#!/usr/bin/env python3

#Libervia Desktop-Kivy
# Copyright (C) 2016-2021 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 functools import partial
import os.path
import json
from libervia.backend.core import log as logging
from libervia.backend.core import exceptions
from libervia.backend.core.i18n import _
from libervia.backend.tools.common import files_utils
from libervia.frontends.quick_frontend import quick_widgets
from libervia.frontends.tools import jid
from ..core.constants import Const as C
from ..core import cagou_widget
from ..core.menu import EntitiesSelectorMenu
from ..core.behaviors import TouchMenuBehavior, FilterBehavior
from ..core.common_widgets import (Identities, ItemWidget, DeviceWidget,
                                       CategorySeparator)
from libervia.desktop_kivy import G
from kivy import properties
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy import utils as kivy_utils

log = logging.getLogger(__name__)


PLUGIN_INFO = {
    "name": _("file sharing"),
    "main": "FileSharing",
    "description": _("share/transfer files between devices"),
    "icon_symbol": "exchange",
}
MODE_VIEW = "view"
MODE_LOCAL = "local"
SELECT_INSTRUCTIONS = _("Please select entities to share with")

if kivy_utils.platform == "android":
    from jnius import autoclass
    Environment = autoclass("android.os.Environment")
    base_dir = Environment.getExternalStorageDirectory().getAbsolutePath()
    def expanduser(path):
        if path == '~' or path.startswith('~/'):
            return path.replace('~', base_dir, 1)
        return path
else:
    expanduser = os.path.expanduser


class ModeBtn(Button):

    def __init__(self, parent, **kwargs):
        super(ModeBtn, self).__init__(**kwargs)
        parent.bind(mode=self.on_mode)
        self.on_mode(parent, parent.mode)

    def on_mode(self, parent, new_mode):
        if new_mode == MODE_VIEW:
            self.text = _("view shared files")
        elif new_mode == MODE_LOCAL:
            self.text = _("share local files")
        else:
            exceptions.InternalError("Unknown mode: {mode}".format(mode=new_mode))


class PathWidget(ItemWidget):

    def __init__(self, filepath, main_wid, **kw):
        name = os.path.basename(filepath)
        self.filepath = os.path.normpath(filepath)
        if self.filepath == '.':
            self.filepath = ''
        super(PathWidget, self).__init__(name=name, main_wid=main_wid, **kw)

    @property
    def is_dir(self):
        raise NotImplementedError

    def do_item_action(self, touch):
        if self.is_dir:
            self.main_wid.current_dir = self.filepath

    def open_menu(self, touch, dt):
        log.debug(_("opening menu for {path}").format(path=self.filepath))
        super(PathWidget, self).open_menu(touch, dt)


class LocalPathWidget(PathWidget):

    @property
    def is_dir(self):
        return os.path.isdir(self.filepath)

    def get_menu_choices(self):
        choices = []
        if self.shared:
            choices.append(dict(text=_('unshare'),
                                index=len(choices)+1,
                                callback=self.main_wid.unshare))
        else:
            choices.append(dict(text=_('share'),
                                index=len(choices)+1,
                                callback=self.main_wid.share))
        return choices


class RemotePathWidget(PathWidget):

    def __init__(self, main_wid, filepath, type_, **kw):
        self.type_ = type_
        super(RemotePathWidget, self).__init__(filepath, main_wid=main_wid, **kw)

    @property
    def is_dir(self):
        return self.type_ == C.FILE_TYPE_DIRECTORY

    def do_item_action(self, touch):
        if self.is_dir:
            if self.filepath == '..':
                self.main_wid.remote_entity = ''
            else:
                super(RemotePathWidget, self).do_item_action(touch)
        else:
            self.main_wid.request_item(self)
            return True

class SharingDeviceWidget(DeviceWidget):

    def do_item_action(self, touch):
        self.main_wid.remote_entity = self.entity_jid
        self.main_wid.remote_dir = ''


class FileSharing(quick_widgets.QuickWidget, cagou_widget.LiberviaDesktopKivyWidget, FilterBehavior,
                  TouchMenuBehavior):
    SINGLE=False
    layout = properties.ObjectProperty()
    mode = properties.OptionProperty(MODE_VIEW, options=[MODE_VIEW, MODE_LOCAL])
    local_dir = properties.StringProperty(expanduser('~'))
    remote_dir = properties.StringProperty('')
    remote_entity = properties.StringProperty('')
    shared_paths = properties.ListProperty()
    use_header_input = True
    signals_registered = False

    def __init__(self, host, target, profiles):
        quick_widgets.QuickWidget.__init__(self, host, target, profiles)
        cagou_widget.LiberviaDesktopKivyWidget.__init__(self)
        FilterBehavior.__init__(self)
        TouchMenuBehavior.__init__(self)
        self.mode_btn = ModeBtn(self)
        self.mode_btn.bind(on_release=self.change_mode)
        self.header_input_add_extra(self.mode_btn)
        self.bind(local_dir=self.update_view,
                  remote_dir=self.update_view,
                  remote_entity=self.update_view)
        self.update_view()
        if not FileSharing.signals_registered:
            # FIXME: we use this hack (registering the signal for the whole class) now
            #        as there is currently no unregisterSignal available in bridges
            G.host.register_signal("fis_shared_path_new",
                                  handler=FileSharing.shared_path_new,
                                  iface="plugin")
            G.host.register_signal("fis_shared_path_removed",
                                  handler=FileSharing.shared_path_removed,
                                  iface="plugin")
            FileSharing.signals_registered = True
        G.host.bridge.fis_local_shares_get(self.profile,
                                        callback=self.fill_paths,
                                        errback=G.host.errback)

    @property
    def current_dir(self):
        return self.local_dir if self.mode == MODE_LOCAL else self.remote_dir

    @current_dir.setter
    def current_dir(self, new_dir):
        if self.mode == MODE_LOCAL:
            self.local_dir = new_dir
        else:
            self.remote_dir = new_dir

    def fill_paths(self, shared_paths):
        self.shared_paths.extend(shared_paths)

    def change_mode(self, mode_btn):
        self.clear_menu()
        opt = self.__class__.mode.options
        new_idx = (opt.index(self.mode)+1) % len(opt)
        self.mode = opt[new_idx]

    def on_mode(self, instance, new_mode):
        self.update_view(None, self.local_dir)

    def on_header_wid_input(self):
        if '/' in self.header_input.text or self.header_input.text == '~':
            self.current_dir = expanduser(self.header_input.text)

    def on_header_wid_input_complete(self, wid, text, **kwargs):
        """we filter items when text is entered in input box"""
        if '/' in text:
            return
        self.do_filter(self.layout,
                       text,
                       lambda c: c.name,
                       width_cb=lambda c: c.base_width,
                       height_cb=lambda c: c.minimum_height,
                       continue_tests=[lambda c: not isinstance(c, ItemWidget),
                                       lambda c: c.name == '..'])


    ## remote sharing callback ##

    def _disco_find_by_features_cb(self, data):
        entities_services, entities_own, entities_roster = data
        for entities_map, title in ((entities_services,
                                     _('services')),
                                    (entities_own,
                                     _('your devices')),
                                    (entities_roster,
                                     _('your contacts devices'))):
            if entities_map:
                self.layout.add_widget(CategorySeparator(text=title))
                for entity_str, entity_ids in entities_map.items():
                    entity_jid = jid.JID(entity_str)
                    item = SharingDeviceWidget(
                        self, entity_jid, Identities(entity_ids))
                    self.layout.add_widget(item)
        if not entities_services and not entities_own and not entities_roster:
            self.layout.add_widget(Label(
                size_hint=(1, 1),
                halign='center',
                text_size=self.size,
                text=_("No sharing device found")))

    def discover_devices(self):
        """Looks for devices handling file "File Information Sharing" and display them"""
        try:
            namespace = self.host.ns_map['fis']
        except KeyError:
            msg = _("can't find file information sharing namespace, "
                    "is the plugin running?")
            log.warning(msg)
            G.host.add_note(_("missing plugin"), msg, C.XMLUI_DATA_LVL_ERROR)
            return
        self.host.bridge.disco_find_by_features(
            [namespace], [], False, True, True, True, False, self.profile,
            callback=self._disco_find_by_features_cb,
            errback=partial(G.host.errback,
                title=_("shared folder error"),
                message=_("can't check sharing devices: {msg}")))

    def fis_list_cb(self, files_data):
        for file_data in files_data:
            filepath = os.path.join(self.current_dir, file_data['name'])
            item = RemotePathWidget(
                filepath=filepath,
                main_wid=self,
                type_=file_data['type'])
            self.layout.add_widget(item)

    def fis_list_eb(self, failure_):
        self.remote_dir = ''
        G.host.add_note(
            _("shared folder error"),
            _("can't list files for {remote_entity}: {msg}").format(
                remote_entity=self.remote_entity,
                msg=failure_),
            level=C.XMLUI_DATA_LVL_WARNING)

    ## view generation ##

    def update_view(self, *args):
        """update items according to current mode, entity and dir"""
        log.debug('updating {}, {}'.format(self.current_dir, args))
        self.layout.clear_widgets()
        self.header_input.text = ''
        self.header_input.hint_text = self.current_dir

        if self.mode == MODE_LOCAL:
            filepath = os.path.join(self.local_dir, '..')
            self.layout.add_widget(LocalPathWidget(filepath=filepath, main_wid=self))
            try:
                files = sorted(os.listdir(self.local_dir))
            except OSError as e:
                msg = _("can't list files in \"{local_dir}\": {msg}").format(
                    local_dir=self.local_dir,
                    msg=e)
                G.host.add_note(
                    _("shared folder error"),
                    msg,
                    level=C.XMLUI_DATA_LVL_WARNING)
                self.local_dir = expanduser('~')
                return
            for f in files:
                filepath = os.path.join(self.local_dir, f)
                self.layout.add_widget(LocalPathWidget(filepath=filepath,
                                                       main_wid=self))
        elif self.mode == MODE_VIEW:
            if not self.remote_entity:
                self.discover_devices()
            else:
                # we always a way to go back
                # so user can return to previous list even in case of error
                parent_path = os.path.join(self.remote_dir, '..')
                item = RemotePathWidget(
                    filepath = parent_path,
                    main_wid=self,
                    type_ = C.FILE_TYPE_DIRECTORY)
                self.layout.add_widget(item)
                self.host.bridge.fis_list(
                    str(self.remote_entity),
                    self.remote_dir,
                    {},
                    self.profile,
                    callback=self.fis_list_cb,
                    errback=self.fis_list_eb)

    ## Share methods ##

    def do_share(self, entities_jids, item):
        if entities_jids:
            access = {'read': {'type': 'whitelist',
                                'jids': entities_jids}}
        else:
            access = {}

        G.host.bridge.fis_share_path(
            item.name,
            item.filepath,
            json.dumps(access, ensure_ascii=False),
            self.profile,
            callback=lambda name: G.host.add_note(
                _("sharing folder"),
                _("{name} is now shared").format(name=name)),
            errback=partial(G.host.errback,
                title=_("sharing folder"),
                message=_("can't share folder: {msg}")))

    def share(self, menu):
        item = self.menu_item
        self.clear_menu()
        EntitiesSelectorMenu(instructions=SELECT_INSTRUCTIONS,
                             callback=partial(self.do_share, item=item)).show()

    def unshare(self, menu):
        item = self.menu_item
        self.clear_menu()
        G.host.bridge.fis_unshare_path(
            item.filepath,
            self.profile,
            callback=lambda: G.host.add_note(
                _("sharing folder"),
                _("{name} is not shared anymore").format(name=item.name)),
            errback=partial(G.host.errback,
                title=_("sharing folder"),
                message=_("can't unshare folder: {msg}")))

    def file_jingle_request_cb(self, progress_id, item, dest_path):
        G.host.add_note(
            _("file request"),
            _("{name} download started at {dest_path}").format(
                name = item.name,
                dest_path = dest_path))

    def request_item(self, item):
        """Retrieve an item from remote entity

        @param item(RemotePathWidget): item to retrieve
        """
        path, name = os.path.split(item.filepath)
        assert name
        assert self.remote_entity
        extra = {'path': path}
        dest_path = files_utils.get_unique_name(os.path.join(G.host.downloads_dir, name))
        G.host.bridge.file_jingle_request(str(self.remote_entity),
                                        str(dest_path),
                                        name,
                                        '',
                                        '',
                                        extra,
                                        self.profile,
                                        callback=partial(self.file_jingle_request_cb,
                                            item=item,
                                            dest_path=dest_path),
                                        errback=partial(G.host.errback,
                                            title = _("file request error"),
                                            message = _("can't request file: {msg}")))

    @classmethod
    def shared_path_new(cls, shared_path, name, profile):
        for wid in G.host.get_visible_list(cls):
            if shared_path not in wid.shared_paths:
                wid.shared_paths.append(shared_path)

    @classmethod
    def shared_path_removed(cls, shared_path, profile):
        for wid in G.host.get_visible_list(cls):
            if shared_path in wid.shared_paths:
                wid.shared_paths.remove(shared_path)
            else:
                log.warning(_("shared path {path} not found in {widget}".format(
                    path = shared_path, widget = wid)))