#ifndef MIGRAPHX_GUARD_OPERATORS_RESHAPE_HPP
#define MIGRAPHX_GUARD_OPERATORS_RESHAPE_HPP

#include <array>
#include <migraphx/check_shapes.hpp>
#include <migraphx/stringutils.hpp>
#include <migraphx/streamutils.hpp>
#include <migraphx/literal.hpp>
#include <migraphx/shape_for_each.hpp>
#include <migraphx/config.hpp>
#include <migraphx/lifetime.hpp>
#include <migraphx/value.hpp>
#include <cmath>
#include <utility>

namespace migraphx {
inline namespace MIGRAPHX_INLINE_NS {
namespace op {

struct reshape
{
    std::vector<int64_t> dims;

    template <class Self, class F>
    static auto reflect(Self& self, F f)
    {
        return pack(f(self.dims, "dims"));
    }

    value attributes() const { return {{"standard_input_shape", true}}; }

    std::string name() const { return "reshape"; }
    shape compute_shape(std::vector<shape> inputs) const
    {
        check_shapes{inputs, *this}.has(1).standard();
        auto&& idims = inputs.front().lens();
        std::vector<std::size_t> rdims(dims.begin(), dims.end());
        auto n_neg_dims = std::count(dims.begin(), dims.end(), -1);
        if(n_neg_dims > 1)
            MIGRAPHX_THROW("Reshape: Dimensions for reshape can only have one -1 dim");

        for(std::size_t i = 0; i < dims.size(); i++)
        {
            if(dims[i] == 0)
                rdims[i] = idims[i];

            // since rdims using size_t type, -1 is the max value
            // is size_t that cause later compuation incorrect
            if(dims[i] == -1)
                rdims[i] = 1;
        }

        if(n_neg_dims > 0)
        {
            size_t missing_dim =
                inputs.front().elements() /
                std::accumulate(rdims.begin(), rdims.end(), 1, std::multiplies<int64_t>());
            for(std::size_t i = 0; i < rdims.size(); i++)
            {
                if(dims[i] == -1)
                    rdims[i] = missing_dim;
            }
        }

        shape s{inputs.front().type(), rdims};
        if(s.elements() != inputs.front().elements())
            MIGRAPHX_THROW("Reshape: Wrong number of elements for reshape: reshape has " +
                           std::to_string(s.elements()) + " elements whereas the input has " +
                           std::to_string(inputs.front().elements()));
        return s;
    }

    argument compute(shape output_shape, std::vector<argument> args) const
    {
        return args[0].reshape(output_shape);
    }

    lifetime get_lifetime() const { return lifetime::borrow; }
    std::ptrdiff_t output_alias(const std::vector<shape>&) const { return 0; }
};

} // namespace op
} // namespace MIGRAPHX_INLINE_NS
} // namespace migraphx

#endif
