#   Copyright (c) 2018 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 platform
import unittest
import numpy as np
from op_test import OpTest
import paddle
import paddle.fluid.core as core
import paddle.fluid as fluid
from paddle.fluid import Program, program_guard


def linear_interp_np(
    input,
    out_w,
    out_size=None,
    actual_shape=None,
    align_corners=True,
    align_mode=0,
    data_layout='NCHW',
):
    if data_layout == "NHWC":
        input = np.transpose(input, (0, 2, 1))  # NHWC => NCHW
    if out_size is not None:
        out_w = out_size[0]
    if actual_shape is not None:
        out_w = actual_shape[0]
    batch_size, channel, in_w = input.shape

    ratio_w = 0.0
    if out_w > 1:
        if align_corners:
            ratio_w = (in_w - 1.0) / (out_w - 1.0)
        else:
            ratio_w = 1.0 * in_w / out_w

    out = np.zeros((batch_size, channel, out_w))

    for j in range(out_w):
        if align_mode == 0 and not align_corners:
            w = int(ratio_w * (j + 0.5) - 0.5)
        else:
            w = int(ratio_w * j)
        w = max(0, w)
        wid = 1 if w < in_w - 1 else 0

        if align_mode == 0 and not align_corners:
            idx_src_w = max(ratio_w * (j + 0.5) - 0.5, 0)
            w1lambda = idx_src_w - w
        else:
            w1lambda = ratio_w * j - w
        w2lambda = 1.0 - w1lambda

        out[:, :, j] = (
            w2lambda * input[:, :, w] + w1lambda * input[:, :, w + wid]
        )

    if data_layout == "NHWC":
        out = np.transpose(out, (0, 2, 1))  # NCHW => NHWC

    return out.astype(input.dtype)


class TestLinearInterpOp(OpTest):
    def setUp(self):
        self.out_size = None
        self.actual_shape = None
        self.data_layout = 'NCHW'
        self.init_test_case()
        self.op_type = "linear_interp"
        input_np = np.random.random(self.input_shape).astype("float64")

        if self.data_layout == "NCHW":
            in_w = self.input_shape[2]
        else:
            in_w = self.input_shape[1]

        if self.scale > 0:
            out_w = int(in_w * self.scale)
        else:
            out_w = self.out_w

        output_np = linear_interp_np(
            input_np,
            out_w,
            self.out_size,
            self.actual_shape,
            self.align_corners,
            self.align_mode,
            self.data_layout,
        )
        self.inputs = {'X': input_np}
        if self.out_size is not None:
            self.inputs['OutSize'] = self.out_size
        if self.actual_shape is not None:
            self.inputs['OutSize'] = self.actual_shape

        self.attrs = {
            'out_w': self.out_w,
            'scale': self.scale,
            'interp_method': self.interp_method,
            'align_corners': self.align_corners,
            'align_mode': self.align_mode,
            'data_layout': self.data_layout,
        }
        self.outputs = {'Out': output_np}

    def test_check_output(self):
        if platform.system() == "Linux":
            self.check_output(atol=1e-7)
        else:
            self.check_output(atol=1e-5)

    def test_check_grad(self):
        self.check_grad(['X'], 'Out', in_place=True)

    def init_test_case(self):
        self.interp_method = 'linear'
        self.input_shape = [1, 3, 100]
        self.out_w = 50
        self.scale = 0.0
        self.out_size = np.array(
            [
                50,
            ]
        ).astype("int32")
        self.align_corners = False
        self.align_mode = 1


class TestLinearInterpOpDataLayout(TestLinearInterpOp):
    def init_test_case(self):
        self.interp_method = 'linear'
        self.input_shape = [1, 3, 100]
        self.out_w = 50
        self.scale = 0.0
        self.out_size = np.array(
            [
                50,
            ]
        ).astype("int32")
        self.align_corners = False
        self.align_mode = 1
        self.data_layout = 'NHWC'


class TestLinearInterpOpAlignMode(TestLinearInterpOp):
    def init_test_case(self):
        self.interp_method = 'linear'
        self.input_shape = [1, 3, 100]
        self.out_w = 50
        self.scale = 0.0
        self.out_size = np.array(
            [
                50,
            ]
        ).astype("int32")
        self.align_corners = False
        self.align_mode = 0


class TestLinearInterpOpScale(TestLinearInterpOp):
    def init_test_case(self):
        self.interp_method = 'linear'
        self.input_shape = [1, 3, 100]
        self.out_w = 50
        self.scale = 0.5
        self.out_size = np.array(
            [
                50,
            ]
        ).astype("int32")
        self.align_corners = False
        self.align_mode = 0


class TestLinearInterpOpSizeTensor(TestLinearInterpOp):
    def setUp(self):
        self.out_size = None
        self.actual_shape = None
        self.data_layout = 'NCHW'
        self.init_test_case()
        self.op_type = "linear_interp"
        input_np = np.random.random(self.input_shape).astype("float64")
        self.shape_by_1Dtensor = False
        self.scale_by_1Dtensor = False

        if self.data_layout == "NCHW":
            in_w = self.input_shape[2]
        else:
            in_w = self.input_shape[1]

        if self.scale > 0:
            out_w = int(in_w * self.scale)
        else:
            out_w = self.out_w

        output_np = linear_interp_np(
            input_np,
            out_w,
            self.out_size,
            self.actual_shape,
            self.align_corners,
            self.align_mode,
            self.data_layout,
        )

        self.inputs = {'X': input_np}
        if self.out_size is not None and self.shape_by_1Dtensor:
            self.inputs['OutSize'] = self.out_size
        elif self.actual_shape is not None and self.shape_by_1Dtensor:
            self.inputs['OutSize'] = self.actual_shape
        else:
            size_tensor = []
            for index, ele in enumerate(self.out_size):
                size_tensor.append(
                    ("x" + str(index), np.ones((1)).astype('int32') * ele)
                )
            self.inputs['SizeTensor'] = size_tensor

        self.attrs = {
            'out_w': self.out_w,
            'scale': self.scale,
            'interp_method': self.interp_method,
            'align_corners': self.align_corners,
            'align_mode': self.align_mode,
            'data_layout': self.data_layout,
        }
        self.outputs = {'Out': output_np}


class TestLinearInterpOpAPI2_0(unittest.TestCase):
    def test_case(self):

        # dygraph
        x_data = np.random.random((1, 3, 128)).astype("float32")
        us_1 = paddle.nn.Upsample(
            size=[
                64,
            ],
            mode='linear',
            align_mode=1,
            align_corners=False,
            data_format='NCW',
        )
        with fluid.dygraph.guard():
            x = fluid.dygraph.to_variable(x_data)
            interp = us_1(x)

            expect = linear_interp_np(
                x_data, out_w=64, align_mode=1, align_corners=False
            )

            np.testing.assert_allclose(interp.numpy(), expect, rtol=1e-05)


class TestResizeLinearOpUint8(OpTest):
    def setUp(self):
        self.out_size = None
        self.actual_shape = None
        self.init_test_case()
        self.op_type = "linear_interp"
        input_np = np.random.random(self.input_shape).astype("uint8")

        if self.scale > 0:
            out_w = int(self.input_shape[3] * self.scale)
        else:
            out_w = self.out_w

        output_np = linear_interp_np(
            input_np,
            out_w,
            self.out_size,
            self.actual_shape,
            self.align_corners,
            self.align_mode,
        )
        self.inputs = {'X': input_np}
        if self.out_size is not None:
            self.inputs['OutSize'] = self.out_size

        self.attrs = {
            'out_w': self.out_w,
            'scale': self.scale,
            'interp_method': self.interp_method,
            'align_corners': self.align_corners,
            'align_mode': self.align_mode,
        }
        self.outputs = {'Out': output_np}

    def test_check_output(self):
        if platform.system() == "Linux":
            self.check_output_with_place(place=core.CPUPlace(), atol=1e-7)
        else:
            self.check_output_with_place(place=core.CPUPlace(), atol=1e-5)

    def init_test_case(self):
        self.interp_method = 'linear'
        self.input_shape = [2, 3, 100]
        self.out_w = 50
        self.scale = 0.0
        self.out_size = np.array(
            [
                50,
            ]
        ).astype("int32")
        self.align_corners = True
        self.align_mode = 1


class TestLinearInterpOpError(unittest.TestCase):
    def test_error(self):
        with program_guard(Program(), Program()):

            def input_shape_error():
                x1 = fluid.data(name="x1", shape=[1], dtype="float32")
                out1 = paddle.nn.Upsample(
                    size=[
                        256,
                    ],
                    data_format='NCW',
                    mode='linear',
                )
                out1_res = out1(x1)

            def data_format_error():
                x2 = fluid.data(name="x2", shape=[1, 3, 128], dtype="float32")
                out2 = paddle.nn.Upsample(
                    size=[
                        256,
                    ],
                    data_format='NHWCD',
                    mode='linear',
                )
                out2_res = out2(x2)

            def out_shape_error():
                x3 = fluid.data(name="x3", shape=[1, 3, 128], dtype="float32")
                out3 = paddle.nn.Upsample(
                    size=[
                        256,
                        256,
                    ],
                    data_format='NHWC',
                    mode='linear',
                )
                out3_res = out3(x3)

            self.assertRaises(ValueError, input_shape_error)
            self.assertRaises(ValueError, data_format_error)
            self.assertRaises(ValueError, out_shape_error)


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