#   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 copy
import unittest

import numpy as np

import paddle

np.random.seed(10)
paddle.seed(10)


class TestNormalAPI(unittest.TestCase):
    def setUp(self):
        self.mean = 1.0
        self.std = 0.0
        self.shape = None
        self.repeat_num = 2000
        self.set_attrs()
        self.dtype = self.get_dtype()
        self.place = (
            paddle.CUDAPlace(0)
            if paddle.fluid.core.is_compiled_with_cuda()
            else paddle.CPUPlace()
        )

    def set_attrs(self):
        self.shape = [8, 12]

    def get_shape(self):
        if isinstance(self.mean, np.ndarray):
            shape = self.mean.shape
        elif isinstance(self.std, np.ndarray):
            shape = self.std.shape
        else:
            shape = self.shape
        return list(shape)

    def get_dtype(self):
        if isinstance(self.mean, np.ndarray):
            return self.mean.dtype
        elif isinstance(self.std, np.ndarray):
            return self.std.dtype
        else:
            return 'float32'

    def static_api(self):
        shape = self.get_shape()
        ret_all_shape = copy.deepcopy(shape)
        ret_all_shape.insert(0, self.repeat_num)
        ret_all = np.zeros(ret_all_shape, self.dtype)
        if isinstance(self.mean, np.ndarray) and isinstance(
            self.std, np.ndarray
        ):
            with paddle.static.program_guard(paddle.static.Program()):
                mean = paddle.static.data(
                    'Mean', self.mean.shape, self.mean.dtype
                )
                std = paddle.static.data('Std', self.std.shape, self.std.dtype)
                out = paddle.normal(mean, std, self.shape)

                exe = paddle.static.Executor(self.place)
                for i in range(self.repeat_num):
                    ret = exe.run(
                        feed={
                            'Mean': self.mean,
                            'Std': self.std.reshape(shape),
                        },
                        fetch_list=[out],
                    )
                    ret_all[i] = ret[0]
            return ret_all
        elif isinstance(self.mean, np.ndarray):
            with paddle.static.program_guard(paddle.static.Program()):
                mean = paddle.static.data(
                    'Mean', self.mean.shape, self.mean.dtype
                )
                out = paddle.normal(mean, self.std, self.shape)

                exe = paddle.static.Executor(self.place)
                for i in range(self.repeat_num):
                    ret = exe.run(feed={'Mean': self.mean}, fetch_list=[out])
                    ret_all[i] = ret[0]
            return ret_all
        elif isinstance(self.std, np.ndarray):
            with paddle.static.program_guard(paddle.static.Program()):
                std = paddle.static.data('Std', self.std.shape, self.std.dtype)
                out = paddle.normal(self.mean, std, self.shape)

                exe = paddle.static.Executor(self.place)
                for i in range(self.repeat_num):
                    ret = exe.run(feed={'Std': self.std}, fetch_list=[out])
                    ret_all[i] = ret[0]
            return ret_all
        else:
            with paddle.static.program_guard(paddle.static.Program()):
                out = paddle.normal(self.mean, self.std, self.shape)

                exe = paddle.static.Executor(self.place)
                for i in range(self.repeat_num):
                    ret = exe.run(fetch_list=[out])
                    ret_all[i] = ret[0]
            return ret_all

    def dygraph_api(self):
        paddle.disable_static(self.place)
        shape = self.get_shape()
        ret_all_shape = copy.deepcopy(shape)
        ret_all_shape.insert(0, self.repeat_num)
        ret_all = np.zeros(ret_all_shape, self.dtype)

        mean = (
            paddle.to_tensor(self.mean)
            if isinstance(self.mean, np.ndarray)
            else self.mean
        )
        std = (
            paddle.to_tensor(self.std)
            if isinstance(self.std, np.ndarray)
            else self.std
        )
        for i in range(self.repeat_num):
            out = paddle.normal(mean, std, self.shape)
            ret_all[i] = out.numpy()
        paddle.enable_static()
        return ret_all

    def test_api(self):
        ret_static = self.static_api()
        ret_dygraph = self.dygraph_api()
        for ret in [ret_static, ret_dygraph]:
            shape_ref = self.get_shape()
            self.assertEqual(shape_ref, list(ret[0].shape))

            ret = ret.flatten().reshape([self.repeat_num, -1])
            mean = np.mean(ret, axis=0)
            std = np.std(ret, axis=0)
            mean_ref = (
                self.mean.flatten()
                if isinstance(self.mean, np.ndarray)
                else self.mean
            )
            std_ref = (
                self.std.flatten()
                if isinstance(self.std, np.ndarray)
                else self.std
            )
            np.testing.assert_allclose(mean_ref, mean, rtol=0.2, atol=0.2)
            np.testing.assert_allclose(std_ref, std, rtol=0.2, atol=0.2)


class TestNormalAPI_mean_is_tensor(TestNormalAPI):
    def set_attrs(self):
        self.mean = np.random.uniform(-2, -1, [2, 3, 4, 5]).astype('float64')


class TestNormalAPI_std_is_tensor(TestNormalAPI):
    def set_attrs(self):
        self.std = np.random.uniform(0.7, 1, [2, 3, 17]).astype('float64')


class TestNormalAPI_mean_std_are_tensor(TestNormalAPI):
    def set_attrs(self):
        self.mean = np.random.uniform(1, 2, [1, 100]).astype('float64')
        self.std = np.random.uniform(0.5, 1, [1, 100]).astype('float64')


class TestNormalAPI_mean_std_are_tensor_with_different_dtype(TestNormalAPI):
    def set_attrs(self):
        self.mean = np.random.uniform(1, 2, [100]).astype('float64')
        self.std = np.random.uniform(1, 2, [100]).astype('float32')


class TestNormalAlias(unittest.TestCase):
    def test_alias(self):
        paddle.disable_static()
        shape = [1, 2, 3]
        out1 = paddle.normal(shape=shape)
        out2 = paddle.tensor.normal(shape=shape)
        out3 = paddle.tensor.random.normal(shape=shape)
        paddle.enable_static()


class TestNormalErrors(unittest.TestCase):
    def test_errors(self):
        with paddle.static.program_guard(paddle.static.Program()):
            mean = [1, 2, 3]
            self.assertRaises(TypeError, paddle.normal, mean)

            std = [1, 2, 3]
            self.assertRaises(TypeError, paddle.normal, std=std)

            mean = paddle.static.data('Mean', [100], 'int32')
            self.assertRaises(TypeError, paddle.normal, mean)

            std = paddle.static.data('Std', [100], 'int32')
            self.assertRaises(TypeError, paddle.normal, mean=1.0, std=std)

            self.assertRaises(TypeError, paddle.normal, shape=1)

            self.assertRaises(TypeError, paddle.normal, shape=[1.0])

            shape = paddle.static.data('Shape', [100], 'float32')
            self.assertRaises(TypeError, paddle.normal, shape=shape)


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