using System.Collections;
using UnityEngine;

[RequireComponent(typeof(CanvasGroup))]
public class MenuFadeIn : MonoBehaviour
{
    public float delay = 0.3f;
    public float duration = 3.5f;

    CanvasGroup _group;
    Coroutine _fadeRoutine;
    bool _started;

    [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.AfterSceneLoad)]
    static void ReactivateFadeImages()
    {
        var fadeComponents = Resources.FindObjectsOfTypeAll<MenuFadeIn>();
        foreach (var fadeComponent in fadeComponents)
        {
            if (!fadeComponent.gameObject.scene.IsValid())
                continue;

            fadeComponent.gameObject.SetActive(true);
        }
    }

    void Awake()
    {
        // Ensure a CanvasGroup exists (SetupMainMenuScene adds one, but be defensive)
        _group = GetComponent<CanvasGroup>();
        if (_group == null) _group = gameObject.AddComponent<CanvasGroup>();

        var canvas = GetComponentInParent<Canvas>();
        if (canvas != null)
            canvas.transform.localScale = Vector3.one;

        _group.alpha = 1f;
        _group.blocksRaycasts = true;
        Debug.Log("[MenuFadeIn] Awake - CanvasGroup ensured, alpha=1");
    }

    void OnEnable()
    {
        if (_group == null) _group = GetComponent<CanvasGroup>() ?? gameObject.AddComponent<CanvasGroup>();

        if (_started)
            BeginFade();
    }

    void Start()
    {
        _started = true;
        BeginFade();
    }

    void BeginFade()
    {
        _group.alpha = 1f;
        _group.blocksRaycasts = true;

        if (_fadeRoutine != null) StopCoroutine(_fadeRoutine);
        _fadeRoutine = StartCoroutine(Fade());
        Debug.Log("[MenuFadeIn] Starting fade (delay=" + delay + ", duration=" + duration + ")");
    }

    void OnDisable()
    {
        if (_fadeRoutine != null)
        {
            StopCoroutine(_fadeRoutine);
            _fadeRoutine = null;
            Debug.Log("[MenuFadeIn] OnDisable - stopped fade coroutine");
        }
    }

    IEnumerator Fade()
    {
        if (delay > 0f) yield return new WaitForSecondsRealtime(delay);

        float t = 0f;
        while (t < duration)
        {
            t += Time.unscaledDeltaTime;
            _group.alpha = 1f - Mathf.Clamp01(t / duration);
            yield return null;
        }

        _group.alpha = 0f;
        _group.blocksRaycasts = false;
        Debug.Log("[MenuFadeIn] Fade finished");
    }
}