using System.Collections;
using UnityEngine;

public class ArrowSequence : MonoBehaviour
{
    [Header("Šipky")]
    public GameObject[] arrows;

    [Header("Časování")]
    public float fadeInDuration = 0.3f;
    public float visibleDuration = 0.5f;
    public float fadeOutDuration = 0.3f;
    public float delayBetween = 0.1f;

    void Start()
    {
        foreach (var arrow in arrows)
            SetAlpha(arrow, 0f);

        StartCoroutine(PlayLoop());
    }

    IEnumerator PlayLoop()
    {
        float singleArrow = fadeInDuration + visibleDuration + fadeOutDuration;
        float fullCycle = arrows.Length * delayBetween + singleArrow;
        float restartAt = fullCycle / 2f;

        while (true)
        {
            StartCoroutine(PlaySequence());
            yield return new WaitForSeconds(restartAt);
        }
    }

    IEnumerator PlaySequence()
    {
        foreach (var arrow in arrows)
        {
            StartCoroutine(AnimateArrow(arrow));
            yield return new WaitForSeconds(delayBetween);
        }
    }

    IEnumerator AnimateArrow(GameObject arrow)
    {
        yield return StartCoroutine(Fade(arrow, 0f, 1f, fadeInDuration));
        yield return new WaitForSeconds(visibleDuration);
        yield return StartCoroutine(Fade(arrow, 1f, 0f, fadeOutDuration));
    }

    IEnumerator Fade(GameObject obj, float from, float to, float duration)
    {
        float elapsed = 0f;
        while (elapsed < duration)
        {
            elapsed += Time.deltaTime;
            float t = Mathf.SmoothStep(0f, 1f, elapsed / duration);
            SetAlpha(obj, Mathf.Lerp(from, to, t));
            yield return null;
        }
        SetAlpha(obj, to);
    }

    void SetAlpha(GameObject obj, float alpha)
    {
        var images = obj.GetComponentsInChildren<UnityEngine.UI.Image>(true);
        foreach (var img in images)
        {
            Color c = img.color;
            c.a = alpha;
            img.color = c;
        }

        var renderers = obj.GetComponentsInChildren<SpriteRenderer>(true);
        foreach (var sr in renderers)
        {
            Color c = sr.color;
            c.a = alpha;
            sr.color = c;
        }
    }
}