/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

#include <torch/extension.h>
#include <vector>

std::vector<at::Tensor> lightconv_cuda_forward(
    at::Tensor input,
    at::Tensor filters,
    int padding_l);

std::vector<at::Tensor> lightconv_cuda_backward(
    at::Tensor gradOutput,
    int padding_l,
    at::Tensor input,
    at::Tensor filters);


#define CHECK_CUDA(x) AT_ASSERTM(x.type().is_cuda(), #x " must be a CUDA tensor")
#define CHECK_CONTIGUOUS(x) AT_ASSERTM(x.is_contiguous(), #x " must be contiguous")
#define CHECK_INPUT(x) CHECK_CUDA(x); CHECK_CONTIGUOUS(x)

std::vector<at::Tensor> lightconv_forward(
    at::Tensor input,
    at::Tensor filters,
    int padding_l) {

    CHECK_INPUT(input);
    CHECK_INPUT(filters);

    return lightconv_cuda_forward(input, filters, padding_l);
}

std::vector<at::Tensor> lightconv_backward(
    at::Tensor gradOutput,
    int padding_l,
    at::Tensor input,
    at::Tensor filters) {

    CHECK_INPUT(gradOutput);
    CHECK_INPUT(input);
    CHECK_INPUT(filters);

    return lightconv_cuda_backward(gradOutput, padding_l, input, filters);
}

PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
    m.def("forward", &lightconv_forward, "lighconv forward (CUDA)");
    m.def("backward", &lightconv_backward, "lighconv backward (CUDA)");
}