// Convert 2D grid of points to Geomview .off file of quadrilaterals.

#include <iostream>
#include <string>

#include "grid2DPoints3D.h"
#include "grid2DIO.h"
#include "writeGrid2DOFF.h"


// ********************* Functions ************************************

/// Replace the file extension of infilename with ".off".
std::string CreateOutFilename(const std::string& infilename) {
    size_t dot_pos = infilename.rfind('.');
    std::string basename;
    if (dot_pos != std::string::npos) {
        basename = infilename.substr(0, dot_pos);
    }
    else {
        basename = infilename;
    }
    return basename + ".off";
}


void UsageMsg(const std::string& command_name) {
    std::cerr << "Usage: " << command_name
              << " {input filename} [{output filename}]\n";
}


// ********************* Main *****************************************

int main(int argc, char* argv[]) {

    if (argc == 1) {
        UsageMsg(argv[0]);
        return 0;
    }

    std::string infilename = argv[1];
    GRID2D_POINTS3D grid2D;

    try {
        OpenReadGrid2DPoints3D(infilename, grid2D);
    }
    catch (const std::exception&) {
        std::cerr << "Exiting...\n";
        return -1;
    }

    std::string outfilename;
    if (argc < 3) {
        outfilename = CreateOutFilename(infilename);
    }
    else {
        outfilename = argv[2];
    }

    WRITE_GRID2D_OFF writeOFF;
    std::vector<std::string> comments_list =
        {"File created from 2D grid of points."};

    try {
        std::cout << "Writing file " << outfilename << ".\n";
        writeOFF.OpenAndWrite(outfilename, grid2D, comments_list);
    }
    catch (const std::exception& e) {
        std::cerr << e.what() << "\n";
        std::cerr << "Exiting...\n";
        return -1;
    }

    return 0;
}