#include <WiFi.h>
#include <ArduinoJson.h>
#include <PubSubClient.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27, 20, 4);
const char* ssid = "Wokwi-GUEST";
const char* password = "";
String payload;
String channel = "ESP32MM";
const char* topic1 = "ESP32MM/led";
const char* topic2 = "ESP32MM/Temperature";
const char* topic3 = "ESP32MM/humidity";

const char* server = "";
const char* username = "";
const char* pw = "";
char ClientID[] = "ds-wokwi";
const int port = 1883;

WiFiClient client;
PubSubClient clientmqtt(server, 1883, client);
// Handle a received message
void callback(char* topic, byte* payload, unsigned int length) {
  LCD.setCursor(0, 0);
  LCD.println("Callback executed");
  Serial.println("MQTT callback executed");
  Serial.print("topic:");
  Serial.println(topic);
  
  char message[length + 1];
  for (int i = 0; i < length; i++)
    message[i] = (char)payload[i];

  Serial.print("received Json:");
  Serial.println(message);
  StaticJsonDocument<1024> doc;
  deserializeJson(doc, message);

  if (strcmp(topic, "ESP32MM/led") == 0) {
    boolean parsedPayload = doc["data"];
    digitalWrite(32, parsedPayload);
    LCD.setCursor(0, 1);
    LCD.println("Led State is: ");
    LCD.println(parsedPayload);
  } else if (strcmp(topic, "ESP32MM/Temperature") == 0) {
    float parsedPayload1 = doc["data"];
    LCD.setCursor(0, 2);
    LCD.println("Temp= ");
    LCD.println(parsedPayload1);
  } else if (strcmp(topic, "ESP32MM/humidity") == 0) {
    float parsedPayload2 = doc["data"];
    LCD.setCursor(0, 3);
    LCD.println("Hum = ");
    LCD.println(parsedPayload2);
  }
}

void setup() {
  LCD.init();
  pinMode(32, OUTPUT);
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  clientmqtt.setServer(server, port);
  Serial.println("Server ready");
  LCD.clear();
  LCD.setCursor(0, 0);
  LCD.println("System Online");

}

void loop() {
  if (!clientmqtt.connected()) {
    Serial.println("MQTT not connected");
    if (clientmqtt.connect(ClientID, username, pw)) {

      Serial.println("MQTT Connected");
      clientmqtt.subscribe(topic1);
      clientmqtt.subscribe(topic2);
      clientmqtt.subscribe(topic3);
      clientmqtt.setCallback(callback);
    }
  }
  else {
    clientmqtt.loop();
  }
}