// ─────────────────────────────────────────────────────────────────────────────
//  WLWeaponGlowFx.cs — 무기 흰 빛 덧그림 도우미 (#916 · 2026-10-17)
//
//  해머 각성(WLHammerQuake #912)과 같은 방식: 소켓 아래 무기 메시마다 같은 메시를 쓰는 자식을 만들어 WL/WeaponGlow 재질(가산 · 테두리)을 씌우고,
//  세기 · 색 · 몸통 덮기 · 테두리를 렌더러별 프로퍼티 블록으로 쓴다(재질 인스턴스 0). End 에서 자식을 지운다.
//  🔴 Debug.LogError 금지(원본 팝업).
// ─────────────────────────────────────────────────────────────────────────────
using System.Collections.Generic;
using UnityEngine;

namespace WL.Combat.Weapon
{
    public sealed class WLWeaponGlowFx
    {
        static readonly Dictionary<string, Material> s_mats = new Dictionary<string, Material>();
        static readonly int kGlow = Shader.PropertyToID("_Glow"), kColor = Shader.PropertyToID("_GlowColor"),
                            kFill = Shader.PropertyToID("_Fill"), kRim = Shader.PropertyToID("_RimPower"),
                            kColor2 = Shader.PropertyToID("_GlowColor2"), kAxis = Shader.PropertyToID("_GradAxis"), kLen = Shader.PropertyToID("_GradLen");   // #958 그라데이션

        readonly List<GameObject> _gos = new List<GameObject>();
        readonly List<Renderer> _rs = new List<Renderer>();
        readonly List<Vector4> _axis = new List<Vector4>();   // #958 렌더러별 그라데이션 축(오브젝트 공간 · w = 손잡이 끝 투영)
        readonly List<float> _len = new List<float>();        // 1 / (칼끝 − 손잡이 투영)
        MaterialPropertyBlock _mpb;

        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.SubsystemRegistration)]
        static void Reset() { s_mats.Clear(); }

        public bool Active { get { return _rs.Count > 0; } }

        /// <summary>socket 아래 켜진 MeshRenderer 마다 덧그림 자식을 만든다 — 만든 수.</summary>
        public int Begin(Transform socket, string materialPath)
        {
            End();
            if (socket == null || string.IsNullOrEmpty(materialPath)) return 0;
            Material mat;
            if (!s_mats.TryGetValue(materialPath, out mat)) { mat = Resources.Load<Material>(materialPath); s_mats[materialPath] = mat; }
            if (mat == null) return 0;
            foreach (var mf in socket.GetComponentsInChildren<MeshFilter>(false))
            {
                var mr = mf.GetComponent<MeshRenderer>();
                if (mr == null || !mr.enabled || mf.sharedMesh == null || mf.name == "[WL] Glow") continue;
                var go = new GameObject("[WL] Glow") { layer = mf.gameObject.layer };
                go.transform.SetParent(mf.transform, false);
                go.AddComponent<MeshFilter>().sharedMesh = mf.sharedMesh;
                var r = go.AddComponent<MeshRenderer>();
                var mats = new Material[Mathf.Max(1, mf.sharedMesh.subMeshCount)];
                for (int i = 0; i < mats.Length; i++) mats[i] = mat;
                r.sharedMaterials = mats; r.enabled = false;
                r.shadowCastingMode = UnityEngine.Rendering.ShadowCastingMode.Off; r.receiveShadows = false;
                r.lightProbeUsage = UnityEngine.Rendering.LightProbeUsage.Off; r.reflectionProbeUsage = UnityEngine.Rendering.ReflectionProbeUsage.Off;
                _gos.Add(go); _rs.Add(r);
                // #958 그라데이션 축 = 메시 경계의 가장 긴 축 · 방향 = 소켓(손잡이) 쪽 끝 → 먼 끝(칼끝)
                var b = mf.sharedMesh.bounds; var s = b.size;
                Vector3 ax = s.x >= s.y && s.x >= s.z ? Vector3.right : (s.y >= s.z ? Vector3.up : Vector3.forward);
                float lo = Vector3.Dot(b.min, ax), hi = Vector3.Dot(b.max, ax);
                float sock = Vector3.Dot(mf.transform.InverseTransformPoint(socket.position), ax);
                if (Mathf.Abs(sock - hi) < Mathf.Abs(sock - lo)) { ax = -ax; float t = lo; lo = -hi; hi = -t; }
                _axis.Add(new Vector4(ax.x, ax.y, ax.z, lo)); _len.Add(hi - lo > 1e-4f ? 1f / (hi - lo) : 0f);
            }
            return _rs.Count;
        }

        /// <summary>#958 손잡이 color → 칼끝 color2 그라데이션(WL/WeaponGlow 의 _GlowColor2 · _GradAxis · _GradLen).</summary>
        public void Set(float glow, Color color, Color color2, float fill, float rimPower)
        {
            if (_rs.Count == 0) return;
            if (_mpb == null) _mpb = new MaterialPropertyBlock();
            for (int i = 0; i < _rs.Count; i++)
            {
                var r = _rs[i]; if (r == null) continue;
                r.enabled = glow > 0.001f;
                _mpb.Clear(); _mpb.SetFloat(kGlow, glow); _mpb.SetColor(kColor, color); _mpb.SetFloat(kFill, fill); _mpb.SetFloat(kRim, rimPower);
                _mpb.SetColor(kColor2, color2); _mpb.SetVector(kAxis, i < _axis.Count ? _axis[i] : Vector4.zero); _mpb.SetFloat(kLen, i < _len.Count ? _len[i] : 0f);
                r.SetPropertyBlock(_mpb);
            }
        }

        public void Set(float glow, Color color, float fill, float rimPower)
        {
            if (_rs.Count == 0) return;
            if (_mpb == null) _mpb = new MaterialPropertyBlock();
            for (int i = 0; i < _rs.Count; i++)
            {
                var r = _rs[i]; if (r == null) continue;
                r.enabled = glow > 0.001f;
                _mpb.Clear(); _mpb.SetFloat(kGlow, glow); _mpb.SetColor(kColor, color); _mpb.SetFloat(kFill, fill); _mpb.SetFloat(kRim, rimPower);
                r.SetPropertyBlock(_mpb);
            }
        }

        public void End()
        {
            for (int i = 0; i < _gos.Count; i++) if (_gos[i] != null) Object.Destroy(_gos[i]);
            _gos.Clear(); _rs.Clear(); _axis.Clear(); _len.Clear();
        }

        /// <summary>socket 아래 가장 큰 메시의 경계 중심(socket 로컬) — 무기 가운데. 없으면 원점.</summary>
        public static Vector3 CenterLocal(Transform socket)
        {
            if (socket == null) return Vector3.zero;
            Vector3 best = Vector3.zero; float bestSize = -1f;
            foreach (var mf in socket.GetComponentsInChildren<MeshFilter>(false))
            {
                var mr = mf.GetComponent<MeshRenderer>(); var mesh = mf.sharedMesh;
                if (mr == null || !mr.enabled || mesh == null || mf.name == "[WL] Glow") continue;
                float size = mesh.bounds.size.sqrMagnitude;
                if (size > bestSize) { bestSize = size; best = socket.InverseTransformPoint(mf.transform.TransformPoint(mesh.bounds.center)); }
            }
            return best;
        }
    }
}