/*******************************************************************************
 * 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 Yurii Shyrma (iuriish@yahoo.com), created on 24.01.2018
//

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

#include <ops/declarable/CustomOperations.h>
#include<ops/declarable/helpers/transforms.h>

namespace nd4j {
namespace ops  {

CUSTOM_OP_IMPL(trace, 1, 1, false, 0, 0) {
    
    auto input  = INPUT_VARIABLE(0);
    auto output = OUTPUT_VARIABLE(0);
    
    REQUIRE_TRUE(input->rankOf() >= 2, 0, "TRACE op: the rank of input array must be >=2, but got %i instead!", input->rankOf());

    helpers::trace(block.launchContext(), *input, *output);

    return Status::OK();
}

    DECLARE_TYPES(trace) {
        getOpDescriptor()->setAllowedInputTypes(0, {ALL_FLOATS})
                ->setAllowedOutputTypes(0, {ALL_FLOATS});
    }

DECLARE_SHAPE_FN(trace) {
    auto inShapeInfo = inputShape->at(0);

    REQUIRE_TRUE(inShapeInfo[0] >= 2, 0, "TRACE op: the rank of input array must be >=2, but got %i instead!", inShapeInfo[0]);    
    const int rank = inShapeInfo[0] - 2;

    Nd4jLong* outShapeInfo(nullptr);
    ALLOCATE(outShapeInfo, block.getWorkspace(), shape::shapeInfoLength(rank), Nd4jLong); 

    outShapeInfo[0] = rank;
    for(int i=1; i <= rank; ++i)
        outShapeInfo[i] = inShapeInfo[i];

    shape::updateStrides(outShapeInfo, shape::order(inShapeInfo));
    auto result = ConstantShapeHelper::getInstance()->createShapeInfo(ShapeDescriptor(outShapeInfo, ArrayOptions::dataType(inShapeInfo)));
    RELEASE(outShapeInfo, block.getWorkspace());
    return SHAPELIST(result);
}

}
}

#endif