#include "deimos/vulkan/vulkan.h"

#include <deimos/core/api_registry.h>
#include <deimos/core/allocator.h>
#include <deimos/core/os.h>
#include <deimos/core/log.h>

static deimos::OsApi* os_api;
static deimos::LogApi* log_api;

namespace deimos
{

class VulkanLoaderImpl : public VulkanLoaderApi
{
    Allocator*            m_allocator;
    gsl::owner<OsDll*>    m_vulkan_dll{};
    
public:
    explicit VulkanLoaderImpl(Allocator* allocator) : m_allocator{allocator} {}
    
    VulkanApi* LoadEntry() override
    {
        if (m_vulkan_dll == nullptr)
        {
            m_vulkan_dll = os_api->dll->Open("vulkan-1.dll");
            if (m_vulkan_dll != nullptr)
            {
                log_api->LogInfo("Vulkan DLL loaded");
            }
            else
            {
                deimos_Panic("Couldn't load Vulkan DLL");
                return nullptr;
            }
        }

        VulkanApi* api = m_allocator->New<VulkanApi>();
#define FN(NAME) api->NAME = (PFN_vk##NAME)os_api->dll->GetSymbol(m_vulkan_dll, "vk" #NAME);
#include "deimos/vulkan/vulkan_entry_functions.inc"
#undef FN
        return api;
    }
};

void RegisterVulkanLoaderApi(ApiRegistry* registry)
{
    os_api = registry->Get<OsApi>();
    log_api = registry->Get<LogApi>();

    auto* allocator_api = registry->Get<AllocatorApi>();
    auto* allocator = allocator_api->CreateChild(allocator_api->system, "Vulkan");

    auto* impl = allocator->New<VulkanLoaderImpl>(allocator);
    registry->Set(impl);
    
    log_api->LogInfo("Vulkan loader API registered");
}

} // namespace deimos