# 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/>.

import logging
from enum import IntEnum
from datetime import datetime, timedelta

from gi.repository import Gtk, GLib

from gajim.common import app
from gajim.common import ged
from gajim.common.const import ArchiveState
from gajim.gtk.util import load_icon

log = logging.getLogger('gajim.gtk.history_sync')


class Pages(IntEnum):
    TIME = 0
    SYNC = 1
    SUMMARY = 2


class HistorySyncAssistant(Gtk.Assistant):
    def __init__(self, account, parent):
        Gtk.Assistant.__init__(self)
        # self.set_title(_('Synchronise History'))
        self.set_resizable(False)
        self.set_default_size(300, -1)
        self.set_name('HistorySyncAssistant')
        self.set_transient_for(parent)
        self.account = account
        self.con = app.connections[self.account]
        self.timedelta = None
        self.now = datetime.utcnow()
        self.query_id = None
        self.start = None
        self.end = None
        self.next = None
        self.hide_buttons()

        own_jid = self.con.get_own_jid().getStripped()

        mam_start = ArchiveState.NEVER
        archive = app.logger.get_archive_infos(own_jid)
        if archive is not None and archive.oldest_mam_timestamp is not None:
            mam_start = int(float(archive.oldest_mam_timestamp))

        if mam_start == ArchiveState.NEVER:
            self.current_start = self.now
        elif mam_start == ArchiveState.ALL:
            self.current_start = datetime.utcfromtimestamp(0)
        else:
            self.current_start = datetime.fromtimestamp(mam_start)

        self.select_time = SelectTimePage(self)
        self.append_page(self.select_time)
        self.set_page_type(self.select_time, Gtk.AssistantPageType.INTRO)

        self.download_history = DownloadHistoryPage(self)
        self.append_page(self.download_history)
        self.set_page_type(self.download_history,
                           Gtk.AssistantPageType.PROGRESS)
        self.set_page_complete(self.download_history, True)

        self.summary = SummaryPage(self)
        self.append_page(self.summary)
        self.set_page_type(self.summary, Gtk.AssistantPageType.SUMMARY)
        self.set_page_complete(self.summary, True)

        app.ged.register_event_handler('archiving-count-received',
                                       ged.GUI1,
                                       self._received_count)
        app.ged.register_event_handler('archiving-interval-finished',
                                       ged.GUI1,
                                       self._received_finished)
        app.ged.register_event_handler('raw-mam-message-received',
                                       ged.PRECORE,
                                       self._nec_mam_message_received)

        self.connect('prepare', self.on_page_change)
        self.connect('destroy', self.on_destroy)
        self.connect("cancel", self.on_close_clicked)
        self.connect("close", self.on_close_clicked)

        if mam_start == ArchiveState.ALL:
            self.set_current_page(Pages.SUMMARY)
            self.summary.nothing_to_do()

        self.show_all()

    def hide_buttons(self):
        '''
        Hide some of the standard buttons that are included in Gtk.Assistant
        '''
        if self.get_property('use-header-bar'):
            action_area = self.get_children()[1]
        else:
            box = self.get_children()[0]
            content_box = box.get_children()[1]
            action_area = content_box.get_children()[1]
        for button in action_area.get_children():
            button_name = Gtk.Buildable.get_name(button)
            if button_name == 'back':
                button.connect('show', self._on_show_button)
            elif button_name == 'forward':
                self.next = button
                button.connect('show', self._on_show_button)

    @staticmethod
    def _on_show_button(button):
        button.hide()

    def prepare_query(self):
        if self.timedelta:
            self.start = self.now - self.timedelta
        self.end = self.current_start

        log.info('get mam_start_date: %s', self.current_start)
        log.info('now: %s', self.now)
        log.info('start: %s', self.start)
        log.info('end: %s', self.end)

        self.query_id = self.con.get_module('MAM').request_archive_count(
            self.start, self.end)

    def _received_count(self, event):
        if event.query_id != self.query_id:
            return

        if event.count is not None:
            self.download_history.count = int(event.count)
        self.query_id = self.con.get_module('MAM').request_archive_interval(
            self.start, self.end)

    def _received_finished(self, event):
        if event.query_id != self.query_id:
            return
        self.query_id = None
        log.info('query finished')
        GLib.idle_add(self.download_history.finished)
        self.set_current_page(Pages.SUMMARY)
        self.summary.finished()

    def _nec_mam_message_received(self, event):
        if event.conn.name != self.account:
            return

        result = event.stanza.getTag('result')
        queryid = result.getAttr('queryid')
        if queryid != self.query_id:
            return

        log.debug('received message')
        GLib.idle_add(self.download_history.set_fraction)

    def on_row_selected(self, listbox, row):
        self.timedelta = row.get_child().get_delta()
        if row:
            self.set_page_complete(self.select_time, True)
        else:
            self.set_page_complete(self.select_time, False)

    def on_page_change(self, assistant, page):
        if page == self.download_history:
            self.next.hide()
            self.prepare_query()

    def on_destroy(self, *args):
        app.ged.remove_event_handler('archiving-count-received',
                                     ged.GUI1,
                                     self._received_count)
        app.ged.remove_event_handler('archiving-interval-finished',
                                     ged.GUI1,
                                     self._received_finished)
        app.ged.remove_event_handler('raw-mam-message-received',
                                     ged.PRECORE,
                                     self._nec_mam_message_received)
        del app.interface.instances[self.account]['history_sync']

    def on_close_clicked(self, *args):
        self.destroy()


class SelectTimePage(Gtk.Box):
    def __init__(self, assistant):
        super().__init__(orientation=Gtk.Orientation.VERTICAL)
        self.set_spacing(18)
        self.assistant = assistant
        label = Gtk.Label(label=_('How far back do you want to go?'))

        listbox = Gtk.ListBox()
        listbox.set_hexpand(False)
        listbox.set_halign(Gtk.Align.CENTER)
        listbox.add(TimeOption(_('One Month'), 1))
        listbox.add(TimeOption(_('Three Months'), 3))
        listbox.add(TimeOption(_('One Year'), 12))
        listbox.add(TimeOption(_('Everything')))
        listbox.connect('row-selected', assistant.on_row_selected)

        for row in listbox.get_children():
            option = row.get_child()
            if not option.get_delta():
                continue
            if assistant.now - option.get_delta() > assistant.current_start:
                row.set_activatable(False)
                row.set_selectable(False)

        self.pack_start(label, True, True, 0)
        self.pack_start(listbox, False, False, 0)


class DownloadHistoryPage(Gtk.Box):
    def __init__(self, assistant):
        super().__init__(orientation=Gtk.Orientation.VERTICAL)
        self.set_spacing(18)
        self.assistant = assistant
        self.count = 0
        self.received = 0

        surface = load_icon('folder-download-symbolic', self, size=64)
        image = Gtk.Image.new_from_surface(surface)

        self.progress = Gtk.ProgressBar()
        self.progress.set_show_text(True)
        self.progress.set_text(_('Connecting...'))
        self.progress.set_pulse_step(0.1)
        self.progress.set_vexpand(True)
        self.progress.set_valign(Gtk.Align.CENTER)

        self.pack_start(image, False, False, 0)
        self.pack_start(self.progress, False, False, 0)

    def set_fraction(self):
        self.received += 1
        if self.count:
            self.progress.set_fraction(self.received / self.count)
            self.progress.set_text(_('%(received)s of %(max)s' % {
                'received': self.received, 'max': self.count}))
        else:
            self.progress.pulse()
            self.progress.set_text(_('Downloaded %s Messages' % self.received))

    def finished(self):
        self.progress.set_fraction(1)


class SummaryPage(Gtk.Box):
    def __init__(self, assistant):
        super().__init__(orientation=Gtk.Orientation.VERTICAL)
        self.set_spacing(18)
        self.assistant = assistant

        self.label = Gtk.Label()
        self.label.set_name('FinishedLabel')
        self.label.set_valign(Gtk.Align.CENTER)

        self.pack_start(self.label, True, True, 0)

    def finished(self):
        received = self.assistant.download_history.received
        finished = _('''
        Finished synchronising your History.
        {received} Messages downloaded.
        '''.format(received=received))
        self.label.set_text(finished)

    def nothing_to_do(self):
        nothing_to_do = _('''
        Gajim is fully synchronised
        with the Archive.
        ''')
        self.label.set_text(nothing_to_do)

    def query_already_running(self):
        already_running = _('''
        There is already a synchronisation in
        progress. Please try later.
        ''')
        self.label.set_text(already_running)


class TimeOption(Gtk.Label):
    def __init__(self, label, months=None):
        super().__init__(label=label)
        self.date = months
        if months:
            self.date = timedelta(days=30 * months)

    def get_delta(self):
        return self.date