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

// Wi-Fi credentials
const char* ssid     = "Wokwi-GUEST";
const char* password = "";

// MQTT broker
const char* mqtt_server = "broker.hivemq.com";

WiFiClient espClient;
PubSubClient client(espClient);

const int ledPin  = 2;   // Onboard LED (output)
const int ledPin1 = 16;  // Switch 1 (input)
const int ledPin2 = 17;  // Switch 2 (input)

const char* topic  = "buet/cse/2105065";  // Subscribe topic (receive ON/OFF from Python)
const char* topic2 = "buet/cse/nigga";    // Publish topic  (send switch state to Python)


void callback(char* topic, byte* payload, unsigned int length) {
  String message;
  for (unsigned int i = 0; i < length; i++) {
    message += (char)payload[i];
  }

  Serial.print("Received [");
  Serial.print(topic);
  Serial.print("] : ");
  Serial.println(message);

  if (message == "ON") {
    digitalWrite(ledPin, HIGH);
    Serial.println("LED turned ON");
  } else if (message == "OFF") {
    digitalWrite(ledPin, LOW);
    Serial.println("LED turned OFF");
  } else if (message == "Switched") {
    Serial.println("Switch 1 was pressed (Python notified us)");
  } else if (message == "Un-switched") {
    Serial.println("Switch 2 was pressed (Python notified us)");
  }
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Connecting to MQTT...");
    if (client.connect("ESP32_Wokwi_LED")) {
      Serial.println("connected");
      client.subscribe(topic);   // Listen for ON/OFF commands from Python
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" — retrying in 5s");
      delay(5000);
    }
  }
}

void setup() {
  pinMode(ledPin,  OUTPUT);
  pinMode(ledPin1, INPUT);
  pinMode(ledPin2, INPUT);
  digitalWrite(ledPin, LOW);

  Serial.begin(115200);

  WiFi.begin(ssid, password);
  Serial.print("Connecting to Wi-Fi...");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println(" Wi-Fi connected!");

  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

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

  // Publish to topic2 when a physical switch is pressed
  if (digitalRead(ledPin1) == HIGH) {
    client.publish(topic2, "Switched-1");
    Serial.println("Switch 1 On Sent");
    delay(500);  // simple debounce
  }
  if (digitalRead(ledPin1) == LOW) {
    client.publish(topic2, "Un-Switched-1");
    Serial.println("Switch 1 Off Sent");
    delay(500);  // simple debounce
  }
  if (digitalRead(ledPin2) == HIGH) {
    client.publish(topic2, "Switched-2");
    Serial.println("Switch 2 On Sent");
    delay(500);  // simple debounce
  }
  if (digitalRead(ledPin2) == LOW) {
    client.publish(topic2, "Un-switched-2");
    Serial.println("Switch 2 Off Sent");
    delay(500);  // simple debounce
  }
}