#if UNITY_EDITOR
using System;
using HotUpdate.UI;
using UnityEditor;

namespace AIGame.EditorTools
{
    /// <summary>UI 图集原图保持未压缩，其他图片按平台设置压缩格式。</summary>
    public sealed class TexturePlatformPostprocessor : AssetPostprocessor
    {
        private void OnPreprocessTexture()
        {
            // 只处理项目图片，不覆盖 Packages 中的包资源。
            if (!assetPath.StartsWith("Assets/", StringComparison.OrdinalIgnoreCase))
                return;

            var importer = (TextureImporter)assetImporter;
            if (UiAtlasPaths.IsTexturePath(assetPath))
            {
                ConfigureUiAtlasSource(importer);
                return;
            }
            // Unity 的 Windows 纹理设置使用 Standalone 平台组。
            SetPlatformFormat(importer, "Standalone", TextureImporterFormat.DXT5);
            SetPlatformFormat(importer, "iPhone", TextureImporterFormat.ASTC_6x6);
            SetPlatformFormat(importer, "Android", TextureImporterFormat.ASTC_6x6);
            SetPlatformFormat(importer, "WebGL", TextureImporterFormat.ASTC_8x8);
        }

        public static bool ConfigureUiAtlasSource(TextureImporter importer)
        {
            if (!UiAtlasPaths.IsTexturePath(importer.assetPath)) return false;
            // 源图使用无损 RGBA32，平台覆盖关闭；最终压缩由 SpriteAtlas 自己处理。
            bool changed = SetUncompressedSource(importer, "DefaultTexturePlatform");
            changed |= SetUncompressedSource(importer, "Standalone");
            changed |= SetUncompressedSource(importer, "iPhone");
            changed |= SetUncompressedSource(importer, "Android");
            changed |= SetUncompressedSource(importer, "WebGL");
            return changed;
        }

        private static bool SetUncompressedSource(TextureImporter importer, string platform)
        {
            var settings = importer.GetPlatformTextureSettings(platform);
            if (!settings.overridden && settings.format == TextureImporterFormat.RGBA32
                && settings.textureCompression == TextureImporterCompression.Uncompressed
                && !settings.crunchedCompression) return false;
            settings.name = platform;
            settings.overridden = false;
            settings.format = TextureImporterFormat.RGBA32;
            settings.textureCompression = TextureImporterCompression.Uncompressed;
            settings.crunchedCompression = false;
            importer.SetPlatformTextureSettings(settings);
            return true;
        }

        private static void SetPlatformFormat(
            TextureImporter importer, string platform, TextureImporterFormat format)
        {
            // 保留尺寸、缩放算法等原有设置，仅覆盖压缩相关选项。
            var settings = importer.GetPlatformTextureSettings(platform);
            settings.name = platform;
            settings.overridden = true;
            settings.format = format;
            settings.crunchedCompression = false;
            importer.SetPlatformTextureSettings(settings);
        }
    }
}
#endif