/**
 * @file   field_collection_global.cc
 *
 * @author Till Junge <till.junge@altermail.ch>
 *
 * @date   11 Aug 2019
 *
 * @brief  Implementation of GlobalFieldCollection
 *
 * Copyright © 2019 Till Junge
 *
 * µGrid is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3, or (at
 * your option) any later version.
 *
 * µGrid is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with µGrid; see the file COPYING. If not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Additional permission under GNU GPL version 3 section 7
 *
 * If you modify this Program, or any covered work, by linking or combining it
 * with proprietary FFT implementations or numerical libraries, containing parts
 * covered by the terms of those libraries' licenses, the licensors of this
 * Program grant you additional permission to convey the resulting work.
 *
 */

#include "field_collection_global.hh"

namespace muGrid {
    /* ---------------------------------------------------------------------- */
    GlobalFieldCollection::GlobalFieldCollection(
        const Index_t &spatial_dimension,
        const SubPtMap_t &nb_sub_pts,
        StorageOrder storage_order)
        : Parent{ValidityDomain::Global, spatial_dimension, nb_sub_pts, storage_order},
          nb_ghosts_left{DynCcoord_t(spatial_dimension)}, nb_ghosts_right{DynCcoord_t(spatial_dimension)} {
    }

    /* ---------------------------------------------------------------------- */
    GlobalFieldCollection::GlobalFieldCollection(
        const DynCcoord_t &nb_domain_grid_pts,
        const DynCcoord_t &nb_subdomain_grid_pts,
        const DynCcoord_t &subdomain_locations,
        const SubPtMap_t &nb_sub_pts,
        StorageOrder storage_order,
        const DynCcoord_t &nb_ghosts_left,
        const DynCcoord_t &nb_ghosts_right)
        : Parent{ValidityDomain::Global, nb_domain_grid_pts.get_dim(), nb_sub_pts, storage_order},
          nb_ghosts_left{nb_ghosts_left.get_dim() == 0 ? DynCcoord_t(nb_domain_grid_pts.get_dim()) : nb_ghosts_left},
          nb_ghosts_right{
              nb_ghosts_right.get_dim() == 0 ? DynCcoord_t(nb_domain_grid_pts.get_dim()) : nb_ghosts_right
          } {
        this->initialise(nb_domain_grid_pts, nb_subdomain_grid_pts, subdomain_locations);
    }

    /* ---------------------------------------------------------------------- */
    GlobalFieldCollection::GlobalFieldCollection(
        const DynCcoord_t &nb_domain_grid_pts,
        const DynCcoord_t &nb_subdomain_grid_pts,
        const DynCcoord_t &subdomain_locations,
        const DynCcoord_t &pixels_strides,
        const SubPtMap_t &nb_sub_pts,
        StorageOrder storage_order,
        const DynCcoord_t &nb_ghosts_left,
        const DynCcoord_t &nb_ghosts_right)
        : Parent{ValidityDomain::Global, nb_domain_grid_pts.get_dim(), nb_sub_pts, storage_order},
          nb_ghosts_left{nb_ghosts_left.get_dim() == 0 ? DynCcoord_t(nb_domain_grid_pts.get_dim()) : nb_ghosts_left},
          nb_ghosts_right{
              nb_ghosts_right.get_dim() == 0 ? DynCcoord_t(nb_domain_grid_pts.get_dim()) : nb_ghosts_right
          } {
        this->initialise(nb_domain_grid_pts, nb_subdomain_grid_pts,
                         subdomain_locations, pixels_strides);
    }

    /* ---------------------------------------------------------------------- */
    GlobalFieldCollection::GlobalFieldCollection(
        const DynCcoord_t &nb_domain_grid_pts,
        const DynCcoord_t &nb_subdomain_grid_pts,
        const DynCcoord_t &subdomain_locations,
        StorageOrder pixels_storage_order,
        const SubPtMap_t &nb_sub_pts,
        StorageOrder storage_order,
        const DynCcoord_t &nb_ghosts_left,
        const DynCcoord_t &nb_ghosts_right)
        : Parent{ValidityDomain::Global, nb_domain_grid_pts.get_dim(), nb_sub_pts, storage_order},
          nb_ghosts_left{nb_ghosts_left.get_dim() == 0 ? DynCcoord_t(nb_domain_grid_pts.get_dim()) : nb_ghosts_left},
          nb_ghosts_right{
              nb_ghosts_right.get_dim() == 0 ? DynCcoord_t(nb_domain_grid_pts.get_dim()) : nb_ghosts_right
          } {
        this->initialise(nb_domain_grid_pts, nb_subdomain_grid_pts, subdomain_locations, pixels_storage_order);
    }

    /* ---------------------------------------------------------------------- */
    void
    GlobalFieldCollection::initialise(const DynCcoord_t &nb_domain_grid_pts,
                                      const DynCcoord_t &nb_subdomain_grid_pts,
                                      const DynCcoord_t &subdomain_locations,
                                      const DynCcoord_t &pixels_strides) {
        // sanity check 1
        auto nb_domain_grid_pts_total{get_nb_from_shape(nb_domain_grid_pts)};
        if (nb_domain_grid_pts_total <= 0) {
            std::stringstream s;
            s << "Invalid nb_domain_grid_pts " << nb_domain_grid_pts << " ("
                    << nb_domain_grid_pts_total << " total grid points) passed during "
                    << "initialisation.";
            throw FieldCollectionError(s.str());
        }
        // sanity check 2 - the subdomain may be empty!
        auto _nb_subdomain_grid_pts{
            nb_subdomain_grid_pts.get_dim() == 0
                ? nb_domain_grid_pts
                : nb_subdomain_grid_pts
        };
        auto nb_subdomain_grid_pts_total{get_nb_from_shape(_nb_subdomain_grid_pts)};
        if (nb_subdomain_grid_pts_total < 0) {
            std::stringstream s;
            s << "Invalid nb_subdomain_grid_pts " << _nb_subdomain_grid_pts << " ("
                    << nb_subdomain_grid_pts_total << " total grid points) passed during "
                    << "initialisation.";
            throw FieldCollectionError(s.str());
        }

        if (this->initialised) {
            throw FieldCollectionError("double initialisation");
        }

        this->nb_domain_grid_pts = nb_domain_grid_pts;
        this->pixels = CcoordOps::DynamicPixels(
            _nb_subdomain_grid_pts, subdomain_locations, pixels_strides);
        this->nb_pixels = CcoordOps::get_size(_nb_subdomain_grid_pts);
        this->nb_buffer_pixels =
                CcoordOps::get_buffer_size(_nb_subdomain_grid_pts, pixels_strides);
        this->allocate_fields();
        this->pixel_indices.resize(this->nb_pixels);
        for (int i{0}; i < this->nb_pixels; ++i) {
            this->pixel_indices[i] = i;
        }
        // needs to be here, or initialise_maps will fail (by design)
        this->initialised = true;
        this->initialise_maps();
    }

    /* ---------------------------------------------------------------------- */
    void
    GlobalFieldCollection::initialise(const DynCcoord_t &nb_domain_grid_pts,
                                      const DynCcoord_t &nb_subdomain_grid_pts,
                                      const DynCcoord_t &subdomain_locations,
                                      StorageOrder pixels_storage_order) {
        if (pixels_storage_order == StorageOrder::Automatic) {
            pixels_storage_order = this->get_storage_order();
        }
        auto _nb_subdomain_grid_pts{
            nb_subdomain_grid_pts.get_dim() == 0
                ? nb_domain_grid_pts
                : nb_subdomain_grid_pts
        };
        this->initialise(
            nb_domain_grid_pts, _nb_subdomain_grid_pts, subdomain_locations,
            pixels_storage_order == StorageOrder::ColMajor
                ? CcoordOps::get_col_major_strides(_nb_subdomain_grid_pts)
                : CcoordOps::get_row_major_strides(_nb_subdomain_grid_pts));
    }

    /* ---------------------------------------------------------------------- */
    const typename GlobalFieldCollection::DynamicPixels &
    GlobalFieldCollection::get_pixels() const {
        if (not(this->initialised)) {
            throw FieldCollectionError(
                "Can't iterate over the collection before it is initialised.");
        }
        return this->pixels;
    }

    /* ---------------------------------------------------------------------- */
    GlobalFieldCollection GlobalFieldCollection::get_empty_clone() const {
        GlobalFieldCollection ret_val{this->get_spatial_dim(), this->nb_sub_pts};
        ret_val.initialise(this->nb_domain_grid_pts,
                           this->pixels.get_nb_subdomain_grid_pts(),
                           this->pixels.get_subdomain_locations());
        return ret_val;
    }

    /* ---------------------------------------------------------------------- */
    Shape_t GlobalFieldCollection::get_pixels_shape() const {
        return static_cast<Shape_t>(this->pixels.get_nb_subdomain_grid_pts());
    }

    /* ---------------------------------------------------------------------- */
    Shape_t GlobalFieldCollection::get_pixels_shape_without_ghosts() const {
        return static_cast<Shape_t>(this->pixels.get_nb_subdomain_grid_pts() -
                                    this->nb_ghosts_left - this->nb_ghosts_right);
    }

    /* ---------------------------------------------------------------------- */
    Shape_t GlobalFieldCollection::get_pixels_offset_without_ghosts() const {
        return Shape_t{this->nb_ghosts_left};
    }

    /* ---------------------------------------------------------------------- */
    Shape_t
    GlobalFieldCollection::get_pixels_strides(Index_t element_size) const {
        Shape_t strides{this->pixels.get_strides()};
        for (auto &&s: strides) {
            s *= element_size;
        }
        return strides;
    }
} // namespace muGrid
