[Cleanup] Hotfix for [p]cleanup after (#2004)

* [Cleanup] Hotfix for [p]cleanup after

* Reformat

* Log warning for any 3rd party devs using broken helper

redbot/cogs/cleanup/cleanup.py

@@ -68,6 +68,12 @@ class Cleanup:
         - The message is less than 14 days old
         - The message is not pinned
         """
+        if after is not None:
+            log.error(
+                "The `after` parameter for the `Cleanup.get_messages_for_deletion` method is "
+                "currently broken, see PRs #1980 and #2004 for details."
+            )
+
         to_delete = []
         too_old = False
 
@@ -238,23 +244,35 @@ class Cleanup:
             await ctx.send(_("This command can only be used on bots with bot accounts."))
             return
 
-        after = await channel.get_message(message_id)
-
-        if not after:
+        try:
+            message = await channel.get_message(message_id)
+        except discord.NotFound:
             await ctx.send(_("Message not found."))
             return
 
-        to_delete = await self.get_messages_for_deletion(
-            ctx, channel, 0, limit=None, after=after, delete_pinned=delete_pinned
-        )
+        if (ctx.message.created_at - message.created_at).days >= 14:
+            await ctx.send("The specified message must be less than 14 days old.")
+            return
+
+        if not delete_pinned:
+            pinned_msgs = await channel.pins()
+            to_exclude = set(m for m in pinned_msgs if m.created_at > message.created_at)
+        else:
+            to_exclude = None
+
+        if to_exclude:
+            to_delete = await channel.history(limit=None, after=message).flatten()
+            to_delete = set(to_delete) - to_exclude
+            await channel.delete_messages(to_delete)
+            num_deleted = len(to_delete)
+        else:
+            num_deleted = len(await channel.purge(limit=None, after=message))
 
         reason = "{}({}) deleted {} messages in channel {}.".format(
-            author.name, author.id, len(to_delete), channel.name
+            author.name, author.id, num_deleted, channel.name
         )
         log.info(reason)
 
-        await mass_purge(to_delete, channel)
-
     @cleanup.command()
     @commands.guild_only()
     async def messages(self, ctx: commands.Context, number: int, delete_pinned: bool = False):