Rapptz.discord.py/discord/iterators.py

"""
The MIT License (MIT)

Copyright (c) 2015-present Rapptz

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
"""

from __future__ import annotations

import asyncio
import datetime
from typing import Awaitable, TYPE_CHECKING, TypeVar, Optional, Any, Callable, Union, List, Tuple, AsyncIterator, Dict

from .errors import InvalidData, NoMoreItems
from .utils import snowflake_time, time_snowflake, maybe_coroutine, utcnow
from .object import Object
from .audit_logs import AuditLogEntry
from .commands import _command_factory
from .enums import CommandType
from .errors import InvalidArgument

__all__ = (
    'ReactionIterator',
    'HistoryIterator',
    'AuditLogIterator',
    'CommandIterator',
    'FakeCommandIterator',
)

if TYPE_CHECKING:
    from .types.audit_log import (
        AuditLog as AuditLogPayload,
    )
    from .types.guild import (
        Guild as GuildPayload,
    )
    from .types.message import (
        Message as MessagePayload,
    )
    from .types.user import (
        PartialUser as PartialUserPayload,
    )

    from .types.threads import (
        Thread as ThreadPayload,
    )

    from .member import Member
    from .user import User
    from .message import Message
    from .guild import Guild
    from .threads import Thread
    from .abc import Snowflake, Messageable
    from .commands import ApplicationCommand
    from .channel import DMChannel

T = TypeVar('T')
OT = TypeVar('OT')
_Func = Callable[[T], Union[OT, Awaitable[OT]]]

OLDEST_OBJECT = Object(id=0)


class _AsyncIterator(AsyncIterator[T]):
    __slots__ = ()

    async def next(self) -> T:
        raise NotImplementedError

    def get(self, **attrs: Any) -> Awaitable[Optional[T]]:
        def predicate(elem: T):
            for attr, val in attrs.items():
                nested = attr.split('__')
                obj = elem
                for attribute in nested:
                    obj = getattr(obj, attribute)

                if obj != val:
                    return False
            return True

        return self.find(predicate)

    async def find(self, predicate: _Func[T, bool]) -> Optional[T]:
        while True:
            try:
                elem = await self.next()
            except NoMoreItems:
                return None

            ret = await maybe_coroutine(predicate, elem)
            if ret:
                return elem

    def chunk(self, max_size: int) -> _ChunkedAsyncIterator[T]:
        if max_size <= 0:
            raise ValueError('Chunk size must be greater than 0')
        return _ChunkedAsyncIterator(self, max_size)

    def map(self, func: _Func[T, OT]) -> _MappedAsyncIterator[OT]:
        return _MappedAsyncIterator(self, func)

    def filter(self, predicate: _Func[T, bool]) -> _FilteredAsyncIterator[T]:
        return _FilteredAsyncIterator(self, predicate)

    async def flatten(self) -> List[T]:
        return [element async for element in self]

    async def __anext__(self) -> T:
        try:
            return await self.next()
        except NoMoreItems:
            raise StopAsyncIteration()


def _identity(x):
    return x


class _ChunkedAsyncIterator(_AsyncIterator[List[T]]):
    def __init__(self, iterator, max_size):
        self.iterator = iterator
        self.max_size = max_size

    async def next(self) -> List[T]:
        ret: List[T] = []
        n = 0
        while n < self.max_size:
            try:
                item = await self.iterator.next()
            except NoMoreItems:
                if ret:
                    return ret
                raise
            else:
                ret.append(item)
                n += 1
        return ret


class _MappedAsyncIterator(_AsyncIterator[T]):
    def __init__(self, iterator, func):
        self.iterator = iterator
        self.func = func

    async def next(self) -> T:
        # This raises NoMoreItems and will propagate appropriately
        item = await self.iterator.next()
        return await maybe_coroutine(self.func, item)


class _FilteredAsyncIterator(_AsyncIterator[T]):
    def __init__(self, iterator, predicate):
        self.iterator = iterator

        if predicate is None:
            predicate = _identity

        self.predicate = predicate

    async def next(self) -> T:
        getter = self.iterator.next
        pred = self.predicate
        while True:
            # propagate NoMoreItems similar to _MappedAsyncIterator
            item = await getter()
            ret = await maybe_coroutine(pred, item)
            if ret:
                return item


class ReactionIterator(_AsyncIterator[Union['User', 'Member']]):
    def __init__(self, message, emoji, limit=100, after=None):
        self.message = message
        self.limit = limit
        self.after = after
        state = message._state
        self.getter = state.http.get_reaction_users
        self.state = state
        self.emoji = emoji
        self.guild = message.guild
        self.channel_id = message.channel.id
        self.users = asyncio.Queue()

    async def next(self) -> Union[User, Member]:
        if self.users.empty():
            await self.fill_users()

        try:
            return self.users.get_nowait()
        except asyncio.QueueEmpty:
            raise NoMoreItems()

    async def fill_users(self):
        # This is a hack because >circular imports<
        from .user import User

        if self.limit > 0:
            retrieve = self.limit if self.limit <= 100 else 100

            after = self.after.id if self.after else None
            data: List[PartialUserPayload] = await self.getter(
                self.channel_id, self.message.id, self.emoji, retrieve, after=after
            )

            if data:
                self.limit -= retrieve
                self.after = Object(id=int(data[-1]['id']))

            if self.guild is None or isinstance(self.guild, Object):
                for element in reversed(data):
                    await self.users.put(User(state=self.state, data=element))
            else:
                for element in reversed(data):
                    member_id = int(element['id'])
                    member = self.guild.get_member(member_id)
                    if member is not None:
                        await self.users.put(member)
                    else:
                        await self.users.put(User(state=self.state, data=element))


class HistoryIterator(_AsyncIterator['Message']):
    """Iterator for receiving a channel's message history.

    The messages endpoint has two behaviours we care about here:
    If ``before`` is specified, the messages endpoint returns the `limit`
    newest messages before ``before``, sorted with newest first. For filling over
    100 messages, update the ``before`` parameter to the oldest message received.
    Messages will be returned in order by time.
    If ``after`` is specified, it returns the ``limit`` oldest messages after
    ``after``, sorted with newest first. For filling over 100 messages, update the
    ``after`` parameter to the newest message received. If messages are not
    reversed, they will be out of order (99-0, 199-100, so on)

    A note that if both ``before`` and ``after`` are specified, ``before`` is ignored by the
    messages endpoint.

    Parameters
    -----------
    messageable: :class:`abc.Messageable`
        Messageable class to retrieve message history from.
    limit: :class:`int`
        Maximum number of messages to retrieve
    before: Optional[Union[:class:`abc.Snowflake`, :class:`datetime.datetime`]]
        Message before which all messages must be.
    after: Optional[Union[:class:`abc.Snowflake`, :class:`datetime.datetime`]]
        Message after which all messages must be.
    around: Optional[Union[:class:`abc.Snowflake`, :class:`datetime.datetime`]]
        Message around which all messages must be. Limit max 101. Note that if
        limit is an even number, this will return at most limit+1 messages.
    oldest_first: Optional[:class:`bool`]
        If set to ``True``, return messages in oldest->newest order. Defaults to
        ``True`` if `after` is specified, otherwise ``False``.
    """

    def __init__(self, messageable, limit, before=None, after=None, around=None, oldest_first=None):

        if isinstance(before, datetime.datetime):
            before = Object(id=time_snowflake(before, high=False))
        if isinstance(after, datetime.datetime):
            after = Object(id=time_snowflake(after, high=True))
        if isinstance(around, datetime.datetime):
            around = Object(id=time_snowflake(around))

        if oldest_first is None:
            self.reverse = after is not None
        else:
            self.reverse = oldest_first

        self.messageable = messageable
        self.limit = limit
        self.before = before
        self.after = after or OLDEST_OBJECT
        self.around = around

        self._filter = None  # Message dict -> bool

        self.state = self.messageable._state
        self.logs_from = self.state.http.logs_from
        self.messages = asyncio.Queue()

        if self.around:
            if self.limit is None:
                raise ValueError('history does not support around with limit=None')
            if self.limit > 101:
                raise ValueError("history max limit 101 when specifying around parameter")
            elif self.limit == 101:
                self.limit = 100  # Thanks Discord

            self._retrieve_messages = self._retrieve_messages_around_strategy  # type: ignore
            if self.before and self.after:
                self._filter = lambda m: self.after.id < int(m['id']) < self.before.id
            elif self.before:
                self._filter = lambda m: int(m['id']) < self.before.id
            elif self.after:
                self._filter = lambda m: self.after.id < int(m['id'])
        else:
            if self.reverse:
                self._retrieve_messages = self._retrieve_messages_after_strategy  # type: ignore
                if self.before:
                    self._filter = lambda m: int(m['id']) < self.before.id
            else:
                self._retrieve_messages = self._retrieve_messages_before_strategy  # type: ignore
                if self.after and self.after != OLDEST_OBJECT:
                    self._filter = lambda m: int(m['id']) > self.after.id

    async def next(self) -> Message:
        if self.messages.empty():
            await self.fill_messages()

        try:
            return self.messages.get_nowait()
        except asyncio.QueueEmpty:
            raise NoMoreItems()

    def _get_retrieve(self):
        l = self.limit
        if l is None or l > 100:
            r = 100
        else:
            r = l
        self.retrieve = r
        return r > 0

    async def fill_messages(self):
        if not hasattr(self, 'channel'): # Do the required set up
            channel = await self.messageable._get_channel()
            self.channel = channel

        if self._get_retrieve():
            data = await self._retrieve_messages(self.retrieve)
            if len(data) < 100:
                self.limit = 0  # Terminate the infinite loop

            if self.reverse:
                data = reversed(data)
            if self._filter:
                data = filter(self._filter, data)

            channel = self.channel
            for element in data:
                await self.messages.put(self.state.create_message(channel=channel, data=element))

    async def _retrieve_messages(self, retrieve) -> List[Message]:
        """Retrieve messages and update next parameters."""
        raise NotImplementedError

    async def _retrieve_messages_before_strategy(self, retrieve):
        """Retrieve messages using before parameter."""
        before = self.before.id if self.before else None
        data: List[MessagePayload] = await self.logs_from(self.channel.id, retrieve, before=before)
        if len(data):
            if self.limit is not None:
                self.limit -= retrieve
            self.before = Object(id=int(data[-1]['id']))
        return data

    async def _retrieve_messages_after_strategy(self, retrieve):
        """Retrieve messages using after parameter."""
        after = self.after.id if self.after else None
        data: List[MessagePayload] = await self.logs_from(self.channel.id, retrieve, after=after)
        if len(data):
            if self.limit is not None:
                self.limit -= retrieve
            self.after = Object(id=int(data[0]['id']))
        return data

    async def _retrieve_messages_around_strategy(self, retrieve):
        """Retrieve messages using around parameter."""
        if self.around:
            around = self.around.id if self.around else None
            data: List[MessagePayload] = await self.logs_from(self.channel.id, retrieve, around=around)
            self.around = None
            return data
        return []


class AuditLogIterator(_AsyncIterator['AuditLogEntry']):
    def __init__(self, guild, limit=None, before=None, after=None, oldest_first=None, user_id=None, action_type=None):
        if isinstance(before, datetime.datetime):
            before = Object(id=time_snowflake(before, high=False))
        if isinstance(after, datetime.datetime):
            after = Object(id=time_snowflake(after, high=True))

        if oldest_first is None:
            self.reverse = after is not None
        else:
            self.reverse = oldest_first

        self.guild = guild
        self.loop = guild._state.loop
        self.request = guild._state.http.get_audit_logs
        self.limit = limit
        self.before = before
        self.user_id = user_id
        self.action_type = action_type
        self.after = OLDEST_OBJECT
        self._users = {}
        self._state = guild._state

        self._filter = None  # entry dict -> bool

        self.entries = asyncio.Queue()

        if self.reverse:
            self._strategy = self._after_strategy
            if self.before:
                self._filter = lambda m: int(m['id']) < self.before.id
        else:
            self._strategy = self._before_strategy
            if self.after and self.after != OLDEST_OBJECT:
                self._filter = lambda m: int(m['id']) > self.after.id

    async def _before_strategy(self, retrieve):
        before = self.before.id if self.before else None
        data: AuditLogPayload = await self.request(
            self.guild.id, limit=retrieve, user_id=self.user_id, action_type=self.action_type, before=before
        )

        entries = data.get('audit_log_entries', [])
        if len(data) and entries:
            if self.limit is not None:
                self.limit -= retrieve
            self.before = Object(id=int(entries[-1]['id']))
        return data.get('users', []), entries

    async def _after_strategy(self, retrieve):
        after = self.after.id if self.after else None
        data: AuditLogPayload = await self.request(
            self.guild.id, limit=retrieve, user_id=self.user_id, action_type=self.action_type, after=after
        )
        entries = data.get('audit_log_entries', [])
        if len(data) and entries:
            if self.limit is not None:
                self.limit -= retrieve
            self.after = Object(id=int(entries[0]['id']))
        return data.get('users', []), entries

    async def next(self) -> AuditLogEntry:
        if self.entries.empty():
            await self._fill()

        try:
            return self.entries.get_nowait()
        except asyncio.QueueEmpty:
            raise NoMoreItems()

    def _get_retrieve(self):
        l = self.limit
        if l is None or l > 100:
            r = 100
        else:
            r = l
        self.retrieve = r
        return r > 0

    async def _fill(self):
        from .user import User

        if self._get_retrieve():
            users, data = await self._strategy(self.retrieve)
            if len(data) < 100:
                self.limit = 0  # terminate the infinite loop

            if self.reverse:
                data = reversed(data)
            if self._filter:
                data = filter(self._filter, data)

            for user in users:
                u = User(data=user, state=self._state)
                self._users[u.id] = u

            for element in data:
                # TODO: remove this if statement later
                if element['action_type'] is None:
                    continue

                await self.entries.put(AuditLogEntry(data=element, users=self._users, guild=self.guild))


class ArchivedThreadIterator(_AsyncIterator['Thread']):
    def __init__(
        self,
        channel_id: int,
        guild: Guild,
        limit: Optional[int],
        joined: bool,
        private: bool,
        before: Optional[Union[Snowflake, datetime.datetime]] = None,
    ):
        self.channel_id = channel_id
        self.guild = guild
        self.limit = limit
        self.joined = joined
        self.private = private
        self.http = guild._state.http

        if joined and not private:
            raise ValueError('Cannot iterate over joined public archived threads')

        self.before: Optional[str]
        if before is None:
            self.before = None
        elif isinstance(before, datetime.datetime):
            if joined:
                self.before = str(time_snowflake(before, high=False))
            else:
                self.before = before.isoformat()
        else:
            if joined:
                self.before = str(before.id)
            else:
                self.before = snowflake_time(before.id).isoformat()

        self.update_before: Callable[[ThreadPayload], str] = self.get_archive_timestamp

        if joined:
            self.endpoint = self.http.get_joined_private_archived_threads
            self.update_before = self.get_thread_id
        elif private:
            self.endpoint = self.http.get_private_archived_threads
        else:
            self.endpoint = self.http.get_public_archived_threads

        self.queue: asyncio.Queue[Thread] = asyncio.Queue()
        self.has_more: bool = True

    async def next(self) -> Thread:
        if self.queue.empty():
            await self.fill_queue()

        try:
            return self.queue.get_nowait()
        except asyncio.QueueEmpty:
            raise NoMoreItems()

    @staticmethod
    def get_archive_timestamp(data: ThreadPayload) -> str:
        return data['thread_metadata']['archive_timestamp']

    @staticmethod
    def get_thread_id(data: ThreadPayload) -> str:
        return data['id']  # type: ignore

    async def fill_queue(self) -> None:
        if not self.has_more:
            raise NoMoreItems()

        limit = 50 if self.limit is None else max(self.limit, 50)
        data = await self.endpoint(self.channel_id, before=self.before, limit=limit)

        # This stuff is obviously WIP because 'members' is always empty
        threads: List[ThreadPayload] = data.get('threads', [])
        for d in reversed(threads):
            self.queue.put_nowait(self.create_thread(d))

        self.has_more = data.get('has_more', False)
        if self.limit is not None:
            self.limit -= len(threads)
            if self.limit <= 0:
                self.has_more = False

        if self.has_more:
            self.before = self.update_before(threads[-1])

    def create_thread(self, data: ThreadPayload) -> Thread:
        from .threads import Thread
        return Thread(guild=self.guild, state=self.guild._state, data=data)


def _is_fake(item: Union[Messageable, Message]) -> bool:  # I hate this too, but <circular imports> and performance exist
    try:
        item.guild  # type: ignore
    except AttributeError:
        return True
    try:
        item.channel.me  # type: ignore
    except AttributeError:
        return False
    return True


class CommandIterator(_AsyncIterator['ApplicationCommand']):
    def __new__(cls, *args, **kwargs) -> Union[CommandIterator, FakeCommandIterator]:
        if _is_fake(args[0]):
            return FakeCommandIterator(*args)
        else:
            return super().__new__(cls)

    def __init__(
        self,
        item: Union[Messageable, Message],
        type: CommandType,
        query: Optional[str] = None,
        limit: Optional[int] = None,
        command_ids: Optional[List[int]] = None,
        **kwargs,
    ) -> None:
        self.item = item
        self.channel = None
        self.state = item._state
        self._tuple = None
        self.type = type
        _, self.cls = _command_factory(int(type))
        self.query = query
        self.limit = limit
        self.command_ids = command_ids
        self.applications: bool = kwargs.get('applications', True)
        self.application: Snowflake = kwargs.get('application', None)
        self.commands = asyncio.Queue()

    async def _process_args(self) -> Tuple[DMChannel, Optional[str], Optional[Union[User, Message]]]:
        item = self.item
        if self.type is CommandType.user:
            channel = await item._get_channel()  # type: ignore
            if getattr(item, 'bot', None):
                item = item
            else:
                item = None
            text = 'user'
        elif self.type is CommandType.message:
            message = self.item
            channel = message.channel  # type: ignore
            text = 'message'
        elif self.type is CommandType.chat_input:
            channel = await item._get_channel()  # type: ignore
            item = None
            text = None
        self._process_kwargs(channel)  # type: ignore
        return channel, text, item  # type: ignore

    def _process_kwargs(self, channel) -> None:
        kwargs = {
            'guild_id': channel.guild.id,
            'type': self.type.value,
            'offset': 0,
        }
        if self.applications:
            kwargs['applications'] = True  # Only sent if it's True...
        if (app := self.application):
            kwargs['application'] = app.id
        if (query := self.query) is not None:
            kwargs['query'] = query
        if (cmds := self.command_ids):
            kwargs['command_ids'] = cmds
        self.kwargs = kwargs

    async def next(self) -> ApplicationCommand:
        if self.commands.empty():
            await self.fill_commands()

        try:
            return self.commands.get_nowait()
        except asyncio.QueueEmpty:
            raise NoMoreItems()

    def _get_retrieve(self):
        l = self.limit
        if l is None or l > 100:
            r = 100
        else:
            r = l
        self.retrieve = r
        return r > 0

    async def fill_commands(self) -> None:
        if not self._tuple:  # Do the required setup
            self._tuple = await self._process_args()

        if not self._get_retrieve():
            return

        state = self.state
        kwargs = self.kwargs
        retrieve = self.retrieve
        nonce = str(time_snowflake(utcnow()))

        def predicate(d):
            return d.get('nonce') == nonce

        data = None
        for _ in range(3):
            await state.ws.request_commands(**kwargs, limit=retrieve, nonce=nonce)
            try:
                data: Optional[Dict[str, Any]] = await asyncio.wait_for(state.ws.wait_for('guild_application_commands_update', predicate), timeout=3)
            except asyncio.TimeoutError:
                pass

        if data is None:
            raise InvalidData('Didn\'t receive a response from Discord')

        cmds = data['application_commands']
        if len(cmds) < retrieve:
            self.limit = 0
        elif self.limit is not None:
            self.limit -= retrieve

        kwargs['offset'] += retrieve

        for cmd in cmds:
            self.commands.put_nowait(self.create_command(cmd))

        for app in data.get('applications', []):
            ...

    def create_command(self, data) -> ApplicationCommand:
        channel, item, value = self._tuple  # type: ignore
        if item is not None:
            kwargs = {item: value}
        else:
            kwargs = {}
        return self.cls(state=channel._state, data=data, channel=channel, **kwargs)


class FakeCommandIterator(_AsyncIterator['ApplicationCommand']):
    def __init__(
        self,
        item: Union[User, Message, DMChannel],
        type: CommandType,
        query: Optional[str] = None,
        limit: Optional[int] = None,
        command_ids: Optional[List[int]] = None,
    ) -> None:
        self.item = item
        self.channel = None
        self._tuple = None
        self.type = type
        _, self.cls = _command_factory(int(type))
        self.query = query
        self.limit = limit
        self.command_ids = command_ids
        self.has_more = False
        self.commands = asyncio.Queue()

    async def _process_args(self) -> Tuple[DMChannel, Optional[str], Optional[Union[User, Message]]]:
        item = self.item
        if self.type is CommandType.user:
            channel = await item._get_channel()  # type: ignore
            if getattr(item, 'bot', None):
                item = item
            else:
                item = None
            text = 'user'
        elif self.type is CommandType.message:
            message = self.item
            channel = message.channel  # type: ignore
            text = 'message'
        elif self.type is CommandType.chat_input:
            channel = await item._get_channel()  # type: ignore
            item = None
            text = None
        if not channel.recipient.bot:
            raise InvalidArgument('User is not a bot')
        return channel, text, item  # type: ignore

    async def next(self) -> ApplicationCommand:
        if self.commands.empty():
            await self.fill_commands()

        try:
            return self.commands.get_nowait()
        except asyncio.QueueEmpty:
            raise NoMoreItems()

    async def fill_commands(self) -> None:
        if self.has_more:
            raise NoMoreItems()

        if not (stuff := self._tuple):
            self._tuple = channel, _, _ = await self._process_args()
        else:
            channel = stuff[0]

        limit = self.limit or -1
        data = await channel._state.http.get_application_commands(channel.recipient.id)
        ids = self.command_ids
        query = self.query and self.query.lower()
        type = self.type.value

        for cmd in data:
            if cmd['type'] != type:
                continue

            if ids:
                if not int(cmd['id']) in ids:
                    continue

            if query:
                if not query in cmd['name'].lower():
                    continue

            self.commands.put_nowait(self.create_command(cmd))
            limit -= 1
            if limit == 0:
                break

        self.has_more = True

    def create_command(self, data) -> ApplicationCommand:
        channel, item, value = self._tuple  # type: ignore
        if item is not None:
            kwargs = {item: value}
        else:
            kwargs = {}
        return self.cls(state=channel._state, data=data, channel=channel, **kwargs)