#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <math.h>

LiquidCrystal_I2C lcd(0x27,16,2);

// -------- PINLER --------
int ldrPin = 34;
int redPin = 25;
int greenPin = 26;
int bluePin = 27;
int buttonPin = 18;

// -------- ZAMAN --------
unsigned long previousMillis = 0;
unsigned long serialMillis = 0;

int interval = 2000;
int screen = 0;

bool lastButtonState = HIGH;

void setup() {
  Serial.begin(115200);

  lcd.init();
  lcd.backlight();

  pinMode(ldrPin, INPUT);

  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);

  pinMode(buttonPin, INPUT_PULLUP);
}

void loop() {

  // -------- FAKE DHT --------
  float temp = 24;
  float hum  = 49;

  // -------- GERÇEK LUX HESABI --------
  int ldrValue = analogRead(ldrPin);

  float voltage = ldrValue / 4095.0;
  float lux = pow((1 - voltage) / voltage, 1.4) * 50;

  // -------- SERIAL (PDF FORMAT) --------
  if (millis() - serialMillis >= 3000) {
    serialMillis = millis();

    Serial.print("Nem: ");
    Serial.print(hum);
    Serial.print("% || Sicaklik: ");
    Serial.print(temp);
    Serial.print("C || Isik: ");
    Serial.print(lux);
    Serial.println(" lux");
  }

  // -------- BUTON --------
  bool buttonState = digitalRead(buttonPin);

  if (buttonState == LOW && lastButtonState == HIGH) {
    interval = (interval == 2000) ? 4000 : 2000;

    Serial.print("LCD suresi degistirildi: ");
    Serial.print(interval / 1000);
    Serial.println(" sn");

    delay(200);
  }

  lastButtonState = buttonState;

  // -------- LCD --------
  if (millis() - previousMillis >= interval) {
    previousMillis = millis();

    lcd.clear();

    // NEM
    if (screen == 0) {
      lcd.setCursor(0,0);
      lcd.print("NEM");
      lcd.setCursor(15,0);
      lcd.print(interval/1000);

      lcd.setCursor(0,1);
      lcd.print(hum);
      lcd.print(" - ");
      lcd.print(hum <= 60 ? "LOW" : "HIGH");
    }

    // SICAKLIK
    else if (screen == 1) {
      lcd.setCursor(0,0);
      lcd.print("SICAKLIK");
      lcd.setCursor(15,0);
      lcd.print(interval/1000);

      lcd.setCursor(0,1);
      lcd.print(temp);
      lcd.print(" - ");

      if (temp < 0) lcd.print("VERY LOW");
      else if (temp <= 30) lcd.print("NORMAL");
      else lcd.print("HIGH");
    }

    // ISIK
    else if (screen == 2) {
      lcd.setCursor(0,0);
      lcd.print("ISIK");
      lcd.setCursor(15,0);
      lcd.print(interval/1000);

      lcd.setCursor(0,1);

      if (lux < 10) lcd.print("KARANLIK");
      else lcd.print("AYDINLIK");
    }

    screen = (screen + 1) % 3;
  }

  // -------- RGB LED (COMMON ANODE) --------

  if (lux < 10) {
    // KARANLIK → MAVİ
    digitalWrite(redPin, HIGH);
    digitalWrite(greenPin, HIGH);
    digitalWrite(bluePin, LOW);
  }
  else {
    if (temp < 0) {
      // VERY LOW → AÇIK MAVİ
      digitalWrite(redPin, HIGH);
      digitalWrite(greenPin, LOW);
      digitalWrite(bluePin, LOW);
    }
    else if (temp <= 30) {
      // NORMAL → YEŞİL
      digitalWrite(redPin, HIGH);
      digitalWrite(greenPin, LOW);
      digitalWrite(bluePin, HIGH);
    }
    else if (temp <= 40) {
      // HIGH → TURUNCU
      digitalWrite(redPin, LOW);
      digitalWrite(greenPin, LOW);
      digitalWrite(bluePin, HIGH);
    }
    else {
      // ÇOK YÜKSEK → KIRMIZI
      digitalWrite(redPin, LOW);
      digitalWrite(greenPin, HIGH);
      digitalWrite(bluePin, HIGH);
    }
  }
}