Add message purging functions to Thread

discord/threads.py

@@ -23,12 +23,14 @@ DEALINGS IN THE SOFTWARE.
 """
 
 from __future__ import annotations
-from discord.types.threads import ThreadMember
-from typing import Dict, Optional, TYPE_CHECKING
+from typing import Callable, Dict, Iterable, List, Optional, Sequence, TYPE_CHECKING
+import time
+import asyncio
 
 from .mixins import Hashable
 from .abc import Messageable
 from .enums import ChannelType, try_enum
+from .errors import ClientException, NoMoreItems
 from .utils import MISSING, parse_time, _get_as_snowflake
 
 __all__ = (
@@ -47,7 +49,7 @@ if TYPE_CHECKING:
     from .channel import TextChannel
     from .member import Member
     from .message import Message
-    from .abc import Snowflake
+    from .abc import Snowflake, SnowflakeTime
     from .state import ConnectionState
 
 
@@ -232,6 +234,175 @@ class Thread(Messageable, Hashable):
         """
         return self._type is ChannelType.news_thread
 
+    async def delete_messages(self, messages: Iterable[Snowflake]) -> None:
+        """|coro|
+
+        Deletes a list of messages. This is similar to :meth:`Message.delete`
+        except it bulk deletes multiple messages.
+
+        As a special case, if the number of messages is 0, then nothing
+        is done. If the number of messages is 1 then single message
+        delete is done. If it's more than two, then bulk delete is used.
+
+        You cannot bulk delete more than 100 messages or messages that
+        are older than 14 days old.
+
+        You must have the :attr:`~Permissions.manage_messages` permission to
+        use this.
+
+        Usable only by bot accounts.
+
+        Parameters
+        -----------
+        messages: Iterable[:class:`abc.Snowflake`]
+            An iterable of messages denoting which ones to bulk delete.
+
+        Raises
+        ------
+        ClientException
+            The number of messages to delete was more than 100.
+        Forbidden
+            You do not have proper permissions to delete the messages or
+            you're not using a bot account.
+        NotFound
+            If single delete, then the message was already deleted.
+        HTTPException
+            Deleting the messages failed.
+        """
+        if not isinstance(messages, (list, tuple)):
+            messages = list(messages)
+
+        if len(messages) == 0:
+            return  # do nothing
+
+        if len(messages) == 1:
+            message_id = messages[0].id
+            await self._state.http.delete_message(self.id, message_id)
+            return
+
+        if len(messages) > 100:
+            raise ClientException('Can only bulk delete messages up to 100 messages')
+
+        message_ids = [m.id for m in messages]
+        await self._state.http.delete_messages(self.id, message_ids)
+
+    async def purge(
+        self,
+        *,
+        limit: int = 100,
+        check: Callable[[Message], bool] = MISSING,
+        before: Optional[SnowflakeTime] = None,
+        after: Optional[SnowflakeTime] = None,
+        around: Optional[SnowflakeTime] = None,
+        oldest_first: Optional[bool] = False,
+        bulk: bool = True,
+    ) -> List[Message]:
+        """|coro|
+
+        Purges a list of messages that meet the criteria given by the predicate
+        ``check``. If a ``check`` is not provided then all messages are deleted
+        without discrimination.
+
+        You must have the :attr:`~Permissions.manage_messages` permission to
+        delete messages even if they are your own (unless you are a user
+        account). The :attr:`~Permissions.read_message_history` permission is
+        also needed to retrieve message history.
+
+        Examples
+        ---------
+
+        Deleting bot's messages ::
+
+            def is_me(m):
+                return m.author == client.user
+
+            deleted = await thread.purge(limit=100, check=is_me)
+            await thread.send(f'Deleted {len(deleted)} message(s)')
+
+        Parameters
+        -----------
+        limit: Optional[:class:`int`]
+            The number of messages to search through. This is not the number
+            of messages that will be deleted, though it can be.
+        check: Callable[[:class:`Message`], :class:`bool`]
+            The function used to check if a message should be deleted.
+            It must take a :class:`Message` as its sole parameter.
+        before: Optional[Union[:class:`abc.Snowflake`, :class:`datetime.datetime`]]
+            Same as ``before`` in :meth:`history`.
+        after: Optional[Union[:class:`abc.Snowflake`, :class:`datetime.datetime`]]
+            Same as ``after`` in :meth:`history`.
+        around: Optional[Union[:class:`abc.Snowflake`, :class:`datetime.datetime`]]
+            Same as ``around`` in :meth:`history`.
+        oldest_first: Optional[:class:`bool`]
+            Same as ``oldest_first`` in :meth:`history`.
+        bulk: :class:`bool`
+            If ``True``, use bulk delete. Setting this to ``False`` is useful for mass-deleting
+            a bot's own messages without :attr:`Permissions.manage_messages`. When ``True``, will
+            fall back to single delete if messages are older than two weeks.
+
+        Raises
+        -------
+        Forbidden
+            You do not have proper permissions to do the actions required.
+        HTTPException
+            Purging the messages failed.
+
+        Returns
+        --------
+        List[:class:`.Message`]
+            The list of messages that were deleted.
+        """
+
+        if check is MISSING:
+            check = lambda m: True
+
+        iterator = self.history(limit=limit, before=before, after=after, oldest_first=oldest_first, around=around)
+        ret: List[Message] = []
+        count = 0
+
+        minimum_time = int((time.time() - 14 * 24 * 60 * 60) * 1000.0 - 1420070400000) << 22
+
+        async def _single_delete_strategy(messages: Iterable[Message]):
+            for m in messages:
+                await m.delete()
+
+        strategy = self.delete_messages if bulk else _single_delete_strategy
+
+        async for message in iterator:
+            if count == 100:
+                to_delete = ret[-100:]
+                await strategy(to_delete)
+                count = 0
+                await asyncio.sleep(1)
+
+            if not check(message):
+                continue
+
+            if message.id < minimum_time:
+                # older than 14 days old
+                if count == 1:
+                    await ret[-1].delete()
+                elif count >= 2:
+                    to_delete = ret[-count:]
+                    await strategy(to_delete)
+
+                count = 0
+                strategy = _single_delete_strategy
+
+            count += 1
+            ret.append(message)
+
+        # SOme messages remaining to poll
+        if count >= 2:
+            # more than 2 messages -> bulk delete
+            to_delete = ret[-count:]
+            await strategy(to_delete)
+        elif count == 1:
+            # delete a single message
+            await ret[-1].delete()
+
+        return ret
+
     async def edit(
         self,
         *,
@@ -386,6 +557,7 @@ class Thread(Messageable, Hashable):
     def _pop_member(self, member_id: int) -> Optional[ThreadMember]:
         return self._members.pop(member_id, None)
 
+
 class ThreadMember(Hashable):
     """Represents a Discord thread member.