# This file is part of Gajim.
#
# SPDX-License-Identifier: GPL-3.0-only

from typing import Any

import logging
import random

from gi.repository import Gtk
from nbxmpp.errors import StanzaError
from nbxmpp.protocol import JID
from nbxmpp.task import Task

from gajim.common import app
from gajim.common import ged
from gajim.common.const import MUC_CREATION_EXAMPLES
from gajim.common.const import MUC_DISCO_ERRORS
from gajim.common.events import AccountConnected
from gajim.common.events import AccountDisconnected
from gajim.common.ged import EventHelper
from gajim.common.helpers import to_user_string
from gajim.common.i18n import _
from gajim.common.util.jid import validate_jid
from gajim.common.util.muc import get_random_muc_localpart

from gajim.gtk.builder import get_builder
from gajim.gtk.dialogs import ErrorDialog
from gajim.gtk.util import ensure_not_destroyed
from gajim.gtk.util import SignalManager
from gajim.gtk.widgets import GajimAppWindow

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


class CreateGroupchatWindow(GajimAppWindow, EventHelper, SignalManager):
    def __init__(self, account: str | None) -> None:
        GajimAppWindow.__init__(
            self,
            name='CreateGroupchat',
            title=_('Create Group Chat'),
            default_width=500
        )

        EventHelper.__init__(self)
        SignalManager.__init__(self)

        self._ui = get_builder('groupchat_creation.ui')
        self.set_child(self._ui.stack)

        self._connect(self._ui.account_combo, 'changed', self._on_account_combo_changed)
        self._connect(
            self._ui.advanced_switch, 'notify::active', self._on_toggle_advanced
        )
        self._connect(self._ui.address_entry, 'changed', self._on_address_entry_changed)
        self._connect(self._ui.create_button, 'clicked', self._on_create_clicked)

        self._account = account
        self._destroyed: bool = False

        self._create_entry_completion()

        self.register_events([
            ('account-connected', ged.GUI2, self._on_account_state),
            ('account-disconnected', ged.GUI2, self._on_account_state)
        ])

        if app.get_number_of_connected_accounts() == 0:
            # This can happen under rare circumstances
            self._ui.stack.set_visible_child_name('no-connection')
            return

        self._update_accounts(account)
        self._ui.create_button.grab_focus()

    def _cleanup(self) -> None:
        self._disconnect_all()
        self._destroyed = True
        self.unregister_events()

    def _on_account_state(self,
                          _event: AccountConnected | AccountDisconnected
                          ) -> None:
        any_account_connected = app.get_number_of_connected_accounts() > 0
        if any_account_connected:
            self._ui.stack.set_visible_child_name('create')
            self._update_accounts()
        else:
            self._ui.stack.set_visible_child_name('no-connection')

    def _update_accounts(self, account: str | None = None) -> None:
        accounts = app.get_enabled_accounts_with_labels(connected_only=True)
        account_liststore = self._ui.account_combo.get_model()
        assert isinstance(account_liststore, Gtk.ListStore)
        account_liststore.clear()

        for acc in accounts:
            account_liststore.append(acc)

        self._ui.account_combo.set_visible(len(accounts) != 1)
        self._ui.account_label.set_visible(len(accounts) != 1)

        if account is None:
            account = accounts[0][0]

        self._ui.account_combo.set_active_id(account)
        self._account = account
        self._fill_placeholders()

    def _create_entry_completion(self) -> None:
        entry_completion = Gtk.EntryCompletion()
        model = Gtk.ListStore(str)
        entry_completion.set_model(model)
        entry_completion.set_text_column(0)

        entry_completion.set_inline_completion(True)
        entry_completion.set_popup_single_match(False)

        self._ui.address_entry.set_completion(entry_completion)

    def _fill_placeholders(self) -> None:
        placeholder = random.choice(MUC_CREATION_EXAMPLES)
        server = self._get_muc_service_jid()

        self._ui.name_entry.set_placeholder_text(
            _('e.g. %s') % placeholder[0])
        self._ui.description_entry.set_placeholder_text(
            _('e.g. %s') % placeholder[1])
        self._ui.address_entry.set_placeholder_text(
            f'{placeholder[2]}@{server}')

    def _has_muc_service(self, account: str) -> bool:
        client = app.get_client(account)
        return client.get_module('MUC').service_jid is not None

    def _get_muc_service_jid(self) -> str:
        assert self._account is not None
        client = app.get_client(self._account)
        service_jid = client.get_module('MUC').service_jid
        if service_jid is None:
            return 'muc.example.org'
        return str(service_jid)

    def _on_account_combo_changed(self, combo: Gtk.ComboBox) -> None:
        self._account = combo.get_active_id()
        if self._account is None:
            model = combo.get_model()
            assert model is not None
            iter_ = model.get_iter_first()
            if not iter_:
                return
            self._account = model[iter_][0]

        self._fill_placeholders()
        self._unset_error()
        self._unset_info()
        self._ui.address_entry.get_buffer().set_text('', 0)

        has_muc_service = self._has_muc_service(self._account)

        self._ui.advanced_switch.set_active(not has_muc_service)
        self._ui.advanced_switch.set_sensitive(has_muc_service)

        if not has_muc_service:
            self._set_info(
                _('Your server does not offer a group chat service. '
                  'Please specify the address of a different server.'))

    def _is_jid_valid(self, text: str) -> bool:
        if not text:
            return True

        try:
            jid = validate_jid(text)
            if jid.resource:
                raise ValueError

        except ValueError:
            return False

        return True

    def _set_processing_state(self, enabled: bool) -> None:
        if enabled:
            self._ui.spinner.start()
            self._ui.create_button.set_sensitive(False)
        else:
            self._ui.spinner.stop()
        self._ui.grid.set_sensitive(not enabled)

    def _unset_info(self) -> None:
        self._ui.info_label.hide()

    def _set_info(self, text: str) -> None:
        self._ui.info_label.set_text(text)
        self._ui.info_label.show()

    def _unset_error(self) -> None:
        self._ui.error_label.hide()
        self._ui.create_button.set_sensitive(True)

    def _set_error(self, text: str) -> None:
        self._ui.error_label.set_text(text)
        self._ui.error_label.show()
        self._ui.create_button.set_sensitive(False)

    def _set_error_from_error(self, error: StanzaError) -> None:
        condition = error.condition or ''
        if condition == 'gone':
            condition = 'already-exists'
        text = MUC_DISCO_ERRORS.get(condition, to_user_string(error))
        self._set_error(text)

    def _set_error_from_error_code(self, error_code: str) -> None:
        self._set_error(MUC_DISCO_ERRORS[error_code])

    def _on_address_entry_changed(self, entry: Gtk.Entry) -> None:
        text = entry.get_text()
        self._update_entry_completion(entry, text)
        self._unset_error()

    def _update_entry_completion(self, entry: Gtk.Entry, text: str) -> None:
        text = entry.get_text()
        if '@' in text:
            text = text.split('@', 1)[0]

        completion = entry.get_completion()
        assert completion is not None
        model = completion.get_model()
        assert isinstance(model, Gtk.ListStore)
        model.clear()

        server = self._get_muc_service_jid()
        model.append([f'{text}@{server}'])

    def _on_toggle_advanced(self, switch: Gtk.Switch, *args: Any) -> None:
        self._unset_error()
        active = switch.get_active()
        self._ui.address_entry.set_visible(active)
        self._ui.address_entry_label.set_visible(active)
        self._ui.public_radio.set_visible(active)
        self._ui.private_radio.set_visible(active)

    def _on_create_clicked(self, _button: Gtk.Button) -> None:
        assert self._account is not None
        if not app.account_is_available(self._account):
            ErrorDialog(
                _('Not Connected'),
                _('You have to be connected to create a group chat.'))
            return

        room_jid = self._ui.address_entry.get_text()
        if not self._ui.advanced_switch.get_active() or not room_jid:
            server = self._get_muc_service_jid()
            room_jid = f'{get_random_muc_localpart()}@{server}'

        if not self._is_jid_valid(room_jid):
            self._set_error(_('Invalid Address'))
            return

        self._set_processing_state(True)
        client = app.get_client(self._account)
        client.get_module('Discovery').disco_info(
            room_jid, callback=self._disco_info_received)

    @ensure_not_destroyed
    def _disco_info_received(self, task: Task) -> None:
        try:
            result = task.finish()
        except StanzaError as error:
            if error.condition == 'item-not-found':
                assert error.jid is not None
                self._create_muc(error.jid)
                return
            self._set_error_from_error(error)

        else:
            self._set_error_from_error_code(
                'already-exists' if result.is_muc else 'not-muc-service')

        self._set_processing_state(False)

    def _create_muc(self, room_jid: str) -> None:
        name = self._ui.name_entry.get_text()
        description = self._ui.description_entry.get_text()
        is_public = self._ui.public_radio.get_active()

        config = {
            # XEP-0045 options
            'muc#roomconfig_roomname': name,
            'muc#roomconfig_roomdesc': description,
            'muc#roomconfig_publicroom': is_public,
            'muc#roomconfig_membersonly': not is_public,
            'muc#roomconfig_whois': 'moderators' if is_public else 'anyone',
            'muc#roomconfig_changesubject': not is_public,

            # Ejabberd options
            'public_list': is_public,
        }

        # Create new group chat by joining
        assert self._account is not None

        if app.window.chat_exists(self._account, JID.from_string(room_jid)):
            log.error('Trying to create groupchat '
                      'which is already added as chat')
            self.close()
            return

        client = app.get_client(self._account)
        client.get_module('MUC').create(room_jid, config)

        self.close()
