# Copyright (c) 2020 PaddlePaddle 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.

import unittest

import numpy as np

import paddle.fluid as fluid
import paddle.fluid.core as core
import paddle.fluid.dygraph as dygraph
from paddle.distributed import init_parallel_env
from paddle.nn import Linear


class MLP(fluid.Layer):
    def __init__(self, param_attr=None, bias_attr=None):
        super().__init__()

        self._linear1 = Linear(784, 10)
        self._linear2 = Linear(10, 10)

    def forward(self, inputs):
        y = self._linear1(inputs)
        y = self._linear2(y)
        return y


class TestDataParallelStateDict(unittest.TestCase):
    def test_data_parallel_state_dict(self):
        with fluid.dygraph.guard():
            init_parallel_env()
            mlp = MLP()
            parallel_mlp = dygraph.parallel.DataParallel(mlp)

            single_state = mlp.state_dict()
            parallel_state = parallel_mlp.state_dict()

            base_para = {}
            place = (
                fluid.CPUPlace()
                if not core.is_compiled_with_cuda()
                else fluid.CUDAPlace(0)
            )
            for k, v in single_state.items():
                self.assertTrue(k in parallel_state)

                np.testing.assert_array_equal(
                    v.numpy(), parallel_state[k].numpy()
                )

                base_para[k] = v.numpy()

            for k, v in parallel_state.items():
                np_t = v.numpy()
                var = v.value().get_tensor()
                var.set(np.zeros_like(np_t), place)

                self.assertTrue(np.sum(np.abs(v.numpy())) == 0)

            parallel_mlp.set_dict(base_para)

            parallel_state = parallel_mlp.state_dict()

            for k, v in parallel_state.items():
                np.testing.assert_array_equal(v.numpy(), base_para[k])

            parallel_mlp.load_dict(base_para)


if __name__ == '__main__':
    unittest.main()