#!/usr/bin/env python3

# helper class for making a SàT frontend
# Copyright (C) 2009-2021 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General 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 Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from libervia.backend.core.i18n import _
from libervia.backend.core.log import getLogger
from libervia.backend.tools.common import data_format
from libervia.backend.core import exceptions
from libervia.frontends.quick_frontend import quick_widgets
from libervia.frontends.quick_frontend.constants import Const as C
from collections import OrderedDict
from libervia.frontends.tools import jid
import time


log = getLogger(__name__)


ROOM_USER_JOINED = "ROOM_USER_JOINED"
ROOM_USER_LEFT = "ROOM_USER_LEFT"
ROOM_USER_MOVED = (ROOM_USER_JOINED, ROOM_USER_LEFT)

# from datetime import datetime

# FIXME: day_format need to be settable (i18n)


class Message:
    """Message metadata"""

    def __init__(
        self,
        parent,
        uid,
        timestamp,
        from_jid,
        to_jid,
        msg,
        subject,
        type_,
        extra,
        profile,
    ):
        self.parent = parent
        self.profile = profile
        self.uid = uid
        self.timestamp = timestamp
        self.from_jid = from_jid
        self.to_jid = to_jid
        self.message = msg
        self.subject = subject
        self.type = type_
        self.extra = extra
        self.nick = self.get_nick(from_jid)
        self._status = None
        # own_mess is True if message was sent by profile's jid
        self.own_mess = (
            (from_jid.resource == self.parent.nick)
            if self.parent.type == C.CHAT_GROUP
            else (from_jid.bare == self.host.profiles[profile].whoami.bare)
        )
        # is user mentioned here ?
        if self.parent.type == C.CHAT_GROUP and not self.own_mess:
            for m in msg.values():
                if self.parent.nick.lower() in m.lower():
                    self._mention = True
                    break
        self.handle_me()
        self.widgets = set()  # widgets linked to this message

    def __str__(self):
        return "Message<{mess_type}>  [{time}]{nick}> {message}".format(
            mess_type=self.type,
            time=self.time_text,
            nick=self.nick,
            message=self.main_message,
        )

    def __contains__(self, item):
        return hasattr(self, item) or item in self.extra

    @property
    def host(self):
        return self.parent.host

    @property
    def info_type(self):
        return self.extra.get("info_type")

    @property
    def mention(self):
        try:
            return self._mention
        except AttributeError:
            return False

    @property
    def history(self):
        """True if message come from history"""
        return self.extra.get("history", False)

    @property
    def main_message(self):
        """currently displayed message"""
        if self.parent.lang in self.message:
            self.selected_lang = self.parent.lang
            return self.message[self.parent.lang]
        try:
            self.selected_lang = ""
            return self.message[""]
        except KeyError:
            try:
                lang, mess = next(iter(self.message.items()))
                self.selected_lang = lang
                return mess
            except StopIteration:
                if not self.attachments:
                    # we may have empty messages if we have attachments
                    log.error("Can't find message for uid {}".format(self.uid))
                return ""

    @property
    def main_message_xhtml(self):
        """rich message"""
        xhtml = {k: v for k, v in self.extra.items() if "html" in k}
        if xhtml:
            # FIXME: we only return first found value for now
            return next(iter(xhtml.values()))

    @property
    def time_text(self):
        """Return timestamp in a nicely formatted way"""
        # if the message was sent before today, we print the full date
        timestamp = time.localtime(self.timestamp)
        time_format = "%c" if timestamp < self.parent.day_change else "%H:%M"
        return time.strftime(time_format, timestamp)

    @property
    def avatar(self):
        """avatar data or None if no avatar is found"""
        entity = self.from_jid
        contact_list = self.host.contact_lists[self.profile]
        try:
            return contact_list.getCache(entity, "avatar")
        except (exceptions.NotFound, KeyError):
            # we don't check the result as the avatar listener will be called
            self.host.bridge.avatar_get(entity, True, self.profile)
            return None

    @property
    def encrypted(self):
        return self.extra.get("encrypted", False)

    def get_nick(self, entity):
        """Return nick of an entity when possible"""
        contact_list = self.host.contact_lists[self.profile]
        if self.type == C.MESS_TYPE_INFO and self.info_type in ROOM_USER_MOVED:
            try:
                return self.extra["user_nick"]
            except KeyError:
                log.error("extra data is missing user nick for uid {}".format(self.uid))
                return ""
        # FIXME: converted get_specials to list for pyjamas
        if self.parent.type == C.CHAT_GROUP or entity in list(
            contact_list.get_specials(C.CONTACT_SPECIAL_GROUP)
        ):
            return entity.resource or ""
        if entity.bare in contact_list:

            try:
                nicknames = contact_list.getCache(entity, "nicknames")
            except (exceptions.NotFound, KeyError):
                # we check result as listener will be called
                self.host.bridge.identity_get(
                    entity.bare, ["nicknames"], True, self.profile
                )
                return entity.node or entity

            if nicknames:
                return nicknames[0]
            else:
                return (
                    contact_list.getCache(entity, "name", default=None)
                    or entity.node
                    or entity
                )

        return entity.node or entity

    @property
    def status(self):
        return self._status

    @status.setter
    def status(self, status):
        if status != self._status:
            self._status = status
            for w in self.widgets:
                w.update({"status": status})

    def handle_me(self):
        """Check if messages starts with "/me " and change them if it is the case

        if several messages (different languages) are presents, they all need to start with "/me "
        """
        # TODO: XHTML-IM /me are not handled
        me = False
        # we need to check /me for every message
        for m in self.message.values():
            if m.startswith("/me "):
                me = True
            else:
                me = False
                break
        if me:
            self.type = C.MESS_TYPE_INFO
            self.extra["info_type"] = "me"
            nick = self.nick
            for lang, mess in self.message.items():
                self.message[lang] = "* " + nick + mess[3:]

    @property
    def attachments(self):
        return self.extra.get(C.KEY_ATTACHMENTS)


class MessageWidget:
    """Base classe for widgets"""

    # This class does nothing and is only used to have a common ancestor

    pass


class Occupant:
    """Occupant metadata"""

    def __init__(self, parent, data, profile):
        self.parent = parent
        self.profile = profile
        self.nick = data["nick"]
        self._entity = data.get("entity")
        self.affiliation = data["affiliation"]
        self.role = data["role"]
        self.widgets = set()  # widgets linked to this occupant
        self._state = None

    @property
    def data(self):
        """reconstruct data dict from attributes"""
        data = {}
        data["nick"] = self.nick
        if self._entity is not None:
            data["entity"] = self._entity
        data["affiliation"] = self.affiliation
        data["role"] = self.role
        return data

    @property
    def jid(self):
        """jid in the room"""
        return jid.JID("{}/{}".format(self.parent.target.bare, self.nick))

    @property
    def real_jid(self):
        """real jid if known else None"""
        return self._entity

    @property
    def host(self):
        return self.parent.host

    @property
    def state(self):
        return self._state

    @state.setter
    def state(self, new_state):
        if new_state != self._state:
            self._state = new_state
            for w in self.widgets:
                w.update({"state": new_state})

    def update(self, update_dict=None):
        for w in self.widgets:
            w.update(update_dict)


class QuickChat(quick_widgets.QuickWidget):
    visible_states = ["chat_state"]  # FIXME: to be removed, used only in quick_games

    def __init__(
        self,
        host,
        target,
        type_=C.CHAT_ONE2ONE,
        nick=None,
        occupants=None,
        subject=None,
        statuses=None,
        profiles=None,
    ):
        """
        @param type_: can be C.CHAT_ONE2ONE for single conversation or C.CHAT_GROUP for
                      chat à la IRC
        """
        self.lang = ""  # default language to use for messages
        quick_widgets.QuickWidget.__init__(self, host, target, profiles=profiles)
        assert type_ in (C.CHAT_ONE2ONE, C.CHAT_GROUP)
        self.current_target = target
        self.type = type_
        self.encrypted = False  # True if this session is currently encrypted
        self._locked = False
        # True when resync is in progress, avoid resynchronising twice when resync is called
        # and history is still being updated. For internal use only
        self._resync_lock = False
        self.set_locked()
        if type_ == C.CHAT_GROUP:
            if target.resource:
                raise exceptions.InternalError(
                    "a group chat entity can't have a resource"
                )
            if nick is None:
                raise exceptions.InternalError("nick must not be None for group chat")

            self.nick = nick
            self.occupants = {}
            self.set_occupants(occupants)
        else:
            if occupants is not None or nick is not None:
                raise exceptions.InternalError(
                    "only group chat can have occupants or nick"
                )
        self.messages = OrderedDict()  # key: uid, value: Message instance
        self.games = {}  # key=game name (unicode), value=instance of quick_games.RoomGame
        self.subject = subject
        self.statuses = set(statuses or [])
        lt = time.localtime()
        self.day_change = (
            lt.tm_year,
            lt.tm_mon,
            lt.tm_mday,
            0,
            0,
            0,
            lt.tm_wday,
            lt.tm_yday,
            lt.tm_isdst,
        )  # struct_time of day changing time
        if self.host.AVATARS_HANDLER:
            self.host.addListener("avatar", self.on_avatar, profiles)

    def set_locked(self):
        """Set locked flag

        To be set when we are waiting for history/search
        """
        # FIXME: we don't use getter/setter here because of pyjamas
        # TODO: use proper getter/setter once we get rid of pyjamas
        if self._locked:
            log.warning("{wid} is already locked!".format(wid=self))
            return
        self._locked = True
        # message_new signals are cached when locked
        self._cache = OrderedDict()
        log.debug("{wid} is now locked".format(wid=self))

    def set_unlocked(self):
        if not self._locked:
            log.debug("{wid} was already unlocked".format(wid=self))
            return
        self._locked = False
        for uid, data in self._cache.items():
            if uid not in self.messages:
                self.message_new(*data)
            else:
                log.debug(
                    "discarding message already in history: {data}, ".format(data=data)
                )
        del self._cache
        log.debug("{wid} is now unlocked".format(wid=self))

    def post_init(self):
        """Method to be called by frontend after widget is initialised

        handle the display of history and subject
        """
        self.history_print(profile=self.profile)
        if self.subject is not None:
            self.set_subject(self.subject)
        if self.host.ENCRYPTION_HANDLERS:
            self.get_encryption_state()

    def on_delete(self):
        if self.host.AVATARS_HANDLER:
            self.host.removeListener("avatar", self.on_avatar)

    @property
    def contact_list(self):
        return self.host.contact_lists[self.profile]

    @property
    def message_widgets_rev(self):
        """Return the history of MessageWidget in reverse chronological order

        Must be implemented by frontend
        """
        raise NotImplementedError

    ## synchornisation handling ##

    @quick_widgets.QuickWidget.sync.setter
    def sync(self, state):
        quick_widgets.QuickWidget.sync.fset(self, state)
        if not state:
            self.set_locked()

    def _resync_complete(self):
        self.sync = True
        self._resync_lock = False

    def occupants_clear(self):
        """Remove all occupants

        Must be overridden by frontends to clear their own representations of occupants
        """
        self.occupants.clear()

    def resync(self):
        if self._resync_lock:
            return
        self._resync_lock = True
        log.debug("resynchronising {self}".format(self=self))
        for mess in reversed(list(self.messages.values())):
            if mess.type == C.MESS_TYPE_INFO:
                continue
            last_message = mess
            break
        else:
            # we have no message yet, we can get normal history
            self.history_print(callback=self._resync_complete, profile=self.profile)
            return
        if self.type == C.CHAT_GROUP:
            self.occupants_clear()
            self.host.bridge.muc_occupants_get(
                str(self.target),
                self.profile,
                callback=self.update_occupants,
                errback=log.error,
            )
        self.history_print(
            size=C.HISTORY_LIMIT_NONE,
            filters={"timestamp_start": last_message.timestamp},
            callback=self._resync_complete,
            profile=self.profile,
        )

    ## Widget management ##

    def __str__(self):
        return "Chat Widget [target: {}, type: {}, profile: {}]".format(
            self.target, self.type, self.profile
        )

    @staticmethod
    def get_widget_hash(target, profiles):
        profile = list(profiles)[0]
        return profile + "\n" + str(target.bare)

    @staticmethod
    def get_private_hash(target, profile):
        """Get unique hash for private conversations

        This method should be used with force_hash to get unique widget for private MUC conversations
        """
        return (str(profile), target)

    def add_target(self, target):
        super(QuickChat, self).add_target(target)
        if target.resource:
            self.current_target = target  # FIXME: tmp, must use resource priority throught contactList instead

    def recreate_args(self, args, kwargs):
        """copy important attribute for a new widget"""
        kwargs["type_"] = self.type
        if self.type == C.CHAT_GROUP:
            kwargs["occupants"] = {o.nick: o.data for o in self.occupants.values()}
        kwargs["subject"] = self.subject
        try:
            kwargs["nick"] = self.nick
        except AttributeError:
            pass

    def on_private_created(self, widget):
        """Method called when a new widget for private conversation (MUC) is created"""
        raise NotImplementedError

    def get_or_create_private_widget(self, entity):
        """Create a widget for private conversation, or get it if it already exists

        @param entity: full jid of the target
        """
        return self.host.widgets.get_or_create_widget(
            QuickChat,
            entity,
            type_=C.CHAT_ONE2ONE,
            force_hash=self.get_private_hash(self.profile, entity),
            on_new_widget=self.on_private_created,
            profile=self.profile,
        )  # we force hash to have a new widget, not this one again

    @property
    def target(self):
        if self.type == C.CHAT_GROUP:
            return self.current_target.bare
        return self.current_target

    ## occupants ##

    def set_occupants(self, occupants):
        """Set the whole list of occupants"""
        assert len(self.occupants) == 0
        for nick, data in occupants.items():
            # XXX: this log is disabled because it's really too verbose
            #      but kept commented as it may be useful for debugging
            # log.debug(u"adding occupant {nick} to {room}".format(
            #     nick=nick, room=self.target))
            self.occupants[nick] = Occupant(self, data, self.profile)

    def update_occupants(self, occupants):
        """Update occupants list

        In opposition to set_occupants, this only add missing occupants and remove
        occupants who have left
        """
        # FIXME: occupants with modified status are not handled
        local_occupants = set(self.occupants)
        updated_occupants = set(occupants)
        left_occupants = local_occupants - updated_occupants
        joined_occupants = updated_occupants - local_occupants
        log.debug(
            "updating occupants for {room}:\n"
            "left: {left_occupants}\n"
            "joined: {joined_occupants}".format(
                room=self.target,
                left_occupants=", ".join(left_occupants),
                joined_occupants=", ".join(joined_occupants),
            )
        )
        for nick in left_occupants:
            self.removeUser(occupants[nick])
        for nick in joined_occupants:
            self.addUser(occupants[nick])

    def addUser(self, occupant_data):
        """Add user if it is not in the group list"""
        occupant = Occupant(self, occupant_data, self.profile)
        self.occupants[occupant.nick] = occupant
        return occupant

    def removeUser(self, occupant_data):
        """Remove a user from the group list"""
        nick = occupant_data["nick"]
        try:
            occupant = self.occupants.pop(nick)
        except KeyError:
            log.warning("Trying to remove an unknown occupant: {}".format(nick))
        else:
            return occupant

    def set_user_nick(self, nick):
        """Set the nick of the user, usefull for e.g. change the color of the user"""
        self.nick = nick

    def change_user_nick(self, old_nick, new_nick):
        """Change nick of a user in group list"""
        log.info(
            "{old} is now known as {new} in room {room_jid}".format(
                old=old_nick, new=new_nick, room_jid=self.target
            )
        )

    ## Messages ##

    def manage_message(self, entity, mess_type):
        """Tell if this chat widget manage an entity and message type couple

        @param entity (jid.JID): (full) jid of the sending entity
        @param mess_type (str): message type as given by message_new
        @return (bool): True if this Chat Widget manage this couple
        """
        if self.type == C.CHAT_GROUP:
            if (
                mess_type in (C.MESS_TYPE_GROUPCHAT, C.MESS_TYPE_INFO)
                and self.target == entity.bare
            ):
                return True
        else:
            if mess_type != C.MESS_TYPE_GROUPCHAT and entity in self.targets:
                return True
        return False

    def update_history(
        self, size=C.HISTORY_LIMIT_DEFAULT, filters=None, profile="@NONE@"
    ):
        """Called when history need to be recreated

        Remove all message from history then call history_print
        Must probably be overriden by frontend to clear widget
        @param size (int): number of messages
        @param filters (str): patterns to filter the history results
        @param profile (str): %(doc_profile)s
        """
        self.set_locked()
        self.messages.clear()
        self.history_print(size, filters, profile=profile)

    def _on_history_printed(self):
        """Method called when history is printed (or failed)

        unlock the widget, and can be used to refresh or scroll down
        the focus after the history is printed
        """
        self.set_unlocked()

    def history_print(
        self, size=C.HISTORY_LIMIT_DEFAULT, filters=None, callback=None, profile="@NONE@"
    ):
        """Print the current history

        Note: self.set_unlocked will be called once history is printed
        @param size (int): number of messages
        @param search (str): pattern to filter the history results
        @param callback(callable, None): method to call when history has been printed
        @param profile (str): %(doc_profile)s
        """
        if filters is None:
            filters = {}
        if size == 0:
            log.debug("Empty history requested, skipping")
            self._on_history_printed()
            return
        log_msg = _("now we print the history")
        if size != C.HISTORY_LIMIT_DEFAULT:
            log_msg += _(" ({} messages)".format(size))
        log.debug(log_msg)

        if self.type == C.CHAT_ONE2ONE:
            special = self.host.contact_lists[self.profile].getCache(
                self.target, C.CONTACT_SPECIAL, create_if_not_found=True, default=None
            )
            if special == C.CONTACT_SPECIAL_GROUP:
                # we have a private conversation
                # so we need full jid for the history
                # (else we would get history from group itself)
                # and to filter out groupchat message
                target = self.target
                filters["not_types"] = C.MESS_TYPE_GROUPCHAT
            else:
                target = self.target.bare
        else:
            # groupchat
            target = self.target.bare
            # FIXME: info not handled correctly
            filters["types"] = C.MESS_TYPE_GROUPCHAT

        self.history_filters = filters

        def _history_get_cb(history):
            # day_format = "%A, %d %b %Y"  # to display the day change
            # previous_day = datetime.now().strftime(day_format)
            # message_day = datetime.fromtimestamp(timestamp).strftime(self.day_format)
            # if previous_day != message_day:
            #     self.print_day_change(message_day)
            #     previous_day = message_day
            for data in history:
                uid, timestamp, from_jid, to_jid, message, subject, type_, extra_s = data
                from_jid = jid.JID(from_jid)
                to_jid = jid.JID(to_jid)
                extra = data_format.deserialise(extra_s)
                # if ((self.type == C.CHAT_GROUP and type_ != C.MESS_TYPE_GROUPCHAT) or
                #    (self.type == C.CHAT_ONE2ONE and type_ == C.MESS_TYPE_GROUPCHAT)):
                #     continue
                extra["history"] = True
                self.messages[uid] = Message(
                    self,
                    uid,
                    timestamp,
                    from_jid,
                    to_jid,
                    message,
                    subject,
                    type_,
                    extra,
                    profile,
                )
            self._on_history_printed()
            if callback is not None:
                callback()

        def _history_get_eb(err):
            log.error(_("Can't get history: {}").format(err))
            self._on_history_printed()
            if callback is not None:
                callback()

        self.host.bridge.history_get(
            str(self.host.profiles[profile].whoami.bare),
            str(target),
            size,
            True,
            {k: str(v) for k, v in filters.items()},
            profile,
            callback=_history_get_cb,
            errback=_history_get_eb,
        )

    def message_encryption_get_cb(self, session_data):
        if session_data:
            session_data = data_format.deserialise(session_data)
            self.message_encryption_started(session_data)

    def message_encryption_get_eb(self, failure_):
        log.error(_("Can't get encryption state: {reason}").format(reason=failure_))

    def get_encryption_state(self):
        """Retrieve encryption state with current target.

        Once state is retrieved, default message_encryption_started will be called if
        suitable
        """
        if self.type == C.CHAT_GROUP:
            return
        self.host.bridge.message_encryption_get(
            str(self.target.bare),
            self.profile,
            callback=self.message_encryption_get_cb,
            errback=self.message_encryption_get_eb,
        )

    def message_new(
        self, uid, timestamp, from_jid, to_jid, msg, subject, type_, extra, profile
    ):
        if self._locked:
            self._cache[uid] = (
                uid,
                timestamp,
                from_jid,
                to_jid,
                msg,
                subject,
                type_,
                extra,
                profile,
            )
            return

        if (
            not msg
            and not subject
            and not extra[C.KEY_ATTACHMENTS]
            and type_ != C.MESS_TYPE_INFO
        ):
            log.warning("Received an empty message for uid {}".format(uid))
            return

        if self.type == C.CHAT_GROUP:
            if to_jid.resource and type_ != C.MESS_TYPE_GROUPCHAT:
                # we have a private message, we forward it to a private conversation
                # widget
                chat_widget = self.get_or_create_private_widget(to_jid)
                chat_widget.message_new(
                    uid, timestamp, from_jid, to_jid, msg, subject, type_, extra, profile
                )
                return
            if type_ == C.MESS_TYPE_INFO:
                try:
                    info_type = extra["info_type"]
                except KeyError:
                    pass
                else:
                    user_data = {
                        k[5:]: v for k, v in extra.items() if k.startswith("user_")
                    }
                    if info_type == ROOM_USER_JOINED:
                        self.addUser(user_data)
                    elif info_type == ROOM_USER_LEFT:
                        self.removeUser(user_data)

        message = Message(
            self, uid, timestamp, from_jid, to_jid, msg, subject, type_, extra, profile
        )
        self.messages[uid] = message

        if "received_timestamp" in extra:
            log.warning("Delayed message received after history, this should not happen")
        self.create_message(message)

    def message_encryption_started(self, session_data):
        self.encrypted = True
        log.debug(
            _("message encryption started with {target} using {encryption}").format(
                target=self.target, encryption=session_data["name"]
            )
        )

    def message_encryption_stopped(self, session_data):
        self.encrypted = False
        log.debug(
            _("message encryption stopped with {target} (was using {encryption})").format(
                target=self.target, encryption=session_data["name"]
            )
        )

    def create_message(self, message, append=False):
        """Must be implemented by frontend to create and show a new message widget

        This is only called on message_new, not on history.
        You need to override history_print to handle the later
        @param message(Message): message data
        """
        raise NotImplementedError

    def is_user_moved(self, message):
        """Return True if message is a user left/joined message

        @param message(Message): message to check
        @return (bool): True is message is user moved info message
        """
        if message.type != C.MESS_TYPE_INFO:
            return False
        try:
            info_type = message.extra["info_type"]
        except KeyError:
            return False
        else:
            return info_type in ROOM_USER_MOVED

    def handle_user_moved(self, message):
        """Check if this message is a UserMoved one, and merge it when possible

        "merge it" means that info message indicating a user joined/left will be
        grouped if no other non-info messages has been sent since
        @param message(Message): message to check
        @return (bool): True if this message has been merged
            if True, a new MessageWidget must not be created and appended to history
        """
        if self.is_user_moved(message):
            for wid in self.message_widgets_rev:
                # we merge in/out messages if no message was sent meanwhile
                if not isinstance(wid, MessageWidget):
                    continue
                elif wid.mess_data.type != C.MESS_TYPE_INFO:
                    return False
                elif (
                    wid.info_type in ROOM_USER_MOVED
                    and wid.mess_data.nick == message.nick
                ):
                    try:
                        count = wid.reentered_count
                    except AttributeError:
                        count = wid.reentered_count = 1
                    nick = wid.mess_data.nick
                    if message.info_type == ROOM_USER_LEFT:
                        wid.message = _("<= {nick} has left the room ({count})").format(
                            nick=nick, count=count
                        )
                    else:
                        wid.message = _(
                            "<=> {nick} re-entered the room ({count})"
                        ).format(nick=nick, count=count)
                        wid.reentered_count += 1
                    return True
        return False

    def print_day_change(self, day):
        """Display the day on a new line.

        @param day(unicode): day to display (or not if this method is not overwritten)
        """
        # FIXME: not called anymore after refactoring
        pass

    ## Room ##

    def set_subject(self, subject):
        """Set title for a group chat"""
        if self.type != C.CHAT_GROUP:
            raise exceptions.InternalError(
                "trying to set subject for a non group chat window"
            )
        self.subject = subject

    def change_subject(self, new_subject):
        """Change the subject of the room

        This change the subject on the room itself (i.e. via XMPP),
        while set_subject change the subject of this widget
        """
        self.host.bridge.muc_subject(str(self.target), new_subject, self.profile)

    def add_game_panel(self, widget):
        """Insert a game panel to this Chat dialog.

        @param widget (Widget): the game panel
        """
        raise NotImplementedError

    def remove_game_panel(self, widget):
        """Remove the game panel from this Chat dialog.

        @param widget (Widget): the game panel
        """
        raise NotImplementedError

    def update(self, entity=None):
        """Update one or all entities.

        @param entity (jid.JID): entity to update
        """
        # FIXME: to remove ?
        raise NotImplementedError

    ## events ##

    def on_chat_state(self, from_jid, state, profile):
        """A chat state has been received"""
        if self.type == C.CHAT_GROUP:
            nick = from_jid.resource
            try:
                self.occupants[nick].state = state
            except KeyError:
                log.warning(
                    "{nick} not found in {room}, ignoring new chat state".format(
                        nick=nick, room=self.target.bare
                    )
                )

    def on_message_state(self, uid, status, profile):
        try:
            mess_data = self.messages[uid]
        except KeyError:
            pass
        else:
            mess_data.status = status

    def on_avatar(self, entity, avatar_data, profile):
        if self.type == C.CHAT_GROUP:
            if entity.bare == self.target:
                try:
                    self.occupants[entity.resource].update({"avatar": avatar_data})
                except KeyError:
                    # can happen for a message in history where the
                    # entity is not here anymore
                    pass

                for m in list(self.messages.values()):
                    if m.nick == entity.resource:
                        for w in m.widgets:
                            w.update({"avatar": avatar_data})
        else:
            if (
                entity.bare == self.target.bare
                or entity.bare == self.host.profiles[profile].whoami.bare
            ):
                log.info("avatar updated for {}".format(entity))
                for m in list(self.messages.values()):
                    if m.from_jid.bare == entity.bare:
                        for w in m.widgets:
                            w.update({"avatar": avatar_data})


quick_widgets.register(QuickChat)