# This should be the only place that we import tensorflow directly.
# Everywhere else is caught by the banned-modules setting for flake8
import tensorflow as tf  # noqa I201
from distutils.version import LooseVersion
import horovod.tensorflow as hvd


# LooseVersion handles things "1.2.3a" or "4.5.6-rc7" fairly sensibly.
_is_tensorflow2 = LooseVersion(tf.__version__) >= LooseVersion("2.0.0")

if _is_tensorflow2:
    import tensorflow.compat.v1 as tf

    tf.disable_v2_behavior()
    tf_logging = tf.logging
else:
    try:
        # Newer versions of tf 1.x will complain that tf.logging is deprecated
        tf_logging = tf.compat.v1.logging
    except AttributeError:
        # Fall back to the safe import, even if it might generate a warning or two.
        tf_logging = tf.logging


def set_warnings_enabled(is_enabled: bool) -> None:
    """
    Enable or disable tensorflow warnings (notably, this disables deprecation warnings.
    :param is_enabled:
    """
    level = tf_logging.WARN if is_enabled else tf_logging.ERROR
    tf_logging.set_verbosity(level)


def generate_session_config() -> tf.ConfigProto:
    """
    Generate a ConfigProto to use for ML-Agents that doesn't consume all of the GPU memory
    and allows for soft placement in the case of multi-GPU.
    """
    config = tf.ConfigProto()
    config.gpu_options.allow_growth = True
    config.gpu_options.visible_device_list = str(hvd.local_rank())

    # For multi-GPU training, set allow_soft_placement to True to allow
    # placing the operation into an alternative device automatically
    # to prevent from exceptions if the device doesn't suppport the operation
    # or the device does not exist
    config.allow_soft_placement = True
    return config