using System.Collections;
using UnityEngine;

public class Twinkler : MonoBehaviour
{
    [SerializeField] float intensity_Min;
    [SerializeField] float intensity_Max;
    [SerializeField] float timeSpan = 1.0f;

    Light cLight;               // Light component attached to the object also attached to this script
    Coroutine twinkleRoutine;   // Coroutine toggler to prevent rapid blinking

    // Start is called before the first frame update
    void Start()
    {
        cLight = GetComponent<Light>(); // Gather component from object
    }

    // Update is called once per frame
    void Update()
    {
        // Stop twinkling if paused
        if (MainMenu.IsPaused)
        {
            if (twinkleRoutine != null)
            {
                StopCoroutine(twinkleRoutine);
                twinkleRoutine = null;
            }
            else
                return;
        }

        twinkleRoutine ??= StartCoroutine(Twinkle());   // Begin the coroutine 
    }

    IEnumerator Twinkle()
    {
        while (true)
        {
            float intensityValue = Random.Range(intensity_Min, intensity_Max);
            if (intensityValue == cLight.intensity) continue;
            else
            {
                float t = 0.01f;
                timeSpan = Mathf.Max(0.1f, timeSpan);
                float dif = (intensityValue - cLight.intensity) * t;
                while (t <= 1)
                {
                    cLight.intensity = Mathf.Clamp(cLight.intensity, intensity_Min, intensity_Max);
                    cLight.intensity += dif;
                    t += 0.01f;

                    yield return null;
                }
            }

            yield return null;
        }
    }
}