# 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-0047: In-Band Bytestreams

from __future__ import annotations

import time

import nbxmpp
from nbxmpp.errors import StanzaError
from nbxmpp.namespaces import Namespace
from nbxmpp.protocol import Iq
from nbxmpp.protocol import NodeProcessed
from nbxmpp.structs import IqProperties
from nbxmpp.structs import StanzaHandler
from nbxmpp.task import Task

from gajim.common import app
from gajim.common import types
from gajim.common.file_props import FileProp
from gajim.common.file_props import FilesProp
from gajim.common.helpers import to_user_string
from gajim.common.modules.base import BaseModule


class IBB(BaseModule):

    _nbxmpp_extends = 'IBB'
    _nbxmpp_methods = [
        'send_open',
        'send_close',
        'send_data',
        'send_reply',
    ]

    def __init__(self, con: types.Client) -> None:
        BaseModule.__init__(self, con)

        self.handlers = [
            StanzaHandler(name='iq',
                          callback=self._ibb_received,
                          ns=Namespace.IBB),
        ]

    def _ibb_received(self,
                      _con: types.xmppClient,
                      stanza: Iq,
                      properties: IqProperties
                      ) -> None:
        if not properties.is_ibb:
            return

        if properties.ibb.type == 'data':
            self._log.info('Data received, sid: %s, seq: %s',
                           properties.ibb.sid, properties.ibb.seq)
            file_props = FilesProp.getFilePropByTransportSid(self._account,
                                                             properties.ibb.sid)
            if not file_props:
                self.send_reply(stanza, nbxmpp.ERR_ITEM_NOT_FOUND)
                raise NodeProcessed

            if file_props.connected:
                self._on_data_received(stanza, file_props, properties)
                self.send_reply(stanza)

        elif properties.ibb.type == 'open':
            self._log.info('Open received, sid: %s, blocksize: %s',
                           properties.ibb.sid, properties.ibb.block_size)

            file_props = FilesProp.getFilePropByTransportSid(self._account,
                                                             properties.ibb.sid)
            if not file_props:
                self.send_reply(stanza, nbxmpp.ERR_ITEM_NOT_FOUND)
                raise NodeProcessed

            file_props.block_size = properties.ibb.block_size
            file_props.direction = '<'
            file_props.seq = 0
            file_props.received_len = 0
            file_props.last_time = time.time()
            file_props.error = 0
            file_props.paused = False
            file_props.connected = True
            file_props.completed = False
            file_props.disconnect_cb = None
            file_props.continue_cb = None
            file_props.syn_id = stanza.getID()
            file_props.fp = open(file_props.file_name, 'wb')  # pylint: disable=consider-using-with  # noqa: E501
            self.send_reply(stanza)

        elif properties.ibb.type == 'close':
            self._log.info('Close received, sid: %s', properties.ibb.sid)
            file_props = FilesProp.getFilePropByTransportSid(self._account,
                                                             properties.ibb.sid)
            if not file_props:
                self.send_reply(stanza, nbxmpp.ERR_ITEM_NOT_FOUND)
                raise NodeProcessed

            self.send_reply(stanza)
            file_props.fp.close()
            file_props.completed = file_props.received_len >= file_props.size
            if not file_props.completed:
                file_props.error = -1
            app.socks5queue.complete_transfer_cb(self._account, file_props)

        raise NodeProcessed

    def _on_data_received(self,
                          stanza: Iq,
                          file_props: FileProp,
                          properties: IqProperties
                          ) -> None:
        ibb = properties.ibb
        if ibb.seq != file_props.seq:
            self.send_reply(stanza, nbxmpp.ERR_UNEXPECTED_REQUEST)
            self.send_close(file_props)
            raise NodeProcessed

        self._log.debug('Data received: sid: %s, %s+%s bytes',
                        ibb.sid, file_props.fp.tell(), len(ibb.data))

        file_props.seq += 1
        file_props.started = True
        file_props.fp.write(ibb.data)
        current_time = time.time()
        file_props.elapsed_time += current_time - file_props.last_time
        file_props.last_time = current_time
        file_props.received_len += len(ibb.data)
        app.socks5queue.progress_transfer_cb(self._account, file_props)
        if file_props.received_len >= file_props.size:
            file_props.completed = True

    def send_open(self, to: str, sid: str, fp: FileProp) -> FileProp:
        self._log.info('Send open to %s, sid: %s', to, sid)
        file_props = FilesProp.getFilePropBySid(sid)
        file_props.direction = '>'
        file_props.block_size = 4096
        file_props.fp = fp
        file_props.seq = -1
        file_props.error = 0
        file_props.paused = False
        file_props.received_len = 0
        file_props.last_time = time.time()
        file_props.connected = True
        file_props.completed = False
        file_props.disconnect_cb = None
        file_props.continue_cb = None
        self._nbxmpp('IBB').send_open(to,
                                      file_props.transport_sid,
                                      4096,
                                      callback=self._on_open_result,
                                      user_data=file_props)
        return file_props

    def _on_open_result(self, task: Task) -> None:
        try:
            task.finish()
        except StanzaError as error:
            app.socks5queue.error_cb('Error', to_user_string(error))
            self._log.warning(error)
            return

        file_props = task.get_user_data()
        self.send_data(file_props)

    def send_close(self, file_props: FileProp) -> None:
        file_props.connected = False
        file_props.fp.close()
        file_props.stopped = True
        to = file_props.receiver
        if file_props.direction == '<':
            to = file_props.sender

        self._log.info('Send close to %s, sid: %s',
                       to, file_props.transport_sid)
        self._nbxmpp('IBB').send_close(to, file_props.transport_sid,
                                       callback=self._on_close_result)

        if file_props.completed:
            app.socks5queue.complete_transfer_cb(self._account, file_props)
        else:
            if file_props.type_ == 's':
                peerjid = file_props.receiver
            else:
                peerjid = file_props.sender
            session = self._con.get_module('Jingle').get_jingle_session(
                peerjid, file_props.sid, 'file')
            # According to the xep, the initiator also cancels
            # the jingle session if there are no more files to send using IBB
            if session.weinitiate:
                session.cancel_session()

    def _on_close_result(self, task: Task) -> None:
        try:
            task.finish()
        except StanzaError as error:
            app.socks5queue.error_cb('Error', to_user_string(error))
            self._log.warning(error)
            return

    def send_data(self, file_props: FileProp) -> None:
        if file_props.completed:
            self.send_close(file_props)
            return

        chunk = file_props.fp.read(file_props.block_size)
        if chunk:
            file_props.seq += 1
            file_props.started = True
            if file_props.seq == 65536:
                file_props.seq = 0

            self._log.info('Send data to %s, sid: %s',
                           file_props.receiver, file_props.transport_sid)
            self._nbxmpp('IBB').send_data(file_props.receiver,
                                          file_props.transport_sid,
                                          file_props.seq,
                                          chunk,
                                          callback=self._on_data_result,
                                          user_data=file_props)
            current_time = time.time()
            file_props.elapsed_time += current_time - file_props.last_time
            file_props.last_time = current_time
            file_props.received_len += len(chunk)
            if file_props.size == file_props.received_len:
                file_props.completed = True
            app.socks5queue.progress_transfer_cb(self._account, file_props)

    def _on_data_result(self, task: Task) -> None:
        try:
            task.finish()
        except StanzaError as error:
            app.socks5queue.error_cb('Error', to_user_string(error))
            self._log.warning(error)
            return

        file_props = task.get_user_data()
        self.send_data(file_props)
