util: Add simple API to query protocol

src/util.c

@@ -198,3 +198,52 @@ calls_find_in_store (GListModel *list,
   return FALSE;
 #endif
 }
+
+/**
+ * get_protocol_from_address:
+ * @target: The target address
+ *
+ * simply checks for the the scheme of an address without doing any validation
+ *
+ * Returns: The protocol used for address, or NULL if could not determine
+ */
+const char *
+get_protocol_from_address (const char *target)
+{
+  g_autofree char *lower = NULL;
+
+  g_return_val_if_fail (target, NULL);
+
+  lower = g_ascii_strdown (target, -1);
+
+  if (g_str_has_prefix (lower, "sips:"))
+    return "sips";
+
+  if (g_str_has_prefix (lower, "sip:"))
+    return "sip";
+
+  if (g_str_has_prefix (lower, "tel:"))
+    return "tel";
+
+  /* could not determine the protocol (which most probably means it's a telephone number) */
+  return NULL;
+}
+
+/**
+ * get_protocol_from_address_with_fallback:
+ * @target: The address to check
+ *
+ * simply checks for the the scheme of an address without doing any validation
+ *
+ * Returns: The protocol used for address, or "tel" as a fallback
+ */
+const char *
+get_protocol_from_address_with_fallback (const char *target)
+{
+  const char *protocol = get_protocol_from_address (target);
+
+  if (!protocol)
+    protocol = "tel";
+
+  return protocol;
+}

src/util.h

@@ -138,6 +138,9 @@ gboolean calls_find_in_store (GListModel *list,
                               gpointer    item,
                               guint      *position);
 
+const char* get_protocol_from_address (const char *target);
+const char* get_protocol_from_address_with_fallback (const char *target);
+
 G_END_DECLS
 
 #endif /* CALLS__UTIL_H__ */