# Copyright (c) OpenMMLab. All rights reserved.
import os
import warnings
from functools import partial

import numpy as np
import onnx
import onnxruntime as rt
import pytest
import torch
import torch.nn as nn
import torch.nn.functional as F
from packaging import version

onnx_file = 'tmp.onnx'


@pytest.fixture(autouse=True)
def run_before_and_after_test():
    # clear onnx_file before test
    if os.path.exists(onnx_file):
        os.remove(onnx_file)

    yield

    # clear onnx_file after test
    if os.path.exists(onnx_file):
        os.remove(onnx_file)


class WrapFunction(nn.Module):

    def __init__(self, wrapped_function):
        super(WrapFunction, self).__init__()
        self.wrapped_function = wrapped_function

    def forward(self, *args, **kwargs):
        return self.wrapped_function(*args, **kwargs)


def process_grid_sample(func, input, grid, ort_custom_op_path=''):
    wrapped_model = WrapFunction(func).eval()

    input_names = ['input', 'grid']
    output_names = ['output']

    with torch.no_grad():
        torch.onnx.export(
            wrapped_model, (input, grid),
            onnx_file,
            export_params=True,
            keep_initializers_as_inputs=True,
            input_names=input_names,
            output_names=output_names,
            opset_version=11)

    onnx_model = onnx.load(onnx_file)

    session_options = rt.SessionOptions()
    if ort_custom_op_path:
        session_options.register_custom_ops_library(ort_custom_op_path)

    # get onnx output
    input_all = [node.name for node in onnx_model.graph.input]
    input_initializer = [node.name for node in onnx_model.graph.initializer]
    net_feed_input = list(set(input_all) - set(input_initializer))
    assert (len(net_feed_input) == 2)
    sess = rt.InferenceSession(onnx_file, session_options)
    ort_result = sess.run(None, {
        'input': input.detach().numpy(),
        'grid': grid.detach().numpy()
    })
    pytorch_results = wrapped_model(input.clone(), grid.clone())
    assert np.allclose(pytorch_results, ort_result, atol=1e-3)


@pytest.mark.parametrize('mode', ['bilinear', 'nearest'])
@pytest.mark.parametrize('padding_mode', ['zeros', 'border', 'reflection'])
@pytest.mark.parametrize('align_corners', [True, False])
def test_grid_sample(mode, padding_mode, align_corners):
    from mmcv.onnx.symbolic import register_extra_symbolics
    opset_version = 11
    register_extra_symbolics(opset_version)

    from mmcv.ops import get_onnxruntime_op_path
    ort_custom_op_path = get_onnxruntime_op_path()
    if not os.path.exists(ort_custom_op_path):
        pytest.skip('custom ops for onnxruntime are not compiled.')

    input = torch.rand(1, 1, 10, 10)
    grid = torch.Tensor([[[1, 0, 0], [0, 1, 0]]])
    grid = F.affine_grid(
        grid, (1, 1, 15, 15), align_corners=align_corners).type_as(input)

    def func(input, grid):
        return F.grid_sample(
            input,
            grid,
            mode=mode,
            padding_mode=padding_mode,
            align_corners=align_corners)

    return process_grid_sample(func, input, grid, ort_custom_op_path)


@pytest.mark.parametrize('align_corners', [True, False])
def test_bilinear_grid_sample(align_corners):
    from mmcv.ops.point_sample import bilinear_grid_sample

    # only support pytorch >= 1.5.0
    if version.parse(torch.__version__) < version.parse('1.5.0'):
        pytest.skip('Only support PyTorch >= 1.5.0')

    input = torch.rand(1, 1, 10, 10)
    grid = torch.Tensor([[[1, 0, 0], [0, 1, 0]]])
    grid = F.affine_grid(
        grid, (1, 1, 15, 15), align_corners=align_corners).type_as(input)

    def func(input, grid):
        return bilinear_grid_sample(input, grid, align_corners=align_corners)

    return process_grid_sample(func, input, grid)


def test_nms():
    if torch.__version__ == 'parrots':
        pytest.skip('onnx is not supported in parrots directly')
    from mmcv.ops import get_onnxruntime_op_path, nms
    np_boxes = np.array([[6.0, 3.0, 8.0, 7.0], [3.0, 6.0, 9.0, 11.0],
                         [3.0, 7.0, 10.0, 12.0], [1.0, 4.0, 13.0, 7.0]],
                        dtype=np.float32)
    np_scores = np.array([0.6, 0.9, 0.7, 0.2], dtype=np.float32)
    boxes = torch.from_numpy(np_boxes)
    scores = torch.from_numpy(np_scores)

    nms = partial(
        nms, iou_threshold=0.3, offset=0, score_threshold=0, max_num=0)
    pytorch_dets, _ = nms(boxes, scores)
    pytorch_score = pytorch_dets[:, 4]

    wrapped_model = WrapFunction(nms)
    wrapped_model.cpu().eval()
    with torch.no_grad():
        torch.onnx.export(
            wrapped_model, (boxes, scores),
            onnx_file,
            export_params=True,
            keep_initializers_as_inputs=True,
            input_names=['boxes', 'scores'],
            opset_version=11)

    onnx_model = onnx.load(onnx_file)
    ort_custom_op_path = get_onnxruntime_op_path()
    session_options = rt.SessionOptions()
    if os.path.exists(ort_custom_op_path):
        session_options.register_custom_ops_library(ort_custom_op_path)

    # get onnx output
    input_all = [node.name for node in onnx_model.graph.input]
    input_initializer = [node.name for node in onnx_model.graph.initializer]
    net_feed_input = list(set(input_all) - set(input_initializer))
    assert (len(net_feed_input) == 2)
    sess = rt.InferenceSession(onnx_file, session_options)
    onnx_dets, _ = sess.run(None, {
        'scores': scores.detach().numpy(),
        'boxes': boxes.detach().numpy()
    })
    onnx_score = onnx_dets[:, 4]
    assert np.allclose(pytorch_score, onnx_score, atol=1e-3)


@pytest.mark.skipif(not torch.cuda.is_available(), reason='test requires GPU')
def test_softnms():
    if torch.__version__ == 'parrots':
        pytest.skip('onnx is not supported in parrots directly')
    from mmcv.ops import get_onnxruntime_op_path, soft_nms

    # only support pytorch >= 1.7.0
    if version.parse(torch.__version__) < version.parse('1.7.0'):
        warnings.warn('test_softnms should be ran with pytorch >= 1.7.0')
        return

    # only support onnxruntime >= 1.5.1
    assert version.parse(rt.__version__) >= version.parse(
        '1.5.1'), 'test_softnms should be ran with onnxruntime >= 1.5.1'

    ort_custom_op_path = get_onnxruntime_op_path()
    if not os.path.exists(ort_custom_op_path):
        pytest.skip('softnms for onnxruntime is not compiled.')

    np_boxes = np.array([[6.0, 3.0, 8.0, 7.0], [3.0, 6.0, 9.0, 11.0],
                         [3.0, 7.0, 10.0, 12.0], [1.0, 4.0, 13.0, 7.0]],
                        dtype=np.float32)
    np_scores = np.array([0.6, 0.9, 0.7, 0.2], dtype=np.float32)

    boxes = torch.from_numpy(np_boxes)
    scores = torch.from_numpy(np_scores)

    configs = [[0.3, 0.5, 0.01, 'linear'], [0.3, 0.5, 0.01, 'gaussian'],
               [0.3, 0.5, 0.01, 'naive']]

    session_options = rt.SessionOptions()
    session_options.register_custom_ops_library(ort_custom_op_path)

    for _iou_threshold, _sigma, _min_score, _method in configs:
        pytorch_dets, pytorch_inds = soft_nms(
            boxes,
            scores,
            iou_threshold=_iou_threshold,
            sigma=_sigma,
            min_score=_min_score,
            method=_method)
        nms = partial(
            soft_nms,
            iou_threshold=_iou_threshold,
            sigma=_sigma,
            min_score=_min_score,
            method=_method)

        wrapped_model = WrapFunction(nms)
        wrapped_model.cpu().eval()
        with torch.no_grad():
            torch.onnx.export(
                wrapped_model, (boxes, scores),
                onnx_file,
                export_params=True,
                keep_initializers_as_inputs=True,
                input_names=['boxes', 'scores'],
                opset_version=11)
        onnx_model = onnx.load(onnx_file)

        # get onnx output
        input_all = [node.name for node in onnx_model.graph.input]
        input_initializer = [
            node.name for node in onnx_model.graph.initializer
        ]
        net_feed_input = list(set(input_all) - set(input_initializer))
        assert (len(net_feed_input) == 2)
        sess = rt.InferenceSession(onnx_file, session_options)
        onnx_dets, onnx_inds = sess.run(None, {
            'scores': scores.detach().numpy(),
            'boxes': boxes.detach().numpy()
        })

        assert np.allclose(pytorch_dets, onnx_dets, atol=1e-3)
        assert np.allclose(onnx_inds, onnx_inds, atol=1e-3)


def test_roialign():
    if torch.__version__ == 'parrots':
        pytest.skip('onnx is not supported in parrots directly')
    try:
        from mmcv.ops import get_onnxruntime_op_path, roi_align
    except (ImportError, ModuleNotFoundError):
        pytest.skip('roi_align op is not successfully compiled')

    ort_custom_op_path = get_onnxruntime_op_path()
    # roi align config
    pool_h = 2
    pool_w = 2
    spatial_scale = 1.0
    sampling_ratio = 2

    inputs = [([[[[1., 2.], [3., 4.]]]], [[0., 0., 0., 1., 1.]]),
              ([[[[1., 2.], [3., 4.]], [[4., 3.],
                                        [2., 1.]]]], [[0., 0., 0., 1., 1.]]),
              ([[[[1., 2., 5., 6.], [3., 4., 7., 8.], [9., 10., 13., 14.],
                  [11., 12., 15., 16.]]]], [[0., 0., 0., 3., 3.]])]

    def warpped_function(torch_input, torch_rois):
        return roi_align(torch_input, torch_rois, (pool_w, pool_h),
                         spatial_scale, sampling_ratio, 'avg', True)

    for case in inputs:
        np_input = np.array(case[0], dtype=np.float32)
        np_rois = np.array(case[1], dtype=np.float32)
        input = torch.from_numpy(np_input)
        rois = torch.from_numpy(np_rois)

        # compute pytorch_output
        with torch.no_grad():
            pytorch_output = roi_align(input, rois, (pool_w, pool_h),
                                       spatial_scale, sampling_ratio, 'avg',
                                       True)

        # export and load onnx model
        wrapped_model = WrapFunction(warpped_function)
        with torch.no_grad():
            torch.onnx.export(
                wrapped_model, (input, rois),
                onnx_file,
                export_params=True,
                keep_initializers_as_inputs=True,
                input_names=['input', 'rois'],
                opset_version=11)

        onnx_model = onnx.load(onnx_file)
        session_options = rt.SessionOptions()
        if os.path.exists(ort_custom_op_path):
            session_options.register_custom_ops_library(ort_custom_op_path)

        # compute onnx_output
        input_all = [node.name for node in onnx_model.graph.input]
        input_initializer = [
            node.name for node in onnx_model.graph.initializer
        ]
        net_feed_input = list(set(input_all) - set(input_initializer))
        assert (len(net_feed_input) == 2)
        sess = rt.InferenceSession(onnx_file, session_options)
        onnx_output = sess.run(None, {
            'input': input.detach().numpy(),
            'rois': rois.detach().numpy()
        })
        onnx_output = onnx_output[0]

        # allclose

        assert np.allclose(pytorch_output, onnx_output, atol=1e-3)


def test_roialign_rotated():
    if torch.__version__ == 'parrots':
        pytest.skip('onnx is not supported in parrots directly')
    try:
        from mmcv.ops import get_onnxruntime_op_path, roi_align_rotated
    except (ImportError, ModuleNotFoundError):
        pytest.skip('roi_align_aligned op is not successfully compiled')

    ort_custom_op_path = get_onnxruntime_op_path()
    if not os.path.exists(ort_custom_op_path):
        pytest.skip('custom ops for onnxruntime are not compiled.')
    # roi align config
    pool_h = 2
    pool_w = 2
    spatial_scale = 1.0
    sampling_ratio = 2

    inputs = [([[[[1., 2.], [3., 4.]]]], [[0., 0.5, 0.5, 1., 1., 0]]),
              ([[[[1., 2.], [3., 4.]]]], [[0., 0.5, 0.5, 1., 1., np.pi / 2]]),
              ([[[[1., 2.], [3., 4.]],
                 [[4., 3.], [2., 1.]]]], [[0., 0.5, 0.5, 1., 1., 0]]),
              ([[[[1., 2., 5., 6.], [3., 4., 7., 8.], [9., 10., 13., 14.],
                  [11., 12., 15., 16.]]]], [[0., 1.5, 1.5, 3., 3., 0]]),
              ([[[[1., 2., 5., 6.], [3., 4., 7., 8.], [9., 10., 13., 14.],
                  [11., 12., 15., 16.]]]], [[0., 1.5, 1.5, 3., 3.,
                                             np.pi / 2]])]

    def warpped_function(torch_input, torch_rois):
        return roi_align_rotated(torch_input, torch_rois, (pool_w, pool_h),
                                 spatial_scale, sampling_ratio, True, False)

    for case in inputs:
        np_input = np.array(case[0], dtype=np.float32)
        np_rois = np.array(case[1], dtype=np.float32)
        input = torch.from_numpy(np_input)
        rois = torch.from_numpy(np_rois)

        # compute pytorch_output
        with torch.no_grad():
            pytorch_output = roi_align_rotated(input, rois, (pool_w, pool_h),
                                               spatial_scale, sampling_ratio,
                                               True, False)

        # export and load onnx model
        wrapped_model = WrapFunction(warpped_function)
        with torch.no_grad():
            torch.onnx.export(
                wrapped_model, (input, rois),
                onnx_file,
                export_params=True,
                keep_initializers_as_inputs=True,
                input_names=['features', 'rois'],
                opset_version=11)

        onnx_model = onnx.load(onnx_file)
        session_options = rt.SessionOptions()
        if os.path.exists(ort_custom_op_path):
            session_options.register_custom_ops_library(ort_custom_op_path)

        # compute onnx_output
        input_all = [node.name for node in onnx_model.graph.input]
        input_initializer = [
            node.name for node in onnx_model.graph.initializer
        ]
        net_feed_input = list(set(input_all) - set(input_initializer))
        assert (len(net_feed_input) == 2)
        sess = rt.InferenceSession(onnx_file, session_options)
        onnx_output = sess.run(None, {
            'features': input.detach().numpy(),
            'rois': rois.detach().numpy()
        })
        onnx_output = onnx_output[0]

        # allclose

        assert np.allclose(pytorch_output, onnx_output, atol=1e-3)


@pytest.mark.skipif(not torch.cuda.is_available(), reason='test requires GPU')
def test_roipool():
    if torch.__version__ == 'parrots':
        pytest.skip('onnx is not supported in parrots directly')
    from mmcv.ops import roi_pool

    # roi pool config
    pool_h = 2
    pool_w = 2
    spatial_scale = 1.0

    inputs = [([[[[1., 2.], [3., 4.]]]], [[0., 0., 0., 1., 1.]]),
              ([[[[1., 2.], [3., 4.]], [[4., 3.],
                                        [2., 1.]]]], [[0., 0., 0., 1., 1.]]),
              ([[[[1., 2., 5., 6.], [3., 4., 7., 8.], [9., 10., 13., 14.],
                  [11., 12., 15., 16.]]]], [[0., 0., 0., 3., 3.]])]

    def warpped_function(torch_input, torch_rois):
        return roi_pool(torch_input, torch_rois, (pool_w, pool_h),
                        spatial_scale)

    for case in inputs:
        np_input = np.array(case[0], dtype=np.float32)
        np_rois = np.array(case[1], dtype=np.float32)
        input = torch.from_numpy(np_input).cuda()
        rois = torch.from_numpy(np_rois).cuda()

        # compute pytorch_output
        with torch.no_grad():
            pytorch_output = roi_pool(input, rois, (pool_w, pool_h),
                                      spatial_scale)
            pytorch_output = pytorch_output.cpu()

        # export and load onnx model
        wrapped_model = WrapFunction(warpped_function)
        with torch.no_grad():
            torch.onnx.export(
                wrapped_model, (input, rois),
                onnx_file,
                export_params=True,
                keep_initializers_as_inputs=True,
                input_names=['input', 'rois'],
                opset_version=11)
        onnx_model = onnx.load(onnx_file)

        # compute onnx_output
        input_all = [node.name for node in onnx_model.graph.input]
        input_initializer = [
            node.name for node in onnx_model.graph.initializer
        ]
        net_feed_input = list(set(input_all) - set(input_initializer))
        assert (len(net_feed_input) == 2)
        sess = rt.InferenceSession(onnx_file)
        onnx_output = sess.run(
            None, {
                'input': input.detach().cpu().numpy(),
                'rois': rois.detach().cpu().numpy()
            })
        onnx_output = onnx_output[0]

        # allclose
        assert np.allclose(pytorch_output, onnx_output, atol=1e-3)


def test_interpolate():
    from mmcv.onnx.symbolic import register_extra_symbolics
    opset_version = 11
    register_extra_symbolics(opset_version)

    def func(feat, scale_factor=2):
        out = F.interpolate(feat, scale_factor=scale_factor)
        return out

    net = WrapFunction(func)
    net = net.cpu().eval()
    dummy_input = torch.randn(2, 4, 8, 8).cpu()
    torch.onnx.export(
        net,
        dummy_input,
        onnx_file,
        input_names=['input'],
        opset_version=opset_version)
    sess = rt.InferenceSession(onnx_file)
    onnx_result = sess.run(None, {'input': dummy_input.detach().numpy()})
    pytorch_result = func(dummy_input).detach().numpy()

    assert np.allclose(pytorch_result, onnx_result, atol=1e-3)


@pytest.mark.parametrize('mode', ['top', 'bottom', 'left', 'right'])
def test_corner_pool(mode, opset=11):
    if torch.__version__ == 'parrots':
        pytest.skip('onnx is not supported in parrots directly')

    from mmcv.ops import get_onnxruntime_op_path
    ort_custom_op_path = get_onnxruntime_op_path()
    if not os.path.exists(ort_custom_op_path):
        pytest.skip('custom ops for onnxruntime are not compiled.')

    from mmcv.ops.corner_pool import CornerPool

    def corner_pool_func(input):
        corner_pool_module = CornerPool(mode)
        return corner_pool_module.corner_pool.apply(input)

    wrapped_model = WrapFunction(corner_pool_func).eval()

    input = torch.rand((2, 3, 9, 12))  # (n,c,h,w)

    with torch.no_grad():
        torch.onnx.export(
            wrapped_model,
            input,
            onnx_file,
            export_params=True,
            keep_initializers_as_inputs=True,
            input_names=['input'],
            output_names=['output'],
            opset_version=opset)

    onnx_model = onnx.load(onnx_file)
    input_all = [node.name for node in onnx_model.graph.input]
    input_initializer = [node.name for node in onnx_model.graph.initializer]
    net_feed_input = list(set(input_all) - set(input_initializer))
    assert (len(net_feed_input) == 1)

    session_options = rt.SessionOptions()
    session_options.register_custom_ops_library(ort_custom_op_path)
    sess = rt.InferenceSession(onnx_file, session_options)
    ort_result = sess.run(None, {'input': input.detach().numpy()})
    pytorch_results = wrapped_model(input.clone())

    assert np.allclose(pytorch_results, ort_result, atol=1e-5)


@pytest.mark.parametrize('key', ['cummax', 'cummin'])
def test_cummax_cummin(key, opset=11):
    if torch.__version__ == 'parrots':
        pytest.skip('onnx is not supported in parrots directly')

    # Note generally `cummax` or `cummin` is exportable to ONNX
    # as long as the pytorch version >= 1.5.0, since `torch.cummax`
    # is only supported with torch >= 1.5.0.
    # But when `cummax` or `cummin` serves as an intermediate component
    # whose outputs is used as inputs for another modules, it's expected
    # that pytorch version must be >= 1.7.0. Otherwise error appears like:
    # `RuntimeError: tuple  appears in op that does not forward tuples,
    # unsupported 'kind: prim::PythonOp`.
    if version.parse(torch.__version__) < version.parse('1.7.0'):
        pytest.skip('test_cummax_cummin should be ran with pytorch >= 1.7.0')

    # register custom op `mmcv::cummax` and `mmcv::cummin`
    from mmcv.onnx.symbolic import register_extra_symbolics
    register_extra_symbolics(opset)

    from mmcv.ops import get_onnxruntime_op_path
    ort_custom_op_path = get_onnxruntime_op_path()
    if not os.path.exists(ort_custom_op_path):
        pytest.skip('custom ops for onnxruntime are not compiled.')

    input_list = [
        # arbitrary shape, e.g. 1-D, 2-D, 3-D, ...
        torch.rand((2, 3, 4, 1, 5)),
        torch.rand((1)),
        torch.rand((2, 0, 1)),  # tensor.numel() is 0
        torch.FloatTensor(),  # empty tensor
    ]

    cummax_cummin_funcs = {'cummax': torch.cummax, 'cummin': torch.cummin}

    for input in input_list:
        ndims = input.dim()
        # valid dim range is [-ndims, ndims-1]
        # test for all `dim` value which is valid
        for dim in range(-ndims, ndims):
            cummax_func = partial(cummax_cummin_funcs[key], dim=dim)
            wrapped_model = WrapFunction(cummax_func).eval()

            with torch.no_grad():
                torch.onnx.export(
                    wrapped_model,
                    input,
                    onnx_file,
                    export_params=True,
                    keep_initializers_as_inputs=True,
                    input_names=['input'],
                    output_names=['output', 'indices'],
                    opset_version=opset)

            onnx_model = onnx.load(onnx_file)
            input_all = [node.name for node in onnx_model.graph.input]
            input_initializer = [
                node.name for node in onnx_model.graph.initializer
            ]
            net_feed_input = list(set(input_all) - set(input_initializer))
            assert (len(net_feed_input) == 1)

            session_options = rt.SessionOptions()
            session_options.register_custom_ops_library(ort_custom_op_path)
            sess = rt.InferenceSession(onnx_file, session_options)
            ort_output, ort_inds = sess.run(None,
                                            {'input': input.detach().numpy()})
            pytorch_output, pytorch_inds = wrapped_model(input.clone())
            pytorch_output = pytorch_output.detach().numpy()
            pytorch_inds = pytorch_inds.detach().numpy()
            assert np.allclose(pytorch_output, ort_output, atol=1e-5)
            assert np.all(pytorch_inds == ort_inds)


@pytest.mark.parametrize('shifts_dims_pair', [([-3, 5], [2, 0]), (5, None)])
def test_roll(shifts_dims_pair):
    opset = 11
    from mmcv.onnx.symbolic import register_extra_symbolics
    register_extra_symbolics(opset)

    input = torch.arange(0, 4 * 5 * 6, dtype=torch.float32).view(4, 5, 6)

    shifts, dims = shifts_dims_pair
    func = partial(torch.roll, shifts=shifts, dims=dims)
    wrapped_model = WrapFunction(func).eval()

    with torch.no_grad():
        torch.onnx.export(
            wrapped_model,
            input,
            onnx_file,
            export_params=True,
            keep_initializers_as_inputs=True,
            input_names=['input'],
            output_names=['output'],
            opset_version=opset)

    onnx_model = onnx.load(onnx_file)
    input_all = [node.name for node in onnx_model.graph.input]
    input_initializer = [node.name for node in onnx_model.graph.initializer]
    net_feed_input = list(set(input_all) - set(input_initializer))
    assert (len(net_feed_input) == 1)

    sess = rt.InferenceSession(onnx_file)
    ort_output = sess.run(None, {'input': input.detach().numpy()})[0]

    with torch.no_grad():
        pytorch_output = wrapped_model(input.clone())

    torch.testing.assert_allclose(ort_output, pytorch_output)


@pytest.mark.skipif(
    torch.__version__ == 'parrots',
    reason='onnx is not supported in parrots directly')
@pytest.mark.skipif(
    not torch.cuda.is_available(),
    reason='modulated_deform_conv2d only supports in GPU')
def test_modulated_deform_conv2d():
    try:
        from mmcv.ops import ModulatedDeformConv2d, get_onnxruntime_op_path
    except (ImportError, ModuleNotFoundError):
        pytest.skip('modulated_deform_conv op is not successfully compiled')

    ort_custom_op_path = get_onnxruntime_op_path()
    if not os.path.exists(ort_custom_op_path):
        pytest.skip('custom ops for onnxruntime are not compiled.')

    # modulated deform conv config
    in_channels = 3
    out_channels = 64
    stride = 1
    padding = 0
    dilation = 1
    groups = 1
    deform_groups = 1
    kernel_size = 3

    input = torch.rand(1, in_channels, 28, 28).cuda()  # (n, c, h, w)
    conv_offset = nn.Conv2d(
        in_channels=3,
        out_channels=deform_groups * 3 * kernel_size * kernel_size,
        kernel_size=kernel_size,
        stride=stride,
        padding=padding,
        dilation=dilation,
        bias=True).cuda()
    conv_offset.cuda()
    out = conv_offset(input)
    o1, o2, mask = torch.chunk(out, 3, dim=1)
    offset = torch.cat((o1, o2), dim=1)
    mask = torch.sigmoid(mask)

    model_with_bias = ModulatedDeformConv2d(
        in_channels,
        out_channels,
        kernel_size,
        stride,
        padding,
        dilation,
        groups,
        deform_groups,
        bias=True)
    model_without_bias = ModulatedDeformConv2d(
        in_channels,
        out_channels,
        kernel_size,
        stride,
        padding,
        dilation,
        groups,
        deform_groups,
        bias=False)
    models = [model_with_bias.cuda(), model_without_bias.cuda()]

    for model in models:
        # export and load onnx model
        with torch.no_grad():
            torch.onnx.export(
                model, (input, offset, mask),
                onnx_file,
                export_params=True,
                keep_initializers_as_inputs=True,
                input_names=['input', 'offset', 'mask'],
                opset_version=11)

        session_options = rt.SessionOptions()
        if os.path.exists(ort_custom_op_path):
            session_options.register_custom_ops_library(ort_custom_op_path)

        # compute onnx_output
        sess = rt.InferenceSession(onnx_file, session_options)
        onnx_output = sess.run(
            None, {
                'input': input.cpu().detach().numpy(),
                'offset': offset.cpu().detach().numpy(),
                'mask': mask.cpu().detach().numpy()
            })[0]

        # compute pytorch_output
        with torch.no_grad():
            pytorch_output = model(input, offset, mask).cpu()
        # allclose
        assert np.allclose(pytorch_output, onnx_output, atol=1e-3)


@pytest.mark.skipif(
    torch.__version__ == 'parrots',
    reason='onnx is not supported in parrots directly')
def test_deform_conv2d(threshold=1e-3):
    try:
        from mmcv.ops import DeformConv2d, get_onnxruntime_op_path
    except (ImportError, ModuleNotFoundError):
        pytest.skip('deform_conv op is not successfully compiled')

    ort_custom_op_path = get_onnxruntime_op_path()
    if not os.path.exists(ort_custom_op_path):
        pytest.skip('custom ops for onnxruntime are not compiled.')

    # deform conv config
    # modulated deform conv config
    in_channels = 1
    out_channels = 64
    stride = 1
    padding = 0
    dilation = 1
    groups = 1
    deform_groups = 1
    kernel_size = 2
    input = [[[[1., 2., 3.], [0., 1., 2.], [3., 5., 2.]]]]
    offset_weight = [[[0.1, 0.4, 0.6, 0.1]], [[0.3, 0.2, 0.1, 0.3]],
                     [[0.5, 0.5, 0.2, 0.8]], [[0.8, 0.3, 0.9, 0.1]],
                     [[0.3, 0.1, 0.2, 0.5]], [[0.3, 0.7, 0.5, 0.3]],
                     [[0.6, 0.2, 0.5, 0.3]], [[0.4, 0.1, 0.8, 0.4]]]
    offset_bias = [0.7, 0.1, 0.8, 0.5, 0.6, 0.5, 0.4, 0.7]
    deform_weight = [[[0.4, 0.2, 0.1, 0.9]]]

    x = torch.tensor(input)
    conv_offset = nn.Conv2d(
        in_channels=in_channels,
        out_channels=deform_groups * 2 * kernel_size * kernel_size,
        kernel_size=kernel_size,
        stride=stride,
        padding=padding,
        dilation=dilation,
        bias=True)

    conv_offset.weight.data = torch.nn.Parameter(
        torch.Tensor(offset_weight).reshape(8, 1, 2, 2))
    conv_offset.bias.data = torch.nn.Parameter(
        torch.Tensor(offset_bias).reshape(8))

    offset = conv_offset(x)

    model = DeformConv2d(in_channels, out_channels, kernel_size, stride,
                         padding, dilation, groups, deform_groups)

    model.weight.data = torch.nn.Parameter(
        torch.Tensor(deform_weight).reshape(1, 1, 2, 2))

    with torch.no_grad():
        torch.onnx.export(
            model, (x, offset),
            onnx_file,
            export_params=True,
            keep_initializers_as_inputs=True,
            input_names=['input', 'offset'],
            opset_version=11)

    session_options = rt.SessionOptions()
    if os.path.exists(ort_custom_op_path):
        session_options.register_custom_ops_library(ort_custom_op_path)

    # compute onnx_output
    sess = rt.InferenceSession(onnx_file, session_options)
    onnx_output = sess.run(
        None, {
            'input': x.cpu().detach().numpy(),
            'offset': offset.cpu().detach().numpy(),
        })[0]

    # compute pytorch_output
    with torch.no_grad():
        pytorch_output = model(x, offset).cpu()
    # allclose
    assert np.allclose(pytorch_output, onnx_output, atol=1e-3)
