Add sub_clyde utility function.

1 files changed, 19 insertions, 0 deletions

diff --git a/bot/utils/messages.py b/bot/utils/messages.py
new file mode 100644
index 00000000..a6c035f9
--- /dev/null
+++ b/bot/utils/messages.py
@@ -0,0 +1,19 @@
+import re
+from typing import Optional
+
+
+def sub_clyde(username: Optional[str]) -> Optional[str]:
+    """
+    Replace "e"/"E" in any "clyde" in `username` with a Cyrillic "е"/"E" and return the new string.
+
+    Discord disallows "clyde" anywhere in the username for webhooks. It will return a 400.
+    Return None only if `username` is None.
+    """
+    def replace_e(match: re.Match) -> str:
+        char = "е" if match[2] == "e" else "Е"
+        return match[1] + char
+
+    if username:
+        return re.sub(r"(clyd)(e)", replace_e, username, flags=re.I)
+    else:
+        return username  # Empty string or None