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

LiquidCrystal_I2C lcd(0x27,16,2);  // set the LCD address to 0x27 for a 16 chars and 2 line display

int startButton = 2;  // assign the start button to pin 2
int resetButton = 3;  // assign the reset button to pin 3
int upButton = 4;     // assign the up button to pin 4
int downButton = 5;   // assign the down button to pin 5
int relayPin = 6;     // assign the relay output to pin 6

int countDownTime = 600; // set the countdown time to 10 minutes (in seconds)
int countDownState = 0;  // keep track of the current state of the countdown timer
int countDownStart = 0;  // keep track of when the countdown timer was started
int countDownCurrent = 0;// keep track of the current time on the countdown timer

void setup() {
  lcd.init();                      // initialize the LCD
  lcd.backlight();                 // turn on the backlight
  pinMode(startButton, INPUT);     // set the start button as an input
  pinMode(resetButton, INPUT);     // set the reset button as an input
  pinMode(upButton, INPUT);        // set the up button as an input
  pinMode(downButton, INPUT);      // set the down button as an input
  pinMode(relayPin, OUTPUT);       // set the relay pin as an output
  lcd.setCursor(0,0);              // set the LCD cursor to the first column of the first row
  lcd.print("Countdown Timer");    // print the title
  lcd.setCursor(0,1);              // set the LCD cursor to the first column of the second row
  lcd.print("Set Time: 10:00");    // print the initial countdown time
}

void loop() {
  int startButtonState = digitalRead(startButton);
  int resetButtonState = digitalRead(resetButton);
  int upButtonState = digitalRead(upButton);
  int downButtonState = digitalRead(downButton);
  
  if (resetButtonState == HIGH) {  // if the reset button is pressed
    countDownState = 0;            // reset the countdown timer state
    countDownCurrent = 0;          // reset the current time on the countdown timer
    digitalWrite(relayPin, LOW);   // turn off the relay output
    lcd.clear();                   // clear the LCD screen
    lcd.setCursor(0,0);            // set the LCD cursor to the first column of the first row
    lcd.print("Countdown Timer");  // reprint the title
    lcd.setCursor(0,1);            // set the LCD cursor to the first column of the second row
    lcd.print("Set Time: 10:00");  // reset the countdown time
  }
  
  if (startButtonState == HIGH && countDownState == 0) {  // if the start button is pressed and the timer is not running
    countDownStart = millis();                            // start the countdown timer
    countDownState = millis ;
    }
}