CLre/CLre/API/Utility/Reflection.cs

using System;
using System.Reflection;
using HarmonyLib;
using Svelto.DataStructures;
using Svelto.ECS;

namespace CLre.API.Utility
{
    public static class Reflection
    {
        // useful function & method prototypes
        public delegate T Getter<T>();

        public delegate bool ExistsV1(EGID egid);

        public delegate bool ExistsV2(int id, int groupid);

        public delegate T QueryEntityViewV1<T>(EGID egid);
        
        public delegate T QueryEntityViewV2<T>(int id, ExclusiveGroup.ExclusiveGroupStruct groupid);

        public delegate ReadOnlyCollectionStruct<T> QueryEntityViews<T>(int group) where T : class, IEntityViewStruct;

        public delegate T[] QueryEntitiesV2<T>(int group, out int count) where T : IEntityStruct;
        
        public delegate T[] QueryEntitiesV1<T>(ExclusiveGroup.ExclusiveGroupStruct group, out int count) where T : IEntityStruct;

        // useful reflection functions
        public static TFuncProto BuildDelegate<TFuncProto>(MethodInfo method) where TFuncProto : Delegate
        {
            return (TFuncProto) Delegate.CreateDelegate(typeof(TFuncProto), method);
        }
        
        public static Delegate BuildDelegateRaw(MethodInfo method, Type TFuncProto)
        {
            return Delegate.CreateDelegate(TFuncProto, method);
        }
        
        public static TFuncProto BuildDelegate<TFuncProto>(MethodInfo method, object instance) where TFuncProto : Delegate
        {
            return (TFuncProto) Delegate.CreateDelegate(typeof(TFuncProto), instance, method, true);
        }
        
        public static Delegate BuildDelegateRaw(MethodInfo method, object instance, Type TFuncProto)
        {
            return Delegate.CreateDelegate(TFuncProto, instance, method, true);
        }

        public static TFuncProto MethodAsDelegate<TFuncProto>(Type class_, string methodName, Type[] parameters = null, Type[] generics = null, object instance = null) where TFuncProto : Delegate
        {
            MethodInfo method = AccessTools.Method(class_, methodName, parameters, generics);
            if (instance != null)
            {
                return BuildDelegate<TFuncProto>(method, instance);
            }
            return BuildDelegate<TFuncProto>(method);
        }
        
        public static Delegate MethodAsDelegateRaw(Type class_, Type TFuncProto, string methodName, Type[] parameters = null, Type[] generics = null, object instance = null)
        {
            MethodInfo method = AccessTools.Method(class_, methodName, parameters, generics);
            if (instance != null)
            {
                return BuildDelegateRaw(method, instance, TFuncProto);
            }
            return BuildDelegateRaw(method, TFuncProto);
        }
        
        public static TFuncProto MethodAsDelegate<TFuncProto>(string typeColonName, Type[] parameters = null, Type[] generics = null, object instance = null) where TFuncProto : Delegate
        {
            MethodInfo method = AccessTools.Method(typeColonName, parameters, generics);
            if (instance != null)
            {
                return BuildDelegate<TFuncProto>(method, instance);
            }
            return BuildDelegate<TFuncProto>(method);
        }
        
        public static Delegate MethodAsDelegateRaw(string typeColonName, Type TFuncProto, Type[] parameters = null, Type[] generics = null, object instance = null)
        {
            MethodInfo method = AccessTools.Method(typeColonName, parameters, generics);
            if (instance != null)
            {
                return BuildDelegateRaw(method, instance, TFuncProto);
            }
            return BuildDelegateRaw(method, TFuncProto);
        }

        public static PropertyInfo GetIndexer(this Type type, Type[] arguments = null, BindingFlags bindingFlags = BindingFlags.GetField | BindingFlags.GetProperty | BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.SetField | BindingFlags.SetProperty | BindingFlags.Static)
        {
            foreach (PropertyInfo p in type.GetProperties(bindingFlags))
            {
                if (arguments == null && p.GetIndexParameters().Length != 0) return p;
                if (arguments != null)
                {
                    uint count = 0;
                    foreach (ParameterInfo param in p.GetIndexParameters())
                    {
                        if (param.ParameterType != arguments[count])
                        {
                            break;
                        }

                        count++;
                    }
                    if (count == arguments.Length)
                    {
                        return p;
                    }
                }
            }
            return null;
        }
    }
}