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

# SAT plugin for Jingle File Transfer (XEP-0234)
# 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 _, D_
from sat.core.constants import Const as C
from sat.core.log import getLogger
log = getLogger(__name__)
from sat.core import exceptions
from sat.tools import xml_tools
from wokkel import disco, iwokkel
from zope.interface import implements
from sat.tools import utils
import os.path
from twisted.words.xish import domish
from twisted.words.protocols.jabber import jid
from twisted.python import failure
from twisted.words.protocols.jabber.xmlstream import XMPPHandler
from twisted.internet import defer


NS_JINGLE_FT = 'urn:xmpp:jingle:apps:file-transfer:4'
CONFIRM = D_(u'{entity} wants to send the file "{name}" to you:\n{desc}\n\nThe file has a size of {size_human}\n\nDo you accept ?')
CONFIRM_TITLE = D_(u'Confirm file transfer')
CONFIRM_OVERWRITE = D_(u'File {} already exists, are you sure you want to overwrite ?')
CONFIRM_OVERWRITE_TITLE = D_(u'File exists')

PLUGIN_INFO = {
    "name": "Jingle File Transfer",
    "import_name": "XEP-0234",
    "type": "XEP",
    "protocols": ["XEP-0234"],
    "dependencies": ["XEP-0166", "XEP-0300", "FILE"],
    "main": "XEP_0234",
    "handler": "yes",
    "description": _("""Implementation of Jingle File Transfer""")
}


class XEP_0234(object):
    # TODO: assure everything is closed when file is sent or session terminate is received

    def __init__(self, host):
        log.info(_("plugin Jingle File Transfer initialization"))
        self.host = host
        self._j = host.plugins["XEP-0166"] # shortcut to access jingle
        self._j.registerApplication(NS_JINGLE_FT, self)
        self._f = host.plugins["FILE"]
        host.bridge.addMethod("fileJingleSend", ".plugin", in_sign='sssss', out_sign='', method=self._fileJingleSend)

    def getHandler(self, profile):
        return XEP_0234_handler()

    def _fileJingleSend(self, peer_jid, filepath, name="", file_desc="", profile=C.PROF_KEY_NONE):
        return self.fileJingleSend(jid.JID(peer_jid), filepath, name or None, file_desc or None, profile)

    def fileJingleSend(self, peer_jid, filepath, name=None, file_desc=None, profile=C.PROF_KEY_NONE):
        self._j.initiate(peer_jid,
                         [{'app_ns': NS_JINGLE_FT,
                           'senders': self._j.ROLE_INITIATOR,
                           'app_kwargs': {'filepath': filepath,
                                          'name': name,
                                          'file_desc': file_desc},
                         }],
                         profile=profile)


    # Dialogs with user
    # the overwrite check is done here

    def _getDestDir(self, session, content_name, content_data, profile):
        """Request confirmation and destination dir to user

        if transfer is confirmed, session is filled
        @param session(dict): jingle session data
        @param content_name(unicode): name of the jingle content
        @param content_data(dict): content informations
        @param profile: %(doc_profile)s
        return (defer.Deferred): True if transfer is accepted
        """
        application_data = content_data['application_data']
        file_data = application_data['file_data']
        d = xml_tools.deferDialog(self.host,
            _(CONFIRM).format(entity=session['peer_jid'].full(), **file_data),
            _(CONFIRM_TITLE),
            type_=C.XMLUI_DIALOG_FILE,
            options={C.XMLUI_DATA_FILETYPE: C.XMLUI_DATA_FILETYPE_DIR},
            profile=profile)
        d.addCallback(self._gotConfirmation, session, content_name, content_data, application_data, profile)
        return d

    def _openFileWrite(self, session, content_name, content_data, file_path, file_data, profile):
        assert 'file_obj' not in content_data
        file_obj = content_data['file_obj'] = self._f.File(
            self.host,
            file_path,
            'w',
            size=file_data['size'],
            profile=profile,
            )
        finished_d = content_data['finished_d'] = defer.Deferred()
        args = [file_obj, session, content_name, content_data, profile]
        finished_d.addCallbacks(self._finishedCb, self._finishedEb, args, None, args)

    def _gotConfirmation(self, data, session, content_name, content_data, application_data, profile):
        """Called when the permission and dest path have been received

        @param data(dict): xmlui data received from file dialog
        @param session(dict): jingle session data
        @param content_name(unicode): name of the jingle content
        @param content_data(dict): content session_data
        @param content_data(dict): application session data
        @param profile: %(doc_profile)s
        return (bool): True if copy is wanted and OK
            False if user wants to cancel
            if fill exists ask confirmation and call again self._getDestDir if needed
        """
        if data.get('cancelled', False):
            return False
        file_data = application_data['file_data']
        path = data['path']
        file_data['file_path'] = file_path = os.path.join(path, file_data['name'])
        log.debug(u'destination file path set to {}'.format(file_path))

        # we manage case where file already exists
        if os.path.exists(file_path):
            def check_overwrite(overwrite):
                if overwrite:
                    self._openFileWrite(session, content_name, content_data, file_path, file_data, profile)
                    return True
                else:
                    return self._getDestDir(session, content_name, content_data, profile)

            exists_d = xml_tools.deferConfirm(
                self.host,
                _(CONFIRM_OVERWRITE).format(file_path),
                _(CONFIRM_OVERWRITE_TITLE),
                profile=profile)
            exists_d.addCallback(check_overwrite)
            return exists_d

        self._openFileWrite(session, content_name, content_data, file_path, file_data, profile)
        return True

    # jingle callbacks

    def jingleSessionInit(self, session, content_name, filepath, name=None, file_desc=None, profile=C.PROF_KEY_NONE):
        content_data = session['contents'][content_name]
        application_data = content_data['application_data']
        assert 'file_path' not in application_data
        application_data['file_path'] = filepath
        file_data = application_data['file_data'] = {}
        file_data['date'] = utils.xmpp_date()
        file_data['desc'] = file_desc or ''
        file_data['media-type'] = "application/octet-stream" # TODO
        file_data['name'] = os.path.basename(filepath) if name is None else name
        file_data['size'] = os.path.getsize(filepath)
        desc_elt = domish.Element((NS_JINGLE_FT, 'description'))
        file_elt = desc_elt.addElement("file")
        for name in ('date', 'desc', 'media-type', 'name', 'size'):
            file_elt.addElement(name, content=unicode(file_data[name]))
        file_elt.addElement("range") # TODO
        file_elt.addChild(self.host.plugins["XEP-0300"].buidHash())
        return desc_elt

    def jingleRequestConfirmation(self, action, session, content_name, desc_elt, profile):
        """This method request confirmation for a jingle session"""
        content_data = session['contents'][content_name]
        if content_data['senders'] not in (self._j.ROLE_INITIATOR, self._j.ROLE_RESPONDER):
            log.warning(u"Bad sender, assuming initiator")
            content_data['senders'] = self._j.ROLE_INITIATOR
        # first we grab file informations
        try:
            file_elt = desc_elt.elements(NS_JINGLE_FT, 'file').next()
        except StopIteration:
            raise failure.Failure(exceptions.DataError)
        file_data = {}
        for name in ('date', 'desc', 'media-type', 'name', 'range', 'size'):
            try:
                file_data[name] = unicode(file_elt.elements(NS_JINGLE_FT, name).next())
            except StopIteration:
                file_data[name] = ''

        try:
            size = file_data['size'] = int(file_data['size'])
        except ValueError:
            raise failure.Failure(exceptions.DataError)
        else:
            # human readable size
            file_data['size_human'] = u'{:.6n} Mio'.format(float(size)/(1024**2))

        name = file_data['name']
        if '/' in name or '\\' in name:
            log.warning(u"File name contain path characters, we replace them: {}".format(name))
            file_data['name'] = name.replace('/', '_').replace('\\', '_')

        # TODO: parse hash using plugin XEP-0300

        content_data['application_data']['file_data'] = file_data

        # now we actualy request permission to user
        return self._getDestDir(session, content_name, content_data, profile)


    def jingleHandler(self, action, session, content_name, desc_elt, profile):
        content_data = session['contents'][content_name]
        application_data = content_data['application_data']
        if action in (self._j.A_ACCEPTED_ACK,):
            pass
        elif action == self._j.A_SESSION_INITIATE:
            file_elt = desc_elt.elements(NS_JINGLE_FT, 'file').next()
            try:
                file_elt.elements(NS_JINGLE_FT, 'range').next()
            except StopIteration:
                # initiator doesn't manage <range>, but we do so we advertise it
                log.debug("adding <range> element")
                file_elt.addElement('range')
        elif action == self._j.A_SESSION_ACCEPT:
            assert not 'file_obj' in content_data
            file_path = application_data['file_path']
            size = application_data['file_data']['size']
            file_obj = content_data['file_obj'] = self._f.File(self.host,
                                                  file_path,
                                                  size=size,
                                                  profile=profile
                                                  )
            finished_d = content_data['finished_d'] = defer.Deferred()
            args = [file_obj, session, content_name, content_data, profile]
            finished_d.addCallbacks(self._finishedCb, self._finishedEb, args, None, args)
        else:
            log.warning(u"FIXME: unmanaged action {}".format(action))
        return desc_elt

    def _finishedCb(self, dummy, file_obj, session, content_name, content_data, profile):
        log.debug(u"File transfer completed successfuly")
        if content_data['senders'] != session['role']:
            # we terminate the session only if we are the received,
            # as recommanded in XEP-0234 §2 (after example 6)
            self._j.contentTerminate(session, content_name, profile=profile)
        file_obj.close()

    def _finishedEb(self, failure, file_obj, session, content_name, content_data, profile):
        log.warning(u"Error while streaming through s5b: {}".format(failure))
        file_obj.close()
        self._j.contentTerminate(session, content_name, reason=self._j.REASON_FAILED_TRANSPORT, profile=profile)


class XEP_0234_handler(XMPPHandler):
    implements(iwokkel.IDisco)

    def getDiscoInfo(self, requestor, target, nodeIdentifier=''):
        return [disco.DiscoFeature(NS_JINGLE_FT)]

    def getDiscoItems(self, requestor, target, nodeIdentifier=''):
        return []