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

namespace Streamingle.Contents.BossRaid
{
    /// <summary>
    /// 페이즈 전환 컷인 연출.
    /// 화면 중앙에 페이즈 이름이 슬라이드 인 → 정지 → 슬라이드 아웃.
    /// </summary>
    public class PhaseTransition : MonoBehaviour
    {
        #region Fields

        [Header("연출 설정")]
        [SerializeField] private float slideInDuration = 0.3f;
        [SerializeField] private float holdDuration = 1.0f;
        [SerializeField] private float slideOutDuration = 0.3f;

        [Header("비주얼")]
        [SerializeField] private Color backgroundColor = new Color(0f, 0f, 0f, 0.7f);
        [SerializeField] private Color textColor = new Color(1f, 0.3f, 0.3f, 1f);
        [SerializeField] private int fontSize = 72;

        private Canvas _canvas;
        private CanvasGroup _canvasGroup;
        private RectTransform _bgRect;
        private Text _text;
        private Coroutine _transitionCoroutine;
        private Font _font;

        #endregion

        #region Unity Messages

        private void Awake()
        {
            _font = BossRaidFontLoader.Load();
            CreateUI();
            _canvasGroup.alpha = 0f;
        }

        #endregion

        #region Public Methods

        public void Play(string phaseName)
        {
            if (_transitionCoroutine != null)
                StopCoroutine(_transitionCoroutine);
            _transitionCoroutine = StartCoroutine(TransitionCoroutine(phaseName));
        }

        #endregion

        #region Private Methods

        private void CreateUI()
        {
            var canvasObj = new GameObject("BossRaid_PhaseTransition");
            canvasObj.transform.SetParent(transform);
            _canvas = canvasObj.AddComponent<Canvas>();
            _canvas.renderMode = RenderMode.ScreenSpaceOverlay;
            _canvas.sortingOrder = 998;
            _canvasGroup = canvasObj.AddComponent<CanvasGroup>();
            _canvasGroup.interactable = false;
            _canvasGroup.blocksRaycasts = false;

            // 배경 바
            var bgObj = new GameObject("PhaseTransition_BG");
            bgObj.transform.SetParent(canvasObj.transform, false);
            _bgRect = bgObj.AddComponent<RectTransform>();
            _bgRect.anchorMin = new Vector2(0f, 0.35f);
            _bgRect.anchorMax = new Vector2(1f, 0.65f);
            _bgRect.offsetMin = Vector2.zero;
            _bgRect.offsetMax = Vector2.zero;
            var bgImg = bgObj.AddComponent<Image>();
            bgImg.color = backgroundColor;
            bgImg.raycastTarget = false;

            // 텍스트
            var textObj = new GameObject("PhaseTransition_Text");
            textObj.transform.SetParent(bgObj.transform, false);
            var textRect = textObj.AddComponent<RectTransform>();
            textRect.anchorMin = Vector2.zero;
            textRect.anchorMax = Vector2.one;
            textRect.offsetMin = Vector2.zero;
            textRect.offsetMax = Vector2.zero;
            _text = textObj.AddComponent<Text>();
            _text.alignment = TextAnchor.MiddleCenter;
            _text.fontSize = fontSize;
            _text.color = textColor;
            _text.fontStyle = FontStyle.Bold;
            _text.horizontalOverflow = HorizontalWrapMode.Overflow;
            _text.raycastTarget = false;
            if (_font != null) _text.font = _font;

            var outline = textObj.AddComponent<Outline>();
            outline.effectColor = Color.black;
            outline.effectDistance = new Vector2(3f, -3f);
        }

        private IEnumerator TransitionCoroutine(string phaseName)
        {
            _text.text = phaseName;
            float screenWidth = Screen.width;

            float elapsed = 0f;
            while (elapsed < slideInDuration)
            {
                elapsed += Time.unscaledDeltaTime;
                float t = elapsed / slideInDuration;
                float ease = 1f - (1f - t) * (1f - t);
                _canvasGroup.alpha = ease;
                _bgRect.anchoredPosition = new Vector2(Mathf.Lerp(screenWidth, 0f, ease), 0f);
                yield return null;
            }
            _canvasGroup.alpha = 1f;
            _bgRect.anchoredPosition = Vector2.zero;

            yield return new WaitForSecondsRealtime(holdDuration);

            elapsed = 0f;
            while (elapsed < slideOutDuration)
            {
                elapsed += Time.unscaledDeltaTime;
                float t = elapsed / slideOutDuration;
                float ease = t * t;
                _canvasGroup.alpha = 1f - ease;
                _bgRect.anchoredPosition = new Vector2(Mathf.Lerp(0f, -screenWidth, ease), 0f);
                yield return null;
            }

            _canvasGroup.alpha = 0f;
            _transitionCoroutine = null;
        }

        #endregion
    }
}