// Kitchen buttons
int Bku = 6;   // button Kitchen UP
int Bkd = 5;   // button Kitchen DOWN

// Dining room buttons
int Bdu = 4;   // button Dining UP
int Bdd = 3;   // button Dining DOWN

// Emergency button
int Be = 8;

int kSensor = 9;
int dSensor = 10;



// LEDs
int Mov_up_LED = 12;//red
int Mov_dwn_LED = 13;//green
int At_Kitchen_LED = 52; //green
int At_Dining_LED = 50;  //red

enum ElevatorState { IDLE, MOVING_UP, MOVING_DOWN, Kitchen, Dinning };
ElevatorState currentState = IDLE;

unsigned long moveStartTime = 0;
const unsigned long moveDuration = 5000;


void setup() {
  Serial.begin(9600);

  pinMode(Bku, INPUT_PULLUP);
  pinMode(Bkd, INPUT_PULLUP);
  pinMode(Bdu, INPUT_PULLUP);
  pinMode(Bdd, INPUT_PULLUP);
  pinMode(Be, INPUT_PULLUP);

  pinMode(kSensor, INPUT_PULLUP);
  pinMode(dSensor, INPUT_PULLUP);


  pinMode(Mov_up_LED, OUTPUT);
  pinMode(Mov_dwn_LED, OUTPUT);
  pinMode(At_Kitchen_LED, OUTPUT);
  pinMode(At_Dining_LED, OUTPUT);
}

void loop() {
  // Button/sensor inputs
  bool be = !digitalRead(Be);
  bool bku = !digitalRead(Bku);
  bool bkd = !digitalRead(Bkd);
  bool bdu = !digitalRead(Bdu);
  bool bdd = !digitalRead(Bdd);

  bool ks = !digitalRead(kSensor);
  bool ds = !digitalRead(dSensor);


  

  if(bku || bdu == 1)
  {
    currentState = MOVING_UP;
    digitalWrite(Mov_up_LED, HIGH);
    moveStartTime = millis();
    Serial.println("Elevator moving up...");
  }
  else if(bkd || bdd == 1)
  {
    currentState = MOVING_DOWN;
    digitalWrite(Mov_dwn_LED, HIGH);
    moveStartTime = millis();
    Serial.println("Elevator moving dn...");
  }



  // Emergency stop
  if (be) {
    currentState = IDLE;
    stopElevator();
    return;
  }
  

  if (ks == 1)
  {
    currentState = Kitchen;
  }
  if (ds == 1)
  {
    currentState = Dinning;
  }


  switch (currentState) {
    case IDLE:
      if ((bku || bdu) && !bkd && !bdd) {//any up pb was pressed, and down pb was not
        currentState = MOVING_UP;
        digitalWrite(Mov_up_LED, HIGH);
        moveStartTime = millis();
        Serial.println("Elevator moving up...");
      }
      else if ((bkd || bdd) && !bku && !bdu) {
          currentState = MOVING_DOWN;
          digitalWrite(Mov_dwn_LED, HIGH);
          moveStartTime = millis();
          Serial.println("Elevator moving down...");
      }
      break;

    case MOVING_UP:
      digitalWrite(At_Kitchen_LED, LOW);
      digitalWrite(At_Dining_LED, LOW);
      if (millis() - moveStartTime >= moveDuration) {// 5s has passed
        digitalWrite(Mov_up_LED, LOW);
        //currentState = Dinning;
        //Serial.println("Reached dining room.");
      }
      break;

    case MOVING_DOWN:
      digitalWrite(At_Kitchen_LED, LOW);
      digitalWrite(At_Dining_LED, LOW);
      if (millis() - moveStartTime >= moveDuration) {
        digitalWrite(Mov_dwn_LED, LOW);
        //currentState = Kitchen;
        //Serial.println("Reached kitchen.");
      }
      break;

    case Kitchen:
      digitalWrite(At_Kitchen_LED, HIGH);
      break;

    case Dinning:
    digitalWrite(At_Dining_LED, HIGH);
    break;
  }

  delay(50); // small debounce
}

void stopElevator() {
  digitalWrite(Mov_up_LED, LOW);
  digitalWrite(Mov_dwn_LED, LOW);
  Serial.println("EMERGENCY STOP: Elevator halted.");
}