MySources/csvfile.hpp

#ifndef CSVFILE_HPP
#define CSVFILE_HPP
#include <boost/lexical_cast.hpp>
#include <boost/tokenizer.hpp>
#include <filesystem>
#include <fstream>
#include <iostream>
#include <sstream>
#include <string>
#include <vector>

class csvFile;

inline static csvFile &endrow(csvFile &file);
inline static csvFile &flush(csvFile &file);

class csvFile {
  std::ofstream fs_;
  bool is_first_;
  const std::string separator_;
  const std::string escape_seq_;
  const std::string special_chars_;

public:
  csvFile(const std::string filename, const bool &overwrite,
          const std::string separator = ",")
      : fs_(), is_first_(true), separator_(separator), escape_seq_("\""),
        special_chars_("\"") {
    fs_.exceptions(std::ios::failbit | std::ios::badbit);
    if (filename.empty()) {
      fs_.copyfmt(std::cout);
      fs_.clear(std::cout.rdstate());
      fs_.basic_ios<char>::rdbuf(std::cout.rdbuf());
    } else {
      if (!std::filesystem::exists(
              std::filesystem::path("../OptimizationResults")
                  .append("statistics.csv"))) {
        std::ofstream outfile(std::filesystem::path("../OptimizationResults")
                                  .append("statistics.csv")
                                  .string());
        outfile.close();
      }
      overwrite ? fs_.open(filename, std::ios::trunc)
                : fs_.open(filename, std::ios::app);
    }
  }

  ~csvFile() {
    flush();
    fs_.close();
  }

  void flush() { fs_.flush(); }

  void endrow() {
    fs_ << std::endl;
    is_first_ = true;
  }

  csvFile &operator<<(csvFile &(*val)(csvFile &)) { return val(*this); }

  csvFile &operator<<(const char *val) { return write(escape(val)); }

  csvFile &operator<<(const std::string &val) { return write(escape(val)); }

  template<typename T>
  csvFile &operator<<(const T &val)
  {
      return write(val);
  }

  template<typename T>
  static std::vector<std::vector<T>> parse(const std::filesystem::path &csvFilepath)
  {
      std::vector<std::vector<T>> resultCSV;
      if (!std::filesystem::exists(csvFilepath)) {
          std::cerr << "The file does not exist:" << csvFilepath.string() << std::endl;
          return resultCSV;
      }

      std::ifstream inputfile(csvFilepath.string().c_str());
      if (!inputfile.is_open()) {
          std::cerr << "Can't open file:" << csvFilepath.string() << std::endl;
          return resultCSV;
      }
      std::vector<T> row;
      std::string line;
      using Tokenizer = boost::tokenizer<boost::escaped_list_separator<char>>;
      while (std::getline(inputfile, line)) {
          Tokenizer tokenizer(line);
          row.resize(std::distance(tokenizer.begin(), tokenizer.end()));
          std::transform(tokenizer.begin(), tokenizer.end(), row.begin(), [](const std::string &el) {
              return boost::lexical_cast<T>(el);
          });
          //          std::cout << std::endl;
          //          row.assign(tokenizer.begin(), tokenizer.end());
          //          for (const auto &el : row) {
          //              std::cout << el << " ";
          //          }
          //          std::cout << std::endl;
          resultCSV.push_back(row);
      }

      return resultCSV;
  }

private:
  template <typename T> csvFile &write(const T &val) {
    if (!is_first_) {
      fs_ << separator_;
    } else {
      is_first_ = false;
    }
    fs_ << val;
    return *this;
  }

  std::string escape(const std::string &val) {
    std::ostringstream result;
    result << '"';
    std::string::size_type to, from = 0u, len = val.length();
    while (from < len && std::string::npos !=
                             (to = val.find_first_of(special_chars_, from))) {
      result << val.substr(from, to - from) << escape_seq_ << val[to];
      from = to + 1;
    }
    result << val.substr(from) << '"';
    return result.str();
  }
};

inline static csvFile &endrow(csvFile &file) {
  file.endrow();
  return file;
}

inline static csvFile &flush(csvFile &file) {
  file.flush();
  return file;
}

#endif // CSVFILE_HPP