Initial commit for http rest bridge

http_rest_frontend/cli/utils.go

@@ -0,0 +1,57 @@
+package cli
+
+import (
+	"github.com/ProtonMail/proton-bridge/pkg/pmapi"
+	"github.com/sirupsen/logrus"
+)
+
+func (f *frontendCLI) processAPIError(err error) {
+	switch err {
+	case pmapi.ErrNoConnection:
+		f.notifyInternetOff()
+	case pmapi.ErrUpgradeApplication:
+		f.notifyNeedUpgrade()
+	}
+}
+
+func (f *frontendCLI) notifyInternetOff() {
+	logrus.Warn("Internet connection is not available.")
+}
+
+func (f *frontendCLI) notifyInternetOn() {
+	logrus.Info("Internet connection is available again.")
+}
+
+func (f *frontendCLI) notifyLogout(address string) {
+	logrus.Infof("Account %s is disconnected. Login to continue using this account with email client.", address)
+}
+
+func (f *frontendCLI) notifyNeedUpgrade() {
+	logrus.Info("Upgrade needed. Please download and install the newest version of application.")
+}
+
+func (f *frontendCLI) notifyCredentialsError() {
+	logrus.Error(`ProtonMail Bridge is not able to detect a supported password manager
+(secret-service or pass). Please install and set up a supported password manager
+and restart the application.
+`)
+}
+
+func (f *frontendCLI) notifyCertIssue() {
+	// Print in 80-column width.
+	logrus.Error(`Connection security error: Your network connection to Proton services may
+be insecure.
+
+Description:
+ProtonMail Bridge was not able to establish a secure connection to Proton
+servers due to a TLS certificate error. This means your connection may
+potentially be insecure and susceptible to monitoring by third parties.
+
+Recommendation:
+* If you trust your network operator, you can continue to use ProtonMail
+  as usual.
+* If you don't trust your network operator, reconnect to ProtonMail over a VPN
+  (such as ProtonVPN) which encrypts your Internet connection, or use
+  a different network to access ProtonMail.
+`)
+}