EnglewoodLAB/Assets/Scripts/UI/UILoading.cs

using System;
using System.Collections;
using UnityEngine;
using UnityEngine.SceneManagement;
using UnityEngine.UI;

namespace EnglewoodLAB
{
    public class UILoading : MonoBehaviour
    {
        private static UILoading instance;

        private const string PREFAB_PATH = "UI/Prefab/Home/UILoading";
        private float loadingDuration = 1.5f;
        private float fadeSpeed = 2.0f;

        private CanvasGroup logoCanvasGroup; // 로고의 CanvasGroup 연결
        private Image progressBar;

        private string nextSceneName = "EnglewoodLAB"; // 이동할 다음 씬 이름

        public static UILoading Instance
        {
            get
            {
                if(instance == null)
                {
                    var obj = FindAnyObjectByType<UILoading>();

                    if (obj != null)
                        instance = obj;
                    else
                        instance = Create();
                }
                return instance;
            }
        }

        private static UILoading Create()
        {
            return Instantiate(Resources.Load<UILoading>(PREFAB_PATH));
        }

        private void Awake()
        {
            if (Instance != this)
            {
                Destroy(gameObject);

                return;
            }
            DontDestroyOnLoad(gameObject);

            logoCanvasGroup = GetComponentInChildren<CanvasGroup>();
            if (progressBar == null)
            {
                var imageTransform = transform.Find("Background/LoadingBarBg/LoadingBarImage");
                if (imageTransform != null)
                {
                    progressBar = imageTransform.GetComponentInChildren<Image>();
                }
                else
                {
                    // 경로로 못 찾으면 자식 전체에서 탐색
                    progressBar = GetComponentInChildren<Image>();
                }
            }
        }

        private void Start()
        {
            LoadScene(nextSceneName);
        }

        public void LoadScene(string sceneName)
        {
            gameObject.SetActive(true);
            SceneManager.sceneLoaded += OnSceneLoaded;
            nextSceneName = sceneName;

            StartCoroutine(LoadProjectProgress());
        }

        private IEnumerator LoadProjectProgress()
        {
            logoCanvasGroup.alpha = 1.0f;
            progressBar.fillAmount = 0.0f;

            AsyncOperation asyncOperation = SceneManager.LoadSceneAsync(nextSceneName);
            asyncOperation.allowSceneActivation = false;

            float timer = 0.0f;
            while (!asyncOperation.isDone)
            {
                yield return null;
                if (asyncOperation.progress < 0.1f)
                    progressBar.fillAmount = asyncOperation.progress;
                else
                {
                    timer += Time.unscaledDeltaTime;
                    progressBar.fillAmount = Mathf.Lerp(0.1f, 1.0f, timer / 3.0f);

                    if (progressBar.fillAmount >= 1.0f)
                    {
                        asyncOperation.allowSceneActivation = true;
                        yield break;
                    }
                }
            }
        }

        private IEnumerator Fade(bool isFadeIn)
        {
            float timer = 0.0f;

            while (timer <= 1.0f)
            {
                yield return null;
                timer += Time.unscaledDeltaTime * 3.0f;

                logoCanvasGroup.alpha = isFadeIn ? Mathf.Lerp(0.0f, 1.0f, timer) : Mathf.Lerp(1.0f, 0.0f, timer);
            }

            // 페이드 아웃이 끝나면 비활성화
            if (!isFadeIn)
                gameObject.SetActive(false);
        }

        private void OnSceneLoaded(Scene arg0, LoadSceneMode arg1)
        {
            if (arg0.name == nextSceneName)
            {
                StartCoroutine(Fade(false));

                SceneManager.sceneLoaded -= OnSceneLoaded;
            }
        }
    }
}