.println("Content-Type: application/json");
      client.print("X-Auth-Token: " + token + "\r\n");
      client.print("Content-Length: ");
      client.println(json.length());
      client.println();
      client.println(json);

      unsigned long timeout = millis();
      while (client.connected() && millis() - timeout < 10000L) {
        // Print HTTP response from server
        while (client.available()) {
          char c = client.read();
          SerialMon.print(c);
          timeout = millis();
        }
      }
      SerialMon.println();
    
      // Close client and disconnect
      client.stop();
      SerialMon.println(F("Server disconnected"));
      modem.gprsDisconnect();
      SerialMon.println(F("GPRS disconnected"));
    }
  }

  delay(5000);
}