runner: initial automatic update (#2141)

src/common/updating/updating.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <optional>
+#include <string>
+#include <future>
+#include <filesystem>
+
+#include <winrt/Windows.Foundation.h>
+
+namespace updating
+{
+    std::wstring get_msi_package_path();
+    bool uninstall_msi_version(const std::wstring& package_path);
+    bool offer_msi_uninstallation();
+
+    std::future<bool> uninstall_previous_msix_version_async();
+
+    struct new_version_download_info
+    {
+        winrt::Windows::Foundation::Uri release_page_uri;
+        std::wstring version_string;
+        winrt::Windows::Foundation::Uri msi_download_url;
+        std::wstring msi_filename;
+    };
+
+    std::future<std::optional<new_version_download_info>> get_new_github_version_info_async();
+    std::future<void> try_autoupdate(const bool download_updates_automatically);
+    std::filesystem::path get_pending_updates_path();
+
+    constexpr inline std::wstring_view installer_filename_pattern = L"powertoyssetup";
+}