Help channels: move time functions to channel module

2 files changed, 39 insertions, 31 deletions

diff --git a/bot/exts/help_channels/_channel.py b/bot/exts/help_channels/_channel.py
index 047f41e89..93c0c7fc9 100644
--- a/bot/exts/help_channels/_channel.py
+++ b/bot/exts/help_channels/_channel.py
@@ -1,15 +1,22 @@
 import logging
 import typing as t
+from datetime import datetime, timedelta
 
 import discord
+from async_rediscache import RedisCache
 
 from bot import constants
+from bot.exts.help_channels import _message
 
 log = logging.getLogger(__name__)
 
 MAX_CHANNELS_PER_CATEGORY = 50
 EXCLUDED_CHANNELS = (constants.Channels.how_to_get_help, constants.Channels.cooldown)
 
+# This dictionary maps a help channel to the time it was claimed
+# RedisCache[discord.TextChannel.id, UtcPosixTimestamp]
+_claim_times = RedisCache(namespace="HelpChannels.claim_times")
+
 
 def get_category_channels(category: discord.CategoryChannel) -> t.Iterable[discord.TextChannel]:
     """Yield the text channels of the `category` in an unsorted manner."""
@@ -21,6 +28,35 @@ def get_category_channels(category: discord.CategoryChannel) -> t.Iterable[disco
             yield channel
 
 
+async def get_idle_time(channel: discord.TextChannel) -> t.Optional[int]:
+    """
+    Return the time elapsed, in seconds, since the last message sent in the `channel`.
+
+    Return None if the channel has no messages.
+    """
+    log.trace(f"Getting the idle time for #{channel} ({channel.id}).")
+
+    msg = await _message.get_last_message(channel)
+    if not msg:
+        log.debug(f"No idle time available; #{channel} ({channel.id}) has no messages.")
+        return None
+
+    idle_time = (datetime.utcnow() - msg.created_at).seconds
+
+    log.trace(f"#{channel} ({channel.id}) has been idle for {idle_time} seconds.")
+    return idle_time
+
+
+async def get_in_use_time(channel_id: int) -> t.Optional[timedelta]:
+    """Return the duration `channel_id` has been in use. Return None if it's not in use."""
+    log.trace(f"Calculating in use time for channel {channel_id}.")
+
+    claimed_timestamp = await _claim_times.get(channel_id)
+    if claimed_timestamp:
+        claimed = datetime.utcfromtimestamp(claimed_timestamp)
+        return datetime.utcnow() - claimed
+
+
 def is_excluded_channel(channel: discord.abc.GuildChannel) -> bool:
     """Check if a channel should be excluded from the help channel system."""
     return not isinstance(channel, discord.TextChannel) or channel.id in EXCLUDED_CHANNELS
diff --git a/bot/exts/help_channels/_cog.py b/bot/exts/help_channels/_cog.py
index 174c40096..390528fde 100644
--- a/bot/exts/help_channels/_cog.py
+++ b/bot/exts/help_channels/_cog.py
@@ -2,7 +2,7 @@ import asyncio
 import logging
 import random
 import typing as t
-from datetime import datetime, timedelta, timezone
+from datetime import datetime, timezone
 
 import discord
 import discord.abc
@@ -201,34 +201,6 @@ class HelpChannels(commands.Cog):
 
         return channel
 
-    async def get_in_use_time(self, channel_id: int) -> t.Optional[timedelta]:
-        """Return the duration `channel_id` has been in use. Return None if it's not in use."""
-        log.trace(f"Calculating in use time for channel {channel_id}.")
-
-        claimed_timestamp = await self.claim_times.get(channel_id)
-        if claimed_timestamp:
-            claimed = datetime.utcfromtimestamp(claimed_timestamp)
-            return datetime.utcnow() - claimed
-
-    @staticmethod
-    async def get_idle_time(channel: discord.TextChannel) -> t.Optional[int]:
-        """
-        Return the time elapsed, in seconds, since the last message sent in the `channel`.
-
-        Return None if the channel has no messages.
-        """
-        log.trace(f"Getting the idle time for #{channel} ({channel.id}).")
-
-        msg = await _message.get_last_message(channel)
-        if not msg:
-            log.debug(f"No idle time available; #{channel} ({channel.id}) has no messages.")
-            return None
-
-        idle_time = (datetime.utcnow() - msg.created_at).seconds
-
-        log.trace(f"#{channel} ({channel.id}) has been idle for {idle_time} seconds.")
-        return idle_time
-
     async def init_available(self) -> None:
         """Initialise the Available category with channels."""
         log.trace("Initialising the Available category with channels.")
@@ -329,7 +301,7 @@ class HelpChannels(commands.Cog):
         else:
             idle_seconds = constants.HelpChannels.deleted_idle_minutes * 60
 
-        time_elapsed = await self.get_idle_time(channel)
+        time_elapsed = await _channel.get_idle_time(channel)
 
         if time_elapsed is None or time_elapsed >= idle_seconds:
             log.info(
@@ -424,7 +396,7 @@ class HelpChannels(commands.Cog):
 
         self.bot.stats.incr(f"help.dormant_calls.{caller}")
 
-        in_use_time = await self.get_in_use_time(channel.id)
+        in_use_time = await _channel.get_in_use_time(channel.id)
         if in_use_time:
             self.bot.stats.timing("help.in_use_time", in_use_time)