path: root/src/openvic-simulation/dataloader/Vic2PathSearch.cpp

#include <openvic-dataloader/detail/CallbackOStream.hpp>

#include <lexy-vdf/KeyValues.hpp>
#include <lexy-vdf/Parser.hpp>

#include "openvic-simulation/types/OrderedContainers.hpp"
#include "openvic-simulation/utility/ConstexprIntToStr.hpp"
#include "openvic-simulation/utility/Logger.hpp"

#include "Dataloader.hpp"

#ifdef _WIN32
#include <Windows.h>

#include "Vic2PathSearch_Windows.hpp"
#endif

#if defined(__APPLE__) && defined(__MACH__)
#include <TargetConditionals.h>
#endif

using namespace OpenVic;
using namespace ovdl;

#if defined(_WIN32) || (defined(__APPLE__) && defined(__MACH__))
#define FILESYSTEM_CASE_INSENSITIVE
#endif

#if !defined(_WIN32)
#define FILESYSTEM_NEEDS_FORWARD_SLASHES
#endif

// Windows and Mac by default act like case insensitive filesystems
static constexpr bool path_equals(std::string_view lhs, std::string_view rhs) {
#if defined(FILESYSTEM_CASE_INSENSITIVE)
   return StringUtils::strings_equal_case_insensitive(lhs, rhs);
#else
   return std::equal(lhs.begin(), lhs.end(), rhs.begin(), rhs.end());
#endif
}

template<typename T>
concept is_filename = std::same_as<T, std::filesystem::path> || std::convertible_to<T, std::string_view>;

static bool filename_equals(const is_filename auto& lhs, const is_filename auto& rhs) {
   auto left = [&lhs] {
      if constexpr (std::same_as<std::decay_t<decltype(lhs)>, std::filesystem::path>) {
         return lhs.filename().string();
      } else {
         return lhs;
      }
   }();
   auto right = [&rhs] {
      if constexpr (std::same_as<std::decay_t<decltype(rhs)>, std::filesystem::path>) {
         return rhs.filename().string();
      } else {
         return rhs;
      }
   }();
   return path_equals(left, right);
}

static fs::path _search_for_game_path(fs::path hint_path = {}) {
   // Apparently max amount of steam libraries is 8, if incorrect please correct it to the correct max amount
   static constexpr int max_amount_of_steam_libraries = 8;
   static constexpr std::string_view Victoria_2_folder = "Victoria 2";
   static constexpr std::string_view v2_game_exe = "v2game.exe";
   static constexpr std::string_view steamapps = "steamapps";
   static constexpr std::string_view libraryfolders = "libraryfolders.vdf";
   static constexpr std::string_view vic2_appmanifest = "appmanifest_42960.acf";
   static constexpr std::string_view common_folder = "common";

   std::error_code error_code;

   // Don't waste time trying to search for Victoria 2 when supplied a valid looking Victoria 2 game directory
   if (filename_equals(Victoria_2_folder, hint_path)) {
      if (fs::is_regular_file(hint_path / v2_game_exe, error_code)) {
         return hint_path;
      }
   }

   const bool hint_path_was_empty = hint_path.empty();
   auto empty_fail_result_callback = [&]<typename... Args>(Args&&... args) -> fs::path {
      if (!hint_path_was_empty) {
         if constexpr (sizeof...(Args) > 0) {
            Logger::info(std::forward<Args>(args)...);
         }
         return _search_for_game_path();
      }
      if constexpr (sizeof...(Args) > 0) {
         Logger::warning(std::forward<Args>(args)...);
      }
      return "";
   };

   if (hint_path_was_empty) {
#if defined(_WIN32)
      static const fs::path registry_path =
         Windows::ReadRegValue<char>(HKEY_LOCAL_MACHINE, "SOFTWARE\\WOW6432Node\\Paradox Interactive\\Victoria 2", "path");

      if (!registry_path.empty()) {
         return registry_path;
      }

#pragma warning(push)
#pragma warning(disable : 4996)
      static const fs::path prog_files = std::string(std::getenv("ProgramFiles"));
      hint_path = prog_files / "Steam";
      if (!fs::is_directory(hint_path, error_code)) {
         static const fs::path prog_files_x86 = std::string(std::getenv("ProgramFiles(x86)"));
         hint_path = prog_files_x86 / "Steam";
         if (!fs::is_directory(hint_path, error_code)) {
            Logger::warning("Could not find path for Steam installation on Windows.");
            return "";
         }
      }
#pragma warning(pop)
      // Cannot support Android
      // Only FreeBSD currently unofficially supports emulating Linux
#elif (defined(__linux__) && !defined(__ANDROID__)) || defined(__FreeBSD__)
      static const fs::path home = std::getenv("HOME");
      hint_path = home / ".steam" / "steam";
      if (fs::is_symlink(hint_path, error_code)) {
         hint_path = fs::read_symlink(hint_path, error_code);
      } else if (!fs::is_directory(hint_path, error_code)) {
         hint_path = home / ".local" / "share" / "Steam";
         if (!fs::is_directory(hint_path, error_code)) {
#ifdef __FreeBSD__
            Logger::warning("Could not find path for Steam installation on FreeBSD.");
#else
            Logger::warning("Could not find path for Steam installation on Linux.");
#endif
            return "";
         }
      }
      // Support only Mac, cannot support iOS
#elif (defined(__APPLE__) && defined(__MACH__)) && TARGET_OS_MAC == 1
      static const fs::path home = std::getenv("HOME");
      hint_path = home / "Library" / "Application Support" / "Steam";
      if (!fs::is_directory(hint_path, error_code)) {
         Logger::warning("Could not find path for Steam installation on Mac.");
         return "";
      }
      // All platforms that reach this point do not seem to even have unofficial Steam support
#else
      Logger::warning("Could not find path for Steam installation on unsupported platform.");
#endif
   }

   // Could not determine Steam install on platform
   if (hint_path.empty()) {
      return empty_fail_result_callback("Steam install path not found.");
   }

   // Supplied path was useless, ignore hint_path
   if (!hint_path_was_empty && !fs::exists(hint_path, error_code)) {
      return _search_for_game_path();
   }

   // Steam Library's directory that will contain Victoria 2
   fs::path vic2_steam_lib_directory;
   fs::path current_path = hint_path;

   // If hinted path is directory that contains steamapps
   bool is_steamapps = false;
   if (fs::is_directory(current_path / steamapps, error_code)) {
      current_path /= steamapps;
      is_steamapps = true;
   }

   // If hinted path is steamapps directory
   bool is_libraryfolders_vdf = false;
   if (is_steamapps || (filename_equals(steamapps, current_path) && fs::is_directory(current_path, error_code))) {
      current_path /= libraryfolders;
      is_libraryfolders_vdf = true;
   }

   bool vic2_install_confirmed = false;
   // if current_path is not a regular file, this is a non-default Steam Library, skip this parser evaluation
   if (fs::is_regular_file(current_path, error_code) &&
      (is_libraryfolders_vdf || filename_equals(libraryfolders, current_path))) {
      lexy_vdf::Parser parser;

      std::string buffer;
      auto error_log_stream = detail::make_callback_stream<char>(
         [](void const* s, std::streamsize n, void* user_data) -> std::streamsize {
            if (s != nullptr && n > 0 && user_data != nullptr) {
               static_cast<std::string*>(user_data)->append(static_cast<char const*>(s), n);
               return n;
            } else {
               Logger::warning("Invalid input to parser error log callback: ", s, " / ", n, " / ", user_data);
               return 0;
            }
         },
         &buffer
      );
      parser.set_error_log_to(error_log_stream);

      parser.load_from_file(current_path);
      if (!parser.parse()) {
         // Could not find or load libraryfolders.vdf, report error as warning
         if (!buffer.empty()) {
            return empty_fail_result_callback(buffer);
         }
         return empty_fail_result_callback("Could not parse VDF at '", current_path, "'.");
      }
      std::optional current_node = *(parser.get_key_values());

      // check "libraryfolders" list
      auto it = current_node.value().find("libraryfolders");
      if (it == current_node.value().end()) {
         return empty_fail_result_callback("Expected libraryfolders.vdf to contain a libraryfolders key.");
      }

      static constexpr auto visit_node = [](auto&& arg) -> std::optional<lexy_vdf::KeyValues> {
         using T = std::decay_t<decltype(arg)>;
         if constexpr (std::is_same_v<T, lexy_vdf::KeyValues>) {
            return arg;
         } else {
            return std::nullopt;
         }
      };

      current_node = std::visit(visit_node, it->second);

      if (!current_node.has_value()) {
         return empty_fail_result_callback("Expected libraryfolders.vdf's libraryfolders key to be a KeyValue dictionary.");
      }

      // Array of strings contain "0" to std::to_string(max_amount_of_steam_libraries - 1)
      static constexpr auto library_indexes = OpenVic::ConstexprIntToStr::make_itosv_array<max_amount_of_steam_libraries>();

      for (const auto& index : library_indexes) {
         decltype(current_node) node = std::nullopt;

         auto it = current_node.value().find(index);
         if (it != current_node.value().end()) {
            node = std::visit(visit_node, it->second);
         }

         // check "apps" list
         decltype(node) apps_node = std::nullopt;
         if (node.has_value()) {
            it = node.value().find("apps");
            if (it != node.value().end()) {
               apps_node = std::visit(visit_node, it->second);
            }
         }

         bool lib_contains_victoria_2 = false;
         if (apps_node.has_value()) {
            lib_contains_victoria_2 = apps_node.value().find("42960") != node.value().end();
         }

         if (lib_contains_victoria_2) {
            it = node.value().find("path");
            if (it != node.value().end()) {
               vic2_steam_lib_directory = std::visit(
                  [](auto&& arg) -> std::string_view {
                     using T = std::decay_t<decltype(arg)>;
                     if constexpr (std::is_same_v<T, std::string>) {
                        return arg;
                     } else {
                        return "";
                     }
                  },
                  it->second
               );
               vic2_install_confirmed = true;
               break;
            }
         }
      }

      if (vic2_steam_lib_directory.empty()) {
         return empty_fail_result_callback("Steam installation appears not to contain Victoria 2.");
      }
   }

   // If current_path points to steamapps/libraryfolders.vdf
   if (vic2_steam_lib_directory.empty()) {
      if (is_libraryfolders_vdf || filename_equals(libraryfolders, current_path)) {
         vic2_steam_lib_directory = current_path.parent_path() / vic2_appmanifest;
      } else if (filename_equals(vic2_appmanifest, current_path)) {
         vic2_steam_lib_directory = current_path;
      }
   }

   // If we could not confirm Victoria 2 was installed via the default Steam installation
   bool is_common_folder = false;
   if (!vic2_install_confirmed) {
      auto parser = lexy_vdf::Parser::from_file(vic2_steam_lib_directory);
      if (!parser.parse()) {
         // Could not find or load appmanifest_42960.acf, report error as warning
         if (parser.get_errors().size() > 1) {
            for (auto& error : parser.get_errors()) {
               // TODO: allow empty_fail_result_callback to use callbacks
               if (hint_path_was_empty) {
                  Logger::warning(error.message);
               } else {
                  Logger::info(error.message);
               }
            }
            return empty_fail_result_callback();
         }
         return empty_fail_result_callback(parser.get_errors().front().message);
      }

      // we can pretty much assume the Victoria 2 directory on Steam is valid from here
      vic2_steam_lib_directory /= common_folder;
      is_common_folder = true;
   } else if (fs::is_directory(vic2_steam_lib_directory / steamapps, error_code)) {
      vic2_steam_lib_directory /= fs::path(steamapps) / common_folder;
      is_common_folder = true;
   }

   bool is_Victoria_2_folder = false;
   if ((is_common_folder || filename_equals(common_folder, vic2_steam_lib_directory)) &&
      fs::is_directory(vic2_steam_lib_directory, error_code)) {
      vic2_steam_lib_directory /= Victoria_2_folder;
      is_Victoria_2_folder = true;
   }
   if ((is_Victoria_2_folder || filename_equals(Victoria_2_folder, vic2_steam_lib_directory)) &&
      fs::is_regular_file(vic2_steam_lib_directory / v2_game_exe, error_code)) {
      return vic2_steam_lib_directory;
   }

   // Hail Mary check ignoring the hint_path
   if (!hint_path_was_empty) {
      return _search_for_game_path();
   }

   Logger::warning("Could not find Victoria 2 game path, this requires manually supplying one.");
   return ""; // The supplied path fits literally none of the criteria
}

fs::path Dataloader::search_for_game_path(fs::path hint_path) {
   struct fshash {
      size_t operator()(const std::filesystem::path& p) const noexcept {
         return std::filesystem::hash_value(p);
      }
   };
   using hint_path_t = fs::path;
   using game_path_t = fs::path;
   static ordered_map<hint_path_t, game_path_t, fshash> _cached_paths;

   auto it = _cached_paths.find(hint_path);
   if (it != _cached_paths.end()) {
      return it->second;
   }

   return _cached_paths[hint_path] = _search_for_game_path(hint_path);
}