draconisplusplus/include/rfl/parsing/to_single_error_message.hpp

#ifndef RFL_PARSING_TOSINGLEERRORMESSAGE_HPP_
#define RFL_PARSING_TOSINGLEERRORMESSAGE_HPP_

#include <optional>
#include <string>
#include <vector>

#include "../internal/strings/replace_all.hpp"

namespace rfl::parsing {

  /// Combines a set of errors to a single, readable error message.
  inline Error to_single_error_message(
      std::vector<Error>         _errors,
      std::optional<std::string> _msg_prefix = std::nullopt,
      size_t                     _err_limit  = 10
  ) {
    if (_errors.size() == 1) {
      return std::move(_errors[0]);
    } else {
      std::string msg =
          _msg_prefix ? *_msg_prefix
                      : "Found " + std::to_string(_errors.size()) + " errors:";
      for (size_t i = 0; i < _errors.size() && i < _err_limit; ++i) {
        msg += "\n" + std::to_string(i + 1) + ") " +
               internal::strings::replace_all(
                   _errors.at(i).what(), "\n", "\n    "
               );
      }
      if (_errors.size() > _err_limit) {
        msg += "\n...\nMore than " + std::to_string(_err_limit) +
               " errors occurred, but I am only showing the "
               "first " +
               std::to_string(_err_limit) + ".";
      }
      return Error(msg);
    }
  }

} // namespace rfl::parsing

#endif