/*******************************************************************************
 * Copyright (c) 2015-2018 Skymind, Inc.
 *
 * 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.
 *
 * 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
 ******************************************************************************/

//
//  @author raver119@gmail.com
//

#include <op_boilerplate.h>
#if NOT_EXCLUDED(OP_squeeze)

#include <ops/declarable/CustomOperations.h>

namespace nd4j {
    namespace ops {
        CUSTOM_OP_IMPL(squeeze, 1, 1, true, 0, -2) {
            auto input = INPUT_VARIABLE(0);
            auto output = OUTPUT_VARIABLE(0);

            std::vector<int> axis;

            if (block.numI() > 0)
                for (int e = 0; e < block.numI(); e++) {
                    int _a = INT_ARG(e);
                    if (_a < 0)
                        _a += input->rankOf();
                        
                    axis.emplace_back(_a);
                }
            else if (block.width() > 1) {
                auto a = INPUT_VARIABLE(1);
                for (int e = 0; e < a->lengthOf(); e++) {
                    int _a = a->e<int>(e);
                    
                    if (_a < 0)
                        _a += input->rankOf();

                    axis.emplace_back(_a);
                }
            }

            if (input->rankOf() == 0 || (input->rankOf() == 1 && input->lengthOf() == 1)) {
                output->assign(input);
                return Status::OK();
            }

            std::vector<Nd4jLong> shape;
            if (axis.size() == 0) {
                for (int d = 0; d < input->rankOf(); d++)
                    if (input->sizeAt(d) > 1)
                        shape.emplace_back(input->sizeAt(d));
            } else {
                for (int d = 0; d < input->rankOf(); d++) {
                    if (input->sizeAt(d) == 1) {
                        if (std::find(axis.begin(), axis.end(), d) == axis.end())
                            shape.emplace_back(input->sizeAt(d));
                    } else shape.emplace_back(input->sizeAt(d));
                }
            }

            if (block.isInplace()) {
                output->reshapei(input->ordering(), shape);
            } else {
                auto tmp = input->reshape(input->ordering(), shape);
                output->assign(tmp);
            }

            return Status::OK();
        }

        DECLARE_TYPES(squeeze) {
            getOpDescriptor()
                    ->setAllowedInputTypes(nd4j::DataType::ANY)
                    ->setSameMode(true);
        }

        DECLARE_SHAPE_FN(squeeze) {
            auto shapeList = SHAPELIST();

            Nd4jLong* newShape;
            auto in = inputShape->at(0);
            auto rank = shape::rank(in);
            auto length = shape::length(in);

            if (rank == 0 || (rank == 1 && length == 1)) {
                shapeList->push_back(ConstantShapeHelper::getInstance()->scalarShapeInfo(ArrayOptions::dataType(in)));
                return shapeList;
            }

            std::vector<int> axis;

            if (block.numI() > 0)
                for (int e = 0; e < block.numI(); e++) {
                    int _a = INT_ARG(e);
                    if (_a < 0)
                        _a += rank;
                        
                    axis.emplace_back(_a);
                }
            else if (block.width() > 1) {
                auto a = INPUT_VARIABLE(1);
                for (int e = 0; e < a->lengthOf(); e++) {
                    int _a = a->e<int>(e);
                    
                    if (_a < 0)
                        _a += rank;

                    axis.emplace_back(_a);
                }
                
            }

            auto order = shape::order(in);
            auto oldShape = shape::shapeOf(in);

            std::vector<Nd4jLong> shape;
            if (axis.size() == 0) {
                for (int d = 0; d < rank; d++)
                    if (oldShape[d] > 1)
                        shape.emplace_back(oldShape[d]);
            } else {
                for (int d = 0; d < rank; d++) {
                    if (oldShape[d] == 1) {
                        if (std::find(axis.begin(), axis.end(), d) == axis.end())
                            shape.emplace_back(oldShape[d]);
                    } else shape.emplace_back(oldShape[d]);
                }
            }

            if (shape.size() == 0) {
                shapeList->push_back(ConstantShapeHelper::getInstance()->scalarShapeInfo(ArrayOptions::dataType(in)));
                return shapeList;
            }

            newShape = ConstantShapeHelper::getInstance()->createShapeInfo(ArrayOptions::dataType(in), order, shape);
            shapeList->push_back(newShape);
            return shapeList;
        }
    }
}

#endif