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

public enum ESceneType
{
    Title,
    Main,
    Max
}

public class SceneTransitionManager : MonoBehaviour
{
    #region Fields
    private float _minLoadTime = 0f;

    private IEnumerator _eLoadScene = null;
    #endregion

    #region Properties
    public ESceneType CurrentSceneType { get; private set; } = ESceneType.Max;
    public bool IsLoading { get; private set; } = false;
    public float LoadProgress { get; private set; } = 0f;
    #endregion

    private void Awake()
    {
        CurrentSceneType = (ESceneType)UnityEngine.SceneManagement.SceneManager.GetActiveScene().buildIndex;
    }

    public void LoadScene(ESceneType sceneType)
    {
        if (_eLoadScene == null)
        {
            LoadProgress = 0f;
            _eLoadScene = this.coroLoadScene(sceneType);
            StartCoroutine(_eLoadScene);
        }
    }

    private IEnumerator coroLoadScene(ESceneType sceneType)
    {
        AsyncOperation async = UnityEngine.SceneManagement.SceneManager.LoadSceneAsync((int)sceneType);
        async.allowSceneActivation = false;

        if (sceneType == ESceneType.Main)
            UnityEngine.SceneManagement.SceneManager.sceneLoaded += this.LateEnter;

        float cnt = 0;

        while (true)
        {
            cnt += Time.deltaTime;
            LoadProgress = async.progress / 0.9f;
            if (async.progress >= 0.9f && cnt >= _minLoadTime && !async.allowSceneActivation)
            {
                CurrentSceneType = sceneType;
                async.allowSceneActivation = true;

                yield return new WaitForSeconds(1f);
                _eLoadScene = null;
                break;
            }
            yield return null;
        }
    }

    private void LateEnter(Scene arg0, LoadSceneMode arg1)
    {
        UnityEngine.SceneManagement.SceneManager.sceneLoaded -= this.LateEnter;
        StartCoroutine(eLateEnter());
    }

    private IEnumerator eLateEnter()
    {
        yield return new WaitForEndOfFrame();
        yield return new WaitForEndOfFrame();


    }
}