#!/usr/bin/env python2
# -*- coding: utf-8 -*-

# SAT plugin for parrot mode (experimental)
# Copyright (C) 2009-2018 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 import exceptions
from sat.core.log import getLogger
log = getLogger(__name__)
from sat.tools.common import regex
from sat.tools import stream
from twisted.internet import defer
import os
import os.path


PLUGIN_INFO = {
    C.PI_NAME: "File sharing component",
    C.PI_IMPORT_NAME: "file_sharing",
    C.PI_MODES: [C.PLUG_MODE_COMPONENT],
    C.PI_TYPE: C.PLUG_TYPE_ENTRY_POINT,
    C.PI_PROTOCOLS: [],
    C.PI_DEPENDENCIES: ["FILE", "XEP-0234", "XEP-0260", "XEP-0261", "XEP-0329"],
    C.PI_RECOMMENDATIONS: [],
    C.PI_MAIN: "FileSharing",
    C.PI_HANDLER: "no",
    C.PI_DESCRIPTION: _(u"""Component hosting and sharing files""")
}

PROGRESS_ID_KEY = 'progress_id'
HASH_ALGO = u'sha-256'


class FileSharing(object):

    def __init__(self, host):
        log.info(_(u"File Sharing initialization"))
        self.host = host
        self._f = host.plugins['FILE']
        self._jf = host.plugins['XEP-0234']
        self._h = host.plugins['XEP-0300']
        host.trigger.add("FILE_getDestDir", self._getDestDirTrigger)
        host.trigger.add("XEP-0234_fileSendingRequest", self._fileSendingRequestTrigger, priority=1000)
        self.files_path = host.getLocalPath(None, C.FILES_DIR, profile=False)

    def profileConnected(self, client):
        path = client.file_tmp_dir = os.path.join(
            self.host.memory.getConfig('', 'local_dir'),
            C.FILES_TMP_DIR,
            regex.pathEscape(client.profile))
        if not os.path.exists(path):
            os.makedirs(path)

    @defer.inlineCallbacks
    def _fileTransferedCb(self, dummy, client, peer_jid, file_data, file_path):
        if file_data[u'hash_algo'] == HASH_ALGO:
            log.debug(_(u"Reusing already generated hash"))
            file_hash = file_data[u'hash_hasher'].hexdigest()
        else:
            hasher = self._h.getHasher(HASH_ALGO)
            with open('file_path') as f:
                file_hash = yield self._h.calculateHash(f, hasher)
        final_path = os.path.join(self.files_path, file_hash)
        if os.path.isfile(final_path):
            log.debug(u"file [{file_hash}] already exists, we can remove temporary one".format(file_hash = file_hash))
            os.unlink(file_path)
        else:
            os.rename(file_path, final_path)
            log.debug(u"file [{file_hash}] moved to {files_path}".format(file_hash=file_hash, files_path=self.files_path))
        self.host.memory.setFile(client,
                                 name=file_data[u'name'],
                                 version=u'',
                                 file_hash=file_hash,
                                 hash_algo=HASH_ALGO,
                                 size=file_data[u'size'],
                                 path=file_data.get(u'path'),
                                 namespace=file_data.get(u'namespace'),
                                 owner=peer_jid)

    def _getDestDirTrigger(self, client, peer_jid, transfer_data, file_data, stream_object):
        if not client.is_component:
            return True, None
        assert stream_object
        assert 'stream_object' not in transfer_data
        assert PROGRESS_ID_KEY in file_data
        filename = file_data['name']
        assert filename and not '/' in filename
        file_tmp_dir = self.host.getLocalPath(client, C.FILES_TMP_DIR, peer_jid.userhost(), component=True, profile=False)
        file_tmp_path = file_data['file_path'] = os.path.join(file_tmp_dir, file_data['name'])

        transfer_data['finished_d'].addCallback(self._fileTransferedCb, client, peer_jid, file_data, file_tmp_path)

        self._f.openFileWrite(client, file_tmp_path, transfer_data, file_data, stream_object)
        return False, defer.succeed(True)

    @defer.inlineCallbacks
    def _retrieveFiles(self, client, session, content_data, content_name, file_data, file_elt):
        peer_jid = session[u'peer_jid']
        try:
            found_files = yield self.host.memory.getFiles(client,
                                                          peer_jid=peer_jid,
                                                          name=file_data.get(u'name'),
                                                          file_hash=file_data.get(u'hash'),
                                                          hash_algo=file_data.get(u'hash_algo'),
                                                          path=file_data.get(u'path'),
                                                          namespace=file_data.get(u'namespace'))
        except exceptions.NotFound:
            found_files = None
        except exceptions.PermissionError:
            log.warning(_(u"{peer_jid} is trying to access an unauthorized file: {name}").format(
                peer_jid=peer_jid, name=file_data.get(u'name')))
            defer.returnValue(False)

        if not found_files:
            log.warning(_(u"no matching file found ({file_data})").format(file_data=file_data))
            defer.returnValue(False)

        # we only use the first found file
        found_file = found_files[0]
        file_hash = found_file[u'hash']
        file_path = os.path.join(self.files_path, file_hash)
        file_data[u'hash_hasher'] = hasher = self._h.getHasher(found_file[u'hash_algo'])
        size = file_data[u'size'] = found_file[u'size']
        file_data[u'file_hash'] = file_hash
        file_data[u'hash_algo'] = found_file[u'hash_algo']

        # we complete file_elt so peer can have some details on the file
        if u'name' not in file_data:
            file_elt.addElement(u'name', content=found_file[u'name'])
        file_elt.addElement(u'size', content=unicode(size))
        content_data['stream_object'] = stream.FileStreamObject(
            self.host,
            client,
            file_path,
            uid=self._jf.getProgressId(session, content_name),
            size=size,
            data_cb=lambda data: hasher.update(data),
            )
        defer.returnValue(True)

    def _fileSendingRequestTrigger(self, client, session, content_data, content_name, file_data, file_elt):
        if not client.is_component:
            return True, None
        else:
            return False, self._retrieveFiles(client, session, content_data, content_name, file_data, file_elt)