Some old work and some new (#3362)

* Some old work, some new

* c:style

* remove wrong version

redbot/cogs/mutes/utils.py

@@ -0,0 +1,53 @@
+import discord
+from redbot.core.i18n import Translator
+
+from .errors import PermError
+
+_ = Translator("Mutes", __file__)
+
+
+def ngettext(singular: str, plural: str, count: int, **fmt_kwargs) -> str:
+    """
+    This isn't a full ngettext.
+
+    Replace this with babel when Red can use that.
+    """
+    return singular.format(**fmt_kwargs) if count == 1 else plural.format(**fmt_kwargs)
+
+
+def hierarchy_check(*, mod: discord.Member, target: discord.Member):
+    """
+    Checks that things are hierarchy safe.
+
+    This does not check the bot can modify permissions.
+    This is assumed to be checked prior to command invocation.
+    
+    Parameters
+    -----------
+    mod : discord.Member
+        The responsible moderator
+    target : discord.Member
+        The target of a mute
+
+    Raises
+    ------
+    PermError
+        Any of:
+            - The target is above either the mod or bot.
+            - The target had the administrator perm
+            - The target is the guild owner
+        This error will contain a user facing error message.
+    """
+    if target == target.guild.owner:
+        raise PermError(friendly_error=_("You can't mute the owner of a guild."))
+
+    if target.guild_permissions.administrator:
+        raise PermError(
+            friendly_error=_("You can't mute someone with the administrator permission.")
+        )
+
+    if target.top_role >= target.guild.me:
+        raise PermError(friendly_error=_("I can't mute this user. (Discord Hierarchy applies)"))
+
+    if target.top_role >= mod.top_role:
+        raise PermError(friendly_error=_("You can't mute this user. (Discord Hierarchy applies)"))