Add a new events.MessageRead

telethon/events/__init__.py

@@ -1123,6 +1123,138 @@ class MessageDeleted(_EventBuilder):
             self.deleted_ids = deleted_ids
 
 
+@_name_inner_event
+class MessageRead(_EventBuilder):
+    """
+    Event fired when one or more messages have been read.
+
+    Args:
+        inbox (:obj:`bool`, optional):
+            If this argument is ``True``, then when you read someone else's
+            messages the event will be fired. By default (``False``) only
+            when messages you sent are read by someone else will fire it.
+    """
+    def __init__(self, inbox=False, chats=None, blacklist_chats=None):
+        super().__init__(chats, blacklist_chats)
+        self.inbox = inbox
+
+    def build(self, update):
+        if isinstance(update, types.UpdateReadHistoryInbox):
+            event = MessageRead.Event(update.peer, update.max_id, False)
+        elif isinstance(update, types.UpdateReadHistoryOutbox):
+            event = MessageRead.Event(update.peer, update.max_id, True)
+        elif isinstance(update, types.UpdateReadChannelInbox):
+            event = MessageRead.Event(types.PeerChannel(update.channel_id),
+                                      update.max_id, False)
+        elif isinstance(update, types.UpdateReadChannelOutbox):
+            event = MessageRead.Event(types.PeerChannel(update.channel_id),
+                                      update.max_id, True)
+        elif isinstance(update, types.UpdateReadMessagesContents):
+            event = MessageRead.Event(message_ids=update.messages,
+                                      contents=True)
+        elif isinstance(update, types.UpdateChannelReadMessagesContents):
+            event = MessageRead.Event(types.PeerChannel(update.channel_id),
+                                      message_ids=update.messages,
+                                      contents=True)
+        else:
+            return
+
+        if self.inbox == event.outbox:
+            return
+
+        event._entities = update.entities
+        return self._filter_event(event)
+
+    class Event(_EventCommon):
+        """
+        Represents the event of one or more messages being read.
+
+        Members:
+            max_id (:obj:`int`):
+                Up to which message ID has been read. Every message
+                with an ID equal or lower to it have been read.
+
+            outbox (:obj:`bool`):
+                ``True`` if someone else has read your messages.
+
+            contents (:obj:`bool`):
+                ``True`` if what was read were the contents of a message.
+                This will be the case when e.g. you play a voice note.
+                It may only be set on ``inbox`` events.
+        """
+        def __init__(self, peer=None, max_id=None, out=False, contents=False,
+                     message_ids=None):
+            self.outbox = out
+            self.contents = contents
+            self._message_ids = message_ids or []
+            self._messages = None
+            self.max_id = max_id or max(message_ids or [], default=None)
+            super().__init__(peer, self.max_id)
+
+        @property
+        def inbox(self):
+            """
+            ``True`` if you have read someone else's messages.
+            """
+            return not self.outbox
+
+        @property
+        def message_ids(self):
+            """
+            The IDs of the messages **which contents'** were read.
+
+            Use :meth:`is_read` if you need to check whether a message
+            was read instead checking if it's in here.
+            """
+            return self._message_ids
+
+        @property
+        def messages(self):
+            """
+            The list of :tl:`Message` **which contents'** were read.
+
+            Use :meth:`is_read` if you need to check whether a message
+            was read instead checking if it's in here.
+            """
+            if self._messages is None:
+                chat = self.input_chat
+                if not chat:
+                    self._messages = []
+                elif isinstance(chat, types.InputPeerChannel):
+                    self._messages =\
+                        self._client(functions.channels.GetMessagesRequest(
+                            chat, self._message_ids
+                        )).messages
+                else:
+                    self._messages =\
+                        self._client(functions.messages.GetMessagesRequest(
+                            self._message_ids
+                        )).messages
+
+            return self._messages
+
+        def is_read(self, message):
+            """
+            Returns ``True`` if the given message (or its ID) has been read.
+
+            If a list-like argument is provided, this method will return a
+            list of booleans indicating which messages have been read.
+            """
+            if utils.is_list_like(message):
+                return [(m if isinstance(m, int) else m.id) <= self.max_id
+                        for m in message]
+            else:
+                return (message if isinstance(message, int)
+                        else message.id) <= self.max_id
+
+        def __contains__(self, message):
+            """``True`` if the message(s) are read message."""
+            if utils.is_list_like(message):
+                return all(self.is_read(message))
+            else:
+                return self.is_read(message)
+
+
 class StopPropagation(Exception):
     """
     If this exception is raised in any of the handlers for a given event,