Add qrcode generator endpoint

backend/src/qrcode_gen.py

@@ -0,0 +1,32 @@
+import qrcode
+import urllib.parse
+from io import BytesIO
+
+
+def create_login_url(base_uri: str, room_id: int, pin: int | None) -> str:
+    parsed = urllib.parse.urlparse(base_uri)
+
+    params = {
+        "room": room_id,
+    }
+
+    if pin is not None:
+        params["pin"] = pin
+
+    parsed = parsed._replace(path="join", query=urllib.parse.urlencode(params))
+
+    return urllib.parse.urlunparse(parsed)
+
+
+def generate_qr(base_uri: str, room_id: int, pin: int | None) -> BytesIO:
+    url = create_login_url(base_uri, room_id, pin)
+
+    qr = qrcode.make(url)
+
+    out = BytesIO()
+
+    qr.save(out, format="jpeg")
+
+    out.seek(0)
+
+    return out