/*
 * Copyright (c) 2018-2020 Arm Limited.
 *
 * SPDX-License-Identifier: MIT
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#include "arm_compute/core/CL/kernels/CLGatherKernel.h"
#include "arm_compute/core/CL/ICLTensor.h"
#include "arm_compute/core/Error.h"
#include "arm_compute/core/utils/misc/ShapeCalculator.h"
#include "support/StringSupport.h"

#include <string>

namespace arm_compute
{
namespace
{
inline Status validate_arguments(const ITensorInfo *input, const ITensorInfo *indices, const ITensorInfo *output, int axis)
{
    ARM_COMPUTE_RETURN_ERROR_ON_NULLPTR(input, indices, output);
    const uint32_t actual_axis = wrap_around(axis, static_cast<int>(input->num_dimensions()));
    ARM_COMPUTE_RETURN_ERROR_ON(indices->num_dimensions() > 1);
    ARM_COMPUTE_RETURN_ERROR_ON(input->num_dimensions() > 4);
    ARM_COMPUTE_RETURN_ERROR_ON(actual_axis >= input->num_dimensions());
    ARM_COMPUTE_RETURN_ERROR_ON(input->data_type() == DataType::UNKNOWN);

    if(output->total_size() != 0)
    {
        ARM_COMPUTE_RETURN_ERROR_ON_MISMATCHING_DATA_TYPES(input, output);
        ARM_COMPUTE_RETURN_ERROR_ON_MISMATCHING_QUANTIZATION_INFO(input, output);
        TensorShape output_shape = arm_compute::misc::shape_calculator::compute_gather_shape(input->tensor_shape(), indices->tensor_shape(), actual_axis);
        ARM_COMPUTE_RETURN_ERROR_ON(output_shape.total_size() != output->tensor_shape().total_size());
    }

    ARM_COMPUTE_RETURN_ERROR_ON_DATA_TYPE_CHANNEL_NOT_IN(indices, 1, DataType::U32, DataType::S32);

    return Status{};
}

std::pair<Status, Window> validate_and_configure_window(ITensorInfo *input, ITensorInfo *indices, ITensorInfo *output, int axis)
{
    ARM_COMPUTE_ERROR_ON_NULLPTR(input, output, indices);
    const uint32_t actual_axis = wrap_around(axis, static_cast<int>(input->num_dimensions()));
    // Output auto initialization if not yet initialized
    TensorShape output_shape = arm_compute::misc::shape_calculator::compute_gather_shape(input->tensor_shape(), indices->tensor_shape(), actual_axis);
    auto_init_if_empty((*output), output_shape, 1, input->data_type());

    // Create window
    Window win = calculate_max_window(*output, Steps());
    output->set_valid_region(ValidRegion(Coordinates(), output->tensor_shape()));

    return std::make_pair(Status{}, win);
}

} // namespace

CLGatherKernel::CLGatherKernel()
    : _input(nullptr), _indices(nullptr), _output(nullptr), _axis(0)
{
}

void CLGatherKernel::configure(const ICLTensor *input, const ICLTensor *indices, ICLTensor *output, int axis)
{
    configure(CLKernelLibrary::get().get_compile_context(), input, indices, output, axis);
}

void CLGatherKernel::configure(const CLCompileContext &compile_context, const ICLTensor *input, const ICLTensor *indices, ICLTensor *output, int axis)
{
    ARM_COMPUTE_ERROR_ON_NULLPTR(input, output, indices);
    ARM_COMPUTE_ERROR_THROW_ON(validate_arguments(input->info(), indices->info(), output->info(), axis));

    // Configure kernel window
    auto win_config = validate_and_configure_window(input->info(), indices->info(), output->info(), axis);
    ARM_COMPUTE_ERROR_THROW_ON(win_config.first);

    _input   = input;
    _output  = output;
    _indices = indices;
    _axis    = wrap_around(axis, static_cast<int>(input->info()->num_dimensions()));

    // Set build options
    CLBuildOptions build_opts;
    build_opts.add_option("-DDATA_TYPE=" + get_cl_unsigned_type_from_element_size(data_size_from_type(input->info()->data_type())));
    build_opts.add_option("-DOUTPUT_DIM_Z=" + support::cpp11::to_string(output->info()->dimension(2)));
    build_opts.add_option("-DINPUT_DIM_Z=" + support::cpp11::to_string(input->info()->dimension(2)));
    build_opts.add_option("-DAXIS=" + support::cpp11::to_string(_axis));

    // Create kernel
    _kernel = create_kernel(compile_context, "gather", build_opts.options());
    ICLKernel::configure_internal(win_config.second);
}

Status CLGatherKernel::validate(const ITensorInfo *input, const ITensorInfo *indices, const ITensorInfo *output, int axis)
{
    ARM_COMPUTE_RETURN_ON_ERROR(validate_arguments(input, indices, output, axis));
    ARM_COMPUTE_RETURN_ON_ERROR(validate_and_configure_window(input->clone().get(), indices->clone().get(), output->clone().get(), axis).first);
    return Status{};
}

void CLGatherKernel::run(const Window &window, cl::CommandQueue &queue)
{
    ARM_COMPUTE_ERROR_ON_UNCONFIGURED_KERNEL(this);
    ARM_COMPUTE_ERROR_ON_INVALID_SUBWINDOW(IKernel::window(), window);

    Window       window_collapsed = window.collapse_if_possible(ICLKernel::window(), Window::DimZ);
    unsigned int idx              = 0;
    add_4D_tensor_argument(idx, _input, window_collapsed);
    add_1D_tensor_argument(idx, _indices, window_collapsed);
    add_4D_tensor_argument(idx, _output, window_collapsed);
    enqueue(queue, *this, window_collapsed, lws_hint());
}
} // namespace arm_compute
