using System;
using Cielonos.MainGame.Buffs.Character;
using Cielonos.MainGame.Characters;
using Lean.Pool;
using Sirenix.OdinInspector;
using SLSUtilities.General;
using SLSUtilities.UI;
using UnityEngine;

namespace Cielonos.MainGame.UI
{
    public class EnemyInfoUnitBase : UIElementBase
    {
        [HideInInspector]
        public CharacterBase enemy;
        [TitleGroup("Bars")]
        public RectTransform barContainer;
        [TitleGroup("Bars")]
        public AttributeBarBase healthBar;
        [TitleGroup("Bars")]
        public AttributeBarBase energyBar;
        [TitleGroup("Bars")]
        public AttributeBarBase stanceBar;
        
        [TitleGroup("Buffs")]
        public RectTransform buffIconContainer;
        
        [TitleGroup("Distance & Scale Settings")]
        public float minShowDistance = 5f;  // 距离小于此值，血条消失（过近）4
        [TitleGroup("Distance & Scale Settings")]
        public float maxShowDistance = 30f; // 距离大于此值，血条消失（过远）
        [TitleGroup("Distance & Scale Settings")]
        public float maxScale = 1f;         // 距离最近 (minShowDistance) 时的最大缩放比例
        [TitleGroup("Distance & Scale Settings")]
        public float minScale = 0.4f;       // 距离最远 (maxShowDistance) 时的最小缩放比例
        
        private float distanceFade = 1f;
        
        [Header("Occlusion Settings")]
        public LayerMask obstacleLayer;     // 遮挡物层级（墙壁、地面等）
        public float occlusionTimer = 0f;       // 被遮挡的计时器
        public float occlusionDelay = 0.5f; // 被遮挡后延迟多久开始消失
        private float occlusionFade = 1f;

        [Header("Alpha & Edge Fade Settings")]
        public float fadeSpeed = 8f;        // 透明度渐变速度 (越大消失越快)
        [Tooltip("从中心到边缘，开始衰减的百分比 (0~1)")]
        public float fadeStartPct = 0.80f;  // 80% 开始消失
        [Tooltip("从中心到边缘，完全透明的百分比 (0~1)")]
        public float fadeEndPct = 0.95f;    // 95% 完全消失
        private float screenFade = 1f;

        [TitleGroup("Colors")]
        public Color normalStanceColor = new Color(1f, 0.78f, 0.58f);
        [TitleGroup("Colors")]
        public Color paralyzedStanceColor = new Color(1f, 0.3f, 0.3f);
        
        public void Initialize(CharacterBase character)
        {
            enemy = character;
            distanceFade = 1f;
            occlusionFade = 1f;
            screenFade = 1f;
            UpdateHealth(true);
            UpdateEnergy(true);
            UpdateStance(true);
        }

        private void Update()
        {
            UpdatePosition();
            UpdateHealth(false);
            UpdateEnergy(false);
            UpdateStance(false);
            canvasGroup.alpha = Mathf.Min(distanceFade, occlusionFade, screenFade);
        }

        public void UpdatePosition()
        {
            if(enemy == null || enemy.statusSm.isDead) LeanPool.Despawn(gameObject);
            
            if(enemy?.bodyPartsSc?.infoUIPoint == null) return;

            Vector3 enemyPos = enemy.CenterPosition;
            Vector3 infoUIPos = enemy.bodyPartsSc.infoUIPoint.position;
            Camera playerCamera = MainGameManager.Player.viewSc.playerCamera;
            
            float cameraDistance = Vector3.Distance(playerCamera.transform.position, infoUIPos);
            float midDistance = (minShowDistance + maxShowDistance) / 2f;
            // 计算距离衰减，在midDistance处达到最大值，minShowDistance和maxShowDistance处为0
            distanceFade = Mathf.InverseLerp(cameraDistance < midDistance ? minShowDistance : maxShowDistance, midDistance, cameraDistance);
            distanceFade = Mathf.Min(distanceFade * 4f, 1f); // 在距离范围内，快速达到完全显示

            Vector3 viewportPos = playerCamera.WorldToViewportPoint(infoUIPos);
            bool isBehindCamera = viewportPos.z < 0;
            if (isBehindCamera)
            {
                screenFade = 0f;
            }
            else
            {
                float normalizedDistX = Mathf.Abs(viewportPos.x - 0.5f) * 2f;
                float normalizedDistY = Mathf.Abs(viewportPos.y - 0.5f) * 2f;
                float maxNormalizedDist = Mathf.Max(normalizedDistX, normalizedDistY);
                screenFade = Mathf.InverseLerp(fadeEndPct, fadeStartPct, maxNormalizedDist);
            }

            // Occlusion check
            if (Physics.Linecast(playerCamera.transform.position, infoUIPos, out RaycastHit hitInfo))
            {
                if (hitInfo.collider.GetComponentInParent<CharacterBase>() != enemy)
                {
                    occlusionTimer += Time.deltaTime;
                }
                else
                {
                    occlusionTimer = 0f;
                }
            }
            else
            {
                // Nothing between camera and enemy — clear line of sight
                occlusionTimer = 0f;
            }

            if (occlusionTimer > occlusionDelay)
            {
                float progress = (occlusionTimer - occlusionDelay) * fadeSpeed;
                occlusionFade = Mathf.Lerp(1f, 0f, progress);
            }
            else
            {
                occlusionFade = 1f;
            }
            
            // Always update position and scale, even when fading out,
            // so the UI is in the correct place when it becomes visible again.
            float t = Mathf.InverseLerp(minShowDistance, maxShowDistance, cameraDistance);
            float currentScale = Mathf.Lerp(maxScale, minScale, t);
            RectTransform areaRect = PlayerCanvas.EnemyInfoUIArea.rectTransform;
            Vector2 enemyScreenPos = SpaceConverter.WorldPointToUILocalPoint(areaRect, infoUIPos, playerCamera, null);
            rectTransform.localScale = Vector3.one * currentScale;
            rectTransform.anchoredPosition = enemyScreenPos;
        }
        
        public void UpdateHealth(bool isInstant = false)
        {
            float currentHealth = enemy.attributeSm[CharacterAttribute.Health];
            float maximumHealth = enemy.attributeSm[CharacterAttribute.MaximumHealth];
            //float ratio = currentHealth / maximumHealth;
            healthBar.UpdateFillImage(currentHealth, maximumHealth);
            //if(!isInstant) healthBar.Blink(Color.white);
        }

        public void UpdateEnergy(bool isInstant = false)
        {
            float currentEnergy = enemy.attributeSm[CharacterAttribute.Energy];
            float maximumEnergy = enemy.attributeSm[CharacterAttribute.MaximumEnergy];
            energyBar.UpdateFillImage(currentEnergy, maximumEnergy);
            //if(!isInstant) energyBar.Blink(Color.white);
        }

        public void UpdateStance(bool isInstant = false)
        {
            if (stanceBar == null) return;
            if (!enemy.attributeSm.Has(CharacterAttribute.MaximumStance) || enemy.attributeSm[CharacterAttribute.MaximumStance] <= 0)
            {
                if (stanceBar.gameObject.activeSelf) stanceBar.gameObject.SetActive(false);
                return;
            }
            if (!stanceBar.gameObject.activeSelf) stanceBar.gameObject.SetActive(true);

            if (enemy.buffSm.TryGetBuff(out ElectronicParalysis buff) && buff.independentStackSubmodule.totalStackAmount > 0)
            {
                float remainingTime = buff.independentStackSubmodule.LongestUnit.remainingTime;
                float maximumTime = buff.independentStackSubmodule.LongestUnit.duration;
                stanceBar.UpdateFillColor(paralyzedStanceColor, true);
                float elapsed = maximumTime - remainingTime;
                stanceBar.UpdateFillImage(elapsed, maximumTime);
            }
            else
            {
                float currentStance = enemy.attributeSm[CharacterAttribute.Stance];
                float maximumStance = enemy.attributeSm[CharacterAttribute.MaximumStance];
                stanceBar.UpdateFillColor(normalStanceColor, true);
                stanceBar.UpdateFillImage(currentStance, maximumStance);
            }
        }
    }
}