from .chatgetter import ChatGetter
from .sendergetter import SenderGetter
from ... import utils
from ...tl import types


class Forward(ChatGetter, SenderGetter):
    """
    Custom class that encapsulates a :tl:`MessageFwdHeader` providing an
    abstraction to easily access information like the original sender.

    Remember that this class implements `ChatGetter
    <telethon.tl.custom.chatgetter.ChatGetter>` and `SenderGetter
    <telethon.tl.custom.sendergetter.SenderGetter>` which means you
    have access to all their sender and chat properties and methods.

    Attributes:

        original_fwd (:tl:`MessageFwdHeader`):
            The original :tl:`MessageFwdHeader` instance.

        Any other attribute:
            Attributes not described here are the same as those available
            in the original :tl:`MessageFwdHeader`.
    """
    def __init__(self, client, original, entities):
        # Copy all the fields, not reference! It would cause memory cycles:
        #   self.original_fwd.original_fwd.original_fwd.original_fwd
        # ...would be valid if we referenced.
        self.__dict__ = dict(original.__dict__)
        self._client = client
        self.original_fwd = original

        sender, input_sender = utils._get_entity_pair(
            original.from_id, entities, client._entity_cache)

        if not original.channel_id:
            peer = chat = input_chat = None
        else:
            peer = types.PeerChannel(original.channel_id)
            chat, input_chat = utils._get_entity_pair(
                 utils.get_peer_id(peer), entities, client._entity_cache)

        ChatGetter.__init__(self, peer, chat=chat, input_chat=input_chat)
        SenderGetter.__init__(self, original.from_id, sender=sender, input_sender=input_sender)

    # TODO We could reload the message