Implemented optional duration parameter in slowmode command

bot/exts/moderation/slowmode.py

@@ -1,14 +1,18 @@
+from datetime import UTC, datetime, timedelta
 from typing import Literal
 
+from async_rediscache import RedisCache
 from dateutil.relativedelta import relativedelta
 from discord import TextChannel, Thread
 from discord.ext.commands import Cog, Context, group, has_any_role
+from pydis_core.utils.scheduling import Scheduler
 
 from bot.bot import Bot
 from bot.constants import Channels, Emojis, MODERATION_ROLES
 from bot.converters import DurationDelta
 from bot.log import get_logger
 from bot.utils import time
+from bot.utils.time import TimestampFormats, discord_timestamp
 
 log = get_logger(__name__)
 
@@ -26,8 +30,15 @@
 class Slowmode(Cog):
     """Commands for getting and setting slowmode delays of text channels."""
 
+    # Stores the expiration timestamp in POSIX format for active slowmodes, keyed by channel ID.
+    slowmode_expiration_cache = RedisCache()
+
+    # Stores the original slowmode interval by channel ID, allowing its restoration after temporary slowmode expires.
+    original_slowmode_cache = RedisCache()
+
     def __init__(self, bot: Bot) -> None:
         self.bot = bot
+        self.scheduler = Scheduler(self.__class__.__name__)
 
     @group(name="slowmode", aliases=["sm"], invoke_without_command=True)
     async def slowmode_group(self, ctx: Context) -> None:
@@ -42,17 +53,29 @@ async def get_slowmode(self, ctx: Context, channel: MessageHolder) -> None:
             channel = ctx.channel
 
         humanized_delay = time.humanize_delta(seconds=channel.slowmode_delay)
-
-        await ctx.send(f"The slowmode delay for {channel.mention} is {humanized_delay}.")
+        if await self.slowmode_expiration_cache.contains(channel.id):
+            expiration_time = await self.slowmode_expiration_cache.get(channel.id)
+            expiration_timestamp = discord_timestamp(expiration_time, TimestampFormats.RELATIVE)
+            await ctx.send(
+                f"The slowmode delay for {channel.mention} is {humanized_delay} and expires in {expiration_timestamp}."
+            )
+        else:
+            await ctx.send(f"The slowmode delay for {channel.mention} is {humanized_delay}.")
 
     @slowmode_group.command(name="set", aliases=["s"])
     async def set_slowmode(
         self,
         ctx: Context,
         channel: MessageHolder,
         delay: DurationDelta | Literal["0s", "0seconds"],
+        duration: DurationDelta | None = None
     ) -> None:
-        """Set the slowmode delay for a text channel."""
+        """
+        Set the slowmode delay for a text channel.
+
+        Supports temporary slowmodes with the `duration` argument that automatically
+        revert to the original delay after expiration.
+        """
         # Use the channel this command was invoked in if one was not given
         if channel is None:
             channel = ctx.channel
@@ -66,37 +89,98 @@ async def set_slowmode(
         humanized_delay = time.humanize_delta(delay)
 
         # Ensure the delay is within discord's limits
-        if slowmode_delay <= SLOWMODE_MAX_DELAY:
-            log.info(f"{ctx.author} set the slowmode delay for #{channel} to {humanized_delay}.")
-
-            await channel.edit(slowmode_delay=slowmode_delay)
-            if channel.id in COMMONLY_SLOWMODED_CHANNELS:
-                log.info(f"Recording slowmode change in stats for {channel.name}.")
-                self.bot.stats.gauge(f"slowmode.{COMMONLY_SLOWMODED_CHANNELS[channel.id]}", slowmode_delay)
+        if not slowmode_delay <= SLOWMODE_MAX_DELAY:
+            log.info(
+                f"{ctx.author} tried to set the slowmode delay of #{channel} to {humanized_delay}, "
+                "which is not between 0 and 6 hours."
+            )
 
             await ctx.send(
-                f"{Emojis.check_mark} The slowmode delay for {channel.mention} is now {humanized_delay}."
+                f"{Emojis.cross_mark} The slowmode delay must be between 0 and 6 hours."
             )
+            return
 
-        else:
+        if duration is not None:
+            slowmode_duration = time.relativedelta_to_timedelta(duration).total_seconds()
+            humanized_duration = time.humanize_delta(duration)
+
+            expiration_time = datetime.now(tz=UTC) + timedelta(seconds=slowmode_duration)
+            expiration_timestamp = discord_timestamp(expiration_time, TimestampFormats.RELATIVE)
+
+            # Only update original_slowmode_cache if the last slowmode was not temporary.
+            if not await self.slowmode_expiration_cache.contains(channel.id):
+                await self.original_slowmode_cache.set(channel.id, channel.slowmode_delay)
+            await self.slowmode_expiration_cache.set(channel.id, expiration_time.timestamp())
+
+            self.scheduler.schedule_at(expiration_time, channel.id, self._revert_slowmode(channel.id))
             log.info(
-                f"{ctx.author} tried to set the slowmode delay of #{channel} to {humanized_delay}, "
-                "which is not between 0 and 6 hours."
+                f"{ctx.author} set the slowmode delay for #{channel} to"
+                f"{humanized_delay} which expires in {humanized_duration}."
             )
+            await channel.edit(slowmode_delay=slowmode_delay)
+            await ctx.send(
+            f"{Emojis.check_mark} The slowmode delay for {channel.mention}"
+            f" is now {humanized_delay} and expires in {expiration_timestamp}."
+        )
+        else:
+            if await self.slowmode_expiration_cache.contains(channel.id):
+                await self.slowmode_expiration_cache.delete(channel.id)
+                await self.original_slowmode_cache.delete(channel.id)
+                self.scheduler.cancel(channel.id)
 
+            log.info(f"{ctx.author} set the slowmode delay for #{channel} to {humanized_delay}.")
+            await channel.edit(slowmode_delay=slowmode_delay)
             await ctx.send(
-                f"{Emojis.cross_mark} The slowmode delay must be between 0 and 6 hours."
+                f"{Emojis.check_mark} The slowmode delay for {channel.mention} is now {humanized_delay}."
             )
+        if channel.id in COMMONLY_SLOWMODED_CHANNELS:
+            log.info(f"Recording slowmode change in stats for {channel.name}.")
+            self.bot.stats.gauge(f"slowmode.{COMMONLY_SLOWMODED_CHANNELS[channel.id]}", slowmode_delay)
+
+    async def _reschedule(self) -> None:
+        log.trace("Rescheduling the expiration of temporary slowmodes from cache.")
+        for channel_id, expiration in await self.slowmode_expiration_cache.items():
+            expiration_datetime = datetime.fromtimestamp(expiration, tz=UTC)
+            channel = self.bot.get_channel(channel_id)
+            log.info(f"Rescheduling slowmode expiration for #{channel} ({channel_id}).")
+            self.scheduler.schedule_at(expiration_datetime, channel_id, self._revert_slowmode(channel_id))
+
+    async def _revert_slowmode(self, channel_id: int) -> None:
+        original_slowmode = await self.original_slowmode_cache.get(channel_id)
+        slowmode_delay = time.humanize_delta(seconds=original_slowmode)
+        channel = self.bot.get_channel(channel_id)
+        log.info(f"Slowmode in #{channel} ({channel.id}) has expired and has reverted to {slowmode_delay}.")
+        await channel.edit(slowmode_delay=original_slowmode)
+        await channel.send(
+            f"{Emojis.check_mark} A previously applied slowmode has expired and has been reverted to {slowmode_delay}."
+        )
+        await self.slowmode_expiration_cache.delete(channel.id)
+        await self.original_slowmode_cache.delete(channel.id)
 
     @slowmode_group.command(name="reset", aliases=["r"])
     async def reset_slowmode(self, ctx: Context, channel: MessageHolder) -> None:
         """Reset the slowmode delay for a text channel to 0 seconds."""
         await self.set_slowmode(ctx, channel, relativedelta(seconds=0))
+        if channel is None:
+            channel = ctx.channel
+        if await self.slowmode_expiration_cache.contains(channel.id):
+            await self.slowmode_expiration_cache.delete(channel.id)
+            await self.original_slowmode_cache.delete(channel.id)
+            self.scheduler.cancel(channel.id)
 
     async def cog_check(self, ctx: Context) -> bool:
         """Only allow moderators to invoke the commands in this cog."""
         return await has_any_role(*MODERATION_ROLES).predicate(ctx)
 
+    async def cog_load(self) -> None:
+        """Wait for guild to become available and reschedule slowmodes which should expire."""
+        await self.bot.wait_until_guild_available()
+        await self._reschedule()
+
+    async def cog_unload(self) -> None:
+        """Cancel all scheduled tasks."""
+        self.scheduler.cancel_all()
+
 
 async def setup(bot: Bot) -> None:
     """Load the Slowmode cog."""

tests/bot/exts/moderation/test_slowmode.py

@@ -1,14 +1,16 @@
-import unittest
+import asyncio
+import datetime
 from unittest import mock
 
 from dateutil.relativedelta import relativedelta
 
 from bot.constants import Emojis
 from bot.exts.moderation.slowmode import Slowmode
+from tests.base import RedisTestCase
 from tests.helpers import MockBot, MockContext, MockTextChannel
 
 
-class SlowmodeTests(unittest.IsolatedAsyncioTestCase):
+class SlowmodeTests(RedisTestCase):
 
     def setUp(self) -> None:
         self.bot = MockBot()
@@ -95,6 +97,114 @@ async def test_reset_slowmode_sets_delay_to_zero(self) -> None:
             self.ctx, text_channel, relativedelta(seconds=0)
         )
 
+    @mock.patch("bot.exts.moderation.slowmode.datetime")
+    async def test_set_slowmode_with_duration(self, mock_datetime) -> None:
+        """Set slowmode with a duration"""
+        mock_datetime.now.return_value = datetime.datetime(2025, 6, 2, 12, 0, 0, tzinfo=datetime.UTC)
+        test_cases = (
+            ("python-general", 6, 6000, f"{Emojis.check_mark} The slowmode delay for #python-general is now 6 seconds"
+             " and expires in <t:1748871600:R>."),
+            ("mod-spam", 5, 600, f"{Emojis.check_mark} The slowmode delay for #mod-spam is now 5 seconds and expires"
+             " in <t:1748866200:R>."),
+            ("changelog", 12, 7200, f"{Emojis.check_mark} The slowmode delay for #changelog is now 12 seconds and"
+             " expires in <t:1748872800:R>.")
+        )
+        for channel_name, seconds, duration, result_msg in test_cases:
+            with self.subTest(
+                channel_mention=channel_name,
+                seconds=seconds,
+                duration=duration,
+                result_msg=result_msg
+            ):
+                text_channel = MockTextChannel(name=channel_name, slowmode_delay=0)
+                await self.cog.set_slowmode(
+                    self.cog,
+                    self.ctx,
+                    text_channel,
+                    relativedelta(seconds=seconds),
+                    duration=relativedelta(seconds=duration)
+                )
+                text_channel.edit.assert_awaited_once_with(slowmode_delay=float(seconds))
+                self.ctx.send.assert_called_once_with(result_msg)
+            self.ctx.reset_mock()
+
+    @mock.patch("bot.exts.moderation.slowmode.datetime", wraps=datetime.datetime)
+    async def test_callback_scheduled(self, mock_datetime, ):
+        """Schedule slowmode to be reverted"""
+        mock_now = datetime.datetime(2025, 6, 2, 12, 0, 0, tzinfo=datetime.UTC)
+        mock_datetime.now.return_value = mock_now
+        self.cog.scheduler=mock.MagicMock(wraps=self.cog.scheduler)
+
+        text_channel = MockTextChannel(name="python-general", slowmode_delay=2, id=123)
+        await self.cog.set_slowmode(
+            self.cog,
+            self.ctx,
+            text_channel,
+            relativedelta(seconds=4),
+            relativedelta(seconds=10))
+
+        args = (mock_now+relativedelta(seconds=10), text_channel.id, mock.ANY)
+        self.cog.scheduler.schedule_at.assert_called_once_with(*args)
+
+    async def test_revert_slowmode_callback(self) -> None:
+        """Check that the slowmode is reverted"""
+        text_channel = MockTextChannel(name="python-general", slowmode_delay=2, id=123)
+        self.bot.get_channel = mock.MagicMock(return_value=text_channel)
+        await self.cog.set_slowmode(
+            self.cog, self.ctx, text_channel, relativedelta(seconds=4), relativedelta(seconds=10)
+            )
+        await self.cog._revert_slowmode(text_channel.id)
+        text_channel.edit.assert_awaited_with(slowmode_delay=2)
+        text_channel.send.assert_called_once_with(
+            f"{Emojis.check_mark} A previously applied slowmode has expired and has been reverted to 2 seconds."
+            )
+
+    async def test_reschedule_slowmodes(self) -> None:
+        """Does not reschedule if cache is empty"""
+        self.cog.scheduler.schedule_at = mock.MagicMock()
+        self.cog._reschedule = mock.AsyncMock()
+        await self.cog.cog_unload()
+        await self.cog.cog_load()
+
+        self.cog._reschedule.assert_called()
+        self.cog.scheduler.schedule_at.assert_not_called()
+
+    async def test_reschedule_upon_reload(self) -> None:
+        """ Check that method `_reschedule` is called upon cog reload"""
+        self.cog._reschedule = mock.AsyncMock(wraps=self.cog._reschedule)
+        await self.cog.cog_unload()
+        await self.cog.cog_load()
+
+        self.cog._reschedule.assert_called()
+
+    @mock.patch("bot.exts.moderation.slowmode.datetime", wraps=datetime.datetime)
+    async def test_reschedules_slowmodes(self, mock_datetime) -> None:
+        """Slowmodes are loaded from cache at cog reload and scheduled to be reverted."""
+        mock_datetime.now.return_value = datetime.datetime(2025, 6, 2, 12, 0, 0, tzinfo=datetime.UTC)
+        mock_now = datetime.datetime(2025, 6, 2, 12, 0, 0, tzinfo=datetime.UTC)
+
+        channels = {}
+        slowmodes = (
+            (123, (mock_now - datetime.timedelta(10)).timestamp(), 2), # expiration in the past
+            (456, (mock_now + datetime.timedelta(20)).timestamp(), 4), # expiration in the future
+        )
+
+        for channel_id, expiration_datetime, delay in slowmodes:
+            channel = MockTextChannel(slowmode_delay=delay, id=channel_id)
+            channels[channel_id] = channel
+            await self.cog.slowmode_expiration_cache.set(channel_id, expiration_datetime)
+            await self.cog.original_slowmode_cache.set(channel_id, delay)
+
+        self.bot.get_channel = mock.MagicMock(side_effect=lambda channel_id: channels.get(channel_id))
+        await self.cog.cog_unload()
+        await self.cog.cog_load()
+        for channel_id in channels:
+            self.assertIn(channel_id, self.cog.scheduler)
+
+        await asyncio.sleep(1) # give scheduled task time to execute
+        channels[123].edit.assert_awaited_once_with(slowmode_delay=channels[123].slowmode_delay)
+        channels[456].edit.assert_not_called()
+
     @mock.patch("bot.exts.moderation.slowmode.has_any_role")
     @mock.patch("bot.exts.moderation.slowmode.MODERATION_ROLES", new=(1, 2, 3))
     async def test_cog_check(self, role_check):