using System.Linq;
using System.Reflection;
using UnityEngine;
using UnityEditor;
using static UnityEngine.ShaderVariantCollection;
using UnityEngine.Rendering;
using System.Collections.Generic;

namespace BFEditor.Resource
{
    public static class ShaderVariantsTools
    {
        // 手动添加的shader变体信息
        static Dictionary<string, List<VariantInfo>> manualInfoDict = new Dictionary<string, List<VariantInfo>>()
        {
        };

        // 忽略的shader，不添加到变体收集中
        static List<string> ingoreShaderList = new List<string>()
        {
            "TextMeshPro",  // 整理好了再收集
        };

        class VariantInfo
        {
            public PassType passType;
            public string[] keywords;

            public VariantInfo(PassType passType, string[] keywords)
            {
                this.passType = passType;
                this.keywords = keywords;
            }
        }

        static MethodInfo GetShaderVariantEntries = null;

        static ShaderVariantCollection EnsureColletion()
        {
            var svc = AssetDatabase.LoadAssetAtPath<ShaderVariantCollection>(ResourceProcessConfig.SHADER_VARIANT_COLLECTION);
            if (svc == null)
            {
                svc = new ShaderVariantCollection();
                AssetDatabase.CreateAsset(svc, ResourceProcessConfig.SHADER_VARIANT_COLLECTION);
            }
            return svc;
        }

        static Shader[] GetShaders()
        {
            var guids = GetBFShaderGUID();
            var shaders = new Shader[guids.Length];
            var index = 0;
            foreach (var guid in guids)
            {
                shaders[index] = AssetDatabase.LoadAssetAtPath<Shader>(AssetDatabase.GUIDToAssetPath(guid));
                index++;
            }
            return shaders;
        }

        static string[] GetBFShaderGUID()
        {
            return AssetDatabase.FindAssets("t:shader", new string[] { ResourceProcessConfig.SHADER_FOLDER_PATH });
        }

        static List<VariantInfo> GetShaderVariantInfos(Shader target)
        {
            if (GetShaderVariantEntries == null)
                GetShaderVariantEntries = typeof(ShaderUtil).GetMethod("GetShaderVariantEntries",
                    BindingFlags.NonPublic | BindingFlags.Static);

            int[] passTypes = null;
            string[] allKeywords = null;
            object[] args = new object[] { target, new ShaderVariantCollection(), passTypes, allKeywords };
            GetShaderVariantEntries.Invoke(null, args);

            passTypes = args[2] as int[];
            allKeywords = args[3] as string[];

            var infos = new List<VariantInfo>();
            var index = 0;
            foreach (string item in allKeywords)
            {
                var temp = item.Split(' ');
                var keywords = new string[temp.Length];
                var index2 = 0;
                foreach (string t in temp)
                {
                    keywords[index2] = t;
                    index2++;
                }
                infos.Add(new VariantInfo((PassType)passTypes[index], keywords));
                index++;
            }
            return infos;
        }

        public static void GenerateVariantCollection(bool needDialog = false)
        {
            // Debug.Log("[bfinfo]收集shader变体...");
            // var svc = EnsureColletion();
            // svc.Clear();

            // var shaders = GetShaders();
            // var index = 0;
            // var totalCount = shaders.Length;
            // foreach (var shader in shaders)
            // {
            //     EditorUtility.DisplayProgressBar("正在收集shader变体", shader.name, (float)(index + 1) / totalCount);

            //     // 收集手动添加的变体信息
            //     if (manualInfoDict.TryGetValue(shader.name, out List<VariantInfo> infos))
            //     {
            //         foreach (var info in infos)
            //         {
            //             svc.Add(new ShaderVariant(shader, info.passType, info.keywords));
            //         }
            //         continue;
            //     }

            //     // 跳过收集
            //     var needContine = false;
            //     foreach (var ingore in ingoreShaderList)
            //     {
            //         if (shader.name.Contains(ingore))
            //         {
            //             needContine = true;
            //             break;
            //         }
            //     }
            //     if (needContine)
            //     {
            //         continue;
            //     }

            //     // 收集所有的变体
            //     var variantInfos = GetShaderVariantInfos(shader);
            //     if (variantInfos.Count >= 10)
            //     {
            //         Debug.LogErrorFormat("shader变体收集: 新增shader变体 shaderName : {0} , 变体 count {1}", shader.name, variantInfos.Count);
            //     }
            //     foreach (var info in variantInfos)
            //     {
            //         if (info.passType == PassType.Normal || info.passType == PassType.ForwardBase || info.passType == PassType.ShadowCaster)
            //         {
            //             bool a = false;
            //             foreach (var keyword in info.keywords)
            //             {
            //                 if (keyword.Contains("INSTANCING_ON"))
            //                 {
            //                     a = true;
            //                     break;
            //                 }
            //             }
            //             if (a)
            //             {
            //                 continue;
            //             }
            //             svc.Add(new ShaderVariant(shader, info.passType, info.keywords));
            //         }
            //     }

            //     index++;
            // }

            // EditorUtility.ClearProgressBar();
            // AssetDatabase.SaveAssets();

            // if (needDialog)
            // {
            //     EditorUtility.DisplayDialog("收集完成", "收集完成", "ok");
            // }
        }

        public static void GenerateShaderVariantCollection()
        {
            GenerateVariantCollection(true);
        }
    }
}