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

// Initialize the LCD with address 0x27, 16 columns and 2 rows
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Pin Definitions
const int floor1 = 2;  // Limit switch for floor 1
const int floor2 = 3;  // Limit switch for floor 2
const int floor3 = 4;  // Limit switch for floor 3

const int callbutton1 = 5;  // Call button for floor 1
const int callbutton2 = 6;  // Call button for floor 2
const int callbutton3 = 7;  // Call button for floor 3

const int relayup = 8;  // Relay to drive elevator up
const int relaydown = 9;  // Relay to drive elevator down
const int buzzer = 10;  // Buzzer for warning or alarm

// Variables
int callelevator1 = 0;
int callelevator2 = 0;
int callelevator3 = 0;

int floor1sense = 0;
int floor2sense = 0;
int floor3sense = 0;

int lastFloorDisplay = 0;  // Track the last displayed floor

// Debouncing constants
const unsigned long debounceDelay = 50; // Debounce delay in milliseconds
unsigned long lastButtonPress = 0;

// Function prototypes
void floor1function();
void floor2function();
void floor3function();
bool readButton(int buttonPin);
void beepPattern(int floor);

void setup() {
  pinMode(floor1, INPUT);
  pinMode(floor2, INPUT);
  pinMode(floor3, INPUT);
  pinMode(callbutton1, INPUT);
  pinMode(callbutton2, INPUT);
  pinMode(callbutton3, INPUT);

  pinMode(relayup, OUTPUT);
  pinMode(relaydown, OUTPUT);
  pinMode(buzzer, OUTPUT);
  
  lcd.begin(16, 2);
  lcd.backlight();
  
  lcd.setCursor(0, 0);
  lcd.print("  SWASTIK STEEL  ");
  lcd.setCursor(0, 1);
  lcd.print("   FURNITURES   ");
  delay(2000);
}

void loop() {
  // Read the state of the call buttons
  bool call1 = readButton(callbutton1);
  bool call2 = readButton(callbutton2);
  bool call3 = readButton(callbutton3);

  // Read the state of the limit switches
  floor1sense = digitalRead(floor1);
  floor2sense = digitalRead(floor2);
  floor3sense = digitalRead(floor3);

  if (call1) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Lift is Called");
    lcd.setCursor(0, 1);
    lcd.print("Floor 1 to Go");
    delay(1000);  // Allow time for button release
    floor1function();
  } else if (call2) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Lift is Called");
    lcd.setCursor(0, 1);
    lcd.print("Floor 2 to Go");
    delay(1000);
    floor2function();
  } else if (call3) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Lift is Called");
    lcd.setCursor(0, 1);
    lcd.print("Floor 3 to Go");
    delay(1000);
    floor3function();
  } else {
    int currentFloorDisplay = 0;
    if (floor1sense == LOW) {
      currentFloorDisplay = 1;
    } else if (floor2sense == LOW) {
      currentFloorDisplay = 2;
    } else if (floor3sense == LOW) {
      currentFloorDisplay = 3;
    }
    
    if (currentFloorDisplay != lastFloorDisplay) {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("At Floor ");
      lcd.print(currentFloorDisplay);
      lastFloorDisplay = currentFloorDisplay;
    }
  }
  
  digitalWrite(relayup, LOW);
  digitalWrite(relaydown, LOW);
  digitalWrite(buzzer, LOW);
  
  delay(10);  // Small delay for smooth operation
}

bool readButton(int buttonPin) {
  if (digitalRead(buttonPin) == LOW) {
    unsigned long currentTime = millis();
    if (currentTime - lastButtonPress > debounceDelay) {
      lastButtonPress = currentTime;
      return true;
    }
  }
  return false;
}

void beepPattern(int floor) {
  switch(floor) {
    case 1:  // Ground floor - BEEP...PAUSE...BEEP
      digitalWrite(buzzer, HIGH);
      delay(200);
      digitalWrite(buzzer, LOW);
      delay(500);
      break;

    case 2:  // 2nd floor - BEEP BEEP...PAUSE...BEEP BEEP
      for (int i = 0; i < 2; i++) {
        digitalWrite(buzzer, HIGH);
        delay(200);
        digitalWrite(buzzer, LOW);
        delay(200);
      }
      delay(500);
      break;

    case 3:  // 3rd floor - BEEP BEEP BEEP...PAUSE...BEEP BEEP BEEP
      for (int i = 0; i < 3; i++) {
        digitalWrite(buzzer, HIGH);
        delay(200);
        digitalWrite(buzzer, LOW);
        delay(200);
      }
      delay(500);
      break;

    default:
      break;
  }
}

void floor1function() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Called floor 1");
  lcd.setCursor(0, 1);
  lcd.print("Moving Down");

  while (floor1sense == HIGH) {
    digitalWrite(relaydown, HIGH);
    beepPattern(1);  // BEEP...PAUSE...BEEP for 1st floor
    floor1sense = digitalRead(floor1);
    delay(10);
  }
  
  digitalWrite(relaydown, LOW);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("At Floor 1");
  delay(2000);
}

void floor2function() {
  lcd.clear();
  
  if (floor3sense == LOW) {
    lcd.setCursor(0, 0);
    lcd.print("Called floor 2");
    lcd.setCursor(0, 1);
    lcd.print("Moving Down");
    
    while (floor2sense == HIGH) {
      digitalWrite(relaydown, HIGH);
      beepPattern(2);  // BEEP BEEP...PAUSE...BEEP BEEP for 2nd floor
      floor2sense = digitalRead(floor2);
      delay(10);
    }
  } else if (floor1sense == LOW) {
    lcd.setCursor(0, 0);
    lcd.print("Called floor 2");
    lcd.setCursor(0, 1);
    lcd.print("Moving Up");
    
    while (floor2sense == HIGH) {
      digitalWrite(relayup, HIGH);
      beepPattern(2);  // BEEP BEEP...PAUSE...BEEP BEEP for 2nd floor
      floor2sense = digitalRead(floor2);
      delay(10);
    }
  }
  
  digitalWrite(relayup, LOW);
  digitalWrite(relaydown, LOW);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("At Floor 2");
  delay(2000);
}

void floor3function() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Called floor 3");
  lcd.setCursor(0, 1);
  lcd.print("Moving Up");

  if (floor2sense == LOW || floor1sense == LOW) {
    while (floor3sense == HIGH) {
      digitalWrite(relayup, HIGH);
      beepPattern(3);  // BEEP BEEP BEEP...PAUSE...BEEP BEEP BEEP for 3rd floor
      floor3sense = digitalRead(floor3);
      delay(10);
    }
  }
  
  digitalWrite(relayup, LOW);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("At Floor 3");
  delay(2000);
}