#include <WiFi.h>
#include <HTTPClient.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27, 16, 2);

// Untuk sensor PIR
#define PIR_PIN 14
int PIR_state = LOW;
int PIR_val = 0;

// Untuk sensor LDR
#define LDR_PIN 34
const float GAMMA = 0.7;
const float RL10 = 50;
int LDR_val;
float lux;

// Untuk connect WiFi & API
const char ssid[] = "Wokwi-GUEST";
const char password[] = "";
String serverName = "https://api.thingspeak.com/update?api_key=NLBEAVPAK2TO2GXM&";

// Untuk perhitungan milis
int interval = 1000;
unsigned long previousMillis = 0;
long lastTime = 0;
long timeOverlay = 500;

void setup() {
  Serial.begin(115200);
  pinMode(PIR_PIN, INPUT); 

  WiFi.begin(ssid, password);
  LCD.init();
  LCD.backlight();

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

  Serial.println("");
  Serial.println("ESP 32 connected");
  LCD.setCursor(0,0);
  LCD.print("ESP 32 connected");
  Serial.println(WiFi.localIP());

  delay(2000);

  LCD.setCursor(0,0);
  LCD.print("   JULIAN A.W   ");
  LCD.setCursor(0,1);
  LCD.print("   2440065264   ");
  delay (500);

  LCD.clear();
  LCD.setCursor(0,0);
  LCD.print("     UASPOSI    ");
  LCD.setCursor(0,1);
  LCD.print("      START     ");
  delay (500);

  LCD.clear();
}

void loop() {
  unsigned long currentMillis = millis();
  
  if ((unsigned long)(currentMillis - previousMillis) >= interval) {
    if(WiFi.status() == WL_CONNECTED) {
      // Deteksi & Perhitungan kecerahan
      LDR_val = analogRead(LDR_PIN); 
      float voltage = LDR_val / 4095. * 5; 
      float resistance = 2000 * voltage / (1 - voltage / 5); 
      lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));

      // Deteksi Jarak PIR
      PIR_val = digitalRead(PIR_PIN);

      LCD.clear();

      LCD.setCursor(0,0);
      LCD.print("Cahaya: ");
      LCD.print(String(lux));

      if (PIR_val == LOW) {
        if (PIR_state == LOW) {

          LCD.setCursor(0,1);
          LCD.print("TIDAK TERDETEKSI");
          delay(1000);
          LCD.setCursor(0,1);
          LCD.print("    GERAKAN     ");

          PIR_state = HIGH;
        }
      } else {
        if (PIR_state == HIGH) {

          LCD.setCursor(0,1);
          LCD.print("   TERDETEKSI   ");
          delay(1000);
          LCD.setCursor(0,1);
          LCD.print("    GERAKAN     ");

          PIR_state = LOW;
        }
      }
      
      sendData(lux, PIR_state);
    } else {
      Serial.println("WiFi Disconnected");
    }

    previousMillis = millis();
  }
}

void sendData(int lux, bool PIR_state) {
  HTTPClient http;

  String url = serverName + "field1=" + lux + "&field2=" + PIR_state;

  http.begin(url.c_str());
  int httpResponseCode = http.GET();

  if (httpResponseCode > 0) {
    Serial.print("HTTP Response Code: ");
    Serial.println(httpResponseCode);
  } else {
    Serial.print("Error Code: ");
    Serial.println(httpResponseCode);
  }

  http.end();
}