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

LiquidCrystal_I2C lcd(0x27, 16, 2);
unsigned long prevMillis = 0;
unsigned long interval = 1000;
int startButton = 2;
int pauseButton = 3;
int stopButton = 4;
int resetButton = 5;
bool isRunning = false;
bool stopButtonPressed = false; // Menandai apakah tombol "Stop" pernah ditekan
int hours = 0;
int minutes = 0;
int seconds = 0;

void setup() {
  lcd.init();
  lcd.backlight();
  pinMode(startButton, INPUT_PULLUP);
  pinMode(pauseButton, INPUT_PULLUP);
  pinMode(stopButton, INPUT_PULLUP);
  pinMode(resetButton, INPUT_PULLUP);
  lcd.setCursor(0, 0);
  lcd.print("Stopwatch: ");
}

void loop() {
  unsigned long currMillis = millis();
  bool startPressed = digitalRead(startButton) == LOW;
  bool pausePressed = digitalRead(pauseButton) == LOW;
  bool stopPressed = digitalRead(stopButton) == LOW;
  bool resetPressed = digitalRead(resetButton) == LOW;

  if (startPressed) {
    if (stopButtonPressed) { // Jika tombol "Stop" telah ditekan sebelumnya
      stopButtonPressed = false; // Reset status tombol "Stop"
      isRunning = false; // Berhenti dari running
      // Reset timer to 00:00:00
      lcd.setCursor(0, 1);
      lcd.print("00:00:00");
      // Reset internal timer variables
      prevMillis = 0;
      hours = 0;
      minutes = 0;
      seconds = 0;
    } else {
      isRunning = !isRunning; // Toggle status running
    }
    delay(10);
  }

  if (pausePressed) {
    isRunning = false;
    delay(10);
  }

  if (isRunning && currMillis - prevMillis >= interval) {
    prevMillis = currMillis;
    seconds++;
    if (seconds == 60) {
      seconds = 0;
      minutes++;
      if (minutes == 60) {
        minutes = 0;
        hours++;
        if (hours == 24) {
          hours = 0;
        }
      }
    }
    lcd.setCursor(0, 1);
    lcd.print((hours < 10 ? "0" : "") + String(hours));
    lcd.print(":");
    lcd.print((minutes < 10 ? "0" : "") + String(minutes));
    lcd.print(":");
    lcd.print((seconds < 10 ? "0" : "") + String(seconds));
  } else if (!isRunning) {
    prevMillis = currMillis;
  }

  if (resetPressed) {
    isRunning = false;
    stopButtonPressed = false; // Reset status tombol "Stop"
    delay(10);
    // Reset timer to 00:00:00
    lcd.setCursor(0, 1);
    lcd.print("00:00:00");
    // Reset internal timer variables
    prevMillis = 0;
    hours = 0;
    minutes = 0;
    seconds = 0;
  }

  if (stopPressed) {
    stopButtonPressed = true; // Menandai bahwa tombol "Stop" telah ditekan
    isRunning = false;
    delay(10);
  }
}