#include <WiFi.h>
#include <HTTPClient.h>

// Ganti dengan informasi WiFi Anda
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// ThingSpeak API URL dan API Keys
const char* server = "http://api.thingspeak.com/update";
const char* writeApiKey = "ZZSLDWS6V48K7SMX";  // Write API Key
const char* readApiKey = "G6CGYCXTKIV7U3N6";   // Read API Key

// Pin LED pada ESP32
const int ledPin = 5;

void setup() {
  Serial.begin(115200);
  
  // Menyiapkan pin LED sebagai OUTPUT
  pinMode(ledPin, OUTPUT);
  
  // Hubungkan ke WiFi
  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected!");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());
}

void loop() {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;

    // URL untuk membaca nilai dari ThingSpeak (menggunakan Read API Key)
    String url = String("http://api.thingspeak.com/fields/1.json?api_key=") + readApiKey;
    http.begin(url);
    
    // Mengambil respon dari ThingSpeak
    int httpResponseCode = http.GET();
    
    if (httpResponseCode > 0) {
      String payload = http.getString();
      Serial.println("Response from ThingSpeak:");
      Serial.println(payload);
      
      // Ambil nilai dari field "LED" (misalnya, menggunakan JSON)
      int ledStatus = parseLEDStatus(payload);
      
      // Kontrol LED berdasarkan nilai dari ThingSpeak
      if (ledStatus == 1) {
        digitalWrite(ledPin, HIGH);  // LED ON
        Serial.println("LED ON");
      } else {
        digitalWrite(ledPin, LOW);  // LED OFF
        Serial.println("LED OFF");
      }
    } else {
      Serial.println("Error on HTTP request");
    }

    // Mengirim data ke ThingSpeak (menggunakan Write API Key)
    int ledStatus = digitalRead(ledPin); // Membaca status LED
    String postData = "api_key=" + String(writeApiKey) + "&field1=" + String(ledStatus);
    
    http.begin(server);  // Mulai HTTP request ke endpoint update
    http.addHeader("Content-Type", "application/x-www-form-urlencoded");

    // Kirimkan data (POST)
    int httpResponseCodePost = http.POST(postData);
    
    if (httpResponseCodePost > 0) {
      Serial.println("Data sent to ThingSpeak: " + postData);
      Serial.println("Response code: " + String(httpResponseCodePost));
    } else {
      Serial.println("Error on HTTP POST request");
    }

    http.end();
  } else {
    Serial.println("WiFi Disconnected");
  }

  // Cek status setiap 15 detik
  delay(15000);
}

// Fungsi untuk mengurai data JSON dari ThingSpeak (mengambil nilai LED)
int parseLEDStatus(String payload) {
  int ledValue = 0;
  int startIndex = payload.indexOf("field1") + 8;
  int endIndex = payload.indexOf(",", startIndex);
  String ledString = payload.substring(startIndex, endIndex);
  ledValue = ledString.toInt();
  return ledValue;
}