enum_name_impl.hpp

/*
MIT License
 
Copyright (c) 2024 mguludag
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
 
#ifndef MGUTILITY_REFLECTION_DETAIL_ENUM_NAME_IMPL_HPP
#define MGUTILITY_REFLECTION_DETAIL_ENUM_NAME_IMPL_HPP
 
// NOLINTNEXTLINE [unused-includes]
#include "enum_for_each.hpp"
#include "meta.hpp"
#include "mgutility/_common/definitions.hpp"
#include "mgutility/std/fixed_string.hpp"
#include "mgutility/std/optional.hpp"
#include "mgutility/std/string_view.hpp"
#include "mgutility/std/utility.hpp"
 
#include <algorithm>
#include <array>
#include <cstddef>
 
#if defined(_MSC_VER) && _MSC_VER < 1910
#error "Requires MSVC 2017 or newer!"
#elif defined(__clang__) && __clang_major__ < 6
#error "Requires clang 6 or newer!"
#elif defined(__GNUC__) && !defined(__clang__) && __GNUC__ < 9
#error "Requires gcc 9 or newer!"
#elif !defined(_MSC_VER) && !defined(__clang__) && !defined(__GNUC__)
#error "Your compiler is not supported!"
#endif
 
#ifdef _MSC_VER
#define __PRETTY_FUNCTION__ __FUNCSIG__
#endif
 
// NOLINTNEXTLINE [modernize-concat-nested-namespaces]
namespace mgutility {
namespace detail {
 
#ifndef MGUTILITY_STRLEN
// NOLINTNEXTLINE [cppcoreguidelines-macro-usage]
#define MGUTILITY_STRLEN(x) sizeof(x) - 1
#endif
 
template <typename T, int Min, int Max> struct enum_name_parse_result {
  static constexpr auto size = std::size_t{Max - Min};
  fixed_string<enum_name_buffer<T>::size * size> blob;
  std::array<pair<std::size_t, std::size_t>, size> ranges;
};
 
template <typename T, int Min, int Max>
using enum_name_array =
    std::array<mgutility::string_view, static_cast<std::size_t>(Max - Min)>;
 
struct enum_type {
private:
  template <typename Enum, Enum... e>
  MGUTILITY_CNSTXPR static mgutility::string_view
  raw_name(detail::enum_sequence<Enum, e...> /*unused*/) noexcept {
#if defined(__GNUC__) && !defined(__clang__) && MGUTILITY_CPLUSPLUS >= 201402L
#define PREFIX                                                                 \
  MGUTILITY_STRLEN("static constexpr mgutility::string_view "                  \
                   "mgutility::detail::enum_type::raw_name(mgutility::detail:" \
                   ":enum_sequence<Enum, e ...>) [with Enum = ")
#elif defined(__clang__) || defined(__GNUC__)
#define PREFIX                                                                 \
  MGUTILITY_STRLEN("static mgutility::string_view "                            \
                   "mgutility::detail::enum_type::raw_name(mgutility::detail:" \
                   ":enum_sequence<Enum, e ...>) [with Enum = ")
#elif defined(_MSC_VER)
#if MGUTILITY_CPLUSPLUS > 201402L
#define PREFIX                                                                 \
  MGUTILITY_STRLEN(                                                            \
      "class std::basic_string_view<char,struct std::char_traits<char> > "     \
      "__cdecl mgutility::detail::enum_type::raw_name")
#else
#define PREFIX                                                                 \
  MGUTILITY_STRLEN("class mgutility::basic_string_view<char> __cdecl "         \
                   "mgutility::detail::enum_type::raw_name")
#endif
#else
#define PREFIX 0
#endif
 
    return mgutility::string_view(__PRETTY_FUNCTION__ + PREFIX,
                                  MGUTILITY_STRLEN(__PRETTY_FUNCTION__) -
                                      PREFIX + 1);
  }
 
  template <typename Enum, int Min, int Max>
  MGUTILITY_CNSTXPR static enum_name_parse_result<Enum, Min, Max>
  parse() noexcept {
    MGUTILITY_CNSTXPR auto str =
        raw_name<Enum>(detail::make_enum_sequence<Enum, Min, Max>{});
 
#if defined(__clang__) || defined(__GNUC__)
#if defined(__clang__)
    auto end = str.rfind(']');
#elif defined(__GNUC__) && !defined(__clang__)
    auto end = str.rfind(';');
#endif
 
    auto enum_names = str.substr(0, end);
 
#elif defined(_MSC_VER)
    // MSVC: different format
    auto pos = str.find(',');
    if (pos == mgutility::string_view::npos)
      return {};
 
    ++pos;
 
    auto end = str.rfind('>');
    auto enum_names = str.substr(pos, end - pos);
 
#else
    return {};
#endif
 
    if (enum_names.empty()) {
      return {};
    }
 
    enum_name_parse_result<Enum, Min, Max> result{};
 
    std::size_t idx = 0;
 
    while (!enum_names.empty() && idx < result.ranges.size()) {
      auto pos = enum_names.find(',');
      if (pos != mgutility::string_view::npos) {
        auto token = enum_names.substr(0, pos);
 
        // remove whitespace
        while (!token.empty() && token.front() == ' ') {
          token = token.substr(1);
        }
 
        while (!token.empty() && token.back() == ' ') {
          token = token.substr(0, token.size() - 1);
        }
 
        std::size_t begin = token.find('(');
        std::size_t end = token.rfind(')');
        if (begin != mgutility::string_view::npos ||
            end != mgutility::string_view::npos) {
          result.ranges[idx++] = {0, 0};
          enum_names = enum_names.substr(pos + 1);
          continue;
        }
 
        std::size_t start = 0;
        if (token.find(':') != mgutility::string_view::npos) {
          start = token.find(':') + 2;
          token = token.substr(start);
        }
 
        auto size = result.blob.size();
        result.blob.append(token);
        result.ranges[idx++] = {size, result.blob.size() - size};
 
        enum_names = enum_names.substr(pos + 1);
        continue;
      }
      enum_names = {};
    }
 
    return result;
  }
 
public:
  template <typename Enum, int Min, int Max>
  MGUTILITY_CNSTXPR static enum_name_parse_result<Enum, Min, Max>
  name() noexcept {
    return parse<Enum, Min, Max>();
  }
};
 
template <typename Enum, int Min, int Max> struct enum_array_cache;
 
template <typename Enum, int Min, int Max> struct enum_array_cache {
 
#if MGUTILITY_CPLUSPLUS > 201402L
 
  static inline constexpr auto parse_result =
      enum_type::template name<Enum, Min, Max>();
 
#else
  // C++11: lazy runtime array
  static enum_name_parse_result<Enum, Min, Max> &value() {
    static enum_name_parse_result<Enum, Min, Max> arr =
        enum_type::template name<Enum, Min, Max>();
 
    return arr;
  }
#endif
 
  static MGUTILITY_CNSTXPR auto
  apply_custom(const enum_name_parse_result<Enum, Min, Max> &result) noexcept
      -> enum_name_array<Enum, Min, Max> {
    enum_name_array<Enum, Min, Max> arr{};
 
    for (std::size_t idx = 0; idx < result.ranges.size(); ++idx) {
      arr[idx] = result.blob.view().substr(result.ranges[idx].first,
                                           result.ranges[idx].second);
    }
 
#if MGUTILITY_CPLUSPLUS >= 201402L
    constexpr auto map = mgutility::custom_enum<Enum>::map;
    for (const auto &pair : map) {
#else
    for (const auto &pair : mgutility::custom_enum<Enum>::map) {
#endif
      if (pair.first >= static_cast<Enum>(Min) &&
          pair.first < static_cast<Enum>(Max)) {
        arr[static_cast<std::size_t>(pair.first) - Min] = pair.second;
      }
    }
 
    return arr;
  }
};
 
template <typename Enum, int Min = mgutility::enum_range<Enum>::min,
          int Max = mgutility::enum_range<Enum>::max>
MGUTILITY_CNSTXPR auto get_enum_array() noexcept
    -> enum_name_array<Enum, Min, Max> {
#if MGUTILITY_CPLUSPLUS > 201402L
  constexpr auto &cache = enum_array_cache<Enum, Min, Max>::parse_result;
  return enum_array_cache<Enum, Min, Max>::apply_custom(cache);
#else
  return enum_array_cache<Enum, Min, Max>::apply_custom(
      enum_array_cache<Enum, Min, Max>::value());
#endif
}
 
template <typename Enum, int Min, int Max>
MGUTILITY_CNSTXPR inline auto to_enum_impl(mgutility::string_view str) noexcept
    -> mgutility::optional<Enum> {
  MGUTILITY_CNSTXPR_CLANG_WA auto arr = get_enum_array<Enum, Min, Max>();
 
  const auto index{detail::find(arr, str)};
  return index == 0 ? mgutility::nullopt
                    : mgutility::optional<Enum>{static_cast<Enum>(index + Min)};
}
 
template <typename Enum, int Min, int Max>
MGUTILITY_CNSTXPR auto to_enum_bitmask_impl(mgutility::string_view str) noexcept
    -> mgutility::optional<Enum> {
 
  // Check if the string contains a '|' character
  if (str.find('|') == mgutility::string_view::npos) {
    return to_enum_impl<Enum, Min, Max>(str);
  }
 
  mgutility::optional<Enum> result{mgutility::nullopt};
  std::size_t index = 0;
 
  for (std::size_t i = 0; i < str.size(); ++i) {
    if (str[i] == '|') {
      auto name = str.substr(index, i - index);
      auto maybe_enum = to_enum_impl<Enum, Min, Max>(name);
 
      if (!name.empty() && maybe_enum) {
        result.emplace(result ? static_cast<Enum>(*result | *maybe_enum)
                              : *maybe_enum);
      }
 
      index = i + 1;
    }
  }
 
  auto maybe_enum = to_enum_impl<Enum, Min, Max>(str.substr(index));
  if (result && maybe_enum) {
    result.emplace(static_cast<Enum>(*result | *maybe_enum));
  } else {
    result.reset();
  }
 
  return result;
}
 
template <typename Enum, int Min, int Max,
          detail::enable_if_t<!detail::has_bit_or<Enum>::value, bool> = true>
MGUTILITY_CNSTXPR auto enum_name_impl(Enum enumValue) noexcept
    -> mgutility::string_view {
  MGUTILITY_CNSTXPR_CLANG_WA auto arr = get_enum_array<Enum, Min, Max>();
  const auto index{(Min < 0 ? -Min : Min) + static_cast<int>(enumValue)};
  if (index < Min || index > static_cast<int>(arr.size()) - 1) {
    return mgutility::string_view{};
  }
 
  return arr[static_cast<size_t>(index)];
}
 
// NOLINTNEXTLINE [modernize-use-constraints]
template <typename Enum, int Min, int Max,
          detail::enable_if_t<detail::has_bit_or<Enum>::value, bool> = true>
MGUTILITY_CNSTXPR_CLANG_WA auto enum_name_impl(Enum enumValue) noexcept
    -> mgutility::fixed_string<enum_name_buffer<Enum>::size> {
 
  // Get the array of enum names
  MGUTILITY_CNSTXPR_CLANG_WA auto arr = get_enum_array<Enum, Min, Max>();
 
  // Calculate the index in the array
  const auto index = (Min < 0 ? -Min : Min) + static_cast<int>(enumValue);
 
  mgutility::fixed_string<enum_name_buffer<Enum>::size> bitmasked_name;
 
  if (index >= 0 && index < static_cast<int>(arr.size())) {
    bitmasked_name.append(arr[static_cast<size_t>(index)]);
  }
 
  if (!bitmasked_name.empty()) {
    return bitmasked_name;
  }
 
  for (auto i = 0; i < Max - Min; ++i) {
    if (i >= 0 && i < static_cast<int>(arr.size()) && arr[i].size() > 0 &&
        (enumValue & static_cast<Enum>(i)) == static_cast<Enum>(i)) {
      bitmasked_name.append(arr[i]).append("|");
    }
  }
 
  // Remove the trailing '|' if present
  if (!bitmasked_name.empty()) {
    bitmasked_name.pop_back();
  }
 
  return bitmasked_name;
}
} // namespace detail
} // namespace mgutility
 
#endif // MGUTILITY_REFLECTION_DETAIL_ENUM_NAME_IMPL_HPP