#!/usr/bin/env python
#
# Copyright (C) 2018 Red Hat, Inc.
#
# 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 General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# Creator/Owner: Kevin Wolf <kwolf@redhat.com>
#
# Check that block node activation and inactivation works with a block graph
# that is built with individually created nodes

import iotests
import os

iotests.verify_image_format(supported_fmts=['qcow2'])
iotests.verify_platform(['linux'])

def enable_migration_events(vm, name):
    iotests.log('Enabling migration QMP events on %s...' % name)
    iotests.log(vm.qmp('migrate-set-capabilities', capabilities=[
        {
            'capability': 'events',
            'state': True
        }
    ]))

def wait_migration(vm):
    while True:
        event = vm.event_wait('MIGRATION')
        iotests.log(event, filters=[iotests.filter_qmp_event])
        if event['data']['status'] == 'completed':
            break

with iotests.FilePath('img') as img_path, \
     iotests.FilePath('backing') as backing_path, \
     iotests.FilePath('mig_fifo_a') as fifo_a, \
     iotests.FilePath('mig_fifo_b') as fifo_b, \
     iotests.VM(path_suffix='a') as vm_a, \
     iotests.VM(path_suffix='b') as vm_b:

    iotests.qemu_img_pipe('create', '-f', iotests.imgfmt, backing_path, '64M')
    iotests.qemu_img_pipe('create', '-f', iotests.imgfmt, img_path, '64M')

    os.mkfifo(fifo_a)
    os.mkfifo(fifo_b)

    iotests.log('Launching source VM...')
    (vm_a.add_blockdev('file,filename=%s,node-name=drive0-file' % (img_path))
         .add_blockdev('%s,file=drive0-file,node-name=drive0' % (iotests.imgfmt))
         .add_blockdev('file,filename=%s,node-name=drive0-backing-file' % (backing_path))
         .add_blockdev('%s,file=drive0-backing-file,node-name=drive0-backing' % (iotests.imgfmt))
         .launch())

    enable_migration_events(vm_a, 'A')

    iotests.log('Launching destination VM...')
    (vm_b.add_blockdev('file,filename=%s,node-name=drive0-file' % (img_path))
         .add_blockdev('%s,file=drive0-file,node-name=drive0' % (iotests.imgfmt))
         .add_blockdev('file,filename=%s,node-name=drive0-backing-file' % (backing_path))
         .add_blockdev('%s,file=drive0-backing-file,node-name=drive0-backing' % (iotests.imgfmt))
         .add_incoming("exec: cat '%s'" % (fifo_a))
         .launch())

    enable_migration_events(vm_b, 'B')

    # Add a child node that was created after the parent node. The reverse case
    # is covered by the -blockdev options above.
    iotests.log(vm_a.qmp('blockdev-snapshot', node='drive0-backing',
                         overlay='drive0'))
    iotests.log(vm_b.qmp('blockdev-snapshot', node='drive0-backing',
                         overlay='drive0'))

    iotests.log('Starting migration to B...')
    iotests.log(vm_a.qmp('migrate', uri='exec:cat >%s' % (fifo_a)))
    with iotests.Timeout(3, 'Migration does not complete'):
        # Wait for the source first (which includes setup=setup)
        wait_migration(vm_a)
        # Wait for the destination second (which does not)
        wait_migration(vm_b)

    iotests.log(vm_a.qmp('query-migrate')['return']['status'])
    iotests.log(vm_b.qmp('query-migrate')['return']['status'])

    iotests.log(vm_a.qmp('query-status'))
    iotests.log(vm_b.qmp('query-status'))

    iotests.log('Add a second parent to drive0-file...')
    iotests.log(vm_b.qmp('blockdev-add', driver='raw', file='drive0-file',
                         node_name='drive0-raw'))

    iotests.log('Restart A with -incoming and second parent...')
    vm_a.shutdown()
    (vm_a.add_blockdev('raw,file=drive0-file,node-name=drive0-raw')
         .add_incoming("exec: cat '%s'" % (fifo_b))
         .launch())

    enable_migration_events(vm_a, 'A')

    iotests.log(vm_a.qmp('blockdev-snapshot', node='drive0-backing',
                         overlay='drive0'))

    iotests.log('Starting migration back to A...')
    iotests.log(vm_b.qmp('migrate', uri='exec:cat >%s' % (fifo_b)))
    with iotests.Timeout(3, 'Migration does not complete'):
        # Wait for the source first (which includes setup=setup)
        wait_migration(vm_b)
        # Wait for the destination second (which does not)
        wait_migration(vm_a)

    iotests.log(vm_a.qmp('query-migrate')['return']['status'])
    iotests.log(vm_b.qmp('query-migrate')['return']['status'])

    iotests.log(vm_a.qmp('query-status'))
    iotests.log(vm_b.qmp('query-status'))