# Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. 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.

import os
from modulus.distributed import DistributedManager
from modulus.distributed import gather_loss

# TODO: Need to figure out how to test parallel set up
def test_gather_loss():
    os.environ["MASTER_ADDR"] = "localhost"
    os.environ["MASTER_PORT"] = "12345"
    os.environ["RANK"] = "0"
    os.environ["WORLD_SIZE"] = "1"
    # Reset class state
    DistributedManager._shared_state = {}
    DistributedManager.initialize()

    manager = DistributedManager()
    assert manager.is_initialized()

    loss = gather_loss(1.0, dst_rank=0, mean=True)
    assert loss == 1.0
    del os.environ["RANK"]
    del os.environ["WORLD_SIZE"]
