Add --file-store flag to select the file library backend

Wire an os|memory selector mirroring the existing Redis-vs-file backend
selection. This marks the seam where a future object-store backend (e.g.
Cloudflare R2 / S3) slots in via hotline.WithFileStore.

1 files changed, 15 insertions, 0 deletions

diff --git a/cmd/mobius-hotline-server/main.go b/cmd/mobius-hotline-server/main.go
index 5191805..35fbcf9 100644
--- a/cmd/mobius-hotline-server/main.go
+++ b/cmd/mobius-hotline-server/main.go
@@ -49,6 +49,7 @@ func main() {
 	tlsCert := flag.String("tls-cert", "", "Path to TLS certificate file")
 	tlsKey := flag.String("tls-key", "", "Path to TLS key file")
 	tlsPort := flag.Int("tls-port", 5600, "Base TLS port. TLS file transfer port is base + 1.")
+	fileStoreBackend := flag.String("file-store", "os", "File library storage backend: os (default) or memory")
 
 	flag.Parse()
 
@@ -103,6 +104,20 @@ func main() {
 		opts = append(opts, hotline.WithTLS(tlsConfig, *tlsPort))
 	}
 
+	// Select the file library storage backend. This is the seam a future object-store backend
+	// (e.g. Cloudflare R2 / S3) slots into, mirroring the Redis-vs-file selection below: build
+	// the concrete FileStore and pass it via hotline.WithFileStore.
+	switch *fileStoreBackend {
+	case "os", "":
+		// Default OSFileStore is set by NewServer; nothing to do.
+	case "memory":
+		opts = append(opts, hotline.WithFileStore(hotline.NewMemFileStore()))
+		slogger.Warn("Using in-memory file store; uploaded files are not persisted")
+	default:
+		slogger.Error("Unknown file-store backend", "backend", *fileStoreBackend)
+		os.Exit(1)
+	}
+
 	srv, err := hotline.NewServer(opts...)
 	if err != nil {
 		slogger.Error("Error starting server", "err", err)