using System;
using System.Collections;
using BigSpace.XRCore.Base;
using UnityEngine;
using UnityEngine.SceneManagement;

namespace BigSpace.XRCore.Scene
{
    public class SceneFadeMgr : MonoSingleton<SceneFadeMgr>
    {
        public float fadeInTime = 1.5f;    // 淡入时间
        public float fadeOutTime = 1.5f;   // 淡出时间
        public Color fadeColor = Color.black; // 淡入淡出的颜色
    
        private Canvas canvas;
        private CanvasGroup canvasGroup;
        private Action fadeCompleteCallback;

        // 引用 SceneChangeAni 实例
        private SceneChangeAni sceneChangeAni;

        protected override void Awake()
        {
            base.Awake();
            sceneChangeAni = FindObjectOfType<SceneChangeAni>(); // 查找场景中的 SceneChangeAni 组件
            //InitializeCanvas();
        }
    
        private void InitializeCanvas()
        {
            canvas = new GameObject("FadeCanvas").AddComponent<Canvas>();
            canvas.renderMode = RenderMode.ScreenSpaceOverlay;
            DontDestroyOnLoad(canvas.gameObject);
    
            canvasGroup = canvas.gameObject.AddComponent<CanvasGroup>();
            canvasGroup.alpha = 0; // 初始透明
            canvasGroup.blocksRaycasts = true;
    
            var image = canvas.gameObject.AddComponent<UnityEngine.UI.Image>();
            image.color = fadeColor;
        }
    
        public IEnumerator FadeOut(Action onComplete)
        {
            fadeCompleteCallback = onComplete;
            if (sceneChangeAni != null)
            {
                // 调用 SceneChangeAni 的 FadeOut 方法
                sceneChangeAni.showFadeAni(false, onComplete);
            }

            yield return null;

            //yield return StartCoroutine(Fade(0, 1, fadeOutTime));
        }
    
        public IEnumerator FadeIn(Action onComplete = null)
        {
            fadeCompleteCallback = onComplete;
            if (sceneChangeAni != null)
            {
                // 调用 SceneChangeAni 的 FadeIn 方法
                sceneChangeAni.showFadeAni(true, onComplete);
            }
            yield return null;

            //yield return StartCoroutine(Fade(1, 0, fadeInTime));
        }
    
        private IEnumerator Fade(float startAlpha, float endAlpha, float duration)
        {
            float time = 0;
            while (time < duration)
            {
                time += Time.deltaTime;
                canvasGroup.alpha = Mathf.Lerp(startAlpha, endAlpha, time / duration);
                yield return null;
            }
    
            canvasGroup.alpha = endAlpha;
            fadeCompleteCallback?.Invoke();
            fadeCompleteCallback = null;
        }
    
        public void LoadSceneWithFade(string sceneName)
        {
            FadeOut(() =>
            {
                SceneManager.LoadSceneAsync(sceneName).completed += (operation) =>
                {
                    FadeIn();
                };
            });
        }
    }
}