int LDRInput=A0; //Set Analog Input A0 for LDR.
const int directionPin = 2;
const int stepPin = 4;
const int SWITCH_PIN = 8;
int stepsPerRotation = 200;
int stepDelayMicros = 1000;
int totalSteps = 4 * stepsPerRotation;
int statostart;


const float GAMMA = 0.7;
const float RL10 = 50;

void setup() {
Serial.begin(9600);
  pinMode(LDRInput,INPUT);
  pinMode(directionPin, OUTPUT);
  pinMode(stepPin, OUTPUT);
  pinMode(SWITCH_PIN, INPUT);

}

void loop() {
int value = analogRead(LDRInput);//Reads the Value of LDR(light).
Serial.println("LDR value is :");//Prints the value of LDR to Serial Monitor.
Serial.println(value); //prints the values coming from the sensor on the screen

float voltage = value / 1024. * 5;
float resistance = 2000 * voltage / (1 - voltage / 5);
Serial.println("Resistance value: ");
Serial.println(resistance);

float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));

  if (lux >=800) {
    Serial.println("Direct sunlight! ");
  } else {
    Serial.println("No direct sunlight!");
  }

delay(1000);

int switchState = digitalRead(SWITCH_PIN);

  // If the library is closed (slide switch is in the LOW state)
  if (switchState == LOW) {
    // Keep the blinds rolled down
    rolldown();
  } else {
    // The library is open, so check the light intensity

    // Check if direct sunlight is detected
    if (lux >= 800) {
      // Roll down the blinds
      rolldown();
    } else {
      // Roll up the blinds
      rollup();
    }
  } 
}

void rolldown(){

  // Loop to generate pulses for the specified number of steps
  digitalWrite(directionPin, HIGH);
  for (int i = 0; i < totalSteps; ++i) {
    // Pulse the STEP pin to generate a step
    digitalWrite(stepPin, HIGH);
    delayMicroseconds(stepDelayMicros);
    digitalWrite(stepPin, LOW);
    delayMicroseconds(stepDelayMicros);
  }

}

void rollup(){
  // Loop to generate pulses for the specified number of steps
 digitalWrite(directionPin, LOW);
  for (int i = 0; i < totalSteps; ++i) {
    // Pulse the STEP pin to generate a step
    digitalWrite(stepPin, HIGH);
    delayMicroseconds(stepDelayMicros);
    digitalWrite(stepPin, LOW);
    delayMicroseconds(stepDelayMicros);
  }
}