CLre/CLre/API/Engines/GameEngines.cs

using HarmonyLib;
using Svelto.DataStructures;
using Svelto.ECS;

namespace CLre.API.Engines
{
    public abstract class GameObsoleteEnginePreBuild : ICLreEngine
    {
        public GameObsoleteEnginePreBuild()
        {
            MainLevel_BuildDeprecatedEngines_Patch.beforeBuildEngines.Add(this);
        }
        
        public abstract void Ready();
        public abstract IEntitiesDB entitiesDB { get; set; }
        public abstract IEntityFactory entityFactory { get; set; }
    }
    
    public abstract class GameObsoleteEnginePostBuild : ICLreEngine
    {
        public GameObsoleteEnginePostBuild()
        {
            MainLevel_BuildDeprecatedEngines_Patch.afterBuildEngines.Add(this);
        }
        
        public abstract void Ready();
        public abstract IEntitiesDB entitiesDB { get; set; }
        public abstract IEntityFactory entityFactory { get; set; }
    }

    [HarmonyPatch(typeof(GameFramework.MainLevel), "BuildDeprecatedEngines")]
    class MainLevel_BuildDeprecatedEngines_Patch
    {
        internal static FasterList<GameObsoleteEnginePreBuild> beforeBuildEngines = new FasterList<GameObsoleteEnginePreBuild>();
        
        internal static FasterList<GameObsoleteEnginePostBuild> afterBuildEngines = new FasterList<GameObsoleteEnginePostBuild>();

        [HarmonyPrefix]
        public static void BeforeMethodCall(GameFramework.MainLevel __instance)
        {
            IEntityFactory factory = AccessTools.Field(typeof(GameFramework.MainLevel), "_entityFactory").GetValue(__instance) as IEntityFactory;
            foreach (ICLreEngine e in beforeBuildEngines)
            {
                e.entityFactory = factory;
                __instance.AddEngine(e);
            }
        }
        
        [HarmonyPostfix]
        public static void AfterMethodCall(GameFramework.MainLevel __instance)
        {
            IEntityFactory factory = AccessTools.Field(typeof(GameFramework.MainLevel), "_entityFactory").GetValue(__instance) as IEntityFactory;
            foreach (ICLreEngine e in afterBuildEngines)
            {
                e.entityFactory = factory;
                __instance.AddEngine(e);
            }
        }
    }
}