/*
LiquidCrystal I2C
PubSubClient
DHT sensor library
*/

#define MQTT_TOPIC  "esp32"
#define LED 4
#define DHTPIN 23
#define DHTTYPE DHT22
#define TIMEDHT 1000

#include <WiFi.h>
#include <PubSubClient.h>
#include <Wire.h>
#include "DHT.h"
#include <LiquidCrystal_I2C.h>

// Add your MQTT Broker IP address, example:
const char* mqtt_server = "51.91.253.169";

WiFiClient espClient;
PubSubClient client(espClient); //lib required for mqtt

LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27, 20, 4);

long lastMsg = 0;
char msg[50];
int value = 0;

float temperature = 0;
float humidity = 0;

// LED Pin
const int ledPin = 4;

uint32_t timerDHT = TIMEDHT;

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(115200);
  pinMode(ledPin, OUTPUT);
  //LCD.init();
  delay(10);

  LCD.init();
  LCD.backlight();
  LCD.setCursor(0, 0);
  LCD.print("Connecting to ");
  LCD.setCursor(0, 1);
  LCD.print("WiFi ");

  WiFi.begin("Wokwi-GUEST", "", 6);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  LCD.setCursor(0, 0);
  LCD.print("WiFi connected");
  LCD.setCursor(0, 1);
  LCD.print("IP: ");
  LCD.println(WiFi.localIP());

  client.setServer(mqtt_server, 1883);//connecting to mqtt server
  client.setCallback(callback);
  //delay(5000);
  connectmqtt();

  dht.begin();
}

void connectmqtt()
{
  client.connect("ESP32_clientID", "2dstem", "2dStem24");  // ESP will connect to mqtt broker with clientID
  {
    Serial.println("connected to MQTT");
    // Once connected, publish an announcement...

    // ... and resubscribe
    client.subscribe("inTopic"); //topic=Demo
    client.publish("outTopic",  "connected to MQTT");

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


void callback(char* topic, byte* payload, unsigned int length) {   //callback includes topic and payload ( from which (topic) the payload is comming)
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i = 0; i < length; i++)
  {
    Serial.print((char)payload[i]);
  }
  if ((char)payload[0] == 'O' && (char)payload[1] == 'N') //on
  {
    digitalWrite(LED, HIGH);
    Serial.println("on");
    client.publish("esp32/out", "LED turned ON");
  }
  else if ((char)payload[0] == 'O' && (char)payload[1] == 'F' && (char)payload[2] == 'F') //off
  {
    digitalWrite(LED, LOW);
    Serial.println(" off");
    client.publish("esp32/out", "LED turned OFF");
  }
  Serial.println();
}

void callback2(char* topic, byte* message, unsigned int length) {
  Serial.print("Message arrived on topic: ");
  Serial.print(topic);
  Serial.print(". Message: ");
  String messageTemp;
  
  for (int i = 0; i < length; i++) {
    Serial.print((char)message[i]);
    messageTemp += (char)message[i];
  }
  Serial.println();

  // Feel free to add more if statements to control more GPIOs with MQTT

  // If a message is received on the topic esp32/output, you check if the message is either "on" or "off". 
  // Changes the output state according to the message
  if (String(topic) == "esp32/out") {
    Serial.print("Changing output to ");
    if(messageTemp == "on"){
      Serial.println("on");
      digitalWrite(ledPin, HIGH);
    }
    else if(messageTemp == "off"){
      Serial.println("off");
      digitalWrite(ledPin, LOW);
    }
  }
}

void reconnect() {
  while (!client.connected()) {
    Serial.println("Attempting MQTT connection...");
    if (client.connect("ESP32_clientID")) {
      Serial.println("connected");
      // Once connected, publish an announcement...
      client.publish("esp32/out", "Nodemcu connected to MQTT");
      // ... and resubscribe
      client.subscribe("esp32/in");

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

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

  long now = millis();
  if (now - lastMsg > 5000) {
    lastMsg = now;
    
    temperature = dht.readTemperature(); 
    // Convert the value to a char array
    char tempString[8];
    dtostrf(temperature, 1, 2, tempString);
    Serial.print("Temperature: ");
    Serial.println(tempString);
    client.publish("esp32/temperature", tempString);

    humidity = dht.readHumidity();    
    // Convert the value to a char array
    char humString[8];
    dtostrf(humidity, 1, 2, humString);
    Serial.print("Humidity: ");
    Serial.println(humString);
    client.publish("esp32/humidity", humString);
  }
}