GODT-980: placeholder for user agent

internal/config/useragent/platform.go

@@ -0,0 +1,51 @@
+// Copyright (c) 2021 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package useragent
+
+import (
+	"os/exec"
+	"runtime"
+	"strings"
+
+	"github.com/Masterminds/semver/v3"
+)
+
+// IsCatalinaOrNewer checks whether host is MacOS Catalina 10.15.x or higher.
+func IsCatalinaOrNewer() bool {
+	if runtime.GOOS != "darwin" {
+		return false
+	}
+
+	rawVersion, err := exec.Command("sw_vers", "-productVersion").Output()
+	if err != nil {
+		return false
+	}
+
+	return isVersionCatalinaOrNewer(strings.TrimSpace(string(rawVersion)))
+}
+
+func isVersionCatalinaOrNewer(rawVersion string) bool {
+	semVersion, err := semver.NewVersion(rawVersion)
+	if err != nil {
+		return false
+	}
+
+	minVersion := semver.MustParse("10.15.0")
+
+	return semVersion.GreaterThan(minVersion) || semVersion.Equal(minVersion)
+}