CountDownTimer

CountDownTimer.cs

using UnityEngine;
using UnityEngine.Events;
using System.Collections;
using TMPro;

public class CountDownTimer : MonoBehaviour
{
    [Header("Timer Settings")]
    [SerializeField] private float startTimeInSeconds = 10f;
    [SerializeField] private TMP_Text timerText;

    [Header("Events")]
    public UnityEvent onTimerCompleted;

    private float remainingTime;

    public void StartTimer(float? overrideTime = null)
    {
        remainingTime = overrideTime ?? startTimeInSeconds;
        StartCoroutine(CountDown());
    }

    public void PauseTimer()
    {
        StopAllCoroutines();
    }

    public void ResumeTimer()
    {
        StartCoroutine(CountDown());
    }

    public void ResetTimer()
    {
        remainingTime = startTimeInSeconds;
        UpdateText();
    }
    IEnumerator CountDown()
    {
        while (remainingTime > 0)
        {
            remainingTime--;
            UpdateText();
            yield return new WaitForSeconds(1f);
        }
        onTimerCompleted?.Invoke();
    }

    private void UpdateText()
    {
        if (timerText != null)
        {
            timerText.text = $"{remainingTime:F0}";
        }
    }
}