# -*- encoding: utf8 -*-
#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2017 Marek Marczykowski-Górecki
#                               <marmarek@invisiblethingslab.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 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 Lesser 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/>.

'''Qubes VM objects.'''

import qubesmgmt.base
import qubesmgmt.storage


class QubesVM(qubesmgmt.base.PropertyHolder):
    '''Qubes domain.'''
    def __init__(self, app, name):
        super(QubesVM, self).__init__(app, 'mgmt.vm.property.', name)
        self._volumes = None

    @property
    def name(self):
        '''Domain name'''
        return self._method_dest

    @name.setter
    def name(self, new_value):
        self.qubesd_call(
            self._method_dest,
            self._method_prefix + 'Set',
            'name',
            str(new_value).encode('utf-8'))
        self._method_dest = new_value
        self._volumes = None
        self.app.domains.clear_cache()

    def __str__(self):
        return self._method_dest

    def __lt__(self, other):
        if isinstance(other, QubesVM):
            return self.name < other.name
        return NotImplemented

    def start(self):
        '''
        Start domain.

        :return:
        '''
        self.qubesd_call(self._method_dest, 'mgmt.vm.Start')

    def shutdown(self, force=False):
        '''
        Shutdown domain.

        :return:
        '''
        # TODO: force parameter
        # TODO: wait parameter (using event?)
        if force:
            raise NotImplementedError
        self.qubesd_call(self._method_dest, 'mgmt.vm.Shutdown')

    def kill(self):
        '''
        Kill domain (forcefuly shutdown).

        :return:
        '''
        self.qubesd_call(self._method_dest, 'mgmt.vm.Kill')

    def pause(self):
        '''
        Pause domain.

        Pause its execution without any prior notification.

        :return:
        '''
        self.qubesd_call(self._method_dest, 'mgmt.vm.Pause')

    def unpause(self):
        '''
        Unpause domain.

        Opposite to :py:meth:`pause`.

        :return:
        '''
        self.qubesd_call(self._method_dest, 'mgmt.vm.Unpause')

    def suspend(self):
        '''
        Suspend domain.

        Give domain a chance to prepare for suspend - for example suspend
        used PCI devices.

        :return:
        '''
        raise NotImplementedError
        #self.qubesd_call(self._method_dest, 'mgmt.vm.Suspend')

    def resume(self):
        '''
        Resume domain.

        Opposite to :py:meth:`suspend`.

        :return:
        '''
        raise NotImplementedError
        #self.qubesd_call(self._method_dest, 'mgmt.vm.Resume')

    def get_power_state(self):
        '''Return power state description string.

        Return value may be one of those:

        =============== ========================================================
        return value    meaning
        =============== ========================================================
        ``'Halted'``    Machine is not active.
        ``'Transient'`` Machine is running, but does not have :program:`guid`
                        or :program:`qrexec` available.
        ``'Running'``   Machine is ready and running.
        ``'Paused'``    Machine is paused.
        ``'Suspended'`` Machine is S3-suspended.
        ``'Halting'``   Machine is in process of shutting down (OS shutdown).
        ``'Dying'``     Machine is in process of shutting down (cleanup).
        ``'Crashed'``   Machine crashed and is unusable.
        ``'NA'``        Machine is in unknown state.
        =============== ========================================================

        .. seealso::

            http://wiki.libvirt.org/page/VM_lifecycle
                Description of VM life cycle from the point of view of libvirt.

            https://libvirt.org/html/libvirt-libvirt-domain.html#virDomainState
                Libvirt's enum describing precise state of a domain.

        '''

        vm_list_info = self.qubesd_call(
            self._method_dest, 'mgmt.vm.List', None, None).decode('ascii')
        #  name class=... state=... other=...
        vm_state = vm_list_info.partition('state=')[2].split(' ')[0]
        return vm_state

    @property
    def volumes(self):
        '''VM disk volumes'''
        if self._volumes is None:
            volumes_list = self.qubesd_call(
                self._method_dest, 'mgmt.vm.volume.List')
            self._volumes = {}
            for volname in volumes_list.decode('ascii').splitlines():
                if not volname:
                    continue
                self._volumes[volname] = qubesmgmt.storage.Volume(self.app,
                    vm=self.name, vm_name=volname)
        return self._volumes

# pylint: disable=abstract-method
class AdminVM(QubesVM):
    '''Dom0'''
    pass


class AppVM(QubesVM):
    '''Application VM'''
    pass


class StandaloneVM(QubesVM):
    '''Standalone Application VM'''
    pass


class TemplateVM(QubesVM):
    '''Template for AppVM'''
    pass


class DispVM(QubesVM):
    '''Disposable VM'''
    pass