#ifndef PYTHONIC_TYPES_NUMPY_IEXPR_HPP
#define PYTHONIC_TYPES_NUMPY_IEXPR_HPP

#include "pythonic/include/types/numpy_iexpr.hpp"

#include "pythonic/include/types/raw_array.hpp"
#include "pythonic/types/ndarray.hpp" // we should remove that dep during a refactoring :-)
#include "pythonic/types/nditerator.hpp"
#include "pythonic/types/tuple.hpp"
#include "pythonic/utils/allocate.hpp"
#include "pythonic/utils/array_helper.hpp"
#include "pythonic/utils/broadcast_copy.hpp"

#include "pythonic/operator_/iadd.hpp"
#include "pythonic/operator_/iand.hpp"
#include "pythonic/operator_/idiv.hpp"
#include "pythonic/operator_/imul.hpp"
#include "pythonic/operator_/ior.hpp"
#include "pythonic/operator_/isub.hpp"
#include "pythonic/operator_/ixor.hpp"

#include <numeric>

PYTHONIC_NS_BEGIN

namespace types
{

  template <class Arg>
  numpy_iexpr<Arg>::numpy_iexpr() : buffer(nullptr)
  {
  }

  template <class Arg>
  template <class Argp> // not using the default one, to make it possible to
  // accept reference and non reference version of Argp
  numpy_iexpr<Arg>::numpy_iexpr(numpy_iexpr<Argp> const &other)
      : arg(other.arg), buffer(other.buffer)
  {
    assert(buffer);
  }
  template <class Arg>
  template <class Argp> // not using the default one, to make it possible to
  // accept reference and non reference version of Argp
  numpy_iexpr<Arg>::numpy_iexpr(numpy_iexpr<Argp &> const &other)
      : arg(const_cast<typename std::decay<Argp>::type &>(other.arg)),
        buffer(other.buffer)
  {
    assert(buffer);
  }

  template <class Arg>
  numpy_iexpr<Arg>::numpy_iexpr(Arg const &arg, long index)
      : arg(arg), buffer(arg.buffer + index * arg.template strides<0>())
  {
    assert(buffer);
  }

  template <class Arg>
  long numpy_iexpr<Arg>::size() const
  {
    return arg.template shape<1>();
  }

  template <class Arg>
  template <class E, class Requires>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator=(E const &expr)
  {
    assert(buffer);
    return utils::broadcast_copy < numpy_iexpr &, E, value,
           value - utils::dim_of<E>::value,
           is_vectorizable &&
               std::is_same<dtype, typename dtype_of<E>::type>::value &&
               types::is_vectorizable<E>::value > (*this, expr);
  }

  template <class Arg>
  template <class Argp, class Requires>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator=(numpy_iexpr<Argp> const &expr)
  {
    if (!buffer) {
      this->~numpy_iexpr();
      return *new (this) numpy_iexpr<Arg>(expr);
    }

    assert(buffer);
    return utils::broadcast_copy < numpy_iexpr &, numpy_iexpr const &, value,
           value - utils::dim_of<numpy_iexpr>::value,
           is_vectorizable && numpy_iexpr<Arg>::is_vectorizable &&
               std::is_same<dtype, typename numpy_iexpr<Arg>::dtype>::value >
                   (*this, expr);
  }

  template <class Arg>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator=(numpy_iexpr<Arg> const &expr)
  {
    if (!buffer) {
      this->~numpy_iexpr();
      return *new (this) numpy_iexpr<Arg>(expr);
    }

    assert(buffer);
    return utils::broadcast_copy < numpy_iexpr &, numpy_iexpr const &, value,
           value - utils::dim_of<numpy_iexpr>::value,
           is_vectorizable && numpy_iexpr<Arg>::is_vectorizable &&
               std::is_same<dtype, typename numpy_iexpr<Arg>::dtype>::value >
                   (*this, expr);
  }

  template <class Arg>
  template <class Op, class Expr>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::update_(Expr const &expr)
  {
    using BExpr =
        typename std::conditional<std::is_scalar<Expr>::value,
                                  broadcast<Expr, dtype>, Expr const &>::type;
    assert(buffer);
    BExpr bexpr = expr;
    utils::broadcast_update<
        Op, numpy_iexpr &, BExpr, value,
        value - (std::is_scalar<Expr>::value + utils::dim_of<Expr>::value),
        is_vectorizable &&
            types::is_vectorizable<typename std::remove_cv<
                typename std::remove_reference<BExpr>::type>::type>::value &&
            std::is_same<dtype, typename dtype_of<typename std::decay<
                                    BExpr>::type>::type>::value>(*this, bexpr);
    return *this;
  }

  template <class Arg>
  template <class E>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator+=(E const &expr)
  {
    return update_<pythonic::operator_::functor::iadd>(expr);
  }

  template <class Arg>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator+=(numpy_iexpr<Arg> const &expr)
  {
    return update_<pythonic::operator_::functor::iadd>(expr);
  }

  template <class Arg>
  template <class E>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator-=(E const &expr)
  {
    return update_<pythonic::operator_::functor::isub>(expr);
  }

  template <class Arg>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator-=(numpy_iexpr<Arg> const &expr)
  {
    return update_<pythonic::operator_::functor::isub>(expr);
  }

  template <class Arg>
  template <class E>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator*=(E const &expr)
  {
    return update_<pythonic::operator_::functor::imul>(expr);
  }

  template <class Arg>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator*=(numpy_iexpr<Arg> const &expr)
  {
    return update_<pythonic::operator_::functor::imul>(expr);
  }

  template <class Arg>
  template <class E>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator/=(E const &expr)
  {
    return update_<pythonic::operator_::functor::idiv>(expr);
  }

  template <class Arg>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator/=(numpy_iexpr<Arg> const &expr)
  {
    return update_<pythonic::operator_::functor::idiv>(expr);
  }

  template <class Arg>
  template <class E>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator&=(E const &expr)
  {
    return update_<pythonic::operator_::functor::iand>(expr);
  }

  template <class Arg>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator&=(numpy_iexpr<Arg> const &expr)
  {
    return update_<pythonic::operator_::functor::iand>(expr);
  }
  template <class Arg>
  template <class E>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator|=(E const &expr)
  {
    return update_<pythonic::operator_::functor::ior>(expr);
  }

  template <class Arg>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator|=(numpy_iexpr<Arg> const &expr)
  {
    return update_<pythonic::operator_::functor::ior>(expr);
  }

  template <class Arg>
  template <class E>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator^=(E const &expr)
  {
    return update_<pythonic::operator_::functor::ixor>(expr);
  }

  template <class Arg>
  numpy_iexpr<Arg> &numpy_iexpr<Arg>::operator^=(numpy_iexpr<Arg> const &expr)
  {
    return update_<pythonic::operator_::functor::ixor>(expr);
  }

  template <class Arg>
  typename numpy_iexpr<Arg>::const_iterator numpy_iexpr<Arg>::begin() const
  {
    return make_const_nditerator < is_strided || value != 1 > ()(*this, 0);
  }

  template <class Arg>
  typename numpy_iexpr<Arg>::const_iterator numpy_iexpr<Arg>::end() const
  {
    return make_const_nditerator < is_strided || value != 1 > ()(*this, size());
  }

  template <class Arg>
  typename numpy_iexpr<Arg>::iterator numpy_iexpr<Arg>::begin()
  {
    return make_nditerator < is_strided || value != 1 > ()(*this, 0);
  }

  template <class Arg>
  typename numpy_iexpr<Arg>::iterator numpy_iexpr<Arg>::end()
  {
    return make_nditerator < is_strided || value != 1 > ()(*this, size());
  }

  template <class Arg>
  typename numpy_iexpr<Arg>::dtype const *numpy_iexpr<Arg>::fbegin() const
  {
    return buffer;
  }

  template <class Arg>
  typename numpy_iexpr<Arg>::dtype const *numpy_iexpr<Arg>::fend() const
  {
    return buffer + flat_size();
  }

  template <class Arg>
  typename numpy_iexpr<Arg>::dtype *numpy_iexpr<Arg>::fbegin()
  {
    return buffer;
  }

  template <class Arg>
  typename numpy_iexpr<Arg>::dtype const *numpy_iexpr<Arg>::fend()
  {
    return buffer + flat_size();
  }

  template <class T0, class T1>
  size_t compute_fast_offset(size_t offset, long mult, T0 const &indices,
                             T1 const &shape, std::integral_constant<long, 0>)
  {
    return offset;
  }

  template <long I, class T0, class T1>
  size_t compute_fast_offset(size_t offset, long mult, T0 const &indices,
                             T1 const &shape, std::integral_constant<long, I>)
  {
    return compute_fast_offset(offset + std::get<I - 1>(indices) * mult,
                               mult * shape.template shape<I>(), indices, shape,
                               std::integral_constant<long, I - 1>());
  }

  template <class Arg>
  typename numpy_iexpr<Arg>::dtype const &
  numpy_iexpr<Arg>::fast(array_tuple<long, value> const &indices) const
  {
    return buffer[compute_fast_offset(
        indices[value - 1], arg.template shape<value>(), indices, arg,
        std::integral_constant<long, value - 1>())];
  }

  template <class Arg>
  typename numpy_iexpr<Arg>::dtype &
  numpy_iexpr<Arg>::fast(array_tuple<long, value> const &indices)
  {
    return const_cast<dtype &>(
        const_cast<numpy_iexpr const &>(*this).fast(indices));
  }

  template <class Arg>
  template <class F>
  typename std::enable_if<
      is_numexpr_arg<F>::value && std::is_same<bool, typename F::dtype>::value,
      numpy_vexpr<numpy_iexpr<Arg>, ndarray<long, pshape<long>>>>::type
  numpy_iexpr<Arg>::fast(F const &filter) const
  {
    long sz = filter.template shape<0>();
    long *raw = utils::allocate<long>(sz);
    long n = 0;
    for (long i = 0; i < sz; ++i)
      if (filter.fast(i))
        raw[n++] = i;
    // reallocate(raw, n);
    long shp[1] = {n};
    return this->fast(
        ndarray<long, pshape<long>>(raw, shp, types::ownership::owned));
  }

#ifdef USE_XSIMD
  template <class Arg>
  template <class vectorizer>
  typename numpy_iexpr<Arg>::simd_iterator
  numpy_iexpr<Arg>::vbegin(vectorizer) const
  {
    return {buffer};
  }

  template <class Arg>
  template <class vectorizer>
  typename numpy_iexpr<Arg>::simd_iterator
  numpy_iexpr<Arg>::vend(vectorizer) const
  {
    using vector_type = typename xsimd::batch<dtype>;
    static const std::size_t vector_size = vector_type::size;
    return {buffer + long(size() / vector_size * vector_size)};
  }

#endif
  template <class Arg>
  auto numpy_iexpr<Arg>::operator[](long i) const & -> decltype(this->fast(i))
  {
    if (i < 0)
      i += size();
    return fast(i);
  }

  template <class Arg>
  auto numpy_iexpr<Arg>::operator[](long i) & -> decltype(this->fast(i))
  {
    if (i < 0)
      i += size();
    return fast(i);
  }

  template <class Arg>
  auto
  numpy_iexpr<Arg>::operator[](long i) && -> decltype(std::move(*this).fast(i))
  {
    if (i < 0)
      i += size();
    return std::move(*this).fast(i);
  }

  template <class Arg>
  template <class Sp>
  typename std::enable_if<is_slice<Sp>::value,
                          numpy_gexpr<numpy_iexpr<Arg>, normalize_t<Sp>>>::type
  numpy_iexpr<Arg>::operator[](Sp const &s0) const
  {
    return make_gexpr(*this, s0);
  }

  template <class Arg>
  template <class Sp, class... S>
  typename std::enable_if<
      is_slice<Sp>::value,
      numpy_gexpr<numpy_iexpr<Arg>, normalize_t<Sp>, normalize_t<S>...>>::type
  numpy_iexpr<Arg>::operator()(Sp const &s0, S const &...s) const
  {
    return make_gexpr(*this, s0, s...);
  }

  template <class Arg>
  template <class F>
  typename std::enable_if<
      is_numexpr_arg<F>::value && std::is_same<bool, typename F::dtype>::value,
      numpy_vexpr<numpy_iexpr<Arg>, ndarray<long, pshape<long>>>>::type
  numpy_iexpr<Arg>::operator[](F const &filter) const
  {
    return fast(filter);
  }

  template <class T0, class T1>
  size_t compute_offset(size_t offset, long mult, T0 const &indices,
                        T1 const &shape, std::integral_constant<long, 0>)
  {
    return offset;
  }

  template <long I, class T0, class T1>
  size_t compute_offset(size_t offset, long mult, T0 const &indices,
                        T1 const &shape, std::integral_constant<long, I>)
  {
    return compute_offset(
        offset + (std::get<I - 1>(indices) < 0
                      ? std::get<I - 1>(indices) + shape.template shape<I>()
                      : std::get<I - 1>(indices)) *
                     mult,
        mult * shape.template shape<I>(), indices, shape,
        std::integral_constant<long, I - 1>());
  }

  template <class Arg>
  typename numpy_iexpr<Arg>::dtype const &
  numpy_iexpr<Arg>::operator[](array_tuple<long, value> const &indices) const
  {
    return buffer[compute_offset(indices[value - 1] < 0
                                     ? indices[value - 1] +
                                           arg.template shape<value>()
                                     : indices[value - 1],
                                 arg.template shape<value>(), indices, arg,
                                 std::integral_constant<long, value - 1>())];
  }

  template <class Arg>
  typename numpy_iexpr<Arg>::dtype &
  numpy_iexpr<Arg>::operator[](array_tuple<long, value> const &indices)
  {
    return const_cast<dtype &>(const_cast<numpy_iexpr const &>(*this)[indices]);
  }

  template <class Arg>
  numpy_iexpr<Arg>::operator bool() const
  {
    if (sutils::any_of(*this, [](long n) { return n != 1; }))
      throw ValueError("The truth value of an array with more than one element "
                       "is ambiguous. Use a.any() or a.all()");
    return *buffer;
  }

  template <class S, size_t... Is>
  long prod_helper(S const &shape, utils::index_sequence<Is...>)
  {
    long res = 1;
    (void)std::initializer_list<long>{
        (res *= (long)(shape.template shape<Is>()))...};
    return res;
  }

  template <class Arg>
  long numpy_iexpr<Arg>::flat_size() const
  {
    return prod_helper(*this, utils::make_index_sequence<value>());
  }

  template <class Arg>
  long numpy_iexpr<Arg>::buffer_offset(Arg const &arg, long index,
                                       utils::int_<0>)
  {
    return index;
  }

  template <class Arg>
  template <class T, class pS, size_t N>
  long numpy_iexpr<Arg>::buffer_offset(ndarray<T, pS> const &arg, long index,
                                       utils::int_<N>)
  {
    return index * arg.template strides<0>();
  }

  template <class Arg>
  template <class E, size_t N>
  long numpy_iexpr<Arg>::buffer_offset(E const &arg, long index, utils::int_<N>)
  {
    return index * arg.template strides<0>();
  }

  template <size_t N>
  template <class T>
  numpy_iexpr<T> numpy_iexpr_helper<N>::get(T &&e, long i)
  {
    return {std::forward<T>(e), i};
  }

  template <class T>
  typename T::dtype &numpy_iexpr_helper<1>::get(T const &e, long i)
  {
    return e.buffer[i * e.template strides<T::value - 1>()];
  }

  template <class T>
  typename T::dtype &numpy_iexpr_helper<1>::get(T &&e, long i)
  {
    return e.buffer[i * e.template strides<T::value - 1>()];
  }

  template <class T>
  typename T::dtype &numpy_iexpr_helper<1>::get(T &e, long i)
  {
    return e.buffer[i * e.template strides<T::value - 1>()];
  }
} // namespace types
PYTHONIC_NS_END

#endif
