#!/usr/bin/python3
#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2012  Agnieszka Kostrzewa <agnieszka.kostrzewa@gmail.com>
# Copyright (C) 2012  Marek Marczykowski <marmarek@mimuw.edu.pl>
#
# This program 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; either version 2
# 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 General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with this program; if not, see <http://www.gnu.org/licenses/>.
#
#

from PyQt5 import QtCore, QtWidgets, QtGui  # pylint: disable=import-error
import os
import os.path
import logging
import logging.handlers

from . import ui_restoredlg  # pylint: disable=no-name-in-module
from . import multiselectwidget
from . import backup_utils
from . import utils

from multiprocessing import Queue
from queue import Empty
from qubesadmin import exc
from qubesadmin.backup import restore


# pylint: disable=too-few-public-methods
class RestoreThread(QtCore.QThread):
    def __init__(self, backup_restore, vms_to_restore):
        QtCore.QThread.__init__(self)
        self.backup_restore = backup_restore
        self.vms_to_restore = vms_to_restore
        self.msg = None
        self.canceled = None

    def run(self):
        err_msg = []
        try:
            self.backup_restore.restore_do(self.vms_to_restore)

        except exc.BackupCancelledError as ex:
            self.canceled = True
            err_msg.append(str(ex))
        except Exception as ex:  # pylint: disable=broad-except
            err_msg.append(str(ex))
            err_msg.append(
                self.tr("Partially restored files left in /var/tmp/restore_*, "
                        "investigate them and/or clean them up"))
        if err_msg:
            self.msg = '<br />'.join(err_msg)
            self.msg = '<b><font color="red">{0}</font></b><br />'.format(
                self.tr("Finished with errors!")) + self.msg
        else:
            self.msg = '<font color="green">{0}</font>'.format(
                self.tr("Finished successfully!"))


class RestoreVMsWindow(ui_restoredlg.Ui_Restore, QtWidgets.QWizard):
    def __init__(self, qt_app, qubes_app, parent=None):
        super().__init__(parent)

        self.qt_app = qt_app
        self.qubes_app = qubes_app

        self.vms_to_restore = None
        self.func_output = []

        self.thread = None

        # Set up logging
        self.feedback_queue = Queue()
        handler = logging.handlers.QueueHandler(self.feedback_queue)
        logger = logging.getLogger('qubesadmin.backup')
        logger.addHandler(handler)
        logger.setLevel(logging.INFO)

        self.backup_restore = None
        self.target_appvm = None

        self.setupUi(self)

        self.dom0_restored_label.setVisible(False)

        self.select_vms_widget = multiselectwidget.MultiSelectWidget(self)
        self.select_vms_layout.insertWidget(1, self.select_vms_widget)

        self.currentIdChanged.connect(self.current_page_changed)
        self.dir_line_edit.textChanged.connect(self.backup_location_changed)

        self.select_dir_page.isComplete = self.has_selected_dir
        self.select_vms_page.isComplete = self.has_selected_vms
        self.confirm_page.isComplete = self.all_vms_good
        # FIXME
        # this causes to run isComplete() twice, I don't know why
        self.select_vms_widget.selectedChanged.connect(
            self.select_vms_page.completeChanged.emit)

        backup_utils.fill_appvms_list(self)

        self.passwd_show_button.pressed.connect(self.show_password)
        self.passwd_show_button.released.connect(self.hide_password)

    def show_password(self):
        self.passphrase_line_edit.setEchoMode(QtWidgets.QLineEdit.Normal)
        self.passwd_show_button.setIcon(QtGui.QIcon(':/eye.svg'))

    def hide_password(self):
        self.passphrase_line_edit.setEchoMode(QtWidgets.QLineEdit.Password)
        self.passwd_show_button.setIcon(QtGui.QIcon(':/eye-off.svg'))

    def setup_application(self):
        self.qt_app.setApplicationName(self.tr("Qubes Restore VMs"))
        self.qt_app.setWindowIcon(QtGui.QIcon.fromTheme("qubes-manager"))

    @QtCore.pyqtSlot(name='on_select_path_button_clicked')
    def select_path_button_clicked(self):
        backup_utils.select_path_button_clicked(self, True)

    def cleanupPage(self, p_int):  # pylint: disable=invalid-name
        if self.page(p_int) is self.select_vms_page:
            self.vms_to_restore = None
        else:
            super().cleanupPage(p_int)

    def __fill_vms_list__(self):
        if self.vms_to_restore is not None:
            return

        self.select_vms_widget.selected_list.clear()
        self.select_vms_widget.available_list.clear()

        self.target_appvm = None
        if self.appvm_combobox.currentIndex() != 0:   # An existing appvm chosen
            self.target_appvm = self.qubes_app.domains[
                str(self.appvm_combobox.currentText())]

        try:
            self.backup_restore = restore.BackupRestore(
                self.qubes_app,
                self.dir_line_edit.text(),
                self.target_appvm,
                self.passphrase_line_edit.text()
            )

            if self.ignore_missing.isChecked():
                self.backup_restore.options.use_default_template = True
                self.backup_restore.options.use_default_netvm = True

            if self.ignore_uname_mismatch.isChecked():
                self.backup_restore.options.ignore_username_mismatch = True

            if self.verify_only.isChecked():
                self.backup_restore.options.verify_only = True

            # pylint: disable=assignment-from-no-return
            self.vms_to_restore = self.backup_restore.get_restore_info()

            for vmname in self.vms_to_restore:
                if vmname.startswith('$'):
                    # Internal info
                    continue
                self.select_vms_widget.available_list.addItem(vmname)
        except exc.QubesException as ex:
            QtWidgets.QMessageBox.warning(
                self, self.tr("Restore error!"), str(ex))
            self.restart()

    def append_output(self, text):
        self.commit_text_edit.append(text)

    def current_page_changed(self, page_id):  # pylint: disable=unused-argument
        if self.currentPage() is self.select_vms_page:
            self.__fill_vms_list__()

        elif self.currentPage() is self.confirm_page:
            # pylint: disable=assignment-from-no-return
            self.vms_to_restore = self.backup_restore.get_restore_info()

            for i in range(self.select_vms_widget.available_list.count()):
                vmname = self.select_vms_widget.available_list.item(i).text()
                del self.vms_to_restore[str(vmname)]

            if 'dom0' in self.vms_to_restore.keys():
                self.dom0_restored_label.setVisible(True)

            self.vms_to_restore = self.backup_restore.restore_info_verify(
                self.vms_to_restore)

            self.func_output = self.backup_restore.get_restore_summary(
                self.vms_to_restore
            )

            self.confirm_text_edit.setReadOnly(True)
            self.confirm_text_edit.setFontFamily("Monospace")
            self.confirm_text_edit.setText(self.func_output)

            self.confirm_page.completeChanged.emit()

        elif self.currentPage() is self.commit_page:
            self.button(self.FinishButton).setDisabled(True)
            self.showFileDialog.setEnabled(True)
            self.showFileDialog.setChecked(self.showFileDialog.isEnabled()
                                           and str(self.dir_line_edit.text())
                                           .count("media/") > 0)

            self.thread = RestoreThread(self.backup_restore,
                                        self.vms_to_restore)
            self.thread.finished.connect(self.thread_finished)

            # Start log timer
            timer = QtCore.QTimer(self)
            timer.timeout.connect(self.update_log)
            timer.start(1000)

            self.thread.start()

    def thread_finished(self):
        self.progress_bar.setMaximum(100)
        self.progress_bar.setValue(100)

        if self.thread.msg:
            QtWidgets.QMessageBox.warning(
                self,
                self.tr("Restore qubes"),
                self.tr(self.thread.msg))

        if self.thread.msg:
            self.append_output(self.thread.msg)

        if self.showFileDialog.isChecked():
            self.append_output(
                '<b><font color="black">{0}</font></b>'.format(
                    self.tr("Please unmount your backup volume and cancel "
                            "the file selection dialog.")))
            backup_utils.select_path_button_clicked(self, False, True)

        self.button(self.FinishButton).setEnabled(True)
        self.button(self.CancelButton).setEnabled(False)
        self.showFileDialog.setEnabled(False)

    def update_log(self):
        try:
            log_record = self.feedback_queue.get_nowait()
            while log_record:
                if log_record.levelno == logging.ERROR or\
                                log_record.levelno == logging.CRITICAL:
                    output = '<font color="red">{0}</font>'.format(
                        log_record.getMessage())
                else:
                    output = log_record.getMessage()
                self.append_output(output)
                log_record = self.feedback_queue.get_nowait()
        except Empty:
            pass

    def all_vms_good(self):
        for vm_info in self.vms_to_restore.values():
            if not vm_info.vm:
                continue
            if not vm_info.good_to_go:
                return False
        return True

    def reject(self):
        if self.currentPage() is self.commit_page and self.thread.isRunning():
            self.backup_restore.canceled = True
            self.append_output('<font color="red">{0}</font>'.format(
                self.tr("Aborting the operation...")))
            self.button(self.CancelButton).setDisabled(True)
        else:
            self.done(0)

    def has_selected_dir(self):
        backup_location = self.dir_line_edit.text()
        if not backup_location:
            return False
        if self.appvm_combobox.currentIndex() == 0:
            if os.path.isfile(backup_location) or \
                    os.path.isfile(os.path.join(backup_location, 'qubes.xml')):
                return True
        else:
            return True

        return False

    def has_selected_vms(self):
        return self.select_vms_widget.selected_list.count() > 0

    def backup_location_changed(self, new_dir=None):
        # pylint: disable=unused-argument
        self.select_dir_page.completeChanged.emit()


def main():
    utils.run_synchronous(RestoreVMsWindow)


if __name__ == "__main__":
    main()
