// Libraries that we used
#include <SPI.h>
#include <Ethernet.h>
#include <PubSubClient.h>
#include <WiFi.h>
#include <Wire.h>
#include <Adafruit_SHT31.h>


int soilmoisturevalue = 0; // for moisture value readings
char soilmoisturearray[16]; // to store the moisture value

float humidityvalue = 0; // for humidity value readings
char humidityarray[16]; // to store the humidity value

float temperaturevalue = 0; // for temperature readings
char temperaturearray[16]; // to store the temperature value

int PIN = 4; // the relay is connected to pin 4 on the ESP32

Adafruit_SHT31 sht31 = Adafruit_SHT31();

const char* ssid = "******"; // The network's name
const char* password = "*******"; // password for the network


const char* mqtt_server   = "hsrw.space"; // MQTT Broker IP address
const char* mqtt_username = "user";
const char* mqtt_password = "mqtt";

const char* myname = "rajshree";
const char* soilmoisture_topic = "/amc2021/rajshree/soil_moisture"; // topic to publish moisture values
const char* humidity_topic = "/amc2021/rajshree/humidity"; // topic to publish humidity values
const char* temperature_topic = "/amc2021/rajshree/temperature"; // topic to publish temperature values
const char* water_pump_topic = "amc2021/rajshree/water_pump"; // topic to turn on water pump based on the soil moisture values

void setup_wifi() {
  delay(10);
  // connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password); //use the defined SSID and password

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print("."); // as long as there is no connection to the Wifi, print one dot with 500ms delay
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP()); // when the connection is established, print two messages and the IP of the Wifi
}
void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();
}

WiFiClient ethClient;
PubSubClient client(ethClient);

void reconnect() { //It will reconnect to the server if the connection is lost using a blocking reconnect function

  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Attempt to connect
    if (client.connect("arduinoClient", mqtt_username, mqtt_password)) {
      Serial.println("connected");

    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void setup()
{
  Serial.begin(57600);

  setup_wifi();

  client.setServer(mqtt_server, 1883); //MQTT data transmission using port 1883
  client.setCallback(callback);

  delay(1500); // Allow the hardware to sort itself out
  Serial.println("SHT31 test");
  if (! sht31.begin(0x44)) {   // 0x44 is the i2c address
    Serial.println("Couldn't find SHT31");
    while (1) delay(1);
  }
  pinMode (PIN, OUTPUT); // sets digital pin 4(the relay) as an output

  client.subscribe (water_pump_topic); // subscribe to water pump topic
}

void loop()
{
  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  reading_data (); // reading data from the different sensors from MQTT_publishing

  delay(2000); // delay by 2 sec



}