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

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

// Konfigurasi Broker MQTT Publik (menggunakan protokol standar port 1883)
const char* mqtt_server = "broker.hivemq.com";
const int mqtt_port = 1883;

WiFiClient espClient;
PubSubClient client(espClient);

// Definisi Pin Sensor dan Aktuator
const int trigPin = 14;
const int echoPin = 12;
const int ledPin = 2;

unsigned long lastMsg = 0;

void setup_wifi() {
  delay(10);
  Serial.println();
  Serial.print("Menghubungkan ke ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

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

  Serial.println("");
  Serial.println("WiFi terhubung!");
  Serial.print("Alamat IP: ");
  Serial.println(WiFi.localIP());
}

// Fungsi callback saat ada pesan MQTT masuk dari Web Dashboard
void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Pesan diterima [");
  Serial.print(topic);
  Serial.print("] ");
  
  String message = "";
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }
  Serial.println(message);

  if (String(topic) == "esp32/command/led") {
    if (message == "ON") {
      digitalWrite(ledPin, HIGH);
      Serial.println("LED Dinyalakan dari Web!");
    } else if (message == "OFF") {
      digitalWrite(ledPin, LOW);
      Serial.println("LED Dimatikan dari Web!");
    }
  }
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Menghubungkan ke MQTT Broker...");
    // Buat ID Klien unik
    String clientId = "ESP32Client-Wokwi-";
    clientId += String(random(0xffff), HEX);
    
    if (client.connect(clientId.c_str())) {
      Serial.println("Terhubung!");
      // Subscribe ke topik perintah LED
      client.subscribe("esp32/command/led");
    } else {
      Serial.print("Gagal, rc=");
      Serial.print(client.state());
      Serial.println(" Coba lagi dalam 5 detik");
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);

  setup_wifi();
  client.setServer(mqtt_server, mqtt_port);
  client.setCallback(callback);
}

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

  unsigned long now = millis();
  // Kirim data sensor setiap 2 detik sekali
  if (now - lastMsg > 2000) {
    lastMsg = now;

    // Pembacaan Sensor HC-SR04
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);

    long duration = pulseIn(echoPin, HIGH);
    float distance = duration * 0.034 / 2; // Menghitung jarak dalam cm

    // Buat format JSON string untuk dikirim
    String payload = "{\"distance\": " + String(distance, 1) + "}";
    
    Serial.print("Publish jarak: ");
    Serial.println(payload);
    
    client.publish("esp32/sensor/hcsr04", payload.c_str());
  }
}