// Copyright 2020 Google LLC
//
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree.

#include <math.h>
#include <stddef.h>
#include <stdint.h>

#include <xnnpack.h>
#include <xnnpack/log.h>
#include <xnnpack/params.h>
#include <xnnpack/subgraph.h>


enum xnn_status xnn_define_average_pooling_2d(
  xnn_subgraph_t subgraph,
  uint32_t input_padding_top,
  uint32_t input_padding_right,
  uint32_t input_padding_bottom,
  uint32_t input_padding_left,
  uint32_t pooling_height,
  uint32_t pooling_width,
  uint32_t stride_height,
  uint32_t stride_width,
  float output_min,
  float output_max,
  uint32_t input_id,
  uint32_t output_id,
  uint32_t flags)
{
  if ((xnn_params.init_flags & XNN_INIT_FLAG_XNNPACK) == 0) {
    xnn_log_error("failed to define %s operator: XNNPACK is not initialized",
      xnn_node_type_to_string(xnn_node_type_average_pooling_2d));
    return xnn_status_uninitialized;
  }

  const uint32_t pooling_size = pooling_height * pooling_width;
  if (pooling_size == 0) {
    xnn_log_error(
      "failed to define %s operator with %" PRIu32 "x%" PRIu32 " pooling size: "
      "pooling size dimensions must be non-zero",
      xnn_node_type_to_string(xnn_node_type_average_pooling_2d), pooling_width, pooling_height);
    return xnn_status_invalid_parameter;
  }

  if (pooling_size == 1) {
    xnn_log_error(
      "failed to define %s operator with 1 pooling element: 1x1 pooling is meaningless",
      xnn_node_type_to_string(xnn_node_type_average_pooling_2d));
    return xnn_status_invalid_parameter;
  }

  if (stride_height == 0 || stride_width == 0) {
    xnn_log_error(
      "failed to define %s operator with %" PRIu32 "x%" PRIu32 " stride: "
      "stride dimensions must be non-zero",
      xnn_node_type_to_string(xnn_node_type_average_pooling_2d), stride_width, stride_height);
    return xnn_status_invalid_parameter;
  }

  if (isnan(output_min)) {
    xnn_log_error(
      "failed to define %s operator with NaN output lower bound: lower bound must be non-NaN",
      xnn_node_type_to_string(xnn_node_type_average_pooling_2d));
    return xnn_status_invalid_parameter;
  }

  if (isnan(output_max)) {
    xnn_log_error(
      "failed to define %s operator with NaN output upper bound: upper bound must be non-NaN",
      xnn_node_type_to_string(xnn_node_type_average_pooling_2d));
    return xnn_status_invalid_parameter;
  }

  if (output_min >= output_max) {
    xnn_log_error(
      "failed to define %s operator with [%.7g, %.7g] output range: lower bound must be below upper bound",
      xnn_node_type_to_string(xnn_node_type_average_pooling_2d), output_min, output_max);
    return xnn_status_invalid_parameter;
  }

  const bool any_padding = (input_padding_left | input_padding_top | input_padding_right | input_padding_bottom) != 0;
  if ((flags & XNN_FLAG_TENSORFLOW_SAME_PADDING) != 0) {
    if (any_padding) {
      xnn_log_error(
        "failed to define %s operator with %" PRIu32 "+%" PRIu32 "x%" PRIu32 "+%" PRIu32" padding: "
        "TensorFlow SAME padding can't be combined with explicit padding specification",
        xnn_node_type_to_string(xnn_node_type_average_pooling_2d),
        input_padding_top, input_padding_left, input_padding_bottom, input_padding_right);
      return xnn_status_invalid_parameter;
    }
  }

  if (input_id >= subgraph->num_values) {
    xnn_log_error(
      "failed to define %s operator with input ID #%" PRIu32 ": invalid Value ID",
      xnn_node_type_to_string(xnn_node_type_average_pooling_2d), input_id);
    return xnn_status_invalid_parameter;
  }

  if (output_id >= subgraph->num_values) {
    xnn_log_error(
      "failed to define %s operator with output ID #%" PRIu32 ": invalid Value ID",
      xnn_node_type_to_string(xnn_node_type_average_pooling_2d), output_id);
    return xnn_status_invalid_parameter;
  }

  struct xnn_node* node = xnn_subgraph_new_node(subgraph);
  if (node == NULL) {
    return xnn_status_out_of_memory;
  }

  node->type = xnn_node_type_average_pooling_2d;
  node->params.pooling_2d.padding_top = input_padding_top;
  node->params.pooling_2d.padding_right = input_padding_right;
  node->params.pooling_2d.padding_bottom = input_padding_bottom;
  node->params.pooling_2d.padding_left = input_padding_left;
  node->params.pooling_2d.pooling_height = pooling_height;
  node->params.pooling_2d.pooling_width = pooling_width;
  node->params.pooling_2d.stride_height = stride_height;
  node->params.pooling_2d.stride_width = stride_width;
  node->activation.output_min = output_min;
  node->activation.output_max = output_max;
  node->num_inputs = 1;
  node->inputs[0] = input_id;
  node->num_outputs = 1;
  node->outputs[0] = output_id;
  node->flags = flags;

  return xnn_status_success;
}