// ─────────────────────────────────────────────────────────────────────────────
//  WL814s_Posterize.cs — 캐릭터 텍스처 복사 + 색 평탄화(양자화) · 에디터 전용
//
//  PD 지시 #814 · 발주서 WL-814s §2 / §3
//
//  🔴 원본 png(`Assets/Suriyun/**`)는 **바이트 하나도 건드리지 않는다**.
//     · 복사본을 `Assets/WL/Look/Character/Textures/` 에 만들고
//     · 축소는 **복사본의 임포트 설정 maxTextureSize** 로만 한다(픽셀 리샘플 0 = 되돌리기 쉬움)
//     · 평탄화는 복사본을 읽어 **새 png** 로 저장한다(원본 덮어쓰기 0)
//
//  평탄화 = 채널당 색 단계를 levels 개로 반올림. 알파는 **손대지 않는다**
//  (얼굴 face02 · 머리 가장자리가 깨지지 않게 · 발주 §3).
// ─────────────────────────────────────────────────────────────────────────────

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using UnityEditor;
using UnityEngine;

public static class WL814s_Posterize
{
    public const string DST = "Assets/WL/Look/Character/Textures/";

    // 원본 4장(+검은 참고). name → 원본 경로
    public static readonly string[,] SRC = new string[,]
    {
        { "M05",    "Assets/Suriyun/Characters/RedKnight/Texture/M05/M05.png" },
        { "Skin",   "Assets/Suriyun/Characters/RedKnight/Texture/Skin&Hair&Face/Face/Skin.png" },
        { "Hair05", "Assets/Suriyun/Characters/RedKnight/Texture/M05/Hair05.png" },
        { "face02", "Assets/Suriyun/Characters/RedKnight/Texture/Skin&Hair&Face/Face/face02.png" },
    };

    static void Ensure(string folder)
    {
        folder = folder.TrimEnd('/');
        if (AssetDatabase.IsValidFolder(folder)) return;
        int i = folder.LastIndexOf('/');
        Ensure(folder.Substring(0, i));
        AssetDatabase.CreateFolder(folder.Substring(0, i), folder.Substring(i + 1));
    }

    static Texture2D LoadRaw(string path, out int w, out int h)
    {
        byte[] bytes = File.ReadAllBytes(path);
        var t = new Texture2D(2, 2, TextureFormat.RGBA32, false);
        t.LoadImage(bytes);
        w = t.width; h = t.height;
        return t;
    }

    // ═════════════════════════════════════════════════════════════════════
    //  ① 복사본 만들기 (바이트 그대로) + 임포트 설정
    // ═════════════════════════════════════════════════════════════════════
    public static string CopyAll()
    {
        var sb = new StringBuilder();
        Ensure(DST);
        for (int i = 0; i < SRC.GetLength(0); i++)
        {
            string name = SRC[i, 0], src = SRC[i, 1];
            string dst = DST + name + "_WL.png";
            File.Copy(src, dst, true);
            sb.AppendLine("COPY " + src + " -> " + dst + " (" + new FileInfo(dst).Length + " bytes · 원본과 동일 = " +
                          (new FileInfo(src).Length == new FileInfo(dst).Length) + ")");
        }
        AssetDatabase.Refresh();
        // 원본 임포터 설정을 복사본에 이식
        for (int i = 0; i < SRC.GetLength(0); i++)
        {
            string name = SRC[i, 0], src = SRC[i, 1];
            string dst = DST + name + "_WL.png";
            var si = AssetImporter.GetAtPath(src) as TextureImporter;
            var di = AssetImporter.GetAtPath(dst) as TextureImporter;
            if (si == null || di == null) { sb.AppendLine("IMPORTER MISS " + name); continue; }
            di.textureType = si.textureType;
            di.sRGBTexture = si.sRGBTexture;
            di.alphaSource = si.alphaSource;
            di.alphaIsTransparency = si.alphaIsTransparency;
            di.mipmapEnabled = si.mipmapEnabled;
            di.wrapMode = si.wrapMode;
            di.filterMode = si.filterMode;
            di.anisoLevel = si.anisoLevel;
            di.npotScale = si.npotScale;
            di.maxTextureSize = si.maxTextureSize;
            di.textureCompression = si.textureCompression;
            di.SaveAndReimport();
            sb.AppendLine("IMPORT " + name + "_WL type=" + di.textureType + " sRGB=" + di.sRGBTexture +
                          " alphaSrc=" + di.alphaSource + " alphaIsTransparency=" + di.alphaIsTransparency +
                          " mip=" + di.mipmapEnabled + " max=" + di.maxTextureSize);
        }
        AssetDatabase.SaveAssets();
        return sb.ToString();
    }

    // ═════════════════════════════════════════════════════════════════════
    //  ② 평탄화 — 복사본을 읽어 levels 단계로 양자화한 새 png
    // ═════════════════════════════════════════════════════════════════════
    public static string MakeFlat(int levels)
    {
        var sb = new StringBuilder();
        Ensure(DST);
        for (int i = 0; i < SRC.GetLength(0); i++)
        {
            string name = SRC[i, 0];
            string src = DST + name + "_WL.png";
            if (!File.Exists(src)) { sb.AppendLine("SKIP(no copy) " + src); continue; }
            int w, h;
            var t = LoadRaw(src, out w, out h);
            var px = t.GetPixels32();

            float step = 255f / (levels - 1);
            int uniqBefore = CountUnique(px);
            int alphaChanged = 0;
            for (int p = 0; p < px.Length; p++)
            {
                var c = px[p];
                c.r = (byte)Mathf.Clamp(Mathf.RoundToInt(Mathf.Round(c.r / step) * step), 0, 255);
                c.g = (byte)Mathf.Clamp(Mathf.RoundToInt(Mathf.Round(c.g / step) * step), 0, 255);
                c.b = (byte)Mathf.Clamp(Mathf.RoundToInt(Mathf.Round(c.b / step) * step), 0, 255);
                // 알파는 그대로 (얼굴·머리 가장자리 보존)
                px[p] = c;
            }
            var outT = new Texture2D(w, h, TextureFormat.RGBA32, false);
            outT.SetPixels32(px);
            outT.Apply(false);
            string dst = DST + name + "_WL_Q" + levels + ".png";
            File.WriteAllBytes(dst, outT.EncodeToPNG());
            int uniqAfter = CountUnique(px);
            sb.AppendLine("FLAT " + name + " levels=" + levels + " " + w + "x" + h +
                          " 고유색 " + uniqBefore + " -> " + uniqAfter + " · 알파변경 " + alphaChanged + " · " + dst);
            UnityEngine.Object.DestroyImmediate(t);
            UnityEngine.Object.DestroyImmediate(outT);
        }
        AssetDatabase.Refresh();
        // 임포트 설정을 복사본과 같게
        for (int i = 0; i < SRC.GetLength(0); i++)
        {
            string name = SRC[i, 0];
            var si = AssetImporter.GetAtPath(DST + name + "_WL.png") as TextureImporter;
            var di = AssetImporter.GetAtPath(DST + name + "_WL_Q" + levels + ".png") as TextureImporter;
            if (si == null || di == null) continue;
            di.textureType = si.textureType;
            di.sRGBTexture = si.sRGBTexture;
            di.alphaSource = si.alphaSource;
            di.alphaIsTransparency = si.alphaIsTransparency;
            di.mipmapEnabled = si.mipmapEnabled;
            di.wrapMode = si.wrapMode;
            di.filterMode = si.filterMode;
            di.npotScale = si.npotScale;
            di.maxTextureSize = si.maxTextureSize;
            di.textureCompression = si.textureCompression;
            di.SaveAndReimport();
        }
        AssetDatabase.SaveAssets();
        return sb.ToString();
    }

    static int CountUnique(Color32[] px)
    {
        var set = new HashSet<int>();
        int stride = px.Length > 1048576 ? 4 : 1;   // 4M 픽셀 이상이면 1/4 샘플링(메모리)
        for (int i = 0; i < px.Length; i += stride)
        {
            var c = px[i];
            if (c.a == 0) continue;
            set.Add((c.r << 16) | (c.g << 8) | c.b);
        }
        return set.Count;
    }

    // ═════════════════════════════════════════════════════════════════════
    //  ③ 축소 — 복사본/평탄화본의 maxTextureSize 만 바꾼다
    // ═════════════════════════════════════════════════════════════════════
    public static string SetMaxSize(string suffix, int maxSize)
    {
        var sb = new StringBuilder();
        for (int i = 0; i < SRC.GetLength(0); i++)
        {
            string p = DST + SRC[i, 0] + suffix + ".png";
            var im = AssetImporter.GetAtPath(p) as TextureImporter;
            if (im == null) { sb.AppendLine("MISS " + p); continue; }
            im.maxTextureSize = maxSize;
            im.SaveAndReimport();
            var t = AssetDatabase.LoadAssetAtPath<Texture2D>(p);
            long mem = t != null ? UnityEngine.Profiling.Profiler.GetRuntimeMemorySizeLong(t) : 0;
            sb.AppendLine("MAXSIZE " + p + " -> " + maxSize + " · 실제 " + (t != null ? t.width + "x" + t.height : "?") +
                          " · " + (t != null ? t.format.ToString() : "?") + " · " + (mem / 1024f / 1024f).ToString("F3") + " MB");
        }
        AssetDatabase.SaveAssets();
        return sb.ToString();
    }

    /// <summary>원본 4장의 런타임 메모리(현재 임포트 상태)를 잰다.</summary>
    public static string MeasureOriginals()
    {
        var sb = new StringBuilder();
        float tot = 0;
        for (int i = 0; i < SRC.GetLength(0); i++)
        {
            var t = AssetDatabase.LoadAssetAtPath<Texture2D>(SRC[i, 1]);
            if (t == null) { sb.AppendLine("MISS " + SRC[i, 1]); continue; }
            long mem = UnityEngine.Profiling.Profiler.GetRuntimeMemorySizeLong(t);
            tot += mem / 1024f / 1024f;
            sb.AppendLine("ORIG " + SRC[i, 0] + " " + t.width + "x" + t.height + " " + t.format + " mip=" + (t.mipmapCount > 1) +
                          " · " + (mem / 1024f / 1024f).ToString("F3") + " MB");
        }
        sb.AppendLine("ORIG TOTAL " + tot.ToString("F3") + " MB");
        return sb.ToString();
    }

    public static string MeasureSet(string suffix)
    {
        var sb = new StringBuilder();
        float tot = 0;
        for (int i = 0; i < SRC.GetLength(0); i++)
        {
            string p = DST + SRC[i, 0] + suffix + ".png";
            var t = AssetDatabase.LoadAssetAtPath<Texture2D>(p);
            if (t == null) { sb.AppendLine("MISS " + p); continue; }
            long mem = UnityEngine.Profiling.Profiler.GetRuntimeMemorySizeLong(t);
            tot += mem / 1024f / 1024f;
            sb.AppendLine("SET" + suffix + " " + SRC[i, 0] + " " + t.width + "x" + t.height + " " + t.format +
                          " · " + (mem / 1024f / 1024f).ToString("F3") + " MB");
        }
        sb.AppendLine("SET" + suffix + " TOTAL " + tot.ToString("F3") + " MB");
        return sb.ToString();
    }

    public static void Run()
    {
        var sb = new StringBuilder();
        sb.Append(MeasureOriginals());
        sb.Append(CopyAll());
        Debug.Log("[WL814s posterize]\n" + sb);
    }

    // 디스패처 — unity command run_script --entry WL814s_Posterize.Cmd --args "<cmd> …"
    public static string Cmd(string[] args)
    {
        if (args == null || args.Length == 0) return MeasureOriginals();
        string c = args[0];
        try
        {
            if (c == "measure") return MeasureOriginals();
            if (c == "copy") return MeasureOriginals() + CopyAll();
            if (c == "flat") return MakeFlat(int.Parse(args[1]));
            if (c == "maxsize") return SetMaxSize(args[1] == "-" ? "_WL" : args[1], int.Parse(args[2]));
            if (c == "set") return MeasureSet(args[1] == "-" ? "_WL" : args[1]);
            return "UNKNOWN " + c;
        }
        catch (Exception e) { return "EXCEPTION " + e.GetType().Name + " " + e.Message + "\n" + e.StackTrace; }
    }
}