#!/usr/bin/env python # # A library that provides a Python interface to the Telegram Bot API # Copyright (C) 2015-2017 # Leandro Toledo de Souza # # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU Lesser Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU Lesser Public License for more details. # # You should have received a copy of the GNU Lesser Public License # along with this program. If not, see [http://www.gnu.org/licenses/]. """ This module contains the ConversationHandler """ import logging from telegram import Update from telegram.ext import (Handler, CallbackQueryHandler, InlineQueryHandler, ChosenInlineResultHandler) from telegram.utils.promise import Promise class ConversationHandler(Handler): """ A handler to hold a conversation with a single user by managing four collections of other handlers. Note that neither posts in Telegram Channels, nor group interactions with multiple users are managed by instances of this class. The first collection, a ``list`` named ``entry_points``, is used to initiate the conversation, for example with a ``CommandHandler`` or ``RegexHandler``. The second collection, a ``dict`` named ``states``, contains the different conversation steps and one or more associated handlers that should be used if the user sends a message when the conversation with them is currently in that state. You will probably use mostly ``MessageHandler`` and ``RegexHandler`` here. The third collection, a ``list`` named ``fallbacks``, is used if the user is currently in a conversation but the state has either no associated handler or the handler that is associated to the state is inappropriate for the update, for example if the update contains a command, but a regular text message is expected. You could use this for a ``/cancel`` command or to let the user know their message was not recognized. The fourth, optional collection of handlers, a ``list`` named ``timed_out_behavior`` is used if the wait for ``run_async`` takes longer than defined in ``run_async_timeout``. For example, you can let the user know that they should wait for a bit before they can continue. To change the state of conversation, the callback function of a handler must return the new state after responding to the user. If it does not return anything (returning ``None`` by default), the state will not change. To end the conversation, the callback function must return ``CallbackHandler.END`` or ``-1``. Args: entry_points (list): A list of ``Handler`` objects that can trigger the start of the conversation. The first handler which ``check_update`` method returns ``True`` will be used. If all return ``False``, the update is not handled. states (dict): A ``dict[object: list[Handler]]`` that defines the different states of conversation a user can be in and one or more associated ``Handler`` objects that should be used in that state. The first handler which ``check_update`` method returns ``True`` will be used. fallbacks (list): A list of handlers that might be used if the user is in a conversation, but every handler for their current state returned ``False`` on ``check_update``. The first handler which ``check_update`` method returns ``True`` will be used. If all return ``False``, the update is not handled. allow_reentry (Optional[bool]): If set to ``True``, a user that is currently in a conversation can restart the conversation by triggering one of the entry points. run_async_timeout (Optional[float]): If the previous handler for this user was running asynchronously using the ``run_async`` decorator, it might not be finished when the next message arrives. This timeout defines how long the conversation handler should wait for the next state to be computed. The default is ``None`` which means it will wait indefinitely. timed_out_behavior (Optional[list]): A list of handlers that might be used if the wait for ``run_async`` timed out. The first handler which ``check_update`` method returns ``True`` will be used. If all return ``False``, the update is not handled. """ END = -1 def __init__(self, entry_points, states, fallbacks, allow_reentry=False, run_async_timeout=None, timed_out_behavior=None, per_chat=True, per_user=True, per_message=False): self.entry_points = entry_points """:type: list[telegram.ext.Handler]""" self.states = states """:type: dict[str: telegram.ext.Handler]""" self.fallbacks = fallbacks """:type: list[telegram.ext.Handler]""" self.allow_reentry = allow_reentry self.run_async_timeout = run_async_timeout self.timed_out_behavior = timed_out_behavior """:type: list[telegram.ext.Handler]""" self.conversations = dict() self.per_user = per_user self.per_chat = per_chat self.per_message = per_message """:type: dict[tuple: object]""" self.current_conversation = None self.current_handler = None self.logger = logging.getLogger(__name__) if not any((self.per_user, self.per_chat, self.per_message)): raise ValueError("'per_user', 'per_chat' and 'per_message' can't all be 'False'") if self.per_message and not self.per_chat: logging.warning("If 'per_message=True' is used, 'per_chat=True' should also be used, " "since message IDs are not globally unique.") all_handlers = list() all_handlers.extend(entry_points) all_handlers.extend(fallbacks) for state_handlers in states.values(): all_handlers.extend(state_handlers) if self.per_message: for handler in all_handlers: if not isinstance(handler, CallbackQueryHandler): logging.warning("If 'per_message=True', all entry points and state handlers" " must be 'CallbackQueryHandler', since no other handlers " "have a message context.") else: for handler in all_handlers: if isinstance(handler, CallbackQueryHandler): logging.warning("If 'per_message=False', 'CallbackQueryHandler' will not be " "tracked for every message.") if self.per_chat: for handler in all_handlers: if isinstance(handler, (InlineQueryHandler, ChosenInlineResultHandler)): logging.warning("If 'per_chat=True', 'InlineQueryHandler' can not be used, " "since inline queries have no chat context.") def _get_key(self, update): chat = update.effective_chat user = update.effective_user key = list() if self.per_chat: key.append(chat.id) if self.per_user: key.append(user.id) if self.per_message: key.append(update.callback_query.inline_message_id or update.callback_query.message.message_id) return tuple(key) def check_update(self, update): # Ignore messages in channels if (not isinstance(update, Update) or update.channel_post or self.per_chat and (update.inline_query or update.chosen_inline_result) or self.per_message and not update.callback_query or update.callback_query and self.per_chat and not update.callback_query.message): return False key = self._get_key(update) state = self.conversations.get(key) # Resolve promises if isinstance(state, tuple) and len(state) is 2 and isinstance(state[1], Promise): self.logger.debug('waiting for promise...') old_state, new_state = state error = False try: res = new_state.result(timeout=self.run_async_timeout) except Exception as exc: self.logger.exception("Promise function raised exception") self.logger.exception("{}".format(exc)) error = True if not error and new_state.done.is_set(): self.update_state(res, key) state = self.conversations.get(key) else: for candidate in (self.timed_out_behavior or []): if candidate.check_update(update): # Save the current user and the selected handler for handle_update self.current_conversation = key self.current_handler = candidate return True else: return False self.logger.debug('selecting conversation %s with state %s' % (str(key), str(state))) handler = None # Search entry points for a match if state is None or self.allow_reentry: for entry_point in self.entry_points: if entry_point.check_update(update): handler = entry_point break else: if state is None: return False # Get the handler list for current state, if we didn't find one yet and we're still here if state is not None and not handler: handlers = self.states.get(state) for candidate in (handlers or []): if candidate.check_update(update): handler = candidate break # Find a fallback handler if all other handlers fail else: for fallback in self.fallbacks: if fallback.check_update(update): handler = fallback break else: return False # Save the current user and the selected handler for handle_update self.current_conversation = key self.current_handler = handler return True def handle_update(self, update, dispatcher): new_state = self.current_handler.handle_update(update, dispatcher) self.update_state(new_state, self.current_conversation) def update_state(self, new_state, key): if new_state == self.END: if key in self.conversations: del self.conversations[key] else: pass elif isinstance(new_state, Promise): self.conversations[key] = (self.conversations.get(key), new_state) elif new_state is not None: self.conversations[key] = new_state