/*******************************************************************************
 * 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_roll)

#include <ops/declarable/headers/parity_ops.h>
#include <ops/declarable/helpers/roll.h>
#include <ops/declarable/helpers/axis.h>

namespace nd4j {
namespace ops {

    CONFIGURABLE_OP_IMPL(roll, 1, 1, true, 0, 0) {
        auto output = OUTPUT_VARIABLE(0);
        auto input = INPUT_VARIABLE(0);
        int inputLen = input->lengthOf();

        bool shiftIsLinear = block.width() == 1;
        std::vector<int> axes;
        std::vector<int> shifts;
        if (block.width() > 1) {
            REQUIRE_TRUE(block.width() == 3, 0, "roll: 3 arguments required for roll - input, shifts and axes. But %i given.", block.width());
            auto axesI = INPUT_VARIABLE(2);
            auto shiftsI = INPUT_VARIABLE(1);
            REQUIRE_TRUE(axesI->rankOf() == shiftsI->rankOf(), 0, "roll: shifts and axes should be the same rank, but %i and %i given.", (int)shiftsI->rankOf(), (int)axesI->rankOf());
            REQUIRE_TRUE(axesI->lengthOf() == shiftsI->lengthOf(), 0, "roll: shifts and axes should be the same length, but %i and %i given.", (int)shiftsI->lengthOf(), (int)axesI->lengthOf());
            helpers::adjustAxis(axesI->lengthOf(), axesI, axes );
            shifts.resize(shiftsI->lengthOf());
            for (Nd4jLong i = 0; i < shiftsI->lengthOf(); i++) {
                auto shift = shiftsI->e<int>(i);
                if (shift < 0) {
                    shift -= input->sizeAt(i) * (shift / inputLen - 1);
                }
                else {
                    shift %= input->sizeAt(i);
                }
                shifts[i] = shift;
            }

        }
        else {
            int shift = INT_ARG(0);
            if (shift < 0) {
                // convert shift to positive value between 1 and inputLen - 1
                shift -= inputLen * (shift / inputLen - 1);
            }
            else
                // cut shift to value between 1 and inputLen - 1
                shift %= inputLen;
            axes.resize(block.getIArguments()->size() - 1);
            if (axes.size())
                shifts.resize(axes.size());//emplace_back(shift);
            else
                shifts.push_back(shift);

            for (auto& s: shifts)
                s = shift;

            for (unsigned e = 0; e < axes.size(); ++e) {
                int axis = INT_ARG(e + 1);
                REQUIRE_TRUE(axis < input->rankOf() && axis >= -input->rankOf(), 0, "roll: axe value should be between -%i and %i, but %i was given.",
                             input->rankOf(), input->rankOf() - 1, axis);
                axes[e] = (axis < 0? (input->rankOf() + axis) : axis);
            }
        }

        if (block.isInplace()) output = input;

        shiftIsLinear = (axes.size() == 0) || (input->rankOf() == 1);

        if (shiftIsLinear) {
            helpers::rollFunctorLinear(block.launchContext(), input, output, shifts[0], block.isInplace());
        }
        else {
            helpers::rollFunctorFull(block.launchContext(), input, output, shifts, axes, block.isInplace());
        }

        return Status::OK();
    }

    DECLARE_TYPES(roll) {
        getOpDescriptor()
                ->setAllowedInputTypes(0,nd4j::DataType::ANY)
                ->setAllowedInputTypes(1,nd4j::DataType::INT32) // TODO: all ints in future
                ->setAllowedInputTypes(2,nd4j::DataType::INT32)
                ->setAllowedOutputTypes(nd4j::DataType::ANY)
                ->setSameMode(true);
    }
}
}

#endif