genkey accepts existing key

internal/handler/keys.go

@@ -71,7 +71,18 @@ func GenerateKey(n string) string {
 func HandleGenKey(w http.ResponseWriter, r *http.Request) {
 	n := r.FormValue("name")
 	if n == "" { n = "User" }
-	k := GenerateKey(n)
+	existingKey := r.FormValue("key")
+	var k string
+	if existingKey != "" {
+		s.mu.Lock()
+		s.Keys[existingKey] = &KeyData{Name: n, Key: existingKey}
+		save()
+		s.mu.Unlock()
+		go BackupKeyToSheet(n, existingKey)
+		k = existingKey
+	} else {
+		k = GenerateKey(n)
+	}
 	w.Header().Set("Content-Type", "application/json")
 	resp := map[string]string{"key": k, "name": n}
 	json.NewEncoder(w).Encode(resp)