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Diffstat (limited to 'bot/cogs/backend/sync/syncers.py')
-rw-r--r-- | bot/cogs/backend/sync/syncers.py | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/bot/cogs/backend/sync/syncers.py b/bot/cogs/backend/sync/syncers.py new file mode 100644 index 000000000..f7ba811bc --- /dev/null +++ b/bot/cogs/backend/sync/syncers.py @@ -0,0 +1,347 @@ +import abc +import asyncio +import logging +import typing as t +from collections import namedtuple +from functools import partial + +import discord +from discord import Guild, HTTPException, Member, Message, Reaction, User +from discord.ext.commands import Context + +from bot import constants +from bot.api import ResponseCodeError +from bot.bot import Bot + +log = logging.getLogger(__name__) + +# These objects are declared as namedtuples because tuples are hashable, +# something that we make use of when diffing site roles against guild roles. +_Role = namedtuple('Role', ('id', 'name', 'colour', 'permissions', 'position')) +_User = namedtuple('User', ('id', 'name', 'discriminator', 'roles', 'in_guild')) +_Diff = namedtuple('Diff', ('created', 'updated', 'deleted')) + + +class Syncer(abc.ABC): + """Base class for synchronising the database with objects in the Discord cache.""" + + _CORE_DEV_MENTION = f"<@&{constants.Roles.core_developers}> " + _REACTION_EMOJIS = (constants.Emojis.check_mark, constants.Emojis.cross_mark) + + def __init__(self, bot: Bot) -> None: + self.bot = bot + + @property + @abc.abstractmethod + def name(self) -> str: + """The name of the syncer; used in output messages and logging.""" + raise NotImplementedError # pragma: no cover + + async def _send_prompt(self, message: t.Optional[Message] = None) -> t.Optional[Message]: + """ + Send a prompt to confirm or abort a sync using reactions and return the sent message. + + If a message is given, it is edited to display the prompt and reactions. Otherwise, a new + message is sent to the dev-core channel and mentions the core developers role. If the + channel cannot be retrieved, return None. + """ + log.trace(f"Sending {self.name} sync confirmation prompt.") + + msg_content = ( + f'Possible cache issue while syncing {self.name}s. ' + f'More than {constants.Sync.max_diff} {self.name}s were changed. ' + f'React to confirm or abort the sync.' + ) + + # Send to core developers if it's an automatic sync. + if not message: + log.trace("Message not provided for confirmation; creating a new one in dev-core.") + channel = self.bot.get_channel(constants.Channels.dev_core) + + if not channel: + log.debug("Failed to get the dev-core channel from cache; attempting to fetch it.") + try: + channel = await self.bot.fetch_channel(constants.Channels.dev_core) + except HTTPException: + log.exception( + f"Failed to fetch channel for sending sync confirmation prompt; " + f"aborting {self.name} sync." + ) + return None + + allowed_roles = [discord.Object(constants.Roles.core_developers)] + message = await channel.send( + f"{self._CORE_DEV_MENTION}{msg_content}", + allowed_mentions=discord.AllowedMentions(everyone=False, roles=allowed_roles) + ) + else: + await message.edit(content=msg_content) + + # Add the initial reactions. + log.trace(f"Adding reactions to {self.name} syncer confirmation prompt.") + for emoji in self._REACTION_EMOJIS: + await message.add_reaction(emoji) + + return message + + def _reaction_check( + self, + author: Member, + message: Message, + reaction: Reaction, + user: t.Union[Member, User] + ) -> bool: + """ + Return True if the `reaction` is a valid confirmation or abort reaction on `message`. + + If the `author` of the prompt is a bot, then a reaction by any core developer will be + considered valid. Otherwise, the author of the reaction (`user`) will have to be the + `author` of the prompt. + """ + # For automatic syncs, check for the core dev role instead of an exact author + has_role = any(constants.Roles.core_developers == role.id for role in user.roles) + return ( + reaction.message.id == message.id + and not user.bot + and (has_role if author.bot else user == author) + and str(reaction.emoji) in self._REACTION_EMOJIS + ) + + async def _wait_for_confirmation(self, author: Member, message: Message) -> bool: + """ + Wait for a confirmation reaction by `author` on `message` and return True if confirmed. + + Uses the `_reaction_check` function to determine if a reaction is valid. + + If there is no reaction within `bot.constants.Sync.confirm_timeout` seconds, return False. + To acknowledge the reaction (or lack thereof), `message` will be edited. + """ + # Preserve the core-dev role mention in the message edits so users aren't confused about + # where notifications came from. + mention = self._CORE_DEV_MENTION if author.bot else "" + + reaction = None + try: + log.trace(f"Waiting for a reaction to the {self.name} syncer confirmation prompt.") + reaction, _ = await self.bot.wait_for( + 'reaction_add', + check=partial(self._reaction_check, author, message), + timeout=constants.Sync.confirm_timeout + ) + except asyncio.TimeoutError: + # reaction will remain none thus sync will be aborted in the finally block below. + log.debug(f"The {self.name} syncer confirmation prompt timed out.") + + if str(reaction) == constants.Emojis.check_mark: + log.trace(f"The {self.name} syncer was confirmed.") + await message.edit(content=f':ok_hand: {mention}{self.name} sync will proceed.') + return True + else: + log.info(f"The {self.name} syncer was aborted or timed out!") + await message.edit( + content=f':warning: {mention}{self.name} sync aborted or timed out!' + ) + return False + + @abc.abstractmethod + async def _get_diff(self, guild: Guild) -> _Diff: + """Return the difference between the cache of `guild` and the database.""" + raise NotImplementedError # pragma: no cover + + @abc.abstractmethod + async def _sync(self, diff: _Diff) -> None: + """Perform the API calls for synchronisation.""" + raise NotImplementedError # pragma: no cover + + async def _get_confirmation_result( + self, + diff_size: int, + author: Member, + message: t.Optional[Message] = None + ) -> t.Tuple[bool, t.Optional[Message]]: + """ + Prompt for confirmation and return a tuple of the result and the prompt message. + + `diff_size` is the size of the diff of the sync. If it is greater than + `bot.constants.Sync.max_diff`, the prompt will be sent. The `author` is the invoked of the + sync and the `message` is an extant message to edit to display the prompt. + + If confirmed or no confirmation was needed, the result is True. The returned message will + either be the given `message` or a new one which was created when sending the prompt. + """ + log.trace(f"Determining if confirmation prompt should be sent for {self.name} syncer.") + if diff_size > constants.Sync.max_diff: + message = await self._send_prompt(message) + if not message: + return False, None # Couldn't get channel. + + confirmed = await self._wait_for_confirmation(author, message) + if not confirmed: + return False, message # Sync aborted. + + return True, message + + async def sync(self, guild: Guild, ctx: t.Optional[Context] = None) -> None: + """ + Synchronise the database with the cache of `guild`. + + If the differences between the cache and the database are greater than + `bot.constants.Sync.max_diff`, then a confirmation prompt will be sent to the dev-core + channel. The confirmation can be optionally redirect to `ctx` instead. + """ + log.info(f"Starting {self.name} syncer.") + + message = None + author = self.bot.user + if ctx: + message = await ctx.send(f"📊 Synchronising {self.name}s.") + author = ctx.author + + diff = await self._get_diff(guild) + diff_dict = diff._asdict() # Ugly method for transforming the NamedTuple into a dict + totals = {k: len(v) for k, v in diff_dict.items() if v is not None} + diff_size = sum(totals.values()) + + confirmed, message = await self._get_confirmation_result(diff_size, author, message) + if not confirmed: + return + + # Preserve the core-dev role mention in the message edits so users aren't confused about + # where notifications came from. + mention = self._CORE_DEV_MENTION if author.bot else "" + + try: + await self._sync(diff) + except ResponseCodeError as e: + log.exception(f"{self.name} syncer failed!") + + # Don't show response text because it's probably some really long HTML. + results = f"status {e.status}\n```{e.response_json or 'See log output for details'}```" + content = f":x: {mention}Synchronisation of {self.name}s failed: {results}" + else: + results = ", ".join(f"{name} `{total}`" for name, total in totals.items()) + log.info(f"{self.name} syncer finished: {results}.") + content = f":ok_hand: {mention}Synchronisation of {self.name}s complete: {results}" + + if message: + await message.edit(content=content) + + +class RoleSyncer(Syncer): + """Synchronise the database with roles in the cache.""" + + name = "role" + + async def _get_diff(self, guild: Guild) -> _Diff: + """Return the difference of roles between the cache of `guild` and the database.""" + log.trace("Getting the diff for roles.") + roles = await self.bot.api_client.get('bot/roles') + + # Pack DB roles and guild roles into one common, hashable format. + # They're hashable so that they're easily comparable with sets later. + db_roles = {_Role(**role_dict) for role_dict in roles} + guild_roles = { + _Role( + id=role.id, + name=role.name, + colour=role.colour.value, + permissions=role.permissions.value, + position=role.position, + ) + for role in guild.roles + } + + guild_role_ids = {role.id for role in guild_roles} + api_role_ids = {role.id for role in db_roles} + new_role_ids = guild_role_ids - api_role_ids + deleted_role_ids = api_role_ids - guild_role_ids + + # New roles are those which are on the cached guild but not on the + # DB guild, going by the role ID. We need to send them in for creation. + roles_to_create = {role for role in guild_roles if role.id in new_role_ids} + roles_to_update = guild_roles - db_roles - roles_to_create + roles_to_delete = {role for role in db_roles if role.id in deleted_role_ids} + + return _Diff(roles_to_create, roles_to_update, roles_to_delete) + + async def _sync(self, diff: _Diff) -> None: + """Synchronise the database with the role cache of `guild`.""" + log.trace("Syncing created roles...") + for role in diff.created: + await self.bot.api_client.post('bot/roles', json=role._asdict()) + + log.trace("Syncing updated roles...") + for role in diff.updated: + await self.bot.api_client.put(f'bot/roles/{role.id}', json=role._asdict()) + + log.trace("Syncing deleted roles...") + for role in diff.deleted: + await self.bot.api_client.delete(f'bot/roles/{role.id}') + + +class UserSyncer(Syncer): + """Synchronise the database with users in the cache.""" + + name = "user" + + async def _get_diff(self, guild: Guild) -> _Diff: + """Return the difference of users between the cache of `guild` and the database.""" + log.trace("Getting the diff for users.") + users = await self.bot.api_client.get('bot/users') + + # Pack DB roles and guild roles into one common, hashable format. + # They're hashable so that they're easily comparable with sets later. + db_users = { + user_dict['id']: _User( + roles=tuple(sorted(user_dict.pop('roles'))), + **user_dict + ) + for user_dict in users + } + guild_users = { + member.id: _User( + id=member.id, + name=member.name, + discriminator=int(member.discriminator), + roles=tuple(sorted(role.id for role in member.roles)), + in_guild=True + ) + for member in guild.members + } + + users_to_create = set() + users_to_update = set() + + for db_user in db_users.values(): + guild_user = guild_users.get(db_user.id) + if guild_user is not None: + if db_user != guild_user: + users_to_update.add(guild_user) + + elif db_user.in_guild: + # The user is known in the DB but not the guild, and the + # DB currently specifies that the user is a member of the guild. + # This means that the user has left since the last sync. + # Update the `in_guild` attribute of the user on the site + # to signify that the user left. + new_api_user = db_user._replace(in_guild=False) + users_to_update.add(new_api_user) + + new_user_ids = set(guild_users.keys()) - set(db_users.keys()) + for user_id in new_user_ids: + # The user is known on the guild but not on the API. This means + # that the user has joined since the last sync. Create it. + new_user = guild_users[user_id] + users_to_create.add(new_user) + + return _Diff(users_to_create, users_to_update, None) + + async def _sync(self, diff: _Diff) -> None: + """Synchronise the database with the user cache of `guild`.""" + log.trace("Syncing created users...") + for user in diff.created: + await self.bot.api_client.post('bot/users', json=user._asdict()) + + log.trace("Syncing updated users...") + for user in diff.updated: + await self.bot.api_client.put(f'bot/users/{user.id}', json=user._asdict()) |