from .chatgetter import ChatGetter
from .sendergetter import SenderGetter
from ... import utils, helpers
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__.update(original.__dict__)
        self.original_fwd = original

        sender_id = sender = input_sender = peer = chat = input_chat = None
        if original.from_id:
            ty = helpers._entity_type(original.from_id)
            if ty == helpers._EntityType.USER:
                sender_id = utils.get_peer_id(original.from_id)
                sender, input_sender = utils._get_entity_pair(
                    sender_id, entities, client._mb_entity_cache)

            elif ty in (helpers._EntityType.CHAT, helpers._EntityType.CHANNEL):
                peer = original.from_id
                chat, input_chat = utils._get_entity_pair(
                    utils.get_peer_id(peer), entities, client._mb_entity_cache)

        # This call resets the client
        ChatGetter.__init__(self, peer, chat=chat, input_chat=input_chat)
        SenderGetter.__init__(self, sender_id, sender=sender, input_sender=input_sender)
        self._client = client

    # TODO We could reload the message