const unsigned long interval = 1000;  // Interval of 1 second
unsigned long previousMillis = 0;
unsigned long countdown = 0;  // Countdown duration in seconds (1 hour)
unsigned long inputjam,inputmenit,inputdetik;
int button=5;
int buttonState=0;
int button2=18;
int button2State=0;
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
const int LCD_ADDRESS = 0x27; 
const int LCD_COLUMNS = 16;
const int LCD_ROWS = 2;
LiquidCrystal_I2C lcd(LCD_ADDRESS, LCD_COLUMNS, LCD_ROWS);
unsigned long hours = countdown / 3600;
unsigned long minutes = (countdown % 3600) / 60;
unsigned long seconds = (countdown % 3600) % 60;

void setup() {
  pinMode(button, INPUT);
  pinMode(button2, INPUT);
  Wire.begin();
  lcd.begin(LCD_COLUMNS, LCD_ROWS);
  
  Serial.begin(9600);  // Initialize serial communication for debugging
  Serial.println("Masukkan timer untuk jam: ");
  while (Serial.available()==0){};
  inputjam = strtoul(Serial.readStringUntil('\n').c_str(),NULL,10); 
  Serial.print("Timer telah diatur menjadi: ");
  Serial.print(inputjam);
  Serial.println(" jam");
  countdown=inputjam*3600;
  Serial.println("Masukkan timer untuk menit: ");
  while (Serial.available()==0){};
  inputmenit = strtoul(Serial.readStringUntil('\n').c_str(),NULL,10); 
  Serial.print("Timer telah diatur menjadi: ");
  Serial.print(inputmenit);
  Serial.println(" menit");
  countdown+=inputmenit*60;
  Serial.println("Masukkan timer untuk detik: ");
  while (Serial.available()==0){};
  inputdetik = strtoul(Serial.readStringUntil('\n').c_str(),NULL,10); 
  Serial.print("Timer telah diatur menjadi: ");
  Serial.print(inputdetik);
  Serial.println(" detik");
  countdown+=inputdetik;
  // Serial.print("TIMER = ");
  // Serial.print(inputjam);
  // Serial.print(" : ");
  // Serial.print(inputmenit);
  // Serial.print(" : ");
  // Serial.println(inputdetik);
  Serial.println("START TIMER");
  lcd.print("Hello, World!");
  delay(2000);
  lcd.clear();
  hours = countdown / 3600;
  minutes = (countdown % 3600) / 60;
  seconds = (countdown % 3600) % 60;
  
}

void loop() {
  buttonState=digitalRead(button);
  button2State=digitalRead(button2);
  lcd.setCursor(0,0);
  if(button2State==1){
    countdown=0;
  }
  if (hours < 10) {
        lcd.print("0");
      }
      lcd.print(hours);
      lcd.print(":");
      if (minutes < 10) {
        lcd.print("0");
      }
      lcd.print(minutes);
      lcd.print(":");
      if (seconds < 10) {
        lcd.print("0");
      }
      lcd.print(seconds);
  if (buttonState==1){
    lcd.setCursor(0,0);
    unsigned long currentMillis = millis();  // Get the current time
    
    // Check if the specified interval has elapsed
    if (currentMillis - previousMillis >= interval) {
      previousMillis = currentMillis;  // Update the previous time
      
      // Decrease the countdown value
      if (countdown > 0) {
        countdown--;
      }
      
      // Convert countdown to hours, minutes, and seconds
      hours = countdown / 3600;
      minutes = (countdown % 3600) / 60;
      seconds = (countdown % 3600) % 60;
      
      // Output the countdown value in HH:MM:SS format
      if (hours < 10) {
        Serial.print("0");
        lcd.print("0");
      }
      Serial.print(hours);
      lcd.print(hours);
      Serial.print(":");
      lcd.print(":");
      if (minutes < 10) {
        Serial.print("0");
        lcd.print("0");
      }
      Serial.print(minutes);
      lcd.print(minutes);
      Serial.print(":");
      lcd.print(":");
      if (seconds < 10) {
        Serial.print("0");
        lcd.print("0");
      }
      Serial.println(seconds);
      lcd.print(seconds);
      
      // Check if the countdown has reached 0
      if (countdown == 0) {
        // Countdown is finished, do something
        Serial.println("Countdown finished!");
      }
      lcd.setCursor(0,1);
      lcd.print("                     ");
    }
  }else{
    lcd.setCursor(0,1);
    lcd.print("click to start");
  }
}