/** Log to a CSV file on your host computer.
 * @example CsvLogger<10,3> logger;
 *          while(true)
 *               logger.append("/path/to/foo.csv", {1.1, 2.2, 3.3})
 * @tparam N_rows Buffer N_rows before writing to disk to minimize lag due to semi-hosting
 * @tparam N_cols Columns of your CSV*/
template <unsigned int N_rows, unsigned int N_cols>
class CsvLogger
{
public:
    void append(const char* path, const std::array<float, N_cols>& row)
    {
        _buffer.at(_row_index++) = row;

        bool buffer_is_full = (_row_index > N_rows-1);
        if (buffer_is_full)
        {
            _row_index =0;
            FILE* log_file = fopen(path, "a");
            for (const auto& row: _buffer)
            {
                for (float col: row)
                {
                    // The CSV values
                    fprintf(log_file, "%.4f,", col);
                }
                fprintf(log_file, "\n");
            }
            fclose(log_file);
        }
    }

private:
    size_t _row_index{0};
    std::array<std::array<float, N_cols>, N_rows> _buffer;
};