[seisoparty] warn about missing DDoS-GUARD cookies

gallery_dl/extractor/seisoparty.py

@@ -20,6 +20,8 @@ class SeisopartyExtractor(Extractor):
     directory_fmt = ("{category}", "{service}", "{username}")
     filename_fmt = "{id}_{title}_{num:>02}_{filename}.{extension}"
     archive_fmt = "{service}_{user}_{id}_{num}"
+    cookiedomain = ".seiso.party"
+    _warning = True
 
     def __init__(self, match):
         Extractor.__init__(self, match)
@@ -28,6 +30,11 @@ class SeisopartyExtractor(Extractor):
             r'href="(https://cdn(?:-\d)?\.seiso\.party/files/[^"]+)').findall
 
     def items(self):
+        if self._warning:
+            if not self._check_cookies(("__ddg1", "__ddg2")):
+                self.log.warning("no DDoS-GUARD cookies set (__ddg1, __ddg2)")
+            SeisopartyExtractor._warning = False
+
         for post in self.posts():
             files = post.pop("files")
             yield Message.Directory, post