// Copyright (c) 2022 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.

#include "paddle/phi/kernels/expand_kernel.h"

#include "paddle/phi/backends/xpu/enforce_xpu.h"
#include "paddle/phi/core/kernel_registry.h"

namespace phi {

template <typename T, typename Context>
void ExpandKernel(const Context& ctx,
                  const DenseTensor& x,
                  const IntArray& shape,
                  DenseTensor* out) {
  using XPUType = typename XPUTypeTrait<T>::Type;
  auto in_dims = x.dims();
  auto expand_shape = shape.GetData();
  auto vec_in_dims = phi::vectorize<int>(in_dims);
  auto diff = expand_shape.size() - vec_in_dims.size();
  vec_in_dims.insert(vec_in_dims.begin(), diff, 1);
  std::vector<int> final_expand_shape(vec_in_dims.size());
  for (size_t i = 0; i < vec_in_dims.size(); ++i) {
    PADDLE_ENFORCE_NE(
        expand_shape[i],
        0,
        phi::errors::InvalidArgument("The expanded size cannot be zero."));
    if (i < diff) {  // expand_shape = [3,4,-1,-1], X = [10,2] -->
                     // final_expand_shape = [3,4,10,2]
      PADDLE_ENFORCE_GT(
          expand_shape[i],
          0,
          phi::errors::InvalidArgument(
              "The expanded size (%d) for non-existing dimensions must be "
              "positive for expand_v2 op.",
              expand_shape[i]));
      final_expand_shape[i] = expand_shape[i];
    } else if (expand_shape[i] > 0) {  // expand_shape = [3,4,10,4], X =
                                       // [10,1] --> final_expand_shape =
                                       // [3,4,10,4]
      if (vec_in_dims[i] != 1) {
        PADDLE_ENFORCE_EQ(
            vec_in_dims[i],
            expand_shape[i],
            phi::errors::InvalidArgument(
                "The value (%d) of the non-singleton dimension does not match"
                " the corresponding value (%d) in shape for expand_v2 op.",
                vec_in_dims[i],
                expand_shape[i]));
        final_expand_shape[i] = expand_shape[i];
      } else {
        final_expand_shape[i] = expand_shape[i];
      }
    } else {  // expand_shape = [3,4,-1,-1], X = [10,2] --> final_expand_shape
              // = [3,4,10,2]
      PADDLE_ENFORCE_EQ(
          expand_shape[i],
          -1,
          phi::errors::InvalidArgument(
              "When the value in shape is negative for expand_v2 op, "
              "only -1 is supported, but the value received is %d.",
              expand_shape[i]));
      final_expand_shape[i] = vec_in_dims[i];
    }
  }

  auto rank = x.dims().size();
  PADDLE_ENFORCE_GE(
      rank,
      0,
      phi::errors::InvalidArgument(
          "The rank of the input 'X' for expand_v2_npu op must be positive, "
          "but the value received is %d.",
          rank));
  auto shape_size = final_expand_shape.size();
  PADDLE_ENFORCE_GE(
      shape_size,
      rank,
      phi::errors::InvalidArgument(
          "The number (%d) of elements of 'shape' for expand_v2_npu op must "
          "be "
          "greater than or equal to the rank (%d) of the input 'X'.",
          shape_size,
          rank));

  DDim out_dims = phi::make_ddim(final_expand_shape);
  out->Resize(out_dims);
  ctx.template Alloc<T>(out);
  auto& x_shape = vec_in_dims;
  auto out_shape = phi::vectorize<int>(out_dims);
  if (shape_size == 0) {
    x_shape = {1};
    out_shape = {1};
  }

  int r = XPU_SUCCESS;
  if (std::is_same<T, bool>::value) {
    auto x_data = reinterpret_cast<const int8_t*>(x.data<T>());
    auto out_data = reinterpret_cast<int8_t*>(out->data<T>());
    r = xpu::broadcast<int8_t>(
        ctx.x_context(), x_data, out_data, x_shape, out_shape);
  } else {
    auto x_data = reinterpret_cast<const XPUType*>(x.data<T>());
    auto out_data = reinterpret_cast<XPUType*>(out->data<T>());
    r = xpu::broadcast<XPUType>(
        ctx.x_context(), x_data, out_data, x_shape, out_shape);
  }
  PADDLE_ENFORCE_EQ(r,
                    XPU_SUCCESS,
                    phi::errors::External("XPU API(broadcast) return wrong "
                                          "value[%d %s] in ExpandV2XPUKernel.",
                                          r,
                                          XPUAPIErrorMsg[r]));
}
}  // namespace phi

PD_REGISTER_KERNEL(expand,
                   XPU,
                   ALL_LAYOUT,
                   phi::ExpandKernel,
                   float,
                   phi::dtype::float16,
                   bool,
                   int,
                   int64_t) {}