PorygonSharp/PorygonSharp/UserData/UserDataHandler.cs

using System;
using System.Collections.Generic;
using System.Reflection;
using System.Runtime.InteropServices;
using PorygonSharp.Utilities;

namespace PorygonSharp.UserData
{
    public static class UserDataHandler
    {
        private static readonly Dictionary<Type, uint> UserDataLookup = new Dictionary<Type, uint>();

        private delegate IntPtr GetterDelegate(IntPtr ptr);
        private delegate void SetterDelegate(IntPtr ptr, IntPtr val);

        public static void RegisterType(string name, Type type)
        {
            var hash = name.ScriptHash();
            RegisterUserDataType(hash);
            UserDataLookup.Add(type, hash);

            var fields = type.GetFields(BindingFlags.Public | BindingFlags.Instance | BindingFlags.Static);
            foreach (var field in fields)
            {
                var getter = new GetterDelegate(ptr =>
                {
                    var obj = GCHandle.FromIntPtr(ptr).Target;
                    var value = field.GetValue(obj);
                    return new EvalValue(value).GetPointer();
                });
                var setter = new SetterDelegate((ptr, val) =>
                {
                    var obj = GCHandle.FromIntPtr(ptr).Target;
                    var evalValue = Convert.ChangeType(new EvalValue(val).GetObjectValue(), field.FieldType);
                    field.SetValue(obj, evalValue);
                });
                var scriptType = ScriptType.ScriptType.GetScriptType(field.FieldType);
                var userDataField = CreateUserDataField(scriptType, Marshal.GetFunctionPointerForDelegate(getter),
                    Marshal.GetFunctionPointerForDelegate(setter));


                var fieldName = field.Name.ScriptHash();
                RegisterUserDataField(hash, fieldName, userDataField);
            }
        }

        public static uint GetTypeId(Type t)
        {
            return UserDataLookup[t];
        }

        [DllImport("libPorygonLang", EntryPoint = "RegisterUserDataType", CallingConvention = CallingConvention.Cdecl)]
        private static extern void RegisterUserDataType(uint hashId);

        [DllImport("libPorygonLang", EntryPoint = "RegisterUserDataField", CallingConvention = CallingConvention.Cdecl)]
        private static extern void RegisterUserDataField(uint hashId, uint fieldId, IntPtr field);

        [DllImport("libPorygonLang", EntryPoint = "CreateUserDataField", CallingConvention = CallingConvention.Cdecl)]
        private static extern IntPtr CreateUserDataField(IntPtr type, IntPtr getter, IntPtr setter);

        [DllImport("libPorygonLang", EntryPoint = "GetUserDataFieldCount", CallingConvention = CallingConvention.Cdecl)]
        private static extern int GetUserDataFieldCount(uint hashId);

    }
}