Help delete pages delay feature (#3433)

* Added 'deletedelay' feature for help

* Fixes

* More fixes

* Use better message when disabling

* Added changelog entry

* Addressed feedback

* Improved the pages check

* Added additional command check

* Improved command description

* Final feedback improvements

changelog.d/3433.feature.rst

@@ -0,0 +1 @@
+Added a ``[p]helpset deletedelay`` command, that lets you set a delay (in seconds) after which help messages / pages will be deleted.

redbot/core/bot.py

@@ -88,6 +88,7 @@ class RedBase(commands.GroupMixin, commands.bot.BotBase, RPCMixin):  # pylint: d
             custom_info=None,
             help__page_char_limit=1000,
             help__max_pages_in_guild=2,
+            help__delete_delay=0,
             help__use_menus=False,
             help__show_hidden=False,
             help__verify_checks=True,
@@ -186,9 +187,9 @@ class RedBase(commands.GroupMixin, commands.bot.BotBase, RPCMixin):  # pylint: d
     def before_invoke(self, coro: T_BIC) -> T_BIC:
         """
         Overridden decorator method for Red's ``before_invoke`` behavior.
-        
+
         This can safely be used purely functionally as well.
-        
+
         3rd party cogs should remove any hooks which they register at unload
         using `remove_before_invoke_hook`
 
@@ -199,12 +200,12 @@ class RedBase(commands.GroupMixin, commands.bot.BotBase, RPCMixin):  # pylint: d
             only called if all checks and argument parsing procedures pass
             without error. If any check or argument parsing procedures fail
             then the hooks are not called.
-        
+
         Parameters
         ----------
         coro: Callable[[commands.Context], Awaitable[Any]]
             The coroutine to register as the pre-invoke hook.
-        
+
         Raises
         ------
         TypeError
@@ -298,7 +299,7 @@ class RedBase(commands.GroupMixin, commands.bot.BotBase, RPCMixin):  # pylint: d
         ------
         TypeError
             Did not provide ``who`` or ``who_id``
-            
+
         Returns
         -------
         bool

redbot/core/commands/help.py

@@ -44,6 +44,7 @@ from . import commands
 from .context import Context
 from ..i18n import Translator
 from ..utils import menus
+from ..utils.mod import mass_purge
 from ..utils._internal_utils import fuzzy_command_search, format_fuzzy_results
 from ..utils.chat_formatting import box, pagify
 
@@ -627,36 +628,52 @@ class RedHelpFormatter:
         Sends pages based on settings.
         """
 
-        if not (
-            ctx.channel.permissions_for(ctx.me).add_reactions
-            and await ctx.bot._config.help.use_menus()
-        ):
+        # save on config calls
+        config_help = await ctx.bot._config.help()
+        channel_permissions = ctx.channel.permissions_for(ctx.me)
 
-            max_pages_in_guild = await ctx.bot._config.help.max_pages_in_guild()
-            destination = ctx.author if len(pages) > max_pages_in_guild else ctx
+        if not (channel_permissions.add_reactions and config_help["use_menus"]):
 
-            if embed:
-                for page in pages:
-                    try:
-                        await destination.send(embed=page)
-                    except discord.Forbidden:
-                        return await ctx.send(
-                            T_(
-                                "I couldn't send the help message to you in DM. "
-                                "Either you blocked me or you disabled DMs in this server."
-                            )
-                        )
-            else:
-                for page in pages:
-                    try:
-                        await destination.send(page)
-                    except discord.Forbidden:
-                        return await ctx.send(
-                            T_(
-                                "I couldn't send the help message to you in DM. "
-                                "Either you blocked me or you disabled DMs in this server."
-                            )
+            max_pages_in_guild = config_help["max_pages_in_guild"]
+            use_DMs = len(pages) > max_pages_in_guild
+            destination = ctx.author if use_DMs else ctx.channel
+            delete_delay = config_help["delete_delay"]
+
+            messages: List[discord.Message] = []
+            for page in pages:
+                try:
+                    if embed:
+                        msg = await destination.send(embed=page)
+                    else:
+                        msg = await destination.send(page)
+                except discord.Forbidden:
+                    return await ctx.send(
+                        T_(
+                            "I couldn't send the help message to you in DM. "
+                            "Either you blocked me or you disabled DMs in this server."
                         )
+                    )
+                else:
+                    messages.append(msg)
+
+            # The if statement takes into account that 'destination' will be
+            # the context channel in non-DM context, reusing 'channel_permissions' to avoid
+            # computing the permissions twice.
+            if (
+                not use_DMs  # we're not in DMs
+                and delete_delay > 0  # delete delay is enabled
+                and channel_permissions.manage_messages  # we can manage messages here
+            ):
+
+                # We need to wrap this in a task to not block after-sending-help interactions.
+                # The channel has to be TextChannel as we can't bulk-delete from DMs
+                async def _delete_delay_help(
+                    channel: discord.TextChannel, messages: List[discord.Message], delay: int
+                ):
+                    await asyncio.sleep(delay)
+                    await mass_purge(messages, channel)
+
+                asyncio.create_task(_delete_delay_help(destination, messages, delete_delay))
         else:
             # Specifically ensuring the menu's message is sent prior to returning
             m = await (ctx.send(embed=pages[0]) if embed else ctx.send(pages[0]))

redbot/core/core_commands.py

@@ -1368,6 +1368,30 @@ class Core(commands.Cog, CoreLogic):
         await ctx.bot._config.help.max_pages_in_guild.set(pages)
         await ctx.send(_("Done. The page limit has been set to {}.").format(pages))
 
+    @helpset.command(name="deletedelay")
+    @commands.bot_has_permissions(manage_messages=True)
+    async def helpset_deletedelay(self, ctx: commands.Context, seconds: int):
+        """Set the delay after which help pages will be deleted.
+
+        The setting is disabled by default, and only applies to non-menu help,
+        sent in server text channels.
+        Setting the delay to 0 disables this feature.
+
+        The bot has to have MANAGE_MESSAGES permission for this to work.
+        """
+        if seconds < 0:
+            await ctx.send(_("You must give a value of zero or greater!"))
+            return
+        if seconds > 60 * 60 * 24 * 14:  # 14 days
+            await ctx.send(_("The delay cannot be longer than 14 days!"))
+            return
+
+        await ctx.bot._config.help.delete_delay.set(seconds)
+        if seconds == 0:
+            await ctx.send(_("Done. Help messages will not be deleted now."))
+        else:
+            await ctx.send(_("Done. The delete delay has been set to {} seconds.").format(seconds))
+
     @helpset.command(name="tagline")
     async def helpset_tagline(self, ctx: commands.Context, *, tagline: str = None):
         """