#   Copyright (c) 2023 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
from op_test import get_device_place

import paddle


def ref_pdist(x, p=2.0):
    dist = np.linalg.norm(x[..., None, :] - x[None, :, :], ord=p, axis=-1)
    res = []
    rows, cols = dist.shape
    for i in range(rows):
        for j in range(cols):
            if i >= j:
                continue
            res.append(dist[i][j])
    return np.array(res)


class TestPdistAPI(unittest.TestCase):
    def setUp(self):
        self.x = np.random.rand(10, 20).astype('float32')
        self.p = 2.0
        self.init_input()
        self.place = get_device_place()

    def init_input(self):
        pass

    def test_static_api(self):
        paddle.enable_static()
        with paddle.static.program_guard(paddle.static.Program()):
            x = paddle.static.data('x', self.x.shape, dtype=self.x.dtype)
            out = paddle.pdist(
                x,
                self.p,
            )
            exe = paddle.static.Executor(self.place)
            res = exe.run(feed={'x': self.x}, fetch_list=[out])
            out_ref = ref_pdist(self.x, self.p)
            np.testing.assert_allclose(out_ref, res[0], rtol=1e-5, atol=1e-5)

    def test_dygraph_api(self):
        paddle.disable_static(self.place)
        x = paddle.to_tensor(self.x)
        out = paddle.pdist(
            x,
            self.p,
        )
        out_ref = ref_pdist(self.x, self.p)
        np.testing.assert_allclose(out_ref, out.numpy(), rtol=1e-5, atol=1e-5)
        paddle.enable_static()


class TestPdistAPICase1_param_p1(TestPdistAPI):
    def init_input(self):
        self.p = 0


class TestPdistAPICase2_param_p2(TestPdistAPI):
    def init_input(self):
        self.p = 1.0


class TestPdistAPICase3_param_p3(TestPdistAPI):
    def init_input(self):
        self.p = 3.0


class TestPdistAPICase4_param_p4(TestPdistAPI):
    def init_input(self):
        self.p = 1.5


class TestPdistAPICase5_param_p5(TestPdistAPI):
    def init_input(self):
        self.p = 2.5


class TestPdistAPICase6_param_p6(TestPdistAPI):
    def init_input(self):
        self.p = float('inf')


class TestPdistAPICase7_input_x1(TestPdistAPI):
    def init_input(self):
        self.x = np.random.rand(50, 20).astype('float64')


class TestPdistShapeError(unittest.TestCase):
    def test_error(self):
        with self.assertRaises(AssertionError):
            self.x = np.random.rand(50, 10, 20).astype('float64')
            self.p = 2.0
            x = paddle.to_tensor(self.x)
            out0 = paddle.pdist(
                x,
                self.p,
            )


class TestPdistAPI_ZeroSize(unittest.TestCase):
    def setUp(self):
        self.init_shape()
        self.x = np.random.rand(*self.shape).astype('float32')
        self.p = 2.0
        self.place = get_device_place()

    def init_shape(self):
        self.shape = (0, 20)

    def test_dygraph_api(self):
        paddle.disable_static(self.place)
        x = paddle.to_tensor(self.x)
        x.stop_gradient = False
        out = paddle.pdist(
            x,
            self.p,
        )
        out_ref = ref_pdist(self.x, self.p)
        np.testing.assert_allclose(out_ref, out.numpy(), rtol=1e-5, atol=1e-5)
        loss = paddle.sum(out)
        loss.backward()
        np.testing.assert_allclose(x.grad.shape, x.shape)
        paddle.enable_static()


class TestPdistAPI_ZeroSize2(TestPdistAPI_ZeroSize):
    def init_shape(self):
        self.shape = (0, 0)


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