#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

//Define the pin numbers for the LEDs and buttons
const int GoLED = 15; //pin number for Green LED
const int FullLED = 2; //pin number for the Red LED
const int GObutton = 5; //pin number for the green push button
const int OUTbutton = 18; //pin number for the red push button
const int RESETbutton = 19; //pin number for black push button

//These variables store the current number of occupants and the reset flag
int x = 0;
int RESET = 0;

//Interrupt service routine to handle the RESET button press
void IRAM_ATTR Restart(){
  RESET = true;
}


void setup(){
  //initialize the LCD and turn on the backlight
  lcd.init();
  lcd.backlight();
  delay(10);

  //Initialize serial communication for debugging at 115200 baud
  Serial.begin(115200);
  Serial.print("PROGRAM READY");
  delay(10);

  //Set pin modes for the LEDs and buttons
  pinMode(GObutton, INPUT);
  pinMode(OUTbutton, INPUT);
  pinMode(RESETbutton, INPUT);
  pinMode(GoLED, OUTPUT);
  pinMode(FullLED, OUTPUT);

  //Attach an interrupt to the RESET button that will call the "Restart" function when the button is pressed
  attachInterrupt(RESETbutton, Restart, RISING);

  //Print "OCCUPANT/S" on the second line of the LCD
  lcd.setCursor(6,1);
  lcd.print("OCCUPANT/S");
  delay(10);
}


void loop(){
  //if the GO button is pressed, increment the number of occupants
  if (digitalRead(GObutton)==HIGH){
    x++;
    delay(300);
  }

  //if the OUT button is pressed, decrement the number of occupants
  else if (digitalRead(OUTbutton)==HIGH){
    x--;
    delay(300);
  }

//if the number of occupants is less than 10, turn on the GoLED and off the FullLED
  if(x < 10){
    digitalWrite(GoLED, HIGH);
    digitalWrite(FullLED, LOW);
    lcd.setCursor(4, 0);
    lcd.print("WELCOME");
    lcd.setCursor(0, 1);
    lcd.print("  ");
    lcd.setCursor(0, 1);
    lcd.print(x);
    delay(100);
  }

  //if the number of occupants is 10 or more, turn on the FullLED and off the GoLED
  else if (x >= 10){
    digitalWrite(FullLED, HIGH);
    digitalWrite(GoLED, LOW);
    lcd.setCursor(4, 0);
    lcd.print(" CLOSED");
    lcd.setCursor(0, 1);
    lcd.print("  ");
    lcd.setCursor(0, 1);
    lcd.print(x);
    x = 10;
    delay(100);
  }

  //if the reset flag is set, reset the number of occupants to 0 and display the welcome message
  if (RESET){
    x = 0;
    digitalWrite(GoLED, HIGH);
    lcd.setCursor(4, 0);
    lcd.print("WELCOME");
    lcd.setCursor(0, 1);
    lcd.print("  ");
    lcd.setCursor(0, 1);
    lcd.print(x);
    RESET = false;
    delay(100);
  }

}