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

// WIFI WOKWI
const char* ssid = "Wokwi-GUEST";
const char* password = "";

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

WiFiClient espClient;
PubSubClient client(espClient);

// PIN
#define TRIG 5
#define ECHO 18
#define LDR 34
#define LED 2

long duration;
int distance;
int ldrValue;

// ===================== CALLBACK (TERIMA DATA DARI NODE-RED)
void callback(char* topic, byte* payload, unsigned int length) {
  String message;

  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }

  Serial.print("Message masuk: ");
  Serial.println(message);

  if (message == "ON") {
    digitalWrite(LED, HIGH);
    Serial.println("LED ON");
  } else {
    digitalWrite(LED, LOW);
    Serial.println("LED OFF");
  }
}

// ===================== SETUP
void setup() {
  Serial.begin(115200);

  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
  pinMode(LED, OUTPUT);

  // CONNECT WIFI
  Serial.println("Connecting WiFi...");
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("\nWiFi Connected!");

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

// ===================== RECONNECT MQTT
void reconnect() {
  while (!client.connected()) {
    Serial.println("Connecting MQTT...");

    if (client.connect("ESP32Client")) {
      Serial.println("MQTT Connected!");
      client.subscribe("iot/led");
    } else {
      Serial.print("Failed, rc=");
      Serial.print(client.state());
      Serial.println(" coba lagi...");
      delay(2000);
    }
  }
}

// ===================== LOOP
void loop() {
  if (!client.connected()) reconnect();
  client.loop();

  // ===== SENSOR ULTRASONIC =====
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);

  duration = pulseIn(ECHO, HIGH);
  distance = duration * 0.034 / 2;

  // ===== SENSOR LDR =====
  ldrValue = analogRead(LDR);

  // ===== KIRIM KE MQTT =====
  client.publish("iot/jarak", String(distance).c_str());
  client.publish("iot/cahaya", String(ldrValue).c_str());

  // ===== DEBUG SERIAL =====
  Serial.print("Jarak: ");
  Serial.print(distance);
  Serial.print(" cm | Cahaya: ");
  Serial.println(ldrValue);

  Serial.println("----------------------");

  delay(2000);
}