#!/usr/bin/env python3
#
# 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 using the job-* QMP commands with block jobs

import iotests

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

img_size = 4 * 1024 * 1024

def pause_wait(vm, job_id):
    with iotests.Timeout(3, "Timeout waiting for job to pause"):
        while True:
            result = vm.qmp('query-jobs')
            for job in result['return']:
                if job['id'] == job_id and job['status'] in ['paused', 'standby']:
                    return job

# Test that block-job-pause/resume and job-pause/resume can be mixed
def test_pause_resume(vm):
    for pause_cmd, pause_arg in [('block-job-pause', 'device'),
                                 ('job-pause', 'id')]:
        for resume_cmd, resume_arg in [('block-job-resume', 'device'),
                                       ('job-resume', 'id')]:
            iotests.log('=== Testing %s/%s ===' % (pause_cmd, resume_cmd))

            iotests.log(vm.qmp(pause_cmd, **{pause_arg: 'job0'}))
            pause_wait(vm, 'job0')
            iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
            result = vm.qmp('query-jobs')
            iotests.log(result)

            old_progress = result['return'][0]['current-progress']
            total_progress = result['return'][0]['total-progress']

            iotests.log(vm.qmp(resume_cmd, **{resume_arg: 'job0'}))
            iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
            if old_progress < total_progress:
                # Wait for the job to advance
                while result['return'][0]['current-progress'] == old_progress:
                    result = vm.qmp('query-jobs')
                iotests.log(result)
            else:
                # Already reached the end, so the job cannot advance
                # any further; therefore, the query-jobs result can be
                # logged immediately
                iotests.log(vm.qmp('query-jobs'))

def test_job_lifecycle(vm, job, job_args, has_ready=False, is_mirror=False):
    global img_size

    iotests.log('')
    iotests.log('')
    iotests.log('Starting block job: %s (auto-finalize: %s; auto-dismiss: %s)' %
                (job,
                 job_args.get('auto-finalize', True),
                 job_args.get('auto-dismiss', True)))
    iotests.log(vm.qmp(job, job_id='job0', **job_args))

    # Depending on the storage, the first request may or may not have completed
    # yet (and the total progress may not have been fully determined yet), so
    # filter out the progress. Later query-job calls don't need the filtering
    # because the progress is made deterministic by the block job speed
    result = vm.qmp('query-jobs')
    for j in result['return']:
        j['current-progress'] = 'FILTERED'
        j['total-progress'] = 'FILTERED'
    iotests.log(result)

    # undefined -> created -> running
    iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
    iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))

    # Wait for total-progress to stabilize
    while vm.qmp('query-jobs')['return'][0]['total-progress'] < img_size:
        pass

    # RUNNING state:
    # pause/resume should work, complete/finalize/dismiss should error out
    iotests.log('')
    iotests.log('Pause/resume in RUNNING')
    test_pause_resume(vm)

    iotests.log(vm.qmp('job-complete', id='job0'))
    iotests.log(vm.qmp('job-finalize', id='job0'))
    iotests.log(vm.qmp('job-dismiss', id='job0'))

    iotests.log(vm.qmp('block-job-complete', device='job0'))
    iotests.log(vm.qmp('block-job-finalize', id='job0'))
    iotests.log(vm.qmp('block-job-dismiss', id='job0'))

    # Let the job complete (or transition to READY if it supports that)
    iotests.log(vm.qmp('block-job-set-speed', device='job0', speed=0))
    if has_ready:
        iotests.log('')
        iotests.log('Waiting for READY state...')
        vm.event_wait('BLOCK_JOB_READY')
        iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
        iotests.log(vm.qmp('query-jobs'))

        # READY state:
        # pause/resume/complete should work, finalize/dismiss should error out
        iotests.log('')
        iotests.log('Pause/resume in READY')
        test_pause_resume(vm)

        iotests.log(vm.qmp('job-finalize', id='job0'))
        iotests.log(vm.qmp('job-dismiss', id='job0'))

        iotests.log(vm.qmp('block-job-finalize', id='job0'))
        iotests.log(vm.qmp('block-job-dismiss', id='job0'))

        # Transition to WAITING
        iotests.log(vm.qmp('job-complete', id='job0'))

    # Move to WAITING and PENDING state
    iotests.log('')
    iotests.log('Waiting for PENDING state...')
    iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
    iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
    if is_mirror:
        iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
        iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))

    if not job_args.get('auto-finalize', True):
        # PENDING state:
        # finalize should work, pause/complete/dismiss should error out
        iotests.log(vm.qmp('query-jobs'))

        iotests.log(vm.qmp('job-pause', id='job0'))
        iotests.log(vm.qmp('job-complete', id='job0'))
        iotests.log(vm.qmp('job-dismiss', id='job0'))

        iotests.log(vm.qmp('block-job-pause', device='job0'))
        iotests.log(vm.qmp('block-job-complete', device='job0'))
        iotests.log(vm.qmp('block-job-dismiss', id='job0'))

        # Transition to CONCLUDED
        iotests.log(vm.qmp('job-finalize', id='job0'))


    # Move to CONCLUDED state
    iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))

    if not job_args.get('auto-dismiss', True):
        # CONCLUDED state:
        # dismiss should work, pause/complete/finalize should error out
        iotests.log(vm.qmp('query-jobs'))

        iotests.log(vm.qmp('job-pause', id='job0'))
        iotests.log(vm.qmp('job-complete', id='job0'))
        iotests.log(vm.qmp('job-finalize', id='job0'))

        iotests.log(vm.qmp('block-job-pause', device='job0'))
        iotests.log(vm.qmp('block-job-complete', device='job0'))
        iotests.log(vm.qmp('block-job-finalize', id='job0'))

        # Transition to NULL
        iotests.log(vm.qmp('job-dismiss', id='job0'))

    # Move to NULL state
    iotests.log(iotests.filter_qmp_event(vm.event_wait('JOB_STATUS_CHANGE')))
    iotests.log(vm.qmp('query-jobs'))


with iotests.FilePath('disk.img') as disk_path, \
     iotests.FilePath('copy.img') as copy_path, \
     iotests.VM() as vm:

    iotests.qemu_img_create('-f', iotests.imgfmt, disk_path, str(img_size))
    iotests.qemu_io('-c', 'write 0 %i' % (img_size),
                    '-f', iotests.imgfmt, disk_path)

    iotests.log('Launching VM...')
    vm.add_blockdev(vm.qmp_to_opts({
        'driver': iotests.imgfmt,
        'node-name': 'drive0-node',
        'file': {
            'driver': 'file',
            'filename': disk_path,
        },
    }))
    vm.launch()

    # In order to keep things deterministic (especially progress in query-job,
    # but related to this also automatic state transitions like job
    # completion), but still get pause points often enough to avoid making this
    # test very slow, it's important to have the right ratio between speed and
    # buf_size.
    #
    # For backup, buf_size is hard-coded to the source image cluster size (64k),
    # so we'll pick the same for mirror. The slice time, i.e. the granularity
    # of the rate limiting is 100ms. With a speed of 256k per second, we can
    # get four pause points per second. This gives us 250ms per iteration,
    # which should be enough to stay deterministic.

    test_job_lifecycle(vm, 'drive-mirror', has_ready=True, job_args={
        'device': 'drive0-node',
        'target': copy_path,
        'sync': 'full',
        'speed': 262144,
        'buf_size': 65536,
    })

    for auto_finalize in [True, False]:
        for auto_dismiss in [True, False]:
            test_job_lifecycle(vm, 'drive-backup', is_mirror=True, job_args={
                'device': 'drive0-node',
                'target': copy_path,
                'sync': 'full',
                'speed': 262144,
                'auto-finalize': auto_finalize,
                'auto-dismiss': auto_dismiss,
            })

    vm.shutdown()