// Include necessary libraries
#include <WiFi.h>
#include <WiFiClient.h>
#include <PubSubClient.h> // For MQTT functionality

// Your Wi-Fi credentials
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

// MQTT Broker and Topic
const char* mqtt_broker = "test.mosquitto.org"; // Public broker
const char* mqtt_topic = "light/control";       // MQTT topic
const int mqtt_port = 1883;
const char* MQTT_CLIENT_ID = "ESP32_client";    // MQTT client ID

// LED pin
#define led_pin 14

WiFiClient espClient;
PubSubClient client(espClient); // MQTT client

// MQTT Callback Function
void mqttCallback(char* topic, byte* payload, unsigned int length) {
  Serial.print("MQTT message received on topic: ");
  Serial.println(topic);

  String message;
  for (unsigned int i = 0; i < length; i++) {
    message += (char)payload[i];
  }
  message.trim(); // Remove any extra whitespace

  Serial.print("Payload: ");
  Serial.println(message);

  // Parse the message and control the LED
  if (message == "1") {
    digitalWrite(led_pin, HIGH); // Turn LED ON
    Serial.println("Action: LED turned ON via MQTT");
  } else if (message == "0") {
    digitalWrite(led_pin, LOW); // Turn LED OFF
    Serial.println("Action: LED turned OFF via MQTT");
  } else {
    Serial.println("Error: Invalid payload received.");
  }

  // Debug LED state
  int led_state = digitalRead(led_pin);
  Serial.print("LED pin state (readback): ");
  Serial.println(led_state == HIGH ? "ON" : "OFF");
}

void setup() {
  // Debug console
  Serial.begin(115200);
  Serial.println("Starting ESP32...");

  // Initialize LED pin
  pinMode(led_pin, OUTPUT);
  digitalWrite(led_pin, LOW); // Start with LED OFF
  Serial.println("LED initialized to OFF state.");

  // Connect to Wi-Fi
  Serial.print("Connecting to Wi-Fi");
  WiFi.begin(ssid, pass);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.println("\nConnected to Wi-Fi");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());

  // Connect to MQTT broker
  Serial.println("Connecting to MQTT broker...");
  client.setServer(mqtt_broker, mqtt_port);
  client.setCallback(mqttCallback);
  while (!client.connected()) {
    Serial.println("Attempting MQTT connection...");
    if (client.connect(MQTT_CLIENT_ID)) {
      Serial.println("Connected to MQTT broker.");
      client.subscribe(mqtt_topic);
      Serial.print("Subscribed to MQTT topic: ");
      Serial.println(mqtt_topic);
    } else {
      Serial.print("Failed to connect to MQTT, rc=");
      Serial.println(client.state());
      delay(2000);
    }
  }
}

void loop() {
  // Keep MQTT client connected
  if (!client.connected()) {
    Serial.println("MQTT connection lost. Reconnecting...");
    while (!client.connected()) {
      if (client.connect(MQTT_CLIENT_ID)) {
        Serial.println("Reconnected to MQTT broker.");
        client.subscribe(mqtt_topic);
        Serial.print("Subscribed to MQTT topic: ");
        Serial.println(mqtt_topic);
      } else {
        Serial.println("Retrying MQTT connection...");
        delay(2000);
      }
    }
  }
  client.loop();
   digitalWrite(led_pin, HIGH); // Turn LED ON
  delay(1000);
  digitalWrite(led_pin, LOW); // Turn LED OFF
  delay(1000);
}