WinUpdater: Check OS and VC++ Redist versions.

Source/Core/UpdaterCommon/Platform.h

@@ -0,0 +1,100 @@
+// Copyright 2018 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <map>
+#include <optional>
+#include <sstream>
+
+#include "Common/CommonTypes.h"
+#include "Common/StringUtil.h"
+
+namespace Platform
+{
+struct BuildVersion
+{
+  u32 major{};
+  u32 minor{};
+  u32 build{};
+  auto operator<=>(BuildVersion const& rhs) const = default;
+  static std::optional<BuildVersion> from_string(const std::string& str)
+  {
+    auto components = SplitString(str, '.');
+    // Allow variable number of components (truncating after "build"), but not
+    // empty.
+    if (components.size() == 0)
+      return {};
+    BuildVersion version;
+    if (!TryParse(components[0], &version.major, 10))
+      return {};
+    if (components.size() > 1 && !TryParse(components[1], &version.minor, 10))
+      return {};
+    if (components.size() > 2 && !TryParse(components[2], &version.build, 10))
+      return {};
+    return version;
+  }
+};
+
+enum class VersionCheckStatus
+{
+  NothingToDo,
+  UpdateOptional,
+  UpdateRequired,
+};
+
+struct VersionCheckResult
+{
+  VersionCheckStatus status{VersionCheckStatus::NothingToDo};
+  std::optional<BuildVersion> current_version{};
+  std::optional<BuildVersion> target_version{};
+};
+
+class BuildInfo
+{
+  using Map = std::map<std::string, std::string>;
+
+public:
+  BuildInfo() = default;
+  BuildInfo(const std::string& content);
+
+  std::optional<std::string> GetString(const std::string& name) const
+  {
+    auto it = map.find(name);
+    if (it == map.end() || it->second.size() == 0)
+      return {};
+    return it->second;
+  }
+
+  std::optional<BuildVersion> GetVersion(const std::string& name) const
+  {
+    auto str = GetString(name);
+    if (!str.has_value())
+      return {};
+    return BuildVersion::from_string(str.value());
+  }
+
+private:
+  void Parse(const std::string& content)
+  {
+    std::stringstream content_stream(content);
+    std::string line;
+    while (std::getline(content_stream, line))
+    {
+      if (line.starts_with("//"))
+        continue;
+      const size_t equals_index = line.find('=');
+      if (equals_index == line.npos)
+        continue;
+      auto key = line.substr(0, equals_index);
+      auto key_it = map.find(key);
+      if (key_it == map.end())
+        continue;
+      key_it->second = line.substr(equals_index + 1);
+    }
+  }
+  Map map;
+};
+
+bool VersionCheck(const BuildInfo& this_build_info, const BuildInfo& next_build_info);
+}  // namespace Platform