#!/usr/bin/env python3

# 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 Any, Final, Self

from pydantic import BaseModel, Field
from twisted.words.protocols.jabber import xmlstream
from twisted.words.xish import domish
from tx_xmpp import disco, itx_xmpp
from zope.interface import implementer

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

log = getLogger(__name__)

EXTRA_KEY: Final = "attached_to"

NS_MESSAGE_ATTACHING = "urn:xmpp:message-attaching:1"


PLUGIN_INFO = {
    C.PI_NAME: "Message Attaching",
    C.PI_IMPORT_NAME: "XEP-0367",
    C.PI_TYPE: "XEP",
    C.PI_MODES: C.PLUG_MODE_BOTH,
    C.PI_PROTOCOLS: ["XEP-0367"],
    C.PI_MAIN: "XEP_0367",
    C.PI_HANDLER: "yes",
    C.PI_DESCRIPTION: _("""Implementation of XEP-0367 (Message Attaching)"""),
}


class AttachedTo(BaseModel):
    """Attach-to resolution data."""

    uid: str | None = Field(
        default=None,
        description="Libervia internal UID of the message to attach to, if resolved.",
    )
    stanza_id: str | None = Field(
        description="XMPP stanza id from <attach-to/>.",
    )

    def to_element(self) -> domish.Element:
        """Build the <attach-to/> element from this instance's data.

        @return: <attach-to/> element.
        @raise exceptions.DataError: If stanza_id is missing.
        """
        if self.stanza_id is None:
            raise exceptions.DataError("stanza_id is missing")
        return domish.Element(
            (NS_MESSAGE_ATTACHING, "attach-to"),
            attribs={"id": self.uid or self.stanza_id},
        )

    @classmethod
    def from_element(cls, element: domish.Element) -> Self:
        """Create an AttachedTo instance from an <attach-to/> element.

        @param element: <attach-to/> element.
        @return: AttachedTo instance with raw_value set, uid to be resolved later.
        """
        return cls(stanza_id=str(element["id"]))


class XEP_0367:

    def __init__(self, host) -> None:
        log.info(f"Plugin {PLUGIN_INFO[C.PI_NAME]!r} initialization.")
        self.host = host
        host.register_namespace("message-attaching", NS_MESSAGE_ATTACHING)
        # priority=10 so "attached_to" is parsed before plugins which need it (e.g.
        # XEP-0447)
        host.trigger.add("message_parse", self._message_parse_trigger, priority=10)

    async def _message_parse_trigger(
        self,
        client: SatXMPPEntity,
        message_elt: domish.Element,
        data: dict[str, Any],
    ) -> bool:
        """Parse <attach-to/> element and resolve UID.

        @param client: Client instance.
        @param message_elt: The <message/> element.
        @param data: Parsed message data.
        @return: True to continue message processing.
        """
        attach_to_elt = next(
            message_elt.elements(NS_MESSAGE_ATTACHING, "attach-to"), None
        )
        if attach_to_elt is not None:
            attached_to = AttachedTo.from_element(attach_to_elt)
            from_jid = data["from"]
            uid = (
                client.mess_id2uid.get((from_jid, attached_to.stanza_id))
                if attached_to.stanza_id is not None
                else None
            )
            if uid is None:
                log.warning(
                    f"No matching UID found for attach-to id {attached_to.stanza_id!r} "
                    f"from {from_jid!r}"
                )
            else:
                attached_to.uid = uid
            data["extra"][EXTRA_KEY] = attached_to.model_dump()
        return True

    def get_handler(self, client: SatXMPPEntity) -> "XEP0367Handler":
        return XEP0367Handler()


@implementer(itx_xmpp.IDisco)
class XEP0367Handler(xmlstream.XMPPHandler):

    def getDiscoInfo(self, requestor: str, target: str, nodeIdentifier: str = "") -> list:
        return [disco.DiscoFeature(NS_MESSAGE_ATTACHING)]

    def getDiscoItems(
        self, requestor: str, target: str, nodeIdentifier: str = ""
    ) -> list:
        return []