#!/usr/bin/python
# -*- coding: utf-8 -*-

# SAT plugin for managing xep-0096
# Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014, 2015 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 sat.core.i18n import _
from sat.core.constants import Const as C
from sat.core.log import getLogger
log = getLogger(__name__)
from twisted.words.xish import domish
from twisted.words.protocols.jabber import jid
from twisted.words.protocols import jabber
import os
from twisted.internet import reactor

from wokkel import data_form

IQ_SET = '/iq[@type="set"]'
PROFILE_NAME = "file-transfer"
PROFILE = "http://jabber.org/protocol/si/profile/" + PROFILE_NAME

PLUGIN_INFO = {
    "name": "XEP-0096 Plugin",
    "import_name": "XEP-0096",
    "type": "XEP",
    "protocols": ["XEP-0096"],
    "dependencies": ["XEP-0020", "XEP-0095", "XEP-0065", "XEP-0047"],
    "main": "XEP_0096",
    "handler": "no",
    "description": _("""Implementation of SI File Transfer""")
}


class XEP_0096(object):

    def __init__(self, host):
        log.info(_("Plugin XEP_0096 initialization"))
        self.host = host
        self.managed_stream_m = [self.host.plugins["XEP-0065"].NAMESPACE,
                                 self.host.plugins["XEP-0047"].NAMESPACE]  # Stream methods managed
        self.host.plugins["XEP-0095"].registerSIProfile(PROFILE_NAME, self.transferRequest)
        host.bridge.addMethod("sendFile", ".plugin", in_sign='ssa{ss}s', out_sign='s', method=self.sendFile)

    def profileConnected(self, profile):
        client = self.host.getClient(profile)
        client._xep_0096_waiting_for_approval = {}  # key = id, value = [transfer data, IdelayedCall Reactor timeout,
                                        # current stream method, [failed stream methods], profile]

    def _kill_id(self, approval_id, profile):
        """Delete a waiting_for_approval id, called after timeout
        @param approval_id: id of _xep_0096_waiting_for_approval"""
        log.info(_("SI File Transfer: TimeOut reached for id %s") % approval_id)
        try:
            client = self.host.getClient(profile)
            del client._xep_0096_waiting_for_approval[approval_id]
        except KeyError:
            log.warning(_("kill id called on a non existant approval id"))

    def transferRequest(self, iq_id, from_jid, si_id, si_mime_type, si_el, profile):
        """Called when a file transfer is requested
        @param iq_id: id of the iq request
        @param from_jid: jid of the sender
        @param si_id: Stream Initiation session id
        @param si_mime_type: Mime type of the file (or default "application/octet-stream" if unknown)
        @param si_el: domish.Element of the request
        @param profile: %(doc_profile)s"""
        log.info(_("XEP-0096 file transfer requested"))
        log.debug(si_el.toXml())
        client = self.host.getClient(profile)
        filename = ""
        file_size = ""
        file_date = None
        file_hash = None
        file_desc = ""
        can_range = False
        file_elts = filter(lambda elt: elt.name == 'file', si_el.elements())
        feature_elts = self.host.plugins["XEP-0020"].getFeatureElt(si_el)

        if file_elts:
            file_el = file_elts[0]
            filename = file_el["name"]
            file_size = file_el["size"]
            file_date = file_el.getAttribute("date", "")
            file_hash = file_el.getAttribute("hash", "")
            log.info(_("File proposed: name=[%(name)s] size=%(size)s") % {'name': filename, 'size': file_size})
            for file_child_el in file_el.elements():
                if file_child_el.name == "desc":
                    file_desc = unicode(file_child_el)
                elif file_child_el.name == "range":
                    can_range = True
        else:
            log.warning(_("No file element found"))
            self.host.plugins["XEP-0095"].sendBadRequestError(iq_id, from_jid, profile)
            return

        if feature_elts:
            feature_el = feature_elts[0]
            data_form.Form.fromElement(feature_el.firstChildElement())
            try:
                stream_method = self.host.plugins["XEP-0020"].negociate(feature_el, 'stream-method', self.managed_stream_m)
            except KeyError:
                log.warning(_("No stream method found"))
                self.host.plugins["XEP-0095"].sendBadRequestError(iq_id, from_jid, profile)
                return
            if not stream_method:
                log.warning(_("Can't find a valid stream method"))
                self.host.plugins["XEP-0095"].sendFailedError(iq_id, from_jid, profile)
                return
        else:
            log.warning(_("No feature element found"))
            self.host.plugins["XEP-0095"].sendBadRequestError(iq_id, from_jid, profile)
            return

        #if we are here, the transfer can start, we just need user's agreement
        data = {"filename": filename, "id": iq_id, "from": from_jid, "size": file_size, "date": file_date, "hash": file_hash, "desc": file_desc, "can_range": str(can_range)}
        client._xep_0096_waiting_for_approval[si_id] = [data, reactor.callLater(300, self._kill_id, si_id, profile), stream_method, []]

        self.host.askConfirmation(si_id, "FILE_TRANSFER", data, self.confirmationCB, profile)

    def _getFileObject(self, dest_path, can_range=False):
        """Open file, put file pointer to the end if the file if needed
        @param dest_path: path of the destination file
        @param can_range: True if the file pointer can be moved
        @return: File Object"""
        return open(dest_path, "ab" if can_range else "wb")

    def confirmationCB(self, sid, accepted, frontend_data, profile):
        """Called on confirmation answer
        @param sid: file transfer session id
        @param accepted: True if file transfer is accepted
        @param frontend_data: data sent by frontend"""
        client = self.host.getClient(profile)
        data, timeout, stream_method, failed_methods = client._xep_0096_waiting_for_approval[sid]
        can_range = data['can_range'] == "True"
        range_offset = 0
        if accepted:
            if timeout.active():
                timeout.cancel()
            try:
                dest_path = frontend_data['dest_path']
            except KeyError:
                log.error(_('dest path not found in frontend_data'))
                del(client._xep_0096_waiting_for_approval[sid])
                return
            if stream_method == self.host.plugins["XEP-0065"].NAMESPACE:
                file_obj = self._getFileObject(dest_path, can_range)
                range_offset = file_obj.tell()
                self.host.plugins["XEP-0065"].prepareToReceive(jid.JID(data['from']), sid, file_obj, int(data["size"]), self._transferSucceeded, self._transferFailed, profile)
            elif stream_method == self.host.plugins["XEP-0047"].NAMESPACE:
                file_obj = self._getFileObject(dest_path, can_range)
                range_offset = file_obj.tell()
                self.host.plugins["XEP-0047"].prepareToReceive(jid.JID(data['from']), sid, file_obj, int(data["size"]), self._transferSucceeded, self._transferFailed, profile)
            else:
                log.error(_("Unknown stream method, this should not happen at this stage, cancelling transfer"))
                del(client._xep_0096_waiting_for_approval[sid])
                return

            #we can send the iq result
            feature_elt = self.host.plugins["XEP-0020"].chooseOption({'stream-method': stream_method})
            misc_elts = []
            misc_elts.append(domish.Element((PROFILE, "file")))
            if can_range:
                range_elt = domish.Element((None, "range"))
                range_elt['offset'] = str(range_offset)
                #TODO: manage range length
                misc_elts.append(range_elt)
            self.host.plugins["XEP-0095"].acceptStream(data["id"], data['from'], feature_elt, misc_elts, profile)
        else:
            log.debug(_("Transfer [%s] refused") % sid)
            self.host.plugins["XEP-0095"].sendRejectedError(data["id"], data['from'], profile=profile)
            del(client._xep_0096_waiting_for_approval[sid])

    def _transferSucceeded(self, sid, file_obj, stream_method, profile):
        """Called by the stream method when transfer successfuly finished
        @param id: stream id"""
        client = self.host.getClient(profile)
        file_obj.close()
        log.info(_('Transfer %s successfuly finished') % sid)
        del(client._xep_0096_waiting_for_approval[sid])

    def _transferFailed(self, sid, file_obj, stream_method, reason, profile):
        """Called when something went wrong with the transfer
        @param id: stream id
        @param reason: can be TIMEOUT, IO_ERROR, PROTOCOL_ERROR"""
        client = self.host.getClient(profile)
        data, timeout, stream_method, failed_methods = client._xep_0096_waiting_for_approval[sid]
        log.warning(_('Transfer %(id)s failed with stream method %(s_method)s: %(reason)s') % {
            'id': sid,
            's_method': stream_method,
            'reason': reason})
        filepath = file_obj.name
        file_obj.close()
        os.remove(filepath)
        #TODO: session remenber (within a time limit) when a stream method fail, and avoid that stream method with full jid for the rest of the session
        log.warning(_("All stream methods failed, can't transfer the file"))
        del(client._xep_0096_waiting_for_approval[sid])

    def fileCb(self, filepath, sid, size, profile, IQ):
        if IQ['type'] == "error":
            stanza_err = jabber.error.exceptionFromStanza(IQ)
            if stanza_err.code == '403' and stanza_err.condition == 'forbidden':
                log.debug(_("File transfer refused by %s") % IQ['from'])
                self.host.bridge.newAlert(_("The contact %s refused your file") % IQ['from'], _("File refused"), "INFO", profile)
            else:
                log.warning(_("Error during file transfer with %s") % IQ['from'])
                self.host.bridge.newAlert(_("Something went wrong during the file transfer session intialisation with %s") % IQ['from'], _("File transfer error"), "ERROR", profile)
            return

        si_elt = IQ.firstChildElement()

        if IQ['type'] != "result" or not si_elt or si_elt.name != "si":
            log.error(_("Protocol error during file transfer"))
            return

        feature_elts = self.host.plugins["XEP-0020"].getFeatureElt(si_elt)
        if not feature_elts:
            log.warning(_("No feature element"))
            return

        choosed_options = self.host.plugins["XEP-0020"].getChoosedOptions(feature_elts[0])
        try:
            stream_method = choosed_options["stream-method"]
        except KeyError:
            log.warning(_("No stream method choosed"))
            return

        range_offset = 0
        range_length = None
        range_elts = filter(lambda elt: elt.name == 'range', si_elt.elements())
        if range_elts:
            range_elt = range_elts[0]
            range_offset = range_elt.getAttribute("offset", 0)
            range_length = range_elt.getAttribute("length")

        if stream_method == self.host.plugins["XEP-0065"].NAMESPACE:
            file_obj = open(filepath, 'r')
            if range_offset:
                file_obj.seek(range_offset)
            self.host.plugins["XEP-0065"].startStream(file_obj, jid.JID(IQ['from']), sid, range_length, self.sendSuccessCb, self.sendFailureCb, size, profile)
        elif stream_method == self.host.plugins["XEP-0047"].NAMESPACE:
            file_obj = open(filepath, 'r')
            if range_offset:
                file_obj.seek(range_offset)
            self.host.plugins["XEP-0047"].startStream(file_obj, jid.JID(IQ['from']), sid, range_length, self.sendSuccessCb, self.sendFailureCb, size, profile)
        else:
            log.warning(_("Invalid stream method received"))

    def sendFile(self, to_jid, filepath, data={}, profile_key=C.PROF_KEY_NONE):
        """send a file using XEP-0096
        @to_jid: recipient
        @filepath: absolute path to the file to send
        @data: dictionnary with the optional following keys:
               - "description": description of the file
        @param profile_key: %(doc_profile_key)s
        @return: an unique id to identify the transfer
        """
        profile = self.host.memory.getProfileName(profile_key)
        if not profile:
            log.warning(_("Trying to send a file from an unknown profile"))
            return ""
        feature_elt = self.host.plugins["XEP-0020"].proposeFeatures({'stream-method': self.managed_stream_m})

        file_transfer_elts = []

        statinfo = os.stat(filepath)
        file_elt = domish.Element((PROFILE, 'file'))
        file_elt['name'] = os.path.basename(filepath)
        size = file_elt['size'] = str(statinfo.st_size)
        file_transfer_elts.append(file_elt)

        file_transfer_elts.append(domish.Element((None, 'range')))

        sid, offer = self.host.plugins["XEP-0095"].proposeStream(jid.JID(to_jid), PROFILE, feature_elt, file_transfer_elts, profile_key=profile)
        offer.addCallback(self.fileCb, filepath, sid, size, profile)
        return sid

    def sendSuccessCb(self, sid, file_obj, stream_method, profile):
        log.info(_('Transfer %(sid)s successfuly finished [%(profile)s]')
             % {"sid": sid, "profile": profile})
        file_obj.close()

    def sendFailureCb(self, sid, file_obj, stream_method, reason, profile):
        file_obj.close()
        log.warning(_('Transfer %(id)s failed with stream method %(s_method)s: %(reason)s [%(profile)s]') % {'id': sid, "s_method": stream_method, 'reason': reason, 'profile': profile})