# For all things related to devices
#### ONLY USE PROVIDED FUNCTIONS, DO NOT USE GLOBAL CONSTANTS ####

import torch

TORCH_CPU_DEVICE = torch.device("cpu")

if(torch.cuda.device_count() > 0):
    TORCH_CUDA_DEVICE = torch.device("cuda")
else:
    print("----- WARNING: CUDA devices not detected. This will cause the model to run very slow! -----")
    print("")
    TORCH_CUDA_DEVICE = None

USE_CUDA = True

# use_cuda
def use_cuda(cuda_bool):
    """
    ----------
    Author: Damon Gwinn
    ----------
    Sets whether to use CUDA (if available), or use the CPU (not recommended)
    ----------
    """

    global USE_CUDA
    USE_CUDA = cuda_bool

# get_device
def get_device():
    """
    ----------
    Author: Damon Gwinn
    ----------
    Grabs the default device. Default device is CUDA if available and use_cuda is not False, CPU otherwise.
    ----------
    """

    if((not USE_CUDA) or (TORCH_CUDA_DEVICE is None)):
        return TORCH_CPU_DEVICE
    else:
        return TORCH_CUDA_DEVICE

# cuda_device
def cuda_device():
    """
    ----------
    Author: Damon Gwinn
    ----------
    Grabs the cuda device (may be None if CUDA is not available)
    ----------
    """

    return TORCH_CUDA_DEVICE

# cpu_device
def cpu_device():
    """
    ----------
    Author: Damon Gwinn
    ----------
    Grabs the cpu device
    ----------
    """

    return TORCH_CPU_DEVICE