using System.Collections.Generic;
using Cielonos.MainGame.Characters;
using UnityEngine;

namespace Cielonos.MainGame
{
    /// <summary>
    /// 索敌评分 Debug 显示组件。
    /// 挂载到场景中任意 GameObject 上，运行时在每个敌人头顶显示当前索敌评分。
    /// 仅在 Debug 模式开启时绘制，不影响正式构建。
    /// </summary>
    public class TargetingDebugDisplay : MonoBehaviour
    {
        [Header("Debug 设置")]
        [Tooltip("是否启用索敌评分显示")]
        public bool enableDebug;

        [Tooltip("索敌评分查询半径")]
        public float debugRadius = 20f;

        [Tooltip("文字显示在敌人头顶的偏移量")]
        public float headOffset = 2.2f;

        [Tooltip("文字大小")]
        public int fontSize = 20;

        [Tooltip("最高分目标的标记颜色")]
        public Color bestTargetColor = Color.green;

        [Tooltip("普通目标的文字颜色")]
        public Color normalColor = Color.white;

        [Tooltip("背景颜色")]
        public Color backgroundColor = new Color(0f, 0f, 0f, 0.6f);

        private List<CombatManager.EnemySubmodule.TargetingScore> _cachedScores = new();
        private readonly Dictionary<CharacterBase, CombatManager.EnemySubmodule.TargetingScore> _scoreMap = new();
        private float _updateInterval = 0.1f;
        private float _nextUpdateTime;

        private GUIStyle _labelStyle;
        private GUIStyle _bgStyle;
        private Texture2D _bgTexture;

        private void Update()
        {
            if (!enableDebug) return;

            if (Time.time >= _nextUpdateTime)
            {
                _nextUpdateTime = Time.time + _updateInterval;
                _cachedScores = CombatManager.EnemySm.GetScoredEnemies(debugRadius);
                _scoreMap.Clear();
                foreach (var score in _cachedScores)
                {
                    _scoreMap[score.target] = score;
                }
            }
        }

        private void OnGUI()
        {
            if (!enableDebug || _cachedScores.Count == 0) return;

            EnsureStyles();

            Camera cam = Camera.main;
            if (cam == null) return;

            bool isFirst = true;
            foreach (var score in _cachedScores)
            {
                if (score.target == null) continue;

                Vector3 worldPos = score.target.centerPoint.position + Vector3.up * headOffset;
                Vector3 screenPos = cam.WorldToScreenPoint(worldPos);

                if (screenPos.z <= 0) continue;

                float guiY = Screen.height - screenPos.y;

                string text = $"Total: {score.totalScore:F2}";
                if (score.bonusScore != 0f)
                {
                    text += $" (Base: {score.baseScore:F2} + Bonus: {score.bonusScore:F2})";
                }
                text += $"\nDist: {score.distanceScore:F2}  Input: {score.inputDirScore:F2}" +
                        $"\nCam: {score.cameraFacingScore:F2}  Sticky: {score.stickyScore:F2}  Lock: {score.lockOnScore:F2}";

                GUIContent content = new GUIContent(text);
                Vector2 size = _labelStyle.CalcSize(content);
                // CalcSize 不考虑换行，用 CalcHeight 代替
                float height = _labelStyle.CalcHeight(content, size.x);
                Rect bgRect = new Rect(screenPos.x - size.x / 2 - 4, guiY - height - 4, size.x + 8, height + 8);
                Rect textRect = new Rect(screenPos.x - size.x / 2, guiY - height, size.x, height);

                GUI.Box(bgRect, GUIContent.none, _bgStyle);
                _labelStyle.normal.textColor = isFirst ? bestTargetColor : normalColor;
                GUI.Label(textRect, content, _labelStyle);

                isFirst = false;
            }
        }

        private void EnsureStyles()
        {
            if (_labelStyle != null) return;

            _bgTexture = new Texture2D(1, 1);
            _bgTexture.SetPixel(0, 0, backgroundColor);
            _bgTexture.Apply();

            _bgStyle = new GUIStyle(GUI.skin.box)
            {
                normal = { background = _bgTexture }
            };

            _labelStyle = new GUIStyle(GUI.skin.label)
            {
                fontSize = fontSize,
                alignment = TextAnchor.UpperCenter,
                wordWrap = false
            };
        }

        private void OnDestroy()
        {
            if (_bgTexture != null)
            {
                Destroy(_bgTexture);
            }
        }
    }
}