#include <Entity/EntityManager.h>

#include <Core/Common/EnumUtils.h>
#include <Data/World.h>
#include <Entity/Entity.h>
#include <game.h>
#include <Graphics/MeshRenderer.h>

EntityID EntityManager::ID = 0;

void InitEntityManager(NonNullPtr<World> world)
{
    EntityManager* newManager = ArenaPushStruct<EntityManager>(world->WorldArena);
    world->EntityManager      = newManager;

    newManager->Entities.Create(world->WorldArena JULIET_DEBUG_PARAM("Entities"));

    ArenaParams by_type_params{ .ReserveSize = Kilobytes(1),
                                .CommitSize  = Kilobytes(1),
                                .Name        = "" JULIET_DEBUG_ONLY(, .CanReserveMore = false) };
    for (uint8 i = 0; i < ENTITY(Count); ++i)
    {
        by_type_params.Name          = kEntity_type_names[i];
        newManager->by_type[i].arena = ArenaAllocate(by_type_params);
        newManager->by_type[i].array = nullptr;
    }
}

void ShutdownEntityManager()
{
    auto& manager = GetEntityManager();
    for (typed_entity_array& type : manager.by_type)
    {
        ArenaRelease(type.arena);
    }

    manager.Entities.Destroy();
}

EntityManager& GetEntityManager()
{
    NonNullPtr entityManager = GetGameState()->World->EntityManager;
    return *entityManager;
}

entity_template* RegisterEntity(EntityManager& manager, Entity* base, DerivedType entity)
{
    base->ID      = EntityManager::ID++;
    base->Derived = entity;

    manager.Entities.PushBack(*base);

    auto* ptr = (entity_template*)ArenaPushSize(manager.by_type[base->Kind->kind].arena, base->Kind->size_of, base->Kind->alignment,
                                                false JULIET_DEBUG_PARAM(kEntity_type_names[base->Kind->kind]));
    MemCopy(ptr, entity, base->Kind->size_of);
    manager.by_type[base->Kind->kind].count += 1;

    ptr->Base = manager.Entities.Back();

    if (manager.by_type[base->Kind->kind].array == nullptr)
    {
        manager.by_type[base->Kind->kind].array = ptr;
    }

    return ptr;
}

void RegisterBaseEntity(EntityManager& manager, Entity&& base)
{
    GetEntityManager().Entities.PushBack(std::move(base));
}

void UpdateEntityManager(EntityManager& manager)
{
    // Todo : inert by definition dont move, but this is for test
    auto& by_type = manager.by_type[ENTITY(Inert)];
    for (index_t i = 0; i < by_type.count; ++i)
    {
        Inert* inert = reinterpret_cast<Inert*>(by_type.array) + i;
        if (inert->MeshInstance != indexMax)
        {
            SetMeshInstanceTransform(inert->MeshInstance, MatrixTranslation(inert->Base->X, inert->Base->Y, inert->Base->Z));
        }
    }
}