#  Copyright (c) 2019 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.

from __future__ import print_function
import unittest
import numpy as np
import paddle
import paddle.fluid as fluid
import paddle.fluid.core as core
from op_test import OpTest

import random


class TestElementwiseModOp(OpTest):
    def init_kernel_type(self):
        self.use_mkldnn = False

    def setUp(self):
        self.op_type = "elementwise_floordiv"
        self.dtype = np.int32
        self.axis = -1
        self.init_dtype()
        self.init_input_output()
        self.init_kernel_type()
        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, 'use_mkldnn': self.use_mkldnn}
        self.outputs = {'Out': self.out}

    def test_check_output(self):
        self.check_output()

    def init_input_output(self):
        self.x = np.random.uniform(0, 10000, [10, 10]).astype(self.dtype)
        self.y = np.random.uniform(0, 1000, [10, 10]).astype(self.dtype)
        self.out = np.floor_divide(self.x, self.y)

    def init_dtype(self):
        pass

    def init_axis(self):
        pass


class TestElementwiseModOpInverse(TestElementwiseModOp):
    def init_input_output(self):
        self.x = np.random.uniform(0, 10000, [10]).astype(self.dtype)
        self.y = np.random.uniform(0, 1000, [10, 10]).astype(self.dtype)
        self.out = np.floor_divide(self.x, self.y)


class TestElementwiseModOp_scalar(TestElementwiseModOp):
    def init_input_output(self):
        scale_x = random.randint(0, 100000000)
        scale_y = random.randint(1, 100000000)
        self.x = (np.random.rand(2, 3, 4) * scale_x).astype(self.dtype)
        self.y = (np.random.rand(1) * scale_y + 1).astype(self.dtype)
        self.out = np.floor_divide(self.x, self.y)


class TestFloorDivideAPI(unittest.TestCase):
    def setUp(self):
        paddle.set_default_dtype("float64")
        self.places = [fluid.CPUPlace()]
        if core.is_compiled_with_cuda():
            self.places.append(fluid.CUDAPlace(0))

    def check_static_result(self, place):
        # rule 1
        with fluid.program_guard(fluid.Program(), fluid.Program()):
            x = fluid.data(name="x", shape=[3], dtype="float64")
            y = np.array([1, 2, 3])
            self.assertRaises(TypeError, paddle.floor_divide, x=x, y=y)

        # rule 2: both the inputs are not Tensor
        with fluid.program_guard(fluid.Program(), fluid.Program()):
            x = 2
            y = 4
            res = paddle.floor_divide(x, y)
            exe = fluid.Executor(place)
            np_z = exe.run(fluid.default_main_program(),
                           feed={},
                           fetch_list=[res])
            self.assertEqual(np_z[0] == 0., True)

        # rule 3: 
        with fluid.program_guard(fluid.Program(), fluid.Program()):
            x = fluid.data(name="x", shape=[3], dtype="float64")
            y = fluid.data(name="y", shape=[3], dtype="float32")
            self.assertRaises(TypeError, paddle.floor_divide, x=x, y=y)

        # rule 4: x is Tensor, y is scalar
        with fluid.program_guard(fluid.Program(), fluid.Program()):
            x = fluid.data(name="x", shape=[3], dtype="float64")
            y = 2
            exe = fluid.Executor(place)
            res = x // y
            np_z = exe.run(fluid.default_main_program(),
                           feed={"x": np.array([2, 3, 4]).astype('float64')},
                           fetch_list=[res])
            z_expected = np.array([1., 1., 2.])
            self.assertEqual((np_z[0] == z_expected).all(), True)

        # rule 5: y is Tensor, x is scalar
        with fluid.program_guard(fluid.Program(), fluid.Program()):
            x = fluid.data(name="x", shape=[3], dtype="float64")
            y = 2
            exe = fluid.Executor(place)
            res = y // x
            np_z = exe.run(fluid.default_main_program(),
                           feed={"x": np.array([2, 8, 4]).astype('float64')},
                           fetch_list=[res])
            z_expected = np.array([1., 0., 0.])
            self.assertEqual((np_z[0] == z_expected).all(), True)

        # rule 6: y is Tensor, x is Tensor
        with fluid.program_guard(fluid.Program(), fluid.Program()):
            x = fluid.data(name="x", shape=[3], dtype="float64")
            y = fluid.data(name="y", shape=[3], dtype="float64")
            exe = fluid.Executor(place)
            res = x // y
            np_z = exe.run(fluid.default_main_program(),
                           feed={
                               "x": np.array([2, 3, 4]).astype('float64'),
                               "y": np.array([1, 5, 2]).astype('float64')
                           },
                           fetch_list=[res])
            z_expected = np.array([2., 0., 2.])
            self.assertEqual((np_z[0] == z_expected).all(), True)

    def test_static(self):
        for place in self.places:
            self.check_static_result(place=place)

    def test_dygraph(self):
        for place in self.places:
            with fluid.dygraph.guard(place):
                # rule 1 : avoid numpy.ndarray
                np_x = np.array([2, 3, 4])
                np_y = np.array([1, 5, 2])
                x = paddle.to_tensor(np_x)
                self.assertRaises(TypeError, paddle.floor_divide, x=x, y=np_y)

                # rule 2: both the inputs are not Tensor
                z = paddle.floor_divide(3, 2)
                self.assertEqual(z.numpy()[0] == 1., True)

                # rule 3: both the inputs are Tensor
                np_x = np.array([2, 3, 4])
                np_y = np.array([1, 5, 2])
                x = paddle.to_tensor(np_x, dtype="float32")
                y = paddle.to_tensor(np_y, dtype="float64")
                self.assertRaises(TypeError, paddle.floor_divide, x=x, y=y)

                # rule 4: x is Tensor, y is scalar
                np_x = np.array([2, 3, 4])
                x = paddle.to_tensor(np_x, dtype="int32")
                y = 2
                z = x // y
                z_expected = np.array([1, 1, 2])
                self.assertEqual((z_expected == z.numpy()).all(), True)

                # rule 5: y is Tensor, x is scalar
                np_x = np.array([2, 1, 4])
                x = paddle.to_tensor(np_x, dtype="int32")
                y = 2
                z = y // x
                z_expected = np.array([1, 2, 0])
                self.assertEqual((z_expected == z.numpy()).all(), True)

                # rule 6: y is Tensor, x is Tensor
                np_x = np.array([2, 3, 4])
                np_y = np.array([1, 5, 2])
                x = paddle.to_tensor(np_x)
                y = paddle.to_tensor(np_y)
                z = x // y
                z_expected = np.array([2., 0., 2.])
                self.assertEqual((z_expected == z.numpy()).all(), True)

        with fluid.dygraph.guard(fluid.CPUPlace()):
            # divide by zero 
            np_x = np.array([2, 3, 4])
            np_y = np.array([0])
            x = paddle.to_tensor(np_x)
            y = paddle.to_tensor(np_y)
            try:
                z = x // y
            except Exception as e:
                print("Error: Divide by zero encounter in floor_divide\n")

            # divide by zero 
            np_x = np.array([2])
            np_y = np.array([0, 0, 0])
            x = paddle.to_tensor(np_x, dtype="int32")
            y = paddle.to_tensor(np_y, dtype="int32")
            try:
                z = x // y
            except Exception as e:
                print("Error: Divide by zero encounter in floor_divide\n")


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