using System.Runtime.CompilerServices;
using Svelto.DataStructures;
using Svelto.ECS.Internal;

namespace Svelto.ECS
{
    public static class EntityNativeDBExtensions
    {
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
       public static AllGroupsEnumerable<T1> QueryEntities<T1>(this EntitiesDB db)
            where T1 :struct, IEntityComponent
        {
            return new AllGroupsEnumerable<T1>(db);
        }
       
       [MethodImpl(MethodImplOptions.AggressiveInlining)]
       public static NB<T> QueryEntitiesAndIndex<T>(this EntitiesDB entitiesDb, EGID entityGID, out uint index) where T : unmanaged, IEntityComponent
       {
           if (entitiesDb.QueryEntitiesAndIndexInternal(entityGID, out index, out NB<T> array) == true)
               return array;

           throw new EntityNotFoundException(entityGID, typeof(T));
       }
       
       [MethodImpl(MethodImplOptions.AggressiveInlining)]
       public static NB<T> QueryEntitiesAndIndex<T>(this EntitiesDB entitiesDb, uint id, ExclusiveGroupStruct group, out uint index) where T : unmanaged, IEntityComponent
       {
           EGID entityGID = new EGID(id, group);
           if (entitiesDb.QueryEntitiesAndIndexInternal(entityGID, out index, out NB<T> array) == true)
               return array;

           throw new EntityNotFoundException(entityGID, typeof(T));
       }

       [MethodImpl(MethodImplOptions.AggressiveInlining)]
       public static bool TryQueryEntitiesAndIndex<T>(this EntitiesDB entitiesDb, EGID entityGID, out uint index, out NB<T> array)
           where T : unmanaged, IEntityComponent
       {
           if (entitiesDb.QueryEntitiesAndIndexInternal(entityGID, out index, out array) == true)
               return true;

           return false;
       }
       
       [MethodImpl(MethodImplOptions.AggressiveInlining)]
       public static bool TryQueryEntitiesAndIndex<T>(this EntitiesDB entitiesDb, uint id, ExclusiveGroupStruct group, out uint index, out NB<T> array)
           where T : unmanaged, IEntityComponent
       {
           if (entitiesDb.QueryEntitiesAndIndexInternal(new EGID(id, group), out index, out array) == true)
               return true;

           return false;
       }
        
       [MethodImpl(MethodImplOptions.AggressiveInlining)]
       static bool QueryEntitiesAndIndexInternal<T>(this EntitiesDB entitiesDb, EGID entityGID, out uint index, out NB<T> buffer) where T : unmanaged, IEntityComponent
       {
           index = 0;
           buffer = default;
           if (entitiesDb.SafeQueryEntityDictionary<T>(entityGID.groupID, out var safeDictionary) == false)
               return false;

           if (safeDictionary.TryFindIndex(entityGID.entityID, out index) == false)
               return false;
            
           buffer = (NB<T>) (safeDictionary as ITypeSafeDictionary<T>).GetValues(out _);

           return true;
       }
       
       [MethodImpl(MethodImplOptions.AggressiveInlining)]
       public static ref T QueryEntity<T>(this EntitiesDB entitiesDb, EGID entityGID) where T : unmanaged, IEntityComponent
       {
           var array = entitiesDb.QueryEntitiesAndIndex<T>(entityGID, out var index);
           
           return ref array[(int) index];
       }

       [MethodImpl(MethodImplOptions.AggressiveInlining)]
       public static ref T QueryEntity<T>(this EntitiesDB entitiesDb, uint id, ExclusiveGroupStruct group) where T : unmanaged, IEntityComponent
       {
           return ref entitiesDb.QueryEntity<T>(new EGID(id, group));
       }
       
       [MethodImpl(MethodImplOptions.AggressiveInlining)]
       public static ref T QueryUniqueEntity<T>(this EntitiesDB entitiesDb, ExclusiveGroupStruct group) where T : unmanaged, IEntityComponent
       {
           var (entities, entitiescount) = entitiesDb.QueryEntities<T>(@group);

#if DEBUG && !PROFILE_SVELTO
           if (entitiescount == 0)
               throw new ECSException("Unique entity not found '".FastConcat(typeof(T).ToString()).FastConcat("'"));
           if (entitiescount != 1)
               throw new ECSException("Unique entities must be unique! '".FastConcat(typeof(T).ToString())
                                                                         .FastConcat("'"));
#endif
           return ref entities[0];
       }
       
       [MethodImpl(MethodImplOptions.AggressiveInlining)]
       public static NB<T> GetArrayAndEntityIndex<T>(this EGIDMapper<T> mapper, uint entityID, out uint index)  where T : unmanaged, IEntityComponent
       {
           if (mapper._map.TryFindIndex(entityID, out index))
           {
               return (NB<T>) mapper._map.GetValues(out _);
           }

           throw new ECSException("Entity not found");
       }

       [MethodImpl(MethodImplOptions.AggressiveInlining)]
       public static bool TryGetArrayAndEntityIndex<T>(this EGIDMapper<T> mapper, uint entityID, out uint index, out NB<T> array)  where T : unmanaged, IEntityComponent
       {
           index = default;
           if (mapper._map != null && mapper._map.TryFindIndex(entityID, out index))
           {
               array = (NB<T>) mapper._map.GetValues(out _);
               return true;
           }

           array = default;
           return false;
       }
    }
}