[Core] Target any user with blacklist / whitelist commands (#1068)

cogs/utils/converters.py

@@ -0,0 +1,46 @@
+from discord.ext.commands.converter import IDConverter
+from discord.ext.commands.errors import BadArgument
+import re
+
+
+# This could've been imported but since it's an internal it's safer
+# to get it here
+def _get_from_servers(bot, getter, argument):
+    result = None
+    for server in bot.servers:
+        result = getattr(server, getter)(argument)
+        if result:
+            return result
+    return result
+
+
+class GlobalUser(IDConverter):
+    """
+    This is an (almost) straight copy of discord.py's Member converter
+    The key difference is that if the command is issued in a server it will
+    first attempt to get the user from that server and upon failing it will
+    attempt to fish it from the global pool
+    """
+    def convert(self):
+        message = self.ctx.message
+        bot = self.ctx.bot
+        match = self._get_id_match() or re.match(r'<@!?([0-9]+)>$', self.argument)
+        server = message.server
+        result = None
+        if match is None:
+            # not a mention...
+            if server:
+                result = server.get_member_named(self.argument)
+            if result is None:
+                result = _get_from_servers(bot, 'get_member_named', self.argument)
+        else:
+            user_id = match.group(1)
+            if server:
+                result = server.get_member(user_id)
+            if result is None:
+                result = _get_from_servers(bot, 'get_member', user_id)
+
+        if result is None:
+            raise BadArgument('User "{}" not found'.format(self.argument))
+
+        return result