import os
import importlib.util


# https://github.com/comfyanonymous/ComfyUI/blob/master/cuda_malloc.py
def get_gpu_names():
    if os.name == 'nt':
        import ctypes

        # Define necessary C structures and types
        class DISPLAY_DEVICEA(ctypes.Structure):
            _fields_ = [
                ('cb', ctypes.c_ulong),
                ('DeviceName', ctypes.c_char * 32),
                ('DeviceString', ctypes.c_char * 128),
                ('StateFlags', ctypes.c_ulong),
                ('DeviceID', ctypes.c_char * 128),
                ('DeviceKey', ctypes.c_char * 128)
            ]

        # Load user32.dll
        user32 = ctypes.windll.user32

        # Call EnumDisplayDevicesA
        def enum_display_devices():
            device_info = DISPLAY_DEVICEA()
            device_info.cb = ctypes.sizeof(device_info)
            device_index = 0
            gpu_names = set()

            while user32.EnumDisplayDevicesA(None, device_index, ctypes.byref(device_info), 0):
                device_index += 1
                gpu_names.add(device_info.DeviceString.decode('utf-8'))
            return gpu_names
        return enum_display_devices()
    else:
        return set()


blacklist = {"GeForce GTX TITAN X", "GeForce GTX 980", "GeForce GTX 970", "GeForce GTX 960", "GeForce GTX 950", "GeForce 945M",
                "GeForce 940M", "GeForce 930M", "GeForce 920M", "GeForce 910M", "GeForce GTX 750", "GeForce GTX 745", "Quadro K620",
                "Quadro K1200", "Quadro K2200", "Quadro M500", "Quadro M520", "Quadro M600", "Quadro M620", "Quadro M1000",
                "Quadro M1200", "Quadro M2000", "Quadro M2200", "Quadro M3000", "Quadro M4000", "Quadro M5000", "Quadro M5500", "Quadro M6000",
                "GeForce MX110", "GeForce MX130", "GeForce 830M", "GeForce 840M", "GeForce GTX 850M", "GeForce GTX 860M",
                "GeForce GTX 1650", "GeForce GTX 1630"
                }


def cuda_malloc_supported():
    try:
        names = get_gpu_names()
    except:
        names = set()
    for x in names:
        if "NVIDIA" in x:
            for b in blacklist:
                if b in x:
                    return False
    return True


def try_cuda_malloc():
    do_cuda_malloc = False

    try:
        version = ""
        torch_spec = importlib.util.find_spec("torch")
        for folder in torch_spec.submodule_search_locations:
            ver_file = os.path.join(folder, "version.py")
            if os.path.isfile(ver_file):
                spec = importlib.util.spec_from_file_location("torch_version_import", ver_file)
                module = importlib.util.module_from_spec(spec)
                spec.loader.exec_module(module)
                version = module.__version__
        if int(version[0]) >= 2:
            do_cuda_malloc = cuda_malloc_supported()
    except:
        pass

    if do_cuda_malloc:
        env_var = os.environ.get('PYTORCH_CUDA_ALLOC_CONF', None)
        if env_var is None:
            env_var = "backend:cudaMallocAsync"
        else:
            env_var += ",backend:cudaMallocAsync"

        os.environ['PYTORCH_CUDA_ALLOC_CONF'] = env_var

        print('Using cudaMallocAsync backend.')
    else:
        print('Failed to use cudaMallocAsync backend.')
    return