Add custom status support (Cog-Creators#6226)

Co-authored-by: Jakub Kuczys <me@jacken.men>

docs/cog_guides/core.rst

@@ -3758,6 +3758,35 @@ Maximum length for a competing status is 128 characters.
 **Arguments:**
     - ``[competing]`` - The text to follow ``Competing in``. Leave blank to clear the current activity status.
 
+.. _core-command-set-status-custom:
+
+"""""""""""""""""
+set status custom
+"""""""""""""""""
+
+.. note:: |owner-lock|
+
+**Syntax**
+
+.. code-block:: none
+
+    [p]set status custom [text]
+
+**Description**
+
+Sets Red's custom status.
+
+This will appear as ``<text>``.
+
+Maximum length for a custom status is 128 characters.
+
+**Examples:**
+    - ``[p]set status custom`` - Clears the activity status.
+    - ``[p]set status custom Running cogs...``
+
+**Arguments:**
+    - ``[text]`` - The custom status text. Leave blank to clear the current activity status.
+
 .. _core-command-set-status-dnd:
 
 """"""""""""""

redbot/core/core_commands.py

@@ -2739,6 +2739,38 @@ async def _set_status_competing(self, ctx: commands.Context, *, competing: str =
         else:
             await ctx.send(_("Competing cleared."))
 
+    @_set_status.command(name="custom")
+    @commands.bot_in_a_guild()
+    @commands.is_owner()
+    async def _set_status_custom(self, ctx: commands.Context, *, text: str = None):
+        """Sets [botname]'s custom status.
+
+        This will appear as `<text>`.
+
+        Maximum length for a custom status is 128 characters.
+
+        **Examples:**
+        - `[p]set status custom` - Clears the activity status.
+        - `[p]set status custom Running cogs...`
+
+        **Arguments:**
+        - `[text]` - The custom status text. Leave blank to clear the current activity status.
+        """
+
+        status = ctx.bot.guilds[0].me.status if len(ctx.bot.guilds) > 0 else discord.Status.online
+        if text:
+            if len(text) > 128:
+                await ctx.send(_("The maximum length of custom statuses is 128 characters."))
+                return
+            activity = discord.Activity(name=text, state=text, type=discord.ActivityType.custom)
+        else:
+            activity = None
+        await ctx.bot.change_presence(status=status, activity=activity)
+        if activity:
+            await ctx.send(_("Custom status set to `{text}`.").format(text=text))
+        else:
+            await ctx.send(_("Custom status cleared."))
+
     async def _set_my_status(self, ctx: commands.Context, status: discord.Status):
         game = ctx.bot.guilds[0].me.activity if len(ctx.bot.guilds) > 0 else None
         await ctx.bot.change_presence(status=status, activity=game)