# 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
from paddle import fluid


def np_pairwise_distance(x, y, p=2.0, epsilon=1e-6, keepdim=False):
    distance = np.linalg.norm(x - y + epsilon, ord=p, axis=-1, keepdims=keepdim)
    return distance


def call_pairwise_distance_layer(x, y, p=2.0, epsilon=1e-6, keepdim='False'):
    pairwise_distance = paddle.nn.PairwiseDistance(
        p=p, epsilon=epsilon, keepdim=keepdim
    )
    distance = pairwise_distance(x=x, y=y)
    return distance


def call_pairwise_distance_functional(
    x, y, p=2.0, epsilon=1e-6, keepdim='False'
):
    distance = paddle.nn.functional.pairwise_distance(
        x=x, y=y, p=p, epsilon=epsilon, keepdim=keepdim
    )
    return distance


def test_static(
    place, x_np, y_np, p=2.0, epsilon=1e-6, keepdim=False, functional=False
):
    prog = paddle.static.Program()
    startup_prog = paddle.static.Program()
    place = (
        fluid.CUDAPlace(0)
        if paddle.fluid.core.is_compiled_with_cuda()
        else fluid.CPUPlace()
    )
    paddle.enable_static()
    with paddle.static.program_guard(prog, startup_prog):
        x = paddle.static.data(name='x', shape=x_np.shape, dtype=x_np.dtype)
        y = paddle.static.data(name='y', shape=y_np.shape, dtype=x_np.dtype)

        if functional:
            distance = call_pairwise_distance_functional(
                x=x, y=y, p=p, epsilon=epsilon, keepdim=keepdim
            )
        else:
            distance = call_pairwise_distance_layer(
                x=x, y=y, p=p, epsilon=epsilon, keepdim=keepdim
            )
        exe = paddle.static.Executor(place)
        static_ret = exe.run(
            prog, feed={'x': x_np, 'y': y_np}, fetch_list=[distance]
        )
        static_ret = static_ret[0]
    paddle.disable_static()
    return static_ret


def test_dygraph(
    place, x_np, y_np, p=2.0, epsilon=1e-6, keepdim=False, functional=False
):
    x = paddle.to_tensor(x_np)
    y = paddle.to_tensor(y_np)
    if functional:
        dy_distance = call_pairwise_distance_functional(
            x=x, y=y, p=p, epsilon=epsilon, keepdim=keepdim
        )
    else:
        dy_distance = call_pairwise_distance_layer(
            x=x, y=y, p=p, epsilon=epsilon, keepdim=keepdim
        )
    dygraph_ret = dy_distance.numpy()
    return dygraph_ret


class TestPairwiseDistance(unittest.TestCase):
    def test_pairwise_distance(self):
        epsilon = 1e-6
        all_shape = [[5], [100, 100]]
        dtypes = ['float32', 'float64']
        p_list = [-1, 0, 1, 2, np.inf, -np.inf]
        places = [paddle.CPUPlace()]
        if paddle.device.is_compiled_with_cuda():
            places.append(paddle.CUDAPlace(0))
        keeps = [False, True]
        for place in places:
            for shape in all_shape:
                for dtype in dtypes:
                    for p in p_list:
                        for keepdim in keeps:
                            x_np = np.random.random(shape).astype(dtype)
                            y_np = np.random.random(shape).astype(dtype)

                            static_ret = test_static(
                                place,
                                x_np,
                                y_np,
                                p,
                                epsilon=epsilon,
                                keepdim=keepdim,
                            )
                            dygraph_ret = test_dygraph(
                                place,
                                x_np,
                                y_np,
                                p,
                                epsilon=epsilon,
                                keepdim=keepdim,
                            )
                            excepted_value = np_pairwise_distance(
                                x_np, y_np, p, epsilon=epsilon, keepdim=keepdim
                            )

                            self.assertEqual(
                                static_ret.shape, excepted_value.shape
                            )
                            self.assertEqual(
                                dygraph_ret.shape, excepted_value.shape
                            )

                            np.testing.assert_allclose(
                                static_ret, excepted_value, rtol=1e-05
                            )
                            np.testing.assert_allclose(
                                dygraph_ret, excepted_value, rtol=1e-05
                            )
                            static_functional_ret = test_static(
                                place,
                                x_np,
                                y_np,
                                p,
                                epsilon=epsilon,
                                keepdim=keepdim,
                            )
                            dygraph_functional_ret = test_dygraph(
                                place,
                                x_np,
                                y_np,
                                p,
                                epsilon=epsilon,
                                keepdim=keepdim,
                            )

                            self.assertEqual(
                                static_functional_ret.shape,
                                excepted_value.shape,
                            )
                            self.assertEqual(
                                dygraph_functional_ret.shape,
                                excepted_value.shape,
                            )

                            np.testing.assert_allclose(
                                static_functional_ret,
                                excepted_value,
                                rtol=1e-05,
                            )
                            np.testing.assert_allclose(
                                dygraph_functional_ret,
                                excepted_value,
                                rtol=1e-05,
                            )

    def test_pairwise_distance_broadcast_1(self):
        shape_x = [100, 100]
        shape_y = [100, 1]
        epsilon = 1e-6
        keepdim = False
        place = paddle.CPUPlace()
        x_np = np.random.random(shape_x).astype('float32')
        y_np = np.random.random(shape_y).astype('float32')
        static_ret = test_static(
            place=place, x_np=x_np, y_np=y_np, epsilon=epsilon, keepdim=keepdim
        )
        dygraph_ret = test_dygraph(
            place=place, x_np=x_np, y_np=y_np, epsilon=epsilon, keepdim=keepdim
        )
        excepted_value = np_pairwise_distance(
            x_np, y_np, epsilon=epsilon, keepdim=keepdim
        )

        self.assertEqual(static_ret.shape, excepted_value.shape)
        self.assertEqual(dygraph_ret.shape, excepted_value.shape)

        np.testing.assert_allclose(static_ret, excepted_value, rtol=1e-05)
        np.testing.assert_allclose(dygraph_ret, excepted_value, rtol=1e-05)

        static_functional_ret = test_static(
            place=place,
            x_np=x_np,
            y_np=y_np,
            epsilon=epsilon,
            keepdim=keepdim,
            functional=True,
        )
        dygraph_functional_ret = test_dygraph(
            place=place,
            x_np=x_np,
            y_np=y_np,
            epsilon=epsilon,
            keepdim=keepdim,
            functional=True,
        )

        self.assertEqual(static_functional_ret.shape, excepted_value.shape)
        self.assertEqual(dygraph_functional_ret.shape, excepted_value.shape)

        np.testing.assert_allclose(
            static_functional_ret, excepted_value, rtol=1e-05
        )
        np.testing.assert_allclose(
            dygraph_functional_ret, excepted_value, rtol=1e-05
        )

    def test_pairwise_distance_broadcast_2(self):
        shape_x = [100, 100]
        shape_y = [100]
        epsilon = 1e-6
        keepdim = False
        place = paddle.CPUPlace()
        x_np = np.random.random(shape_x).astype('float32')
        y_np = np.random.random(shape_y).astype('float32')
        static_ret = test_static(
            place=place, x_np=x_np, y_np=y_np, epsilon=epsilon, keepdim=keepdim
        )
        dygraph_ret = test_dygraph(
            place=place, x_np=x_np, y_np=y_np, epsilon=epsilon, keepdim=keepdim
        )

        excepted_value = np_pairwise_distance(
            x_np, y_np, epsilon=epsilon, keepdim=keepdim
        )

        self.assertEqual(static_ret.shape, excepted_value.shape)
        self.assertEqual(dygraph_ret.shape, excepted_value.shape)

        np.testing.assert_allclose(static_ret, excepted_value, rtol=1e-05)
        np.testing.assert_allclose(dygraph_ret, excepted_value, rtol=1e-05)

        static_functional_ret = test_static(
            place=place,
            x_np=x_np,
            y_np=y_np,
            epsilon=epsilon,
            keepdim=keepdim,
            functional=True,
        )
        dygraph_functional_ret = test_dygraph(
            place=place,
            x_np=x_np,
            y_np=y_np,
            epsilon=epsilon,
            keepdim=keepdim,
            functional=True,
        )

        self.assertEqual(static_functional_ret.shape, excepted_value.shape)
        self.assertEqual(dygraph_functional_ret.shape, excepted_value.shape)

        np.testing.assert_allclose(
            static_functional_ret, excepted_value, rtol=1e-05
        )
        np.testing.assert_allclose(
            dygraph_functional_ret, excepted_value, rtol=1e-05
        )

    def test_pairwise_distance_fp16(self):
        shape = [100, 100]
        if not paddle.device.is_compiled_with_cuda():
            return
        place = paddle.CUDAPlace(0)
        x_np = np.random.random(shape).astype('float16')
        y_np = np.random.random(shape).astype('float16')
        static_ret = test_static(place, x_np, y_np)


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