# Copyright 2020 The TensorFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ==============================================================================
"""Utility functions for tests using TPUStrategy."""

import tensorflow.compat.v2 as tf

from absl import flags

FLAGS = flags.FLAGS
flags.DEFINE_string("tpu", "", "Name of TPU to connect to.")
flags.DEFINE_string("project", None, "Name of GCP project with TPU.")
flags.DEFINE_string("zone", None, "Name of GCP zone with TPU.")


def get_tpu_cluster_resolver():
  resolver = tf.distribute.cluster_resolver.TPUClusterResolver(
      tpu=FLAGS.tpu,
      zone=FLAGS.zone,
      project=FLAGS.project,
  )
  return resolver


def get_tpu_strategy():
  resolver = get_tpu_cluster_resolver()
  tf.config.experimental_connect_to_cluster(resolver)
  tf.tpu.experimental.initialize_tpu_system(resolver)
  return tf.distribute.experimental.TPUStrategy(resolver)
