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

namespace Streamingle.Contents.BossRaid
{
    /// <summary>
    /// 데미지 숫자 팝업을 생성하고 관리합니다.
    /// WorldSpace Canvas에서 숫자가 튀어나와 중력으로 떨어집니다.
    /// </summary>
    public class DamagePopup : MonoBehaviour
    {
        #region Fields

        [Header("프리팹")]
        [SerializeField]
        [Tooltip("데미지 숫자 프리팹. 없으면 자동 생성")]
        private GameObject popupPrefab;

        [Header("일반 히트")]
        [SerializeField] private Color normalColor = Color.white;
        [SerializeField] private int normalFontSize = 32;

        [Header("크리티컬")]
        [SerializeField] private Color criticalColor = new Color(1f, 0.2f, 0.2f);
        [SerializeField] private int criticalFontSize = 48;

        [Header("애니메이션")]
        [SerializeField] private float popupDuration = 1.2f;
        [SerializeField] private float upwardForce = 3f;
        [SerializeField] private float gravity = 8f;

        [Header("위치")]
        [SerializeField]
        [Tooltip("바운더리 외곽 여유 (콜라이더 경계 밖으로 얼마나 더 퍼질지)")]
        private float spreadMargin = 0.5f;

        [SerializeField]
        [Tooltip("바운더리가 없을 때 기본 X 퍼짐")]
        private float fallbackSpreadX = 1f;

        [SerializeField]
        [Tooltip("바운더리가 없을 때 기본 높이 오프셋")]
        private float fallbackHeightOffset = 1.5f;

        private Canvas _worldCanvas;
        private Font _font;

        #endregion

        #region Unity Messages

        private void Awake()
        {
            _font = BossRaidFontLoader.Load();
            EnsureWorldCanvas();
        }

        #endregion

        #region Public Methods

        /// <summary>
        /// 데미지 숫자를 생성합니다.
        /// bounds가 있으면 바운더리 외곽 범위에서 랜덤 위치에 생성됩니다.
        /// </summary>
        public void Spawn(int damage, bool isCritical, Vector3 worldPosition, Bounds? bounds = null)
        {
            EnsureWorldCanvas();

            var go = CreatePopupObject();
            var text = go.GetComponent<Text>();
            if (text == null) text = go.GetComponentInChildren<Text>();

            if (text != null)
            {
                text.text = damage.ToString();
                text.color = isCritical ? criticalColor : normalColor;
                text.fontSize = isCritical ? criticalFontSize : normalFontSize;
                if (isCritical) text.fontStyle = FontStyle.Bold;
            }

            Vector3 spawnPos;
            if (bounds.HasValue)
            {
                var b = bounds.Value;
                // 바운더리 외곽에서 랜덤 위치
                float halfX = b.extents.x + spreadMargin;
                float topY = b.max.y + spreadMargin;
                float bottomY = b.center.y;

                spawnPos = new Vector3(
                    b.center.x + Random.Range(-halfX, halfX),
                    Random.Range(bottomY, topY),
                    b.center.z
                );
            }
            else
            {
                spawnPos = worldPosition + new Vector3(
                    Random.Range(-fallbackSpreadX, fallbackSpreadX),
                    fallbackHeightOffset + Random.Range(0f, 1f),
                    0f
                );
            }

            go.transform.position = spawnPos;

            StartCoroutine(AnimatePopup(go, isCritical));
        }

        #endregion

        #region Private Methods

        private void EnsureWorldCanvas()
        {
            if (_worldCanvas != null) return;

            var canvasObj = new GameObject("BossRaid_DamagePopupCanvas");
            canvasObj.transform.SetParent(transform);
            _worldCanvas = canvasObj.AddComponent<Canvas>();
            _worldCanvas.renderMode = RenderMode.WorldSpace;
            _worldCanvas.sortingOrder = 100;

            var rectTransform = canvasObj.GetComponent<RectTransform>();
            rectTransform.sizeDelta = new Vector2(10f, 10f);
            rectTransform.localScale = Vector3.one * 0.01f;
        }

        private GameObject CreatePopupObject()
        {
            if (popupPrefab != null)
                return Instantiate(popupPrefab, _worldCanvas.transform);

            var go = new GameObject("DamageNumber");
            go.transform.SetParent(_worldCanvas.transform);

            var text = go.AddComponent<Text>();
            text.alignment = TextAnchor.MiddleCenter;
            text.horizontalOverflow = HorizontalWrapMode.Overflow;
            text.verticalOverflow = VerticalWrapMode.Overflow;
            text.raycastTarget = false;
            if (_font != null) text.font = _font;

            var rect = go.GetComponent<RectTransform>();
            rect.sizeDelta = new Vector2(400f, 200f);
            rect.localScale = Vector3.one;

            // 아웃라인 (가독성)
            var outline = go.AddComponent<Outline>();
            outline.effectColor = Color.black;
            outline.effectDistance = new Vector2(2f, -2f);

            return go;
        }

        private IEnumerator AnimatePopup(GameObject go, bool isCritical)
        {
            if (go == null) yield break;

            Vector3 startPos = go.transform.position;
            float velocityY = upwardForce * (isCritical ? 1.3f : 1f);
            float velocityX = Random.Range(-0.5f, 0.5f);
            float elapsed = 0f;

            Vector3 startScale = go.transform.localScale;
            Vector3 peakScale = startScale * (isCritical ? 1.5f : 1.2f);

            var text = go.GetComponent<Text>();

            while (elapsed < popupDuration)
            {
                elapsed += Time.deltaTime;
                float t = elapsed / popupDuration;

                velocityY -= gravity * Time.deltaTime;
                startPos.x += velocityX * Time.deltaTime;
                startPos.y += velocityY * Time.deltaTime;
                go.transform.position = startPos;

                float scaleT = t < 0.2f ? t / 0.2f : 1f;
                go.transform.localScale = Vector3.Lerp(peakScale, startScale, scaleT);

                float alpha = t < 0.6f ? 1f : 1f - ((t - 0.6f) / 0.4f);
                if (text != null)
                {
                    var c = text.color;
                    c.a = alpha;
                    text.color = c;
                }

                if (Camera.main != null)
                    go.transform.rotation = Camera.main.transform.rotation;

                yield return null;
            }

            Destroy(go);
        }

        #endregion
    }
}