// Boost.Geometry

// This file was modified by Oracle on 2018.
// Modifications copyright (c) 2018, Oracle and/or its affiliates.
// Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle

// Use, modification and distribution is subject to the Boost Software License,
// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

#ifndef BOOST_GEOMETRY_SRS_PROJECTIONS_GRIDS_HPP
#define BOOST_GEOMETRY_SRS_PROJECTIONS_GRIDS_HPP


#include <boost/geometry/srs/projections/impl/pj_gridinfo.hpp>

#include <fstream>


namespace boost { namespace geometry
{

namespace srs
{

// Forward declarations for functions declarations below
class grids;

template <typename GridsStorage>
class projection_grids;

} // namespace srs
namespace projections { namespace detail
{

// Forward declaratios of grids friends
template <typename StreamPolicy>
inline bool pj_gridlist_merge_gridfile(std::string const& gridname,
                                       StreamPolicy const& stream_policy,
                                       srs::grids & grids,
                                       std::vector<std::size_t> & gridindexes);
template <bool Inverse, typename CalcT, typename StreamPolicy, typename Range>
inline bool pj_apply_gridshift_3(StreamPolicy const& stream_policy,
                                 Range & range,
                                 srs::grids & grids,
                                 std::vector<std::size_t> const& gridindexes);

// Forward declaratios of projection_grids friends
template <typename Par, typename GridsStorage>
inline void pj_gridlist_from_nadgrids(Par const& defn,
                                      srs::projection_grids<GridsStorage> & grids);
template <bool Inverse, typename Par, typename Range, typename Grids>
inline bool pj_apply_gridshift_2(Par const& defn, Range & range, Grids const& grids);

}} // namespace projections::detail

namespace srs
{

class grids
{
public:
    std::size_t size() const
    {
        return gridinfo.size();
    }

    bool empty() const
    {
        return gridinfo.empty();
    }

private:
    template <typename StreamPolicy>
    friend inline bool projections::detail::pj_gridlist_merge_gridfile(
                            std::string const& gridname,
                            StreamPolicy const& stream_policy,
                            srs::grids & grids,
                            std::vector<std::size_t> & gridindexes);
    template <bool Inverse, typename CalcT, typename StreamPolicy, typename Range>
    friend inline bool projections::detail::pj_apply_gridshift_3(
                            StreamPolicy const& stream_policy,
                            Range & range,
                            srs::grids & grids,
                            std::vector<std::size_t> const& gridindexes);

    projections::detail::pj_gridinfo gridinfo;

};

struct ifstream_policy
{
    typedef std::ifstream stream_type;

    static inline void open(stream_type & is, std::string const& gridname)
    {
        is.open(gridname.c_str(), std::ios::binary);
    }
};

template
<
    typename StreamPolicy = srs::ifstream_policy,
    typename Grids = grids
>
struct grids_storage
{
    typedef StreamPolicy stream_policy_type;
    typedef Grids grids_type;

    grids_storage()
    {}

    explicit grids_storage(stream_policy_type const& policy)
        : stream_policy(policy)
    {}

    stream_policy_type stream_policy;
    grids_type hgrids;
};


template <typename GridsStorage = grids_storage<> >
class projection_grids
{
public:
    projection_grids(GridsStorage & storage)
        : storage_ptr(boost::addressof(storage))
    {}

    std::size_t size() const
    {
        return hindexes.size();
    }

    bool empty() const
    {
        return hindexes.empty();
    }

private:
    template <typename Par, typename GridsStor>
    friend inline void projections::detail::pj_gridlist_from_nadgrids(
                            Par const& defn,
                            srs::projection_grids<GridsStor> & grids);
    template <bool Inverse, typename Par, typename Range, typename Grids>
    friend inline bool projections::detail::pj_apply_gridshift_2(
                            Par const& defn, Range & range, Grids const& grids);

    GridsStorage * const storage_ptr;
    std::vector<std::size_t> hindexes;
};


template <typename GridsStorage = grids_storage<> >
struct transformation_grids
{
    explicit transformation_grids(GridsStorage & storage)
        : src_grids(storage)
        , dst_grids(storage)
    {}

    projection_grids<GridsStorage> src_grids;
    projection_grids<GridsStorage> dst_grids;
};


namespace detail
{

struct empty_grids_storage {};
struct empty_projection_grids {};

} // namespace detail


template <>
struct transformation_grids<detail::empty_grids_storage>
{
    detail::empty_projection_grids src_grids;
    detail::empty_projection_grids dst_grids;
};


}}} // namespace boost::geometry::srs


#endif // BOOST_GEOMETRY_SRS_PROJECTIONS_GRIDS_HPP