# 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/>.

# XEP-0313: Message Archive Management

import logging
import time
from datetime import datetime, timedelta

import nbxmpp
from nbxmpp.structs import StanzaHandler

from gajim.common import app
from gajim.common.nec import NetworkEvent
from gajim.common.nec import NetworkIncomingEvent
from gajim.common.const import ArchiveState
from gajim.common.const import KindConstant
from gajim.common.const import SyncThreshold
from gajim.common.caps_cache import muc_caps_cache
from gajim.common.helpers import get_sync_threshold
from gajim.common.helpers import AdditionalDataDict
from gajim.common.modules.misc import parse_delay
from gajim.common.modules.misc import parse_oob
from gajim.common.modules.misc import parse_correction
from gajim.common.modules.util import get_eme_message

log = logging.getLogger('gajim.c.m.archiving')


class MAM:
    def __init__(self, con):
        self._con = con
        self._account = con.name

        self.handlers = [
            StanzaHandler(name='message',
                          callback=self._mam_message_received,
                          priority=51),
        ]

        self.available = False
        self.archiving_namespace = None
        self._mam_query_ids = {}

        # Holds archive jids where catch up was successful
        self._catch_up_finished = []

    def pass_disco(self, from_, _identities, features, _data, _node):
        if nbxmpp.NS_MAM_2 in features:
            self.archiving_namespace = nbxmpp.NS_MAM_2
        elif nbxmpp.NS_MAM_1 in features:
            self.archiving_namespace = nbxmpp.NS_MAM_1
        else:
            return

        self.available = True
        log.info('Discovered MAM %s: %s', self.archiving_namespace, from_)

        app.nec.push_incoming_event(
            NetworkEvent('feature-discovered',
                         account=self._account,
                         feature=self.archiving_namespace))

    def _from_valid_archive(self, stanza, properties):
        if properties.type.is_groupchat:
            expected_archive = properties.jid
        else:
            expected_archive = self._con.get_own_jid()

        return properties.mam.archive.bareMatch(expected_archive)

    def _get_unique_id(self, properties):
        if properties.type.is_groupchat:
            return properties.mam.id, None

        if properties.is_self_message:
            return None, properties.id

        if properties.is_muc_pm:
            return properties.mam.id, properties.id

        if self._con.get_own_jid().bareMatch(properties.jid):
            # message we sent
            return properties.mam.id, properties.id

        # A message we received
        return properties.mam.id, None

    def _mam_message_received(self, _con, stanza, properties):
        if not properties.is_mam_message:
            return

        app.nec.push_incoming_event(
            NetworkIncomingEvent('raw-mam-message-received',
                                 conn=self._con,
                                 stanza=stanza))

        if not self._from_valid_archive(stanza, properties):
            log.warning('Message from invalid archive %s',
                        properties.mam.archive)
            raise nbxmpp.NodeProcessed

        log.info('Received message from archive: %s', properties.mam.archive)
        if not self._is_valid_request(properties):
            log.warning('Invalid MAM Message: unknown query id %s',
                        properties.mam.query_id)
            log.debug(stanza)
            raise nbxmpp.NodeProcessed

        event_attrs = {}

        groupchat = properties.type.is_groupchat

        if groupchat:
            event_attrs.update(self._parse_gc_attrs(properties))
        else:
            event_attrs.update(self._parse_chat_attrs(stanza, properties))

        stanza_id, message_id = self._get_unique_id(properties)

        if properties.mam.is_ver_2:
            # Search only with stanza-id for duplicates on mam:2
            if app.logger.find_stanza_id(self._account,
                                         str(properties.mam.archive),
                                         stanza_id,
                                         message_id,
                                         groupchat=groupchat):
                log.info('Found duplicate with stanza-id: %s, message-id: %s',
                         stanza_id, message_id)
                raise nbxmpp.NodeProcessed

        event_attrs.update(
            {'conn': self._con,
             'additional_data': AdditionalDataDict(),
             'encrypted': False,
             'timestamp': properties.mam.timestamp,
             'self_message': properties.is_self_message,
             'groupchat': groupchat,
             'muc_pm': properties.is_muc_pm,
             'stanza_id': stanza_id,
             'origin_id': message_id,
             'message_id': properties.id,
             'correct_id': None,
             'archive_jid': properties.mam.archive,
             'msgtxt': properties.body,
             'message': stanza,
             'stanza': stanza,
             'namespace': properties.mam.namespace,
             })

        if groupchat:
            event = MamGcMessageReceivedEvent(None, **event_attrs)
        else:
            event = MamMessageReceivedEvent(None, **event_attrs)

        if properties.is_encrypted:
            event.additional_data['encrypted'] = properties.encrypted.additional_data
            self._decryption_finished(event)
        else:
            app.plugin_manager.extension_point(
                'decrypt', self._con, event, self._decryption_finished)
            if not event.encrypted:
                if properties.eme is not None:
                    event.msgtxt = get_eme_message(properties.eme)
                self._decryption_finished(event)

        raise nbxmpp.NodeProcessed

    @staticmethod
    def _parse_gc_attrs(properties):
        real_jid = None
        if properties.muc_user is not None:
            real_jid = properties.muc_user.jid
        return {'with_': properties.jid,
                'nick': properties.muc_nickname,
                'real_jid': real_jid,
                'kind': KindConstant.GC_MSG}

    def _parse_chat_attrs(self, stanza, properties):
        frm = properties.jid
        to = stanza.getTo()
        if frm.bareMatch(self._con.get_own_jid()):
            with_ = to
            kind = KindConstant.CHAT_MSG_SENT
        else:
            with_ = frm
            kind = KindConstant.CHAT_MSG_RECV

        return {'with_': with_,
                'nick': None,
                'kind': kind}

    def _decryption_finished(self, event):
        if not event.msgtxt:
            # For example Chatstates, Receipts, Chatmarkers
            log.debug(event.message.getProperties())
            return

        user_timestamp = parse_delay(event.stanza)
        if user_timestamp is not None:
            # Record it as a user timestamp
            event.additional_data.set_value(
                'gajim', 'user_timestamp', user_timestamp)

        event.correct_id = parse_correction(event.message)
        parse_oob(event)

        with_ = event.with_.getStripped()
        if event.muc_pm:
            # we store the message with the full JID
            with_ = str(event.with_)

        stanza_id = event.stanza_id
        if event.self_message:
            # Self messages can only be deduped with origin-id
            if event.origin_id is None:
                log.warning('Self message without origin-id found')
                return
            stanza_id = event.origin_id

        if event.namespace == nbxmpp.NS_MAM_1:
            if app.logger.search_for_duplicate(
                    self._account, with_, event.timestamp, event.msgtxt):
                log.info('Found duplicate with fallback for mam:1')
                return

        app.logger.insert_into_logs(self._account,
                                    with_,
                                    event.timestamp,
                                    event.kind,
                                    unread=False,
                                    message=event.msgtxt,
                                    contact_name=event.nick,
                                    additional_data=event.additional_data,
                                    stanza_id=stanza_id,
                                    message_id=event.message_id)

        app.nec.push_incoming_event(
            MamDecryptedMessageReceived(None, **vars(event)))

    def _is_valid_request(self, properties):
        valid_id = self._mam_query_ids.get(str(properties.mam.archive), None)
        return valid_id == properties.mam.query_id

    def _get_query_id(self, jid):
        query_id = self._con.connection.getAnID()
        self._mam_query_ids[jid] = query_id
        return query_id

    @staticmethod
    def _parse_iq(stanza):
        if not nbxmpp.isResultNode(stanza):
            log.error('Error on MAM query: %s', stanza.getError())
            raise InvalidMamIQ

        fin = stanza.getTag('fin')
        if fin is None:
            log.error('Malformed MAM query result received: %s', stanza)
            raise InvalidMamIQ

        set_ = fin.getTag('set', namespace=nbxmpp.NS_RSM)
        if set_ is None:
            log.error(
                'Malformed MAM query result received (no "set" Node): %s',
                stanza)
            raise InvalidMamIQ
        return fin, set_

    def _get_from_jid(self, stanza):
        jid = stanza.getFrom()
        if jid is None:
            # No from means, iq from our own archive
            jid = self._con.get_own_jid().getStripped()
        else:
            jid = jid.getStripped()
        return jid

    def request_archive_count(self, start_date, end_date):
        jid = self._con.get_own_jid().getStripped()
        log.info('Request archive count from: %s', jid)
        query_id = self._get_query_id(jid)
        query = self._get_archive_query(
            query_id, start=start_date, end=end_date, max_=0)
        self._con.connection.SendAndCallForResponse(
            query, self._received_count, {'query_id': query_id})
        return query_id

    def _received_count(self, _con, stanza, query_id):
        try:
            _, set_ = self._parse_iq(stanza)
        except InvalidMamIQ:
            return

        jid = self._get_from_jid(stanza)
        self._mam_query_ids.pop(jid)

        count = set_.getTagData('count')
        log.info('Received archive count: %s', count)
        app.nec.push_incoming_event(ArchivingCountReceived(
            None, query_id=query_id, count=count))

    def request_archive_on_signin(self):
        own_jid = self._con.get_own_jid().getStripped()

        if own_jid in self._mam_query_ids:
            log.warning('MAM request for %s already running', own_jid)
            return

        archive = app.logger.get_archive_infos(own_jid)

        # Migration of last_mam_id from config to DB
        if archive is not None:
            mam_id = archive.last_mam_id
        else:
            mam_id = app.config.get_per(
                'accounts', self._account, 'last_mam_id')
            if mam_id:
                app.config.del_per('accounts', self._account, 'last_mam_id')

        start_date = None
        query_id = self._get_query_id(own_jid)
        if mam_id:
            log.info('MAM query after: %s', mam_id)
            query = self._get_archive_query(query_id, after=mam_id)
        else:
            # First Start, we request the last week
            start_date = datetime.utcnow() - timedelta(days=7)
            log.info('First start: query archive start: %s', start_date)
            query = self._get_archive_query(query_id, start=start_date)

        if own_jid in self._catch_up_finished:
            self._catch_up_finished.remove(own_jid)
        self._send_archive_query(query, query_id, start_date)

    def request_archive_on_muc_join(self, jid):
        archive = app.logger.get_archive_infos(jid)
        threshold = get_sync_threshold(jid, archive)
        log.info('Threshold for %s: %s', jid, threshold)
        query_id = self._get_query_id(jid)
        start_date = None
        if archive is None or archive.last_mam_id is None:
            # First Start, we dont request history
            # Depending on what a MUC saves, there could be thousands
            # of Messages even in just one day.
            start_date = datetime.utcnow() - timedelta(days=1)
            log.info('First join: query archive %s from: %s', jid, start_date)
            query = self._get_archive_query(
                query_id, jid=jid, start=start_date)

        elif threshold == SyncThreshold.NO_THRESHOLD:
            # Not our first join and no threshold set
            log.info('Request from archive: %s, after mam-id %s',
                     jid, archive.last_mam_id)
            query = self._get_archive_query(
                query_id, jid=jid, after=archive.last_mam_id)

        else:
            # Not our first join, check how much time elapsed since our
            # last join and check against threshold
            last_timestamp = archive.last_muc_timestamp
            if last_timestamp is None:
                log.info('No last muc timestamp found ( mam:1? )')
                last_timestamp = 0

            last = datetime.utcfromtimestamp(float(last_timestamp))
            if datetime.utcnow() - last > timedelta(days=threshold):
                # To much time has elapsed since last join, apply threshold
                start_date = datetime.utcnow() - timedelta(days=threshold)
                log.info('Too much time elapsed since last join, '
                         'request from: %s, threshold: %s',
                         start_date, threshold)
                query = self._get_archive_query(
                    query_id, jid=jid, start=start_date)
            else:
                # Request from last mam-id
                log.info('Request from archive %s after %s:',
                         jid, archive.last_mam_id)
                query = self._get_archive_query(
                    query_id, jid=jid, after=archive.last_mam_id)

        if jid in self._catch_up_finished:
            self._catch_up_finished.remove(jid)
        self._send_archive_query(query, query_id, start_date, groupchat=True)

    def _send_archive_query(self, query, query_id, start_date=None,
                            groupchat=False):
        self._con.connection.SendAndCallForResponse(
            query, self._result_finished, {'query_id': query_id,
                                           'start_date': start_date,
                                           'groupchat': groupchat})

    def _result_finished(self, _con, stanza, query_id, start_date, groupchat):
        try:
            fin, set_ = self._parse_iq(stanza)
        except InvalidMamIQ:
            return

        jid = self._get_from_jid(stanza)

        last = set_.getTagData('last')
        if last is None:
            log.info('End of MAM query, no items retrieved')
            self._catch_up_finished.append(jid)
            self._mam_query_ids.pop(jid)
            return

        complete = fin.getAttr('complete')
        if complete != 'true':
            app.logger.set_archive_infos(jid, last_mam_id=last)
            self._mam_query_ids.pop(jid)
            query_id = self._get_query_id(jid)
            query = self._get_archive_query(query_id, jid=jid, after=last)
            self._send_archive_query(query, query_id, groupchat=groupchat)
        else:
            self._mam_query_ids.pop(jid)
            app.logger.set_archive_infos(
                jid, last_mam_id=last, last_muc_timestamp=time.time())
            if start_date is not None and not groupchat:
                # Record the earliest timestamp we request from
                # the account archive. For the account archive we only
                # set start_date at the very first request.
                app.logger.set_archive_infos(
                    jid, oldest_mam_timestamp=start_date.timestamp())

            self._catch_up_finished.append(jid)
            log.info('End of MAM query, last mam id: %s', last)

    def request_archive_interval(self, start_date, end_date, after=None,
                                 query_id=None):
        jid = self._con.get_own_jid().getStripped()
        if after is None:
            log.info('Request intervall from %s to %s from %s',
                     start_date, end_date, jid)
        else:
            log.info('Query page after %s from %s',
                     after, jid)
        if query_id is None:
            query_id = self._get_query_id(jid)
        self._mam_query_ids[jid] = query_id
        query = self._get_archive_query(query_id, start=start_date,
                                        end=end_date, after=after, max_=30)

        self._con.connection.SendAndCallForResponse(
            query, self._intervall_result, {'query_id': query_id,
                                            'start_date': start_date,
                                            'end_date': end_date})
        return query_id

    def _intervall_result(self, _con, stanza, query_id,
                          start_date, end_date):
        try:
            fin, set_ = self._parse_iq(stanza)
        except InvalidMamIQ:
            return

        jid = self._get_from_jid(stanza)
        self._mam_query_ids.pop(jid)
        if start_date:
            timestamp = start_date.timestamp()
        else:
            timestamp = ArchiveState.ALL

        last = set_.getTagData('last')
        if last is None:
            app.nec.push_incoming_event(ArchivingIntervalFinished(
                None, query_id=query_id))
            app.logger.set_archive_infos(
                jid, oldest_mam_timestamp=timestamp)
            log.info('End of MAM request, no items retrieved')
            return

        complete = fin.getAttr('complete')
        if complete != 'true':
            self.request_archive_interval(start_date, end_date, last, query_id)
        else:
            log.info('Request finished')
            app.logger.set_archive_infos(
                jid, oldest_mam_timestamp=timestamp)
            app.nec.push_incoming_event(ArchivingIntervalFinished(
                None, query_id=query_id))

    def _get_archive_query(self, query_id, jid=None, start=None, end=None,
                           with_=None, after=None, max_=70):
        # Muc archive query?
        namespace = muc_caps_cache.get_mam_namespace(jid)
        if namespace is None:
            # Query to our own archive
            namespace = self.archiving_namespace

        iq = nbxmpp.Iq('set', to=jid)
        query = iq.addChild('query', namespace=namespace)
        form = query.addChild(node=nbxmpp.DataForm(typ='submit'))
        field = nbxmpp.DataField(typ='hidden',
                                 name='FORM_TYPE',
                                 value=namespace)
        form.addChild(node=field)
        if start:
            field = nbxmpp.DataField(
                typ='text-single',
                name='start',
                value=start.strftime('%Y-%m-%dT%H:%M:%SZ'))
            form.addChild(node=field)
        if end:
            field = nbxmpp.DataField(typ='text-single',
                                     name='end',
                                     value=end.strftime('%Y-%m-%dT%H:%M:%SZ'))
            form.addChild(node=field)
        if with_:
            field = nbxmpp.DataField(typ='jid-single',
                                     name='with',
                                     value=with_)
            form.addChild(node=field)

        set_ = query.setTag('set', namespace=nbxmpp.NS_RSM)
        set_.setTagData('max', max_)
        if after:
            set_.setTagData('after', after)
        query.setAttr('queryid', query_id)
        return iq

    def save_archive_id(self, jid, stanza_id, timestamp):
        if jid is None:
            jid = self._con.get_own_jid().getStripped()
        if jid not in self._catch_up_finished:
            return
        log.info('Save: %s: %s, %s', jid, stanza_id, timestamp)
        if stanza_id is None:
            # mam:1
            app.logger.set_archive_infos(jid, last_muc_timestamp=timestamp)
        else:
            # mam:2
            app.logger.set_archive_infos(
                jid, last_mam_id=stanza_id, last_muc_timestamp=timestamp)

    def request_mam_preferences(self):
        log.info('Request MAM preferences')
        iq = nbxmpp.Iq('get', self.archiving_namespace)
        iq.setQuery('prefs')
        self._con.connection.SendAndCallForResponse(
            iq, self._preferences_received)

    def _preferences_received(self, stanza):
        if not nbxmpp.isResultNode(stanza):
            log.info('Error: %s', stanza.getError())
            app.nec.push_incoming_event(MAMPreferenceError(
                None, conn=self._con, error=stanza.getError()))
            return

        log.info('Received MAM preferences')
        prefs = stanza.getTag('prefs', namespace=self.archiving_namespace)
        if prefs is None:
            log.error('Malformed stanza (no prefs node): %s', stanza)
            return

        rules = []
        default = prefs.getAttr('default')
        for item in prefs.getTag('always').getTags('jid'):
            rules.append((item.getData(), 'Always'))

        for item in prefs.getTag('never').getTags('jid'):
            rules.append((item.getData(), 'Never'))

        app.nec.push_incoming_event(MAMPreferenceReceived(
            None, conn=self._con, rules=rules, default=default))

    def set_mam_preferences(self, rules, default):
        iq = nbxmpp.Iq(typ='set')
        prefs = iq.addChild(name='prefs',
                            namespace=self.archiving_namespace,
                            attrs={'default': default})
        always = prefs.addChild(name='always')
        never = prefs.addChild(name='never')
        for item in rules:
            jid, archive = item
            if archive:
                always.addChild(name='jid').setData(jid)
            else:
                never.addChild(name='jid').setData(jid)

        self._con.connection.SendAndCallForResponse(
            iq, self._preferences_saved)

    def _preferences_saved(self, stanza):
        if not nbxmpp.isResultNode(stanza):
            log.info('Error: %s', stanza.getError())
            app.nec.push_incoming_event(MAMPreferenceError(
                None, conn=self._con, error=stanza.getError()))
        else:
            log.info('Preferences saved')
            app.nec.push_incoming_event(
                MAMPreferenceSaved(None, conn=self._con))


class MamMessageReceivedEvent(NetworkIncomingEvent):
    name = 'mam-message-received'


class MamGcMessageReceivedEvent(NetworkIncomingEvent):
    name = 'mam-gc-message-received'


class MamDecryptedMessageReceived(NetworkIncomingEvent):
    name = 'mam-decrypted-message-received'


class MAMPreferenceError(NetworkIncomingEvent):
    name = 'mam-prefs-error'


class MAMPreferenceReceived(NetworkIncomingEvent):
    name = 'mam-prefs-received'


class MAMPreferenceSaved(NetworkIncomingEvent):
    name = 'mam-prefs-saved'


class ArchivingCountReceived(NetworkIncomingEvent):
    name = 'archiving-count-received'


class ArchivingIntervalFinished(NetworkIncomingEvent):
    name = 'archiving-interval-finished'


class ArchivingErrorReceived(NetworkIncomingEvent):
    name = 'archiving-error-received'


class InvalidMamIQ(Exception):
    pass


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