#  Copyright (c) 2021 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 paddle.fluid as fluid
import paddle
from op_test import OpTest

import numpy as np
import unittest
import sys

sys.path.append("..")

paddle.enable_static()
SEED = 2021


def ComputeGrad(x, y, out, axis):
    grad = 1 / out.size
    shape_x = x.shape
    shape_y = y.shape
    shape_out = out.shape
    reduce_axes_x = []
    reduce_axes_y = []

    if shape_x != shape_out:
        if len(shape_x) < len(shape_out):
            src_axis = axis
        else:
            src_axis = 0

        for ax in range(len(shape_out)):
            if (ax < src_axis or ax >= src_axis + len(shape_x)) or (
                shape_out[ax] > 1 and shape_x[ax - src_axis] == 1
            ):
                reduce_axes_x.append(ax)

    if shape_y != shape_out:
        if len(shape_y) < len(shape_out):
            src_axis = axis
        else:
            src_axis = 0

        for ax in range(len(shape_out)):
            if (ax < src_axis or ax >= src_axis + len(shape_y)) or (
                shape_out[ax] > 1 and shape_y[ax - src_axis] == 1
            ):
                reduce_axes_y.append(ax)

    if len(reduce_axes_x) > 0:
        for i in reduce_axes_x:
            x = np.expand_dims(x, axis=i)

    if len(reduce_axes_y) > 0:
        for i in reduce_axes_y:
            y = np.expand_dims(y, axis=i)

    dx = y * np.power(x, y - 1) * grad
    dy = np.log(x) * np.power(x, y) * grad

    if len(reduce_axes_x) > 0:
        for i, element in enumerate(reduce_axes_x):
            dx = np.add.reduce(dx, element - i)

    if len(reduce_axes_y) > 0:
        for i, element in enumerate(reduce_axes_y):
            dy = np.add.reduce(dy, element - i)

    return dx, dy


class TestElementwisePow(OpTest):
    def setUp(self):
        self.set_npu()
        self.op_type = "elementwise_pow"
        self.place = paddle.NPUPlace(0)

        self.init_dtype()
        self.init_input_output()
        self.init_axis()

        self.inputs = {
            'X': OpTest.np_dtype_to_fluid_dtype(self.x),
            'Y': OpTest.np_dtype_to_fluid_dtype(self.y),
        }
        self.attrs = {'axis': self.axis}
        self.outputs = {'Out': self.out}

    def set_npu(self):
        self.__class__.use_npu = True

    def init_dtype(self):
        self.dtype = np.float32

    def test_check_output(self):
        self.check_output_with_place(self.place)

    def init_axis(self):
        self.axis = -1

    def init_input_output(self):
        np.random.seed(SEED)
        self.x = np.random.uniform(1, 2, [11, 17]).astype(self.dtype)
        self.y = np.random.uniform(1, 2, [11, 17]).astype(self.dtype)
        self.out = np.power(self.x, self.y)

    def test_check_grad_normal(self):
        dx, dy = ComputeGrad(self.x, self.y, self.out, self.axis)
        self.check_grad_with_place(
            self.place, ['X', 'Y'], 'Out', user_defined_grads=[dx, dy]
        )

    def test_check_grad_ingore_x(self):
        _, dy = ComputeGrad(self.x, self.y, self.out, self.axis)
        self.check_grad_with_place(
            self.place,
            ['Y'],
            'Out',
            no_grad_set=set("X"),
            user_defined_grads=[dy],
        )

    def test_check_grad_ingore_y(self):
        dx, _ = ComputeGrad(self.x, self.y, self.out, self.axis)
        self.check_grad_with_place(
            self.place,
            ['X'],
            'Out',
            no_grad_set=set("Y"),
            user_defined_grads=[dx],
        )


class TestElementwisePowFp16(TestElementwisePow):
    def init_input_output(self):
        np.random.seed(SEED)
        self.x = np.random.uniform(1, 2, [11, 17]).astype(self.dtype)
        self.y = np.random.uniform(1, 2, [11, 17]).astype(self.dtype)
        self.out = np.power(self.x, self.y)

    def set_npu(self):
        self.__class__.use_npu = True
        self.__class__.no_need_check_grad = True

    def init_dtype(self):
        self.dtype = np.float16

    def test_check_output(self):
        self.check_output_with_place(self.place, atol=1e-5)


class TestElementwisePowDouble(TestElementwisePow):
    def init_input_output(self):
        np.random.seed(SEED)
        self.x = np.random.uniform(1, 2, [11, 17]).astype(self.dtype)
        self.y = np.random.uniform(1, 2, [11, 17]).astype(self.dtype)
        self.out = np.power(self.x, self.y)

    def set_npu(self):
        self.__class__.use_npu = True
        self.__class__.no_need_check_grad = True

    def init_dtype(self):
        self.dtype = np.float64

    def test_check_output(self):
        self.check_output_with_place(self.place, atol=1e-5)


class TestElementwisePowOp_broadcast_0(TestElementwisePow):
    def init_axis(self):
        self.axis = 1

    def init_input_output(self):
        np.random.seed(SEED)
        self.x = np.random.uniform(1, 2, [11, 17]).astype(self.dtype)
        self.y = np.random.uniform(1, 2, [1, 11, 17]).astype(self.dtype)
        self.out = np.power(self.x, self.y)

    def test_check_grad_normal(self):
        dx, dy = ComputeGrad(self.x, self.y, self.out, self.axis)
        self.check_grad_with_place(
            self.place, ['X', 'Y'], 'Out', user_defined_grads=[dx, dy]
        )

    def test_check_grad_ingore_x(self):
        _, dy = ComputeGrad(self.x, self.y, self.out, self.axis)
        self.check_grad_with_place(
            self.place,
            ['Y'],
            'Out',
            no_grad_set=set("X"),
            user_defined_grads=[dy],
        )

    def test_check_grad_ingore_y(self):
        dx, _ = ComputeGrad(self.x, self.y, self.out, self.axis)
        self.check_grad_with_place(
            self.place,
            ['X'],
            'Out',
            no_grad_set=set("Y"),
            user_defined_grads=[dx],
        )


class TestElementwisePowOp_broadcast_1(TestElementwisePow):
    def init_axis(self):
        self.axis = 1

    def init_input_output(self):
        np.random.seed(SEED)
        self.x = np.random.uniform(1, 2, [2, 100, 1]).astype(self.dtype)
        self.y = np.random.uniform(1, 2, [100]).astype(self.dtype)
        self.out = np.power(self.x, self.y.reshape(1, 100, 1))

    def test_check_grad_normal(self):
        dx, dy = ComputeGrad(self.x, self.y, self.out, self.axis)
        self.check_grad_with_place(
            self.place, ['X', 'Y'], 'Out', user_defined_grads=[dx, dy]
        )

    def test_check_grad_ingore_x(self):
        _, dy = ComputeGrad(self.x, self.y, self.out, self.axis)
        self.check_grad_with_place(
            self.place,
            ['Y'],
            'Out',
            no_grad_set=set("X"),
            user_defined_grads=[dy],
        )

    def test_check_grad_ingore_y(self):
        dx, _ = ComputeGrad(self.x, self.y, self.out, self.axis)
        self.check_grad_with_place(
            self.place,
            ['X'],
            'Out',
            no_grad_set=set("Y"),
            user_defined_grads=[dx],
        )


class TestElementwisePowOp_broadcast_2(TestElementwisePow):
    def init_axis(self):
        self.axis = 0

    def init_input_output(self):
        np.random.seed(SEED)
        self.x = np.random.uniform(0.1, 1, [100, 3, 1]).astype(self.dtype)
        self.y = np.random.uniform(0.1, 1, [100]).astype(self.dtype)
        self.out = np.power(self.x, self.y.reshape(100, 1, 1))

    def test_check_grad_normal(self):
        dx, dy = ComputeGrad(self.x, self.y, self.out, self.axis)
        self.check_grad_with_place(
            self.place, ['X', 'Y'], 'Out', user_defined_grads=[dx, dy]
        )

    def test_check_grad_ingore_x(self):
        _, dy = ComputeGrad(self.x, self.y, self.out, self.axis)
        self.check_grad_with_place(
            self.place,
            ['Y'],
            'Out',
            no_grad_set=set("X"),
            user_defined_grads=[dy],
        )

    def test_check_grad_ingore_y(self):
        dx, _ = ComputeGrad(self.x, self.y, self.out, self.axis)
        self.check_grad_with_place(
            self.place,
            ['X'],
            'Out',
            no_grad_set=set("Y"),
            user_defined_grads=[dx],
        )


class TestElementwisePowNet(unittest.TestCase):
    def _test(self, run_npu=True):
        main_prog = paddle.static.Program()
        startup_prog = paddle.static.Program()
        main_prog.random_seed = SEED
        startup_prog.random_seed = SEED
        np.random.seed(SEED)

        a_np = np.random.random(size=(32, 32)).astype('float32')
        b_np = np.random.random(size=(32, 32)).astype('float32')
        label_np = np.random.randint(2, size=(32, 1)).astype('int64')

        with paddle.static.program_guard(main_prog, startup_prog):
            a = paddle.static.data(name="a", shape=[32, 32], dtype='float32')
            b = paddle.static.data(name="b", shape=[32, 32], dtype='float32')
            label = paddle.static.data(
                name="label", shape=[32, 1], dtype='int64'
            )

            c = paddle.pow(a, b)

            fc_1 = paddle.static.nn.fc(x=c, size=128)
            prediction = paddle.static.nn.fc(x=fc_1, size=2, activation='softmax')

            cost = paddle.nn.functional.cross_entropy(input=prediction, label=label, reduction='none', use_softmax=False)
            loss = paddle.mean(cost)
            sgd = fluid.optimizer.SGD(learning_rate=0.01)
            sgd.minimize(loss)

        if run_npu:
            place = paddle.NPUPlace(0)
        else:
            place = paddle.CPUPlace()

        exe = paddle.static.Executor(place)
        exe.run(startup_prog)

        print("Start run on {}".format(place))
        for epoch in range(100):

            pred_res, loss_res = exe.run(
                main_prog,
                feed={"a": a_np, "b": b_np, "label": label_np},
                fetch_list=[prediction, loss],
            )
            if epoch % 10 == 0:
                print(
                    "Epoch {} | Prediction[0]: {}, Loss: {}".format(
                        epoch, pred_res[0], loss_res
                    )
                )

        return pred_res, loss_res

    def test_npu(self):
        cpu_pred, cpu_loss = self._test(False)
        npu_pred, npu_loss = self._test(True)

        np.testing.assert_allclose(npu_pred, cpu_pred, rtol=1e-6)
        np.testing.assert_allclose(npu_loss, cpu_loss, rtol=1e-6)


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