/* ******************************************************************************
 *
 *
 * This program and the accompanying materials are made available under the
 * terms of the Apache License, Version 2.0 which is available at
 * https://www.apache.org/licenses/LICENSE-2.0.
 *
 *  See the NOTICE file distributed with this work for additional
 *  information regarding copyright ownership.
 * 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.
 *
 * SPDX-License-Identifier: Apache-2.0
 ******************************************************************************/

//
// Created by george@skymind.io on 2/21/2018.
// Modified by sgazeos@gmail.com on 4/4/2018

#include <system/op_boilerplate.h>
#if NOT_EXCLUDED(OP_sufficient_statistics)

#include <ops/declarable/CustomOperations.h>
#include <ops/declarable/helpers/axis.h>
namespace sd {
namespace ops {
CUSTOM_OP_IMPL(sufficient_statistics, 2, 3, false, 0, 0) {
  auto input = INPUT_VARIABLE(0);
  auto axisVector = INPUT_VARIABLE(1);
  auto dataCount = OUTPUT_VARIABLE(0);

  auto sum = OUTPUT_VARIABLE(1);
  auto squares = OUTPUT_VARIABLE(2);

  std::vector<LongType> axis(axisVector->lengthOf());

  // axis might be dynamic (i.e. tf mode)
  helpers::adjustAxis(input->rankOf(), axisVector, axis);

  input->reduceAlongDimension(reduce::SquaredNorm, squares, &axis);
  input->reduceAlongDimension(reduce::Sum, sum, &axis);
  auto count = NDArrayFactory::create(input->dataType(), input->lengthOf() / sum->lengthOf());
  dataCount->assign(count);
  if (block.numT() > 0) {
    auto shift = OUTPUT_VARIABLE(3);
#ifdef HAS_DOUBLE
    double shiftValue = static_cast<double>(T_ARG(0));
    shift->assign(shiftValue);
#elif defined(HAS_FLOAT32)
    float shiftValue = static_cast<float>(T_ARG(0));
    shift->assign(shiftValue);
#else
#error "No floating-point type available for sufficient_statistics operation"
#endif
  }

  delete count;
  return Status::OK;
}

DECLARE_TYPES(sufficient_statistics) {
  getOpDescriptor()->setAllowedInputTypes(0, {ALL_INTS, ALL_FLOATS});
  getOpDescriptor()->setAllowedInputTypes(1, {INT32, INT64});
  getOpDescriptor()->setAllowedOutputTypes(0, INHERIT);
  getOpDescriptor()->setAllowedOutputTypes(1, INHERIT);
  getOpDescriptor()->setAllowedOutputTypes(2, INHERIT);
}

DECLARE_SHAPE_FN(sufficient_statistics) {
  auto axisVector = INPUT_VARIABLE(1);
  std::vector<LongType> axis(axisVector->lengthOf());

  auto input = INPUT_VARIABLE(0);
  helpers::adjustAxis(input->rankOf(), axisVector, axis);

  auto scalarShape = ConstantShapeHelper::getInstance().scalarShapeInfo(ArrayOptions::dataType(inputShape->at(0)));
  auto sumShape = ShapeUtils::evalReduceShapeInfo('c', &axis, *input, false, false, block.workspace());

  auto squareShape = ShapeUtils::evalReduceShapeInfo('c', &axis, *input, false, false, block.workspace());

  auto shapeList = SHAPELIST(scalarShape, sumShape, squareShape);
  if (block.numT() > 0)
    shapeList->push_back(ConstantShapeHelper::getInstance().scalarShapeInfo(ArrayOptions::dataType(inputShape->at(0))));

  return shapeList;
}
}  // namespace ops

}  // namespace sd

#endif