#include <Wire.h>
#include "RTClib.h"

RTC_DS3231 rtc;
DateTime future;
bool countdownActive = false;

void setup() {
  Serial.begin(9600);
  while (!Serial) {
    ; // Wait for serial port to connect.
  }

  if (!rtc.begin()) {
    Serial.println("Couldn't find RTC");
    while (1);
  }

  Serial.println("Enter countdown time as hours, minutes, and seconds. Format: HH MM SS");
}

void loop() {
  if (!countdownActive && Serial.available()) {
    int hours = Serial.parseInt();
    int minutes = Serial.parseInt();
    int seconds = Serial.parseInt();

    if (hours >= 0 && minutes >= 0 && seconds >= 0) {
      Serial.print("Starting countdown for ");
      Serial.print(hours);
      Serial.print(" hours, ");
      Serial.print(minutes);
      Serial.print(" minutes, ");
      Serial.print(seconds);
      Serial.println(" seconds.");

      future = rtc.now() + TimeSpan(0, hours, minutes, seconds);
      countdownActive = true;
    }
  }

  if (countdownActive && rtc.now() < future) {
    DateTime now = rtc.now();
    TimeSpan remaining = future - now;

    Serial.print(remaining.hours());
    Serial.print(':');
    Serial.print(remaining.minutes());
    Serial.print(':');
    Serial.println(remaining.seconds());

    delay(1000); // Update every second
  } else if (countdownActive) {
    Serial.println("Countdown finished!");
    Serial.println("Enter next countdown time as hours, minutes, and seconds. Format: HH MM SS");
    countdownActive = false;
  }
}