Handle off-topic channel names that are invalid for servers in Server Discovery

bot/exts/fun/off_topic_names.py

@@ -5,11 +5,13 @@
 import random
 from functools import partial
 
-from discord import ButtonStyle, Colour, Embed, Interaction
+from discord import ButtonStyle, Colour, Embed, HTTPException, Interaction
+from discord.abc import GuildChannel
 from discord.ext import tasks
 from discord.ext.commands import Cog, Context, group, has_any_role
 from discord.ui import Button, View
 from pydis_core.site_api import ResponseCodeError
+from pydis_core.utils.channel import get_or_fetch_channel
 
 from bot.bot import Bot
 from bot.constants import Bot as BotConfig, Channels, MODERATION_ROLES, NEGATIVE_REPLIES
@@ -23,6 +25,7 @@
 OTN_FORMATTER = "ot{number}-{name}"
 OT_NUMBER_INDEX = 2
 NAME_START_INDEX = 4
+MAX_RENAME_ATTEMPTS = 3
 
 log = get_logger(__name__)
 
@@ -46,29 +49,137 @@ async def cog_unload(self) -> None:
         self.update_names.clear_exception_types()
         self.update_names.stop()
 
-    @tasks.loop(time=datetime.time(), reconnect=True)
-    async def update_names(self) -> None:
-        """Background updater task that performs the daily channel name update."""
-        await self.bot.wait_until_guild_available()
-
+    async def _fetch_ot_names(self, count: int) -> list[str]:
         try:
-            channel_0_name, channel_1_name, channel_2_name = await self.bot.api_client.get(
-                "bot/off-topic-channel-names", params={"random_items": 3}
+            return await self.bot.api_client.get(
+                "bot/off-topic-channel-names", params={"random_items": count}
             )
         except ResponseCodeError as e:
             log.error(f"Failed to get new off-topic channel names: code {e.response.status}")
             raise
 
-        channel_0, channel_1, channel_2 = (self.bot.get_channel(channel_id) for channel_id in CHANNELS)
+    @tasks.loop(time=datetime.time(), reconnect=True)
+    async def update_names(self) -> None:
+        """Background updater task that performs the daily channel name update."""
+        await self.bot.wait_until_guild_available()
 
-        await channel_0.edit(name=OTN_FORMATTER.format(number=0, name=channel_0_name))
-        await channel_1.edit(name=OTN_FORMATTER.format(number=1, name=channel_1_name))
-        await channel_2.edit(name=OTN_FORMATTER.format(number=2, name=channel_2_name))
+        ot_channels = [await get_or_fetch_channel(self.bot, channel) for channel in CHANNELS]
+        num_ot_channels = len(CHANNELS)
+
+        channel_name_pool = iter(await self._fetch_ot_names(num_ot_channels))
+
+        renamed_ot_channels: set[int] = set()
+        deactivated_ot_names: list[str] = []
+
+        exit_early = False
+        for ot_indx, ot_channel in enumerate(ot_channels):
+            if exit_early:
+                break
+
+            attempt = 0
+            while attempt < MAX_RENAME_ATTEMPTS:
+                attempt += 1
+                try:
+                    new_name = next(channel_name_pool)
+                except StopIteration:
+                    mod_meta = await get_or_fetch_channel(self.bot, Channels.mod_meta)
+
+                    failed_to_rename = [
+                        ot_channel.mention for ot_channel in ot_channels if ot_channel.id not in renamed_ot_channels
+                    ]
+                    await mod_meta.send(
+                        f":x: The pool of off-topic names ran out whilst attempting to rename {ot_channel.mention}.\n"
+                        f"The following off-topic channels have not been renamed: {' '.join(failed_to_rename)}"
+                    )
+                    exit_early = True
+                    break
+
+                new_channel_name = OTN_FORMATTER.format(number=ot_indx, name=new_name)
+                try:
+                    old_channel_name = ot_channel.name
+                    log.debug(
+                        f"Attempt #{attempt} / {MAX_RENAME_ATTEMPTS} to rename "
+                        f"#{old_channel_name} to #{new_channel_name}"
+                    )
+
+                    await ot_channel.edit(name=new_channel_name)
+                    log.debug(f"Successfully updated off-topic name #{old_channel_name} to #{new_channel_name}")
+                except HTTPException as e:
+                    # We need to handle code 50035 ("invalid form body"),
+                    # which we get when the new channel name isn't allowed.
+                    #
+                    # For more information see https://github.com/python-discord/bot/issues/2500
+                    if (e.code != 50035):
+                        # The error isn't the one we want to handle so re-raise
+                        log.error(f"Failed to rename #{ot_channel.name} to #{new_channel_name}")
+                        raise
+
+                    # Deactivate the name since it's not valid
+                    log.info(
+                        f"Failed to rename #{ot_channel.name} to #{new_channel_name} as it's not "
+                        "a valid name for servers in Server Discovery so removing it from the rota."
+                    )
+                    await self.bot.api_client.patch(
+                        f"bot/off-topic-channel-names/{new_name}",
+                        data={"active": False}
+                    )
+                    deactivated_ot_names.append(new_name)
+                    log.debug(f"Successfully removed {new_name} from the pool of off-topic channel names.")
+
+                    # Add a replacement off-topic channel name to the pool if it will be used
+                    if len(deactivated_ot_names) < (num_ot_channels * MAX_RENAME_ATTEMPTS):
+                        channel_name_pool = iter([*channel_name_pool, *await self._fetch_ot_names(1)])
+                else:
+                    renamed_ot_channels.add(ot_channel.id)
+                    break
+
+        if deactivated_ot_names:
+            failed_to_rename = [ot_channel for ot_channel in ot_channels if ot_channel.id not in renamed_ot_channels]
+            await self.handle_failed_renames(self.bot, deactivated_ot_names, failed_to_rename)
+
+    @staticmethod
+    async def handle_failed_renames(
+        bot: Bot,
+        deactivated_names: list[str],
+        ot_channels_not_renamed: list[GuildChannel]
+    ) -> None:
+        """Sends an appropriate warning/error message to mod-meta for each ot channel that had a failed rename."""
+        num_failures = len(deactivated_names)
+
+        # Handle pluralisations
+        if num_failures == 1:
+            name_or_names = "name"
+            its_or_theyre = "it's"
+            deactivated_names_joined = f"`{deactivated_names[0]}`"
+        else:
+            name_or_names = "names"
+            its_or_theyre = "they're"
+            deactivated_names_joined = (
+                ", ".join(f"`{name}`" for name in deactivated_names[:-1]) +
+                f", and `{deactivated_names[-1]}`"
+            )
 
-        log.debug(
-            "Updated off-topic channel names to"
-            f" {channel_0_name}, {channel_1_name} and {channel_2_name}"
+        message = (
+            f":warning: The following {num_failures} off-topic channel {name_or_names} failed, as {its_or_theyre} "
+            f"not valid for servers in Server Discovery: {deactivated_names_joined}."
         )
+        if num_ot_channels_not_renamed := len(ot_channels_not_renamed):
+            if num_ot_channels_not_renamed == 1:
+                ot_channels_not_renamed = ot_channels_not_renamed[0].mention
+            else:
+                ot_channels_not_renamed_joined = (
+                    ", ".join(ot_channel.mention for ot_channel in ot_channels_not_renamed[:-1]) +
+                    f" and {ot_channels_not_renamed[-1].mention}"
+                )
+            message += (
+                f"\n:x: Was unable to rename {ot_channels_not_renamed_joined} "
+                f"within the configured maximum {MAX_RENAME_ATTEMPTS} attempts."
+            )
+        else:
+            message += ("\n:white_check_mark: All off-topic channels were successfully renamed to other names.")
+
+        mod_meta_channel = await get_or_fetch_channel(bot, Channels.mod_meta)
+        await mod_meta_channel.send(message)
 
     async def toggle_ot_name_activity(self, ctx: Context, name: str, active: bool) -> None:
         """Toggle active attribute for an off-topic name."""
@@ -185,24 +296,24 @@ async def re_roll_command(self, ctx: Context, ot_channel_index: int | None = Non
             "bot/off-topic-channel-names", params={"random_items": 1}
         )
         try:
-            new_channel_name = response[0]
+            new_name = response[0]
         except IndexError:
             await ctx.send("Out of active off-topic names. Add new names to reroll.")
             return
 
         async def rename_channel() -> None:
             """Rename off-topic channel and log events."""
             await channel.edit(
-                name=OTN_FORMATTER.format(number=old_channel_name[OT_NUMBER_INDEX], name=new_channel_name)
+                name=OTN_FORMATTER.format(number=old_channel_name[OT_NUMBER_INDEX], name=new_name)
             )
             log.info(
                 f"{ctx.author} Off-topic channel re-named from `{old_ot_name}` "
-                f"to `{new_channel_name}`."
+                f"to `{new_name}`."
             )
 
             await ctx.message.reply(
                 f":ok_hand: Off-topic channel re-named from `{old_ot_name}` "
-                f"to `{new_channel_name}`. "
+                f"to `{new_name}`. "
             )
 
         try: