#!/usr/bin/env python3

# Libervia plugin for XEP-0444
# Copyright (C) 2009-2026 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 typing import Iterable, List

from twisted.internet import defer
from twisted.words.protocols.jabber import jid, xmlstream
from twisted.words.xish import domish
from tx_xmpp import disco, itx_xmpp
from zope.interface import implementer

import emoji
from libervia.backend.core import exceptions
from libervia.backend.core.constants import Const as C
from libervia.backend.core.core_types import SatXMPPEntity
from libervia.backend.core.i18n import _
from libervia.backend.core.log import getLogger
from libervia.backend.memory.sqla_mapping import History
from libervia.backend.models.core import MessageReactionData
from libervia.backend.tools.utils import aio
from libervia.backend.memory.sqla import select
from sqlalchemy.orm.attributes import flag_modified

log = getLogger(__name__)

PLUGIN_INFO = {
    C.PI_NAME: "Message Reactions",
    C.PI_IMPORT_NAME: "XEP-0444",
    C.PI_TYPE: C.PLUG_TYPE_XEP,
    C.PI_MODES: C.PLUG_MODE_BOTH,
    C.PI_PROTOCOLS: ["XEP-0444"],
    C.PI_DEPENDENCIES: ["XEP-0045", "XEP-0334"],
    C.PI_MAIN: "XEP_0444",
    C.PI_HANDLER: "yes",
    C.PI_DESCRIPTION: _("""Message Reactions implementation"""),
}

NS_REACTIONS = "urn:xmpp:reactions:0"


class XEP_0444:
    # TODO: implement and use occupant-ID (XEP-0421), and check sender (see
    #   https://xmpp.org/extensions/xep-0444.html#acceptable-reactions).
    def __init__(self, host):
        log.info(f"plugin {PLUGIN_INFO[C.PI_NAME]!r} initialization")
        host.register_namespace("reactions", NS_REACTIONS)
        self.host = host
        self._m = host.plugins["XEP-0045"]
        self._h = host.plugins["XEP-0334"]
        host.bridge.add_method(
            "message_reactions_set",
            ".plugin",
            in_sign="sasss",
            out_sign="",
            method=self._reactions_set,
            async_=True,
        )
        host.trigger.add("message_received", self._message_received_trigger)

    def get_handler(self, client):
        return XEP_0444_Handler()

    async def _message_received_trigger(
        self,
        client: SatXMPPEntity,
        message_elt: domish.Element,
        post_treat: defer.Deferred,
    ) -> bool:
        reactions_elt = next(message_elt.elements(NS_REACTIONS, "reactions"), None)
        if reactions_elt is not None:
            reaction_id = reactions_elt.getAttribute("id")
            message_type = message_elt.getAttribute("type")
            history = await self.host.memory.storage.get_history_from_xmpp_id(
                client, reaction_id, message_type
            )
            if history is None:
                log.warning(
                    f"Can't find matching message for reaction: {reactions_elt.toXml()}"
                )
            else:
                if not reaction_id:
                    log.warning(f"Invalid reaction: {reactions_elt.toXml()}")
                    return False
                from_jid = jid.JID(message_elt["from"])
                reactions = set()
                for reaction_elt in reactions_elt.elements("reaction"):
                    reaction = str(reaction_elt)
                    if (
                        not emoji.purely_emoji(reaction)
                        or emoji.emoji_count(reaction) != 1
                    ):
                        log.warning(f"Ignoring invalid reaction: {reaction_elt.toXml()}.")
                        continue
                    reactions.add(reaction)
                await self.update_history_reactions(client, history, from_jid, reactions)

            return False

        return True

    def _reactions_set(
        self,
        message_id: str,
        reactions: List[str],
        update_type: str = "replace",
        profile: str = C.PROF_KEY_NONE,
    ) -> defer.Deferred[None]:
        client = self.host.get_client(profile)
        return defer.ensureDeferred(
            self.set_reactions(client, message_id, reactions, update_type)
        )

    async def get_history_from_uid(
        self, client: SatXMPPEntity, message_id: str
    ) -> History:
        """Retrieve the chat history associated with a given message ID.

        @param message_id: The Libervia specific identifier of the message

        @return: An instance of History containing the chat history, messages, and
            subjects related to the specified message ID.

        @raises exceptions.NotFound: The history corresponding to the given message ID is
            not found in the database.
        """
        history = await self.host.memory.storage.get(
            client,
            History,
            History.uid,
            message_id,
        )
        if history is None:
            raise exceptions.NotFound(
                f"message to retract not found in database ({message_id})"
            )
        return history

    def send_reactions(
        self,
        client: SatXMPPEntity,
        dest_jid: jid.JID,
        message_type: str,
        message_id: str,
        reactions: Iterable[str],
    ) -> None:
        """Send the <message> stanza containing the reactions

        @param dest_jid: recipient of the reaction
        @param message_id: either origin ID or stanza ID
            see https://xmpp.org/extensions/xep-0444.html#business-id
        """
        message_elt = domish.Element((None, "message"))
        message_elt["from"] = client.jid.full()
        message_elt["to"] = dest_jid.full()
        message_elt["type"] = message_type
        reactions_elt = message_elt.addElement((NS_REACTIONS, "reactions"))
        reactions_elt["id"] = message_id
        for r in set(reactions):
            reactions_elt.addElement("reaction", content=r)
        self._h.add_hint_elements(message_elt, [self._h.HINT_STORE])
        client.send(message_elt)

    def convert_to_replace_update(
        self,
        current_reactions: set[str],
        reactions_new: Iterable[str],
        update_type: str,
    ) -> set[str]:
        """Convert the given update to a replace update.

        @param current_reactions: reaction of reacting JID before update
        @param reactions_new: New reactions to be updated.
        @param update_type: Original type of update (add, remove, toggle, replace).
        @return: reactions for a replace operation.

        @raise ValueError: invalid ``update_type``.
        """
        new_reactions_set = set(reactions_new)

        if update_type == "replace":
            return new_reactions_set

        if update_type == "add":
            replace_reactions = current_reactions | new_reactions_set
        elif update_type == "remove":
            replace_reactions = current_reactions - new_reactions_set
        elif update_type == "toggle":
            replace_reactions = current_reactions ^ new_reactions_set
        else:
            raise ValueError(f"Invalid update type: {update_type!r}")

        return replace_reactions

    async def update_history_reactions(
        self,
        client: SatXMPPEntity,
        history: History,
        reacting_jid: jid.JID,
        reactions_new: Iterable[str],
        update_type: str = "replace",
        store: bool = True,
    ) -> set[str]:
        """Update reactions in History instance and optionally store and signal it.

        @param history: storage History instance to be updated
        @param reacting_jid: author of the reactions
        @param reactions_new: new reactions to update
        @param update_type: Original type of update (add, remove, toggle, replace).
        @param store: if True, update history in storage, and send a `message_update`
            signal with the new reactions.
        @return: set of reactions for this JID for a "replace" update
        """
        # FIXME: handle race conditions
        if history.type == C.MESS_TYPE_GROUPCHAT:
            entity_jid_s = reacting_jid.full()
        else:
            entity_jid_s = reacting_jid.userhost()
        if history.extra is None:
            history.extra = {}
        extra = history.extra
        reactions = extra.get("reactions", {})

        current_reactions = {
            reaction for reaction, jids in reactions.items() if entity_jid_s in jids
        }
        reactions_replace_set = self.convert_to_replace_update(
            current_reactions, reactions_new, update_type
        )

        for reaction in current_reactions - reactions_replace_set:
            reaction_jids = reactions[reaction]
            reaction_jids.remove(entity_jid_s)
            if not reaction_jids:
                del reactions[reaction]

        for reaction in reactions_replace_set - current_reactions:
            reactions.setdefault(reaction, []).append(entity_jid_s)

        # we want to have a constant order in reactions
        extra["reactions"] = dict(sorted(reactions.items()))

        if store:
            # FIXME: this is not a clean way to flag "extra" as modified, but a deepcopy
            # is for some reason not working here.
            flag_modified(history, "extra")
            await self.host.memory.storage.add(history)
            # we send the signal for frontends update
            data = MessageReactionData(reactions=extra["reactions"])
            self.host.bridge.message_update(
                history.uid,
                C.MESS_UPDATE_REACTION,
                data.model_dump_json(),
                client.profile,
            )

        return reactions_replace_set

    async def set_reactions(
        self,
        client: SatXMPPEntity,
        message_id: str,
        reactions: Iterable[str],
        update_type: str = "replace",
    ) -> None:
        """Set and replace reactions to a message

        @param message_id: internal ID of the message
        @param rections: lsit of emojis to used to react to the message
            use empty list to remove all reactions
        @param update_type: how to use the reaction to make the update, can be "replace",
            "add", "remove" or "toggle".
        """
        if not message_id:
            raise ValueError("message_id can't be empty")

        history = await self.get_history_from_uid(client, message_id)
        if history.type == C.MESS_TYPE_GROUPCHAT:
            mess_id = history.stanza_id
        else:
            mess_id = history.origin_id

        if mess_id is None:
            raise exceptions.DataError(
                "target message has neither origin-id nor message-id, we can't send a "
                "reaction"
            )

        if history.source == client.jid.userhost():
            dest_jid = history.dest_jid
        else:
            dest_jid = history.source_jid

        if history.type == C.MESS_TYPE_GROUPCHAT:
            # the reaction is for the chat room itself
            dest_jid = dest_jid.userhostJID()
            reacting_jid = self._m.get_room_user_jid(client, dest_jid)
            # we don't store reactions for MUC, at this will be done when we receive back
            # the reaction
            store = False
        else:
            # we use bare JIDs for one2one message, except if the recipient is from a MUC
            if self._m.is_room(client, dest_jid):
                # this is a private message in a room, we need to use the MUC JID
                reacting_jid = self._m.get_room_user_jid(client, dest_jid.userhostJID())
            else:
                # this is a classic one2one message, we need the bare JID
                reacting_jid = client.jid.userhostJID()
                dest_jid = dest_jid.userhostJID()
            store = True

        reaction_replace_set = await self.update_history_reactions(
            client, history, reacting_jid, reactions, update_type, store
        )

        self.send_reactions(client, dest_jid, history.type, mess_id, reaction_replace_set)


@implementer(itx_xmpp.IDisco)
class XEP_0444_Handler(xmlstream.XMPPHandler):
    def getDiscoInfo(self, requestor, service, nodeIdentifier=""):
        return [disco.DiscoFeature(NS_REACTIONS)]

    def getDiscoItems(self, requestor, service, nodeIdentifier=""):
        return []