//==================================================================================================
/*
  ROTGEN - Runtime Overlay for Eigen
  Copyright : CODE RECKONS
  SPDX-License-Identifier: BSL-1.0
*/
//==================================================================================================

//==================================================================================================
/*
  This file is a X-File to generate various block_impl_* definitions variant
*/
//==================================================================================================

//==================================================================================================
// Internal payload
//==================================================================================================
struct CLASSNAME::payload
{
  using stride_type       = Eigen::Stride<Eigen::Dynamic,Eigen::Dynamic>;
  using matrix_type       = Eigen::Matrix<TYPE,Eigen::Dynamic,Eigen::Dynamic,STORAGE_ORDER>;
  using matrix_block_type = Eigen::Block<matrix_type CONST>;
  using matrix_storage_t  = std::pair<matrix_block_type, matrix_type CONST*>;
  using map_type          = Eigen::Map<matrix_type CONST,Eigen::Unaligned,stride_type>;
  using map_block_type    = Eigen::Block<map_type CONST>;
  using map_storage_t     = std::pair<map_block_type, map_type CONST*>;
  using data_type         = std::variant<matrix_storage_t, map_storage_t>;

  data_type      data;
  rotgen::Index  abs_i0 = 0;  // absolute start row in original matrix
  rotgen::Index  abs_j0 = 0;  // absolute start col in original matrix
  rotgen::Index  rel_i0 = 0;  // relative start row in original matrix
  rotgen::Index  rel_j0 = 0;  // relative start col in original matrix

  template <typename Func>
  void apply(Func f)        { std::visit([&](auto& blk) { return f(blk.first); }, data); }

  template <typename Func>
  void apply(Func f) const  { std::visit([&](auto const& blk) { return f(blk.first); }, data); }

  payload (data_type const& o) : data(o) {}

  payload (SOURCENAME CONST& o, rotgen::Index i0, rotgen::Index j0, rotgen::Index ni, rotgen::Index nj)
          : data(matrix_storage_t{matrix_block_type{o.storage()->data,i0,j0,ni,nj},&o.storage()->data})
          , abs_i0(i0), abs_j0(j0), rel_i0(i0), rel_j0(j0)
          {}

  payload (MAPNAME CONST& o, rotgen::Index i0, rotgen::Index j0, rotgen::Index ni, rotgen::Index nj)
          : data(map_storage_t{map_block_type{o.storage()->data,i0,j0,ni,nj},&o.storage()->data})
          , abs_i0(i0), abs_j0(j0), rel_i0(i0), rel_j0(j0)
  {}
};

  //==================================================================================================
  // Constructors & Special Members
  //==================================================================================================
  CLASSNAME::CLASSNAME(SOURCENAME CONST& r, Index i0, Index j0, Index ni, Index nj)
  : storage_(std::make_unique<payload>(r, i0,j0,ni,nj))
  {}

  CLASSNAME::CLASSNAME(MAPNAME CONST& r, Index i0, Index j0, Index ni, Index nj)
  : storage_(std::make_unique<payload>(r, i0,j0,ni,nj))
  {}

  // We're building a block from a block - So we have to dig around the internals
  CLASSNAME::CLASSNAME(payload const& o, Index i0, Index j0, Index ni, Index nj)
  {
    // Compute absolute indices from the parent stored block
    Index abs_i0 = 0;
    Index abs_j0 = 0;
    std::visit( [&](auto const& blk)
                {
                  abs_i0 = blk.first.startRow() + i0;
                  abs_j0 = blk.first.startCol() + j0;
                }
              , o.data
              );

    // Build a payload::data_type that holds the child block using absolute indices
    payload::data_type new_data =
      std::visit([&]<typename T>(T const& blk) -> payload::data_type
      {
        auto& [parent_block, ref] = blk;
        using block_type = typename T::first_type;
        return T{ block_type{ *ref, abs_i0, abs_j0, ni, nj }, ref };
      }, o.data);

    storage_ = std::make_unique<payload>(new_data);
    storage_->abs_i0 = abs_i0;
    storage_->abs_j0 = abs_j0;
    storage_->rel_i0 = i0;
    storage_->rel_j0 = j0;
  }

  CLASSNAME::CLASSNAME(CLASSNAME const& o)
  : storage_(std::make_unique<payload>(o.storage_->data))
  {}

  CLASSNAME::CLASSNAME(CLASSNAME&&) noexcept = default;

  #if !defined(USE_CONST)
  CLASSNAME&  CLASSNAME::operator=(CLASSNAME const& o)
  {
    if (this != &o) { storage_->data = o.storage_->data; }
    return *this;
  }

  CLASSNAME& CLASSNAME::operator=(CLASSNAME&& o) noexcept
  {
    if (this != &o) { storage_->data = std::move(o.storage_->data); }
    return *this;
  }
  #endif


  CLASSNAME::~CLASSNAME() = default;

  #if !defined(USE_CONST)
  void CLASSNAME::assign(SOURCENAME const& m)
  {
    storage_->apply([&](auto& blk)
    {
      blk = m.storage()->data;
    });
  }
  #endif

  //==================================================================================================
  // Matrix API
  //==================================================================================================
  rotgen::Index CLASSNAME::rows() const
  {
    rotgen::Index that;
    storage_->apply([&](const auto& blk) { that = blk.rows(); });
    return that;
  }

  rotgen::Index CLASSNAME::cols() const
  {
    rotgen::Index that;
    storage_->apply([&](const auto& blk) { that = blk.cols(); });
    return that;
  }

  rotgen::Index CLASSNAME::size() const
  {
    rotgen::Index that;
    storage_->apply([&](const auto& blk) { that = blk.size(); });
    return that;
  }

  rotgen::Index CLASSNAME::innerStride() const
  {
    rotgen::Index that;
    storage_->apply([&](const auto& blk) { that = blk.innerStride(); });
    return that;
  }

  rotgen::Index CLASSNAME::outerStride() const
  {
    rotgen::Index that;
    storage_->apply([&](const auto& blk) { that = blk.outerStride(); });
    return that;
  }

  rotgen::Index CLASSNAME::startRow() const
  {
    return storage_->rel_i0;
  }

  rotgen::Index CLASSNAME::startCol() const
  {
    return storage_->rel_j0;
  }

  // Element access by (i,j)
  #if !defined(USE_CONST)
  TYPE& CLASSNAME::operator()(Index i, Index j)
  {
    TYPE* ptr = nullptr;
    storage_->apply([&](auto& blk) { ptr = &blk(i,j); });
    return *ptr;
  }
  #endif

  TYPE CLASSNAME::operator()(Index i, Index j) const
  {
    TYPE ptr;
    storage_->apply([&](auto const& blk) { ptr = blk(i,j); });
    return ptr;
  }

  // Element access by linear index
  #if !defined(USE_CONST)
  TYPE& CLASSNAME::operator()(Index index)
  {
    TYPE* ptr = nullptr;
    storage_->apply([&](auto& blk) { ptr = blk.data() + index; });
    return *ptr;
  }
  #endif

  TYPE CLASSNAME::operator()(Index index) const
  {
    TYPE ptr;
    storage_->apply([&](auto const& blk) { ptr = *(blk.data() + index); });
    return ptr;
  }

  // Raw pointer access
  #if !defined(USE_CONST)
  TYPE* CLASSNAME::data()
  {
    TYPE* ptr = nullptr;
    storage_->apply([&](auto& blk) { ptr = blk.data(); });
    return ptr;
  }
  #endif

  TYPE const* CLASSNAME::data() const
  {
    TYPE const* ptr = nullptr;
    storage_->apply([&](auto const& blk) { ptr = blk.data(); });
    return ptr;
  }

  //==================================================================================================
  // Matrix operations
  //==================================================================================================
  SOURCENAME CLASSNAME::normalized() const
  {
    SOURCENAME result;
    storage_->apply([&](const auto& blk) { result.storage()->assign(blk.normalized().eval()); });
    return result;
  }

  TRANSSOURCENAME CLASSNAME::transpose() const
  {
    TRANSSOURCENAME result;
    storage_->apply([&](const auto& blk) { result.storage()->assign(blk.transpose().eval()); });
    return result;
  }

  SOURCENAME CLASSNAME::conjugate() const
  {
    SOURCENAME result;
    storage_->apply([&](const auto& blk) { result.storage()->assign(blk.conjugate().eval()); });
    return result;
  }

  TRANSSOURCENAME CLASSNAME::adjoint() const
  {
    TRANSSOURCENAME result;
    storage_->apply([&](const auto& blk) { result.storage()->assign(blk.adjoint().eval()); });
    return result;
  }

  SOURCENAME CLASSNAME::cwiseAbs() const
  {
    SOURCENAME result;
    storage_->apply([&](const auto& blk) { result.storage()->assign(blk.cwiseAbs().eval()); });
    return result;
  }

  SOURCENAME CLASSNAME::cwiseAbs2() const
  {
    SOURCENAME result;
    storage_->apply([&](const auto& blk) { result.storage()->assign(blk.cwiseAbs2().eval()); });
    return result;
  }

  SOURCENAME CLASSNAME::cwiseInverse() const
  {
    SOURCENAME result;
    storage_->apply([&](const auto& blk) { result.storage()->assign(blk.cwiseInverse().eval()); });
    return result;
  }

  SOURCENAME CLASSNAME::cwiseSqrt() const
  {
    SOURCENAME result;
    storage_->apply([&](const auto& blk) { result.storage()->assign(blk.cwiseSqrt().eval()); });
    return result;
  }

  #if !defined(USE_CONST)
  void CLASSNAME::normalize()
  {
    storage_->apply([](auto& blk) { blk.normalize(); });
  }

  void CLASSNAME::transposeInPlace()
  {
    storage_->apply([](auto& blk) { blk.transposeInPlace(); });
  }

  void CLASSNAME::adjointInPlace()
  {
    storage_->apply([](auto& blk) { blk.adjointInPlace(); });
  }
  #endif

  //==================================================================================================
  // Reductions
  //==================================================================================================
  TYPE CLASSNAME::sum() const
  {
    TYPE val{};
    storage_->apply([&](const auto& blk) { val = blk.sum(); });
    return val;
  }

  TYPE CLASSNAME::prod() const
  {
    TYPE val{};
    storage_->apply([&](const auto& blk) { val = blk.prod(); });
    return val;
  }

  TYPE CLASSNAME::mean() const
  {
    TYPE val{};
    storage_->apply([&](const auto& blk) { val = blk.mean(); });
    return val;
  }

  TYPE CLASSNAME::trace() const
  {
    TYPE val{};
    storage_->apply([&](const auto& blk) { val = blk.trace(); });
    return val;
  }

  TYPE CLASSNAME::minCoeff() const
  {
    TYPE val{};
    storage_->apply([&](const auto& blk) { val = blk.minCoeff(); });
    return val;
  }

  TYPE CLASSNAME::maxCoeff() const
  {
    TYPE val{};
    storage_->apply([&](const auto& blk) { val = blk.maxCoeff(); });
    return val;
  }

  TYPE CLASSNAME::minCoeff(Index* row, Index* col) const
  {
    TYPE val{};
    storage_->apply([&](const auto& blk) { val = blk.minCoeff(row, col); });
    return val;
  }

  TYPE CLASSNAME::maxCoeff(Index* row, Index* col) const
  {
    TYPE val{};
    storage_->apply([&](const auto& blk) { val = blk.maxCoeff(row, col); });
    return val;
  }

  TYPE CLASSNAME::squaredNorm() const
  {
    TYPE val{};
    storage_->apply([&](const auto& blk) { val = blk.squaredNorm(); });
    return val;
  }

  TYPE CLASSNAME::norm() const
  {
    TYPE val{};
    storage_->apply([&](const auto& blk) { val = blk.norm(); });
    return val;
  }

  TYPE CLASSNAME::lpNorm(int p) const
  {
    TYPE val{};
    storage_->apply([&](const auto& blk)
    {
      if      (p == 1)  val = blk.template lpNorm<1>();
      else if (p == 2)  val = blk.template lpNorm<2>();
      else              val = blk.template lpNorm<Eigen::Infinity>();
    });
    return val;
  }

  //==================================================================================================
  // Operators
  //==================================================================================================
  ROTGEN_EXPORT std::ostream& operator<<(std::ostream& os, CLASSNAME const& m)
  {
    m.storage_->apply([&](const auto& blk) { os << blk; });
    return os;
  }

  ROTGEN_EXPORT bool operator==(CLASSNAME const& lhs, CLASSNAME const& rhs)
  {
    return std::visit ( [](auto const& lhs_blk, auto const& rhs_blk) { return lhs_blk.first == rhs_blk.first; }
                      , lhs.storage_->data
                      , rhs.storage_->data
                      );
  }

  ROTGEN_EXPORT bool operator!=(CLASSNAME const& lhs, CLASSNAME const& rhs)
  {
    return std::visit ( [](auto const& lhs_blk, auto const& rhs_blk) { return lhs_blk.first != rhs_blk.first; }
                      , lhs.storage_->data
                      , rhs.storage_->data
                      );
  }


  SOURCENAME CLASSNAME::operator-() const
  {
    SOURCENAME result;
    storage_->apply([&](const auto& blk) { result.storage()->assign(blk); });
    return -result;
  }

  #if !defined(USE_CONST)
  CLASSNAME& CLASSNAME::operator+=(CLASSNAME const& rhs)
  {
    std::visit( [](auto& lhs_blk, auto const& rhs_blk) { lhs_blk.first += rhs_blk.first; }
              , storage_->data
              , rhs.storage_->data
              );
    return *this;
  }

  CLASSNAME& CLASSNAME::operator-=(CLASSNAME const& rhs)
  {
    std::visit( [](auto& lhs_blk, auto const& rhs_blk) { lhs_blk.first -= rhs_blk.first; }
              , storage_->data
              , rhs.storage_->data
              );
    return *this;
  }

  CLASSNAME& CLASSNAME::operator*=(CLASSNAME const& rhs)
  {
    std::visit( [](auto& lhs_blk, auto const& rhs_blk) { lhs_blk.first *= rhs_blk.first; }
              , storage_->data
              , rhs.storage_->data
              );
    return *this;
  }

  CLASSNAME& CLASSNAME::operator*=(TYPE s)
  {
    storage_->apply([&](auto& blk) { blk *= s; });
    return *this;
  }

  CLASSNAME& CLASSNAME::operator/=(TYPE s)
  {
    storage_->apply([&](auto& blk) { blk /= s; });
    return *this;
  }
  #endif

  SOURCENAME CLASSNAME::add(CLASSNAME const& rhs) const
  {
    SOURCENAME result;
    result.storage()->assign( std::visit( [](auto const& lhs_blk, auto const& rhs_blk)
                                          {
                                            return (lhs_blk.first + rhs_blk.first).eval();
                                          }
                                        , storage_->data
                                        , rhs.storage_->data
                                        )
                            );
    return result;
  }

  SOURCENAME CLASSNAME::sub(CLASSNAME const& rhs) const
  {
    SOURCENAME result;
    result.storage()->assign( std::visit( [](auto const& lhs_blk, auto const& rhs_blk)
                                          {
                                            return (lhs_blk.first - rhs_blk.first).eval();
                                          }
                                        , storage_->data
                                        , rhs.storage_->data
                                        )
                            );
    return result;
  }

  SOURCENAME CLASSNAME::mul(CLASSNAME const& rhs) const
  {
    SOURCENAME result;
    result.storage()->assign( std::visit( [](auto const& lhs_blk, auto const& rhs_blk)
                                          {
                                            return (lhs_blk.first * rhs_blk.first).eval();
                                          }
                                        , storage_->data
                                        , rhs.storage_->data
                                        )
                            );
    return result;
  }

  SOURCENAME CLASSNAME::mul(TYPE s) const
  {
    SOURCENAME result;
    result.storage()->assign( std::visit( [s](auto const& lhs_blk)
                                          {
                                            return (lhs_blk.first * s).eval();
                                          }
                                        , storage_->data
                                        )
                            );
    return result;
  }

  SOURCENAME CLASSNAME::div(TYPE s) const
  {
    SOURCENAME result;
    result.storage()->assign( std::visit( [s](auto const& lhs_blk)
                                          {
                                            return (lhs_blk.first / s).eval();
                                          }
                                        , storage_->data
                                        )
                            );
    return result;
  }