using System;
using System.Collections.Generic;
using System.Reflection;
using System.Runtime.CompilerServices;

namespace AlicizaX.UI.Runtime
{
    public static class UIResRegistry
    {
        public readonly struct UIResInfo
        {
            public readonly string Location;
            public readonly EUIResLoadType LoadType;

            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            public UIResInfo(string location, EUIResLoadType loadType)
            {
                Location = location;
                LoadType = loadType;
            }
        }

        private static readonly Dictionary<RuntimeTypeHandle, UIResInfo> _typeHandleMap = new();

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static void Register(Type holderType, string location, EUIResLoadType loadType)
        {
            RuntimeTypeHandle handle = holderType.TypeHandle;
            _typeHandleMap[handle] = new UIResInfo(location, loadType);
        }

        public static bool TryGet(RuntimeTypeHandle handle, out UIResInfo info)
        {
            if (_typeHandleMap.TryGetValue(handle, out info))
            {
                return true;
            }

            return TryReflectAndRegister(Type.GetTypeFromHandle(handle), out info);
        }

        [MethodImpl(MethodImplOptions.NoInlining)]
        private static bool TryReflectAndRegister(Type holderType, out UIResInfo info)
        {
            if (holderType == null)
            {
                info = default;
                return false;
            }

            return TryReflectAndRegisterInternal(holderType, out info);
        }

        [MethodImpl(MethodImplOptions.NoInlining)]
        private static bool TryReflectAndRegisterInternal(Type holderType, out UIResInfo info)
        {
            try
            {
                IList<CustomAttributeData> attributes = CustomAttributeData.GetCustomAttributes(holderType);
                for (int i = 0; i < attributes.Count; i++)
                {
                    CustomAttributeData attribute = attributes[i];
                    if (attribute.AttributeType.Name != nameof(UIResAttribute))
                    {
                        continue;
                    }

                    IList<CustomAttributeTypedArgument> args = attribute.ConstructorArguments;
                    string resLocation = args.Count > 0 ? (string)(args[0].Value ?? string.Empty) : string.Empty;
                    EUIResLoadType resLoadType = args.Count > 1
                        ? (EUIResLoadType)(args[1].Value ?? EUIResLoadType.AssetBundle)
                        : EUIResLoadType.AssetBundle;

                    Register(holderType, resLocation, resLoadType);
                    info = _typeHandleMap[holderType.TypeHandle];
                    return true;
                }
            }
            catch (Exception ex)
            {
                Log.Error($"[UI] Failed to register UI resource for {holderType.FullName}: {ex.Message}");
            }

            info = default;
            return false;
        }
    }
}