// WL772_MatFix.cs — PD 지시 #772 : 맵 프리팹의 마젠타(셰이더 깨짐 / null 머티리얼) 진단 + URP 업그레이드
//   진단 : unity command run_script --file AgentScripts/WL772_MatFix.cs --entry WL772_MatFix.Diag --args '["Assets/Res_Addr/Map/WL_Nature03.prefab"]'
//   수리 : ... --entry WL772_MatFix.Fix --args '["Assets/Res_Addr/Map/WL_Nature03.prefab"]'
// Fix 는 머티리얼 에셋의 셰이더만 Built-in → URP 로 승격한다(MaterialUpgrader). 프리팹은 건드리지 않는다.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
using UnityEditor.Rendering;
#endif

public static class WL772_MatFix
{
#if UNITY_EDITOR
    static readonly string[] BuiltIn = { "Standard", "Standard (Specular setup)", "Legacy Shaders/", "Mobile/", "Particles/", "Nature/", "Unlit/Texture", "Unlit/Color", "Unlit/Transparent" };

    static List<Material> Collect(string prefabPath, StringBuilder sb)
    {
        var bad = new List<Material>();
        var root = PrefabUtility.LoadPrefabContents(prefabPath);
        try
        {
            var seen = new HashSet<string>();
            foreach (var r in root.GetComponentsInChildren<Renderer>(true))
                foreach (var m in r.sharedMaterials)
                {
                    if (m == null) { if (seen.Add("NULLSLOT:" + r.name)) sb.AppendLine("  null 머티리얼 슬롯 — " + r.name); continue; }
                    var sn = m.shader != null ? m.shader.name : "(shader null)";
                    bool broken = m.shader == null || sn == "Hidden/InternalErrorShader" || BuiltIn.Any(b => sn.StartsWith(b));
                    if (!broken) continue;
                    var path = AssetDatabase.GetAssetPath(m);
                    if (!seen.Add(path + "|" + sn)) continue;
                    sb.AppendLine(string.Format("  [{0}] {1}  ← {2}", sn, m.name, path));
                    if (!string.IsNullOrEmpty(path) && path.StartsWith("Assets/")) bad.Add(m);
                }
        }
        finally { PrefabUtility.UnloadPrefabContents(root); }
        return bad;
    }

    public static object Diag(string prefabPath)
    {
        var sb = new StringBuilder("# " + prefabPath + "\n");
        var bad = Collect(prefabPath, sb);
        sb.AppendLine("수리 대상 머티리얼 = " + bad.Count);
        return sb.ToString();
    }

    public static object Fix(string prefabPath)
    {
        var sb = new StringBuilder("# " + prefabPath + "\n");
        var bad = Collect(prefabPath, sb);
        int ok = 0, fail = 0;
        foreach (var m in bad)
        {
            var before = m.shader != null ? m.shader.name : "(null)";
            try
            {
                MaterialUpgrader.Upgrade(m, new UnityEditor.Rendering.Universal.StandardUpgrader(before), MaterialUpgrader.UpgradeFlags.None);
            }
            catch { }
            if (m.shader == null || m.shader.name == before || m.shader.name == "Hidden/InternalErrorShader")
            {
                // 폴백: URP Lit 로 직접 지정하고 주요 값을 옮긴다
                var col = m.HasProperty("_Color") ? m.GetColor("_Color") : Color.white;
                var tex = m.HasProperty("_MainTex") ? m.GetTexture("_MainTex") : null;
                var lit = Shader.Find("Universal Render Pipeline/Lit");
                if (lit == null) { fail++; sb.AppendLine("  FAIL(URP Lit 없음) " + m.name); continue; }
                m.shader = lit;
                if (m.HasProperty("_BaseColor")) m.SetColor("_BaseColor", col);
                if (tex != null && m.HasProperty("_BaseMap")) m.SetTexture("_BaseMap", tex);
            }
            EditorUtility.SetDirty(m);
            ok++;
            sb.AppendLine(string.Format("  {0} : {1} -> {2}", m.name, before, m.shader != null ? m.shader.name : "(null)"));
        }
        AssetDatabase.SaveAssets();
        sb.AppendLine(string.Format("업그레이드 {0} · 실패 {1}", ok, fail));
        return sb.ToString();
    }
#endif
}