#include <WiFi.h>
#include <MQTT.h>

// LDR and LED Pins
#define LDR_PIN 34    // ADC1 GPIO pin for LDR
#define LED_PIN 15    // GPIO pin for LED

bool ledState = LOW;  // Tracks the current state of the LED

// WiFi Configuration
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// MQTT Configuration
const char* mqttServer = "mountainrat662.cloud.shiftr.io";
const char* mqttUser = "mountainrat662";
const char* mqttPassword = "b0X48fxDejD3HhdU";
const int mqttPort = 1883;
const char* topic = "esp32/ledStatus";
const char* willTopic = "esp32/status";

// Create MQTT client instance
WiFiClient net;
MQTTClient client(256);

void connectToWiFi() {
  Serial.print("Connecting to WiFi");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected!");
}

void connectToMQTT() {
  Serial.print("Connecting to MQTT");
  client.begin(mqttServer, mqttPort, net);  // Set server and WiFi client
  while (!client.connect("ESP32Client", mqttUser, mqttPassword)) {  // Only pass clientID, user, and password
    Serial.print(".");
    delay(1000);
  }
  Serial.println("\nMQTT connected!");
  client.publish(willTopic, "Online", true);  // Publish online status with retain flag
}

void setup() {
  pinMode(LED_PIN, OUTPUT);  // Set LED pin as output
  Serial.begin(115200);      // Start Serial Monitor

  connectToWiFi();
  connectToMQTT();
}

void loop() {
  if (!client.connected()) {
    connectToMQTT();  // Reconnect to MQTT if disconnected
  }
  client.loop();  // Maintain MQTT connection

  int ldrValue = analogRead(LDR_PIN);   // Read LDR value from ADC1 pin
  bool newLedState = (ldrValue <= 300) ? HIGH : LOW;  // Determine new LED state

  if (newLedState != ledState) {  // Change the state only if it's different
    ledState = newLedState;       // Update the current state
    digitalWrite(LED_PIN, ledState);  // Apply the new state to the LED

    // Print status to Serial Monitor
    Serial.print("LDR Value: ");
    Serial.print(ldrValue);
    Serial.print(" | LED State: ");
    Serial.println(ledState == HIGH ? "ON" : "OFF");

    // Publish LED state to MQTT with retain flag
    String ledStatus = ledState == HIGH ? "ON" : "OFF";
    client.publish(topic, ledStatus.c_str(), true);
  }

  delay(100);  // Small delay to avoid excessive polling
}