#if UNITY_NATIVE
using System.Runtime.CompilerServices;
using Svelto.Common;
using Svelto.DataStructures;
using Svelto.ECS.Internal;

namespace Svelto.ECS
{
    public static class UnityEntityDBExtensions
    {
        internal static NativeEGIDMapper<T> ToNativeEGIDMapper<T>(this TypeSafeDictionary<T> dic,
            ExclusiveGroupStruct groupStructId) where T : unmanaged, IEntityComponent
        {
            var mapper = new NativeEGIDMapper<T>(groupStructId, dic.implUnmgd);

            return mapper;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static NativeEGIDMapper<T>  QueryNativeMappedEntities<T>(this EntitiesDB entitiesDb, ExclusiveGroupStruct groupStructId)
            where T : unmanaged, IEntityComponent
        {
            if (entitiesDb.SafeQueryEntityDictionary<T>(groupStructId, out var typeSafeDictionary) == false)
                throw new EntityGroupNotFoundException(typeof(T), groupStructId.ToName());

            return (typeSafeDictionary as TypeSafeDictionary<T>).ToNativeEGIDMapper(groupStructId);
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static bool TryQueryNativeMappedEntities<T>(this EntitiesDB entitiesDb, ExclusiveGroupStruct groupStructId,
                                                           out NativeEGIDMapper<T> mapper)
            where T : unmanaged, IEntityComponent
        {
            mapper = default;
            if (entitiesDb.SafeQueryEntityDictionary<T>(groupStructId, out var typeSafeDictionary) == false ||
                typeSafeDictionary.count == 0)
                return false;

            mapper = (typeSafeDictionary as TypeSafeDictionary<T>).ToNativeEGIDMapper(groupStructId);

            return true;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static NativeEGIDMultiMapper<T> QueryNativeMappedEntities<T>(this EntitiesDB entitiesDb,
            LocalFasterReadOnlyList<ExclusiveGroupStruct> groups)
            where T : unmanaged, IEntityComponent
        {
            var dictionary =
                new SveltoDictionary<ExclusiveGroupStruct, SveltoDictionary<uint, T, 
                            NativeStrategy<FasterDictionaryNode<uint>>,
                            NativeStrategy<T>, 
                            NativeStrategy<int>>, 
                        NativeStrategy<FasterDictionaryNode<ExclusiveGroupStruct>>, 
                        NativeStrategy<SveltoDictionary<uint, T, 
                            NativeStrategy<FasterDictionaryNode<uint>>, 
                            NativeStrategy<T>,
                            NativeStrategy<int>>>,
                    NativeStrategy<int>> 
                    ((uint) groups.count, Allocator.TempJob);
        
            foreach (var group in groups)
            {
                if (entitiesDb.SafeQueryEntityDictionary<T>(group, out var typeSafeDictionary) == true)
                    if (typeSafeDictionary.count > 0)
                        dictionary.Add(group, ((TypeSafeDictionary<T>)typeSafeDictionary).implUnmgd);
            }
            
            return new NativeEGIDMultiMapper<T>(dictionary);
        }
    }
}
#endif