// Functions to write grid2DPoints3D as a Geomview .off file.

#include "writeGrid2DOFF.h"

#include <fstream>
#include <iostream>
#include <stdexcept>


void WRITE_GRID2D_OFF::WriteHeader(std::ostream& file) const {
    file << Header() << "\n";
}


void WRITE_GRID2D_OFF::WriteComment(std::ostream& file,
                                     const std::string& msg) const
{
    file << "# " << msg << "\n";
}


void WRITE_GRID2D_OFF::WriteNumElements(std::ostream& file,
                                         const GRID2D_POINTS3D& grid2D) const
{
    file << grid2D.NumPoints() << " "
         << grid2D.NumQuadrilaterals() << " 0\n";
}


void WRITE_GRID2D_OFF::WritePointCoordinates(std::ostream& file,
                                               const GRID2D_POINTS3D& grid2D) const
{
    for (int irow = 0; irow < grid2D.NumRows(); irow++) {
        for (int jcol = 0; jcol < grid2D.NumCols(); jcol++) {
            auto c = grid2D.Coord(irow, jcol);
            file << c[0] << " " << c[1] << " " << c[2] << "\n";
        }
    }
}


void WRITE_GRID2D_OFF::WriteQuadrilaterals(std::ostream& file,
                                             const GRID2D_POINTS3D& grid2D) const
{
    if (grid2D.NumRows() < 2 || grid2D.NumCols() < 2) {
        // Nothing to write.
        return;
    }

    for (int irow = 0; irow < grid2D.NumRows() - 1; irow++) {
        for (int icol = 0; icol < grid2D.NumCols() - 1; icol++) {
            int iv0 = grid2D.PointIndex(irow, icol);
            int iv1 = iv0 + 1;
            int iv2 = iv1 + grid2D.NumCols();
            int iv3 = iv0 + grid2D.NumCols();
            file << "4 " << iv0 << " " << iv1
                 << " " << iv2 << " " << iv3 << "\n";
        }
    }
}


void WRITE_GRID2D_OFF::Write(std::ostream& file,
                               const GRID2D_POINTS3D& grid2D,
                               const std::vector<std::string>& comment_list) const
{
    WriteHeader(file);
    for (const auto& comment : comment_list) {
        WriteComment(file, comment);
    }
    WriteNumElements(file, grid2D);
    WritePointCoordinates(file, grid2D);
    file << "\n";
    WriteQuadrilaterals(file, grid2D);
}


void WRITE_GRID2D_OFF::OpenAndWrite(
    const std::string& filename,
    const GRID2D_POINTS3D& grid2D,
    const std::vector<std::string>& comment_list) const
{
    try {
        std::ofstream outfile(filename);
        if (!outfile.is_open()) {
            std::cerr << "Cannot open output file " << filename << ".\n";
            throw std::runtime_error(
                "Cannot open output file " + filename + " for writing.");
        }
        Write(outfile, grid2D, comment_list);
    }
    catch (const std::out_of_range& e) {
        std::cerr << "Error writing file " << filename
                  << ".\n " << e.what() << "\n";
        throw;
    }
    catch (const std::runtime_error& e) {
        std::cerr << "Error writing file " << filename
                  << ".\n " << e.what() << "\n";
        throw;
    }
    catch (const std::exception& e) {
        std::cerr << "Error writing file " << filename
                  << ".\n " << e.what() << "\n";
        throw;
    }
}