# This file is part of Gajim.
#
# Gajim is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published
# by the Free Software Foundation; version 3 only.
#
# Gajim 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Gajim. If not, see <http://www.gnu.org/licenses/>.

"""
Handles the jingle signalling protocol
"""

#TODO:
# * things in XEP 0176, including:
#      - http://xmpp.org/extensions/xep-0176.html#protocol-restarts
#      - http://xmpp.org/extensions/xep-0176.html#fallback
# * XEP 0177 (raw udp)

# * UI:
#   - make state and codec information available to the user
#   - video integration
#   * config:
#     - codecs

import logging

import nbxmpp
from nbxmpp.namespaces import Namespace
from nbxmpp.structs import StanzaHandler

from gajim.common import helpers
from gajim.common import app
from gajim.common import jingle_xtls
from gajim.common.modules.base import BaseModule

from gajim.common.jingle_session import JingleSession
from gajim.common.jingle_session import JingleStates
from gajim.common.jingle_ft import JingleFileTransfer
from gajim.common.jingle_transport import JingleTransportSocks5
from gajim.common.jingle_transport import JingleTransportIBB
from gajim.common.jingle_rtp import JingleAudio, JingleVideo

logger = logging.getLogger('gajim.c.m.jingle')


class Jingle(BaseModule):
    def __init__(self, con):
        BaseModule.__init__(self, con)

        self.handlers = [
            StanzaHandler(name='iq',
                          typ='result',
                          callback=self._on_jingle_iq),
            StanzaHandler(name='iq',
                          typ='error',
                          callback=self._on_jingle_iq),
            StanzaHandler(name='iq',
                          typ='set',
                          ns=Namespace.JINGLE,
                          callback=self._on_jingle_iq),
            StanzaHandler(name='iq',
                          typ='get',
                          ns=Namespace.PUBKEY_PUBKEY,
                          callback=self._on_pubkey_request),
            StanzaHandler(name='iq',
                          typ='result',
                          ns=Namespace.PUBKEY_PUBKEY,
                          callback=self._pubkey_result_received),
        ]

        # dictionary: sessionid => JingleSession object
        self._sessions = {}

        # dictionary: (jid, iq stanza id) => JingleSession object,
        # one time callbacks
        self.__iq_responses = {}
        self.files = []

    def delete_jingle_session(self, sid):
        """
        Remove a jingle session from a jingle stanza dispatcher
        """
        if sid in self._sessions:
            #FIXME: Move this elsewhere?
            for content in list(self._sessions[sid].contents.values()):
                content.destroy()
            self._sessions[sid].callbacks = []
            del self._sessions[sid]

    def _on_pubkey_request(self, con, stanza, _properties):
        jid_from = helpers.get_full_jid_from_iq(stanza)
        self._log.info('Pubkey request from %s', jid_from)
        sid = stanza.getAttr('id')
        jingle_xtls.send_cert(con, jid_from, sid)
        raise nbxmpp.NodeProcessed

    def _pubkey_result_received(self, con, stanza, _properties):
        jid_from = helpers.get_full_jid_from_iq(stanza)
        self._log.info('Pubkey result from %s', jid_from)
        jingle_xtls.handle_new_cert(con, stanza, jid_from)

    def _on_jingle_iq(self, _con, stanza, _properties):
        """
        The jingle stanza dispatcher

        Route jingle stanza to proper JingleSession object, or create one if it
        is a new session.

        TODO: Also check if the stanza isn't an error stanza, if so route it
        adequately.
        """
        # get data
        try:
            jid = helpers.get_full_jid_from_iq(stanza)
        except helpers.InvalidFormat:
            logger.warning('Invalid JID: %s, ignoring it', stanza.getFrom())
            return
        id_ = stanza.getID()
        if (jid, id_) in self.__iq_responses.keys():
            self.__iq_responses[(jid, id_)].on_stanza(stanza)
            del self.__iq_responses[(jid, id_)]
            raise nbxmpp.NodeProcessed
        jingle = stanza.getTag('jingle')
        # a jingle element is not necessary in iq-result stanza
        # don't check for that
        if jingle:
            sid = jingle.getAttr('sid')
        else:
            sid = None
            for sesn in self._sessions.values():
                if id_ in sesn.iq_ids:
                    sesn.on_stanza(stanza)
            return
        # do we need to create a new jingle object
        if sid not in self._sessions:
            #TODO: tie-breaking and other things...
            newjingle = JingleSession(self._con, weinitiate=False, jid=jid,
                                      iq_id=id_, sid=sid)
            self._sessions[sid] = newjingle
        # we already have such session in dispatcher...
        self._sessions[sid].collect_iq_id(id_)
        self._sessions[sid].on_stanza(stanza)
        # Delete invalid/unneeded sessions
        if sid in self._sessions and \
        self._sessions[sid].state == JingleStates.ENDED:
            self.delete_jingle_session(sid)
        raise nbxmpp.NodeProcessed

    def start_audio(self, jid):
        if self.get_jingle_session(jid, media='audio'):
            return self.get_jingle_session(jid, media='audio').sid
        jingle = self.get_jingle_session(jid, media='video')
        if jingle:
            jingle.add_content('voice', JingleAudio(jingle))
        else:
            jingle = JingleSession(self._con, weinitiate=True, jid=jid)
            self._sessions[jingle.sid] = jingle
            jingle.add_content('voice', JingleAudio(jingle))
            jingle.start_session()
        return jingle.sid

    def start_video(self, jid):
        if self.get_jingle_session(jid, media='video'):
            return self.get_jingle_session(jid, media='video').sid
        jingle = self.get_jingle_session(jid, media='audio')
        if jingle:
            video = JingleVideo(jingle)
            jingle.add_content('video', video)
        else:
            jingle = JingleSession(self._con, weinitiate=True, jid=jid)
            self._sessions[jingle.sid] = jingle
            video = JingleVideo(jingle)
            jingle.add_content('video', video)
            jingle.start_session()
        return jingle.sid

    def start_audio_video(self, jid):
        if self.get_jingle_session(jid, media='video'):
            return self.get_jingle_session(jid, media='video').sid
        audio_session = self.get_jingle_session(jid, media='audio')
        video_session = self.get_jingle_session(jid, media='video')
        if audio_session and video_session:
            return audio_session.sid
        if audio_session:
            video = JingleVideo(audio_session)
            audio_session.add_content('video', video)
            return audio_session.sid
        if video_session:
            audio = JingleAudio(video_session)
            video_session.add_content('audio', audio)
            return video_session.sid

        jingle_session = JingleSession(self._con, weinitiate=True, jid=jid)
        self._sessions[jingle_session.sid] = jingle_session
        audio = JingleAudio(jingle_session)
        video = JingleVideo(jingle_session)
        jingle_session.add_content('audio', audio)
        jingle_session.add_content('video', video)
        jingle_session.start_session()
        return jingle_session.sid

    def start_file_transfer(self, jid, file_props, request=False):
        logger.info("start file transfer with file: %s", file_props)
        contact = app.contacts.get_contact_with_highest_priority(
            self._account, app.get_jid_without_resource(jid))
        if app.contacts.is_gc_contact(self._account, jid):
            gcc = jid.split('/')
            if len(gcc) == 2:
                contact = app.contacts.get_gc_contact(self._account,
                                                      gcc[0],
                                                      gcc[1])
        if contact is None:
            return None
        use_security = contact.supports(Namespace.JINGLE_XTLS)
        jingle = JingleSession(self._con,
                               weinitiate=True,
                               jid=jid,
                               werequest=request)
        # this is a file transfer
        jingle.session_type_ft = True
        self._sessions[jingle.sid] = jingle
        file_props.sid = jingle.sid

        if contact.supports(Namespace.JINGLE_BYTESTREAM):
            transport = JingleTransportSocks5()
        elif contact.supports(Namespace.JINGLE_IBB):
            transport = JingleTransportIBB()
        else:
            transport = None

        senders = 'initiator'
        if request:
            senders = 'responder'
        transfer = JingleFileTransfer(jingle,
                                      transport=transport,
                                      file_props=file_props,
                                      use_security=use_security,
                                      senders=senders)
        file_props.transport_sid = transport.sid
        file_props.algo = self.__hash_support(contact)
        jingle.add_content('file' + helpers.get_random_string(), transfer)
        jingle.start_session()
        return transfer.transport.sid

    @staticmethod
    def __hash_support(contact):
        if contact.supports(Namespace.HASHES_2):
            if contact.supports(Namespace.HASHES_BLAKE2B_512):
                return 'blake2b-512'
            if contact.supports(Namespace.HASHES_BLAKE2B_256):
                return 'blake2b-256'
            if contact.supports(Namespace.HASHES_SHA3_512):
                return 'sha3-512'
            if contact.supports(Namespace.HASHES_SHA3_256):
                return 'sha3-256'
            if contact.supports(Namespace.HASHES_SHA512):
                return 'sha-512'
            if contact.supports(Namespace.HASHES_SHA256):
                return 'sha-256'
        return None

    def get_jingle_sessions(self, jid, sid=None, media=None):
        if sid:
            return [se for se in self._sessions.values() if se.sid == sid]

        sessions = [se for se in self._sessions.values() if se.peerjid == jid]
        if media:
            if media not in ('audio', 'video', 'file'):
                return []
            return [se for se in sessions if se.get_content(media)]
        return sessions

    def set_file_info(self, file_):
        # Saves information about the files we have transferred
        # in case they need to be requested again.
        self.files.append(file_)

    def get_file_info(self, peerjid, hash_=None, name=None, _account=None):
        if hash_:
            for file in self.files: # DEBUG
                #if f['hash'] == '1294809248109223':
                if file['hash'] == hash_ and file['peerjid'] == peerjid:
                    return file
        elif name:
            for file in self.files:
                if file['name'] == name and file['peerjid'] == peerjid:
                    return file
        return None

    def get_jingle_session(self, jid, sid=None, media=None):
        if sid:
            if sid in self._sessions:
                return self._sessions[sid]
            return None
        if media:
            if media not in ('audio', 'video', 'file'):
                return None
            for session in self._sessions.values():
                if session.peerjid == jid and session.get_content(media):
                    return session
        return None


def get_instance(*args, **kwargs):
    return Jingle(*args, **kwargs), 'Jingle'