#include <WiFi.h>
#include <WiFiClient.h>
#include <PubSubClient.h>

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* hostname = "broker.hivemq.com";
WiFiClient espClient;
PubSubClient client(espClient);
const char* espClientName = "IOT/PROJECT/AC";
int PORTNUM = 1883;

#define ADC_IN A5

bool ACState = LOW;
bool ACOverride = false; // Flag to indicate if AC state is controlled by MQTT
unsigned long previousMillis = 0;
unsigned long interval = 2000;

void setup_wifi()
{
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED)
  {
    delay(1000);
    Serial.print(".");
  }
  Serial.println();
  Serial.print("Connected to ");
  Serial.println(ssid);
  Serial.print("Given IP by the router to ESP32 is ");
  Serial.println(WiFi.localIP());
}

void connectMQTT()
{
  while (!client.connected())
  {
    Serial.println("Connecting to MQTT...");
    if (client.connect(espClientName))
    {
      Serial.println("Connected");
      MQTTSubscribe();
    }
    else
    {
      Serial.print("Failed with state ");
      Serial.print(client.state());
      delay(2000);
    }
  }
}

void callback(char* topic, byte* payload, unsigned int length)
{
  String messageTemp;
  Serial.print("Data received from broker: ");
  for (int i = 0; i < length; i++)
  {
    Serial.print((char)payload[i]);
    messageTemp += (char)payload[i];
  }
  Serial.println();

  if (String(topic) == "IOT/PROJECT/AC")
  {
    if (messageTemp == "ON")
    {
      ACState = HIGH;
      ACOverride = true;
      digitalWrite(18, ACState);
      Serial.println("AC turned ON via MQTT PANEL");
    }
    else if (messageTemp == "OFF")
    {
      ACState = LOW;
      ACOverride = true;
      digitalWrite(18, ACState);
      Serial.println("AC turned OFF via MQTT PANEL");
    }
  }
}

void setup_MQTT()
{
  client.setServer(hostname, PORTNUM);
  client.setCallback(callback);
}

void MQTTSubscribe()
{
  client.subscribe("IOT/PROJECT/AC");
}

void setup()
{
  Serial.begin(115200);
  pinMode(18, OUTPUT);

  setup_wifi();
  setup_MQTT();
}

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

  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= interval)
  {
    previousMillis = currentMillis;
    int adcRes = analogRead(ADC_IN);
    Serial.println(adcRes);

    if (!ACOverride) // Only control AC based on temperature if not overridden by MQTT
    {
      if (adcRes > 2600)
      {
        ACState = HIGH;
        Serial.println("Temperature > 26C. Turning on AC.");
      }
      else
      {
        ACState = LOW;
        Serial.println("Temperature < 26C. Turning off AC.");
      }
      digitalWrite(18, ACState);
    }
  }
}