"""
Qemu task
"""
from cStringIO import StringIO

import contextlib
import logging
import os

from teuthology import misc as teuthology
from teuthology import contextutil
from teuthology.task import rbd
from ..orchestra import run

log = logging.getLogger(__name__)

DEFAULT_NUM_RBD = 1
DEFAULT_IMAGE_URL = 'http://ceph.com/qa/ubuntu-12.04.qcow2'
DEFAULT_MEM = 4096 # in megabytes

@contextlib.contextmanager
def create_dirs(ctx, config):
    """
    Handle directory creation and cleanup
    """
    testdir = teuthology.get_testdir(ctx)
    for client, client_config in config.iteritems():
        assert 'test' in client_config, 'You must specify a test to run'
        (remote,) = ctx.cluster.only(client).remotes.keys()
        remote.run(
            args=[
                'install', '-d', '-m0755', '--',
                '{tdir}/qemu'.format(tdir=testdir),
                '{tdir}/archive/qemu'.format(tdir=testdir),
                ]
            )
    try:
        yield
    finally:
        for client, client_config in config.iteritems():
            assert 'test' in client_config, 'You must specify a test to run'
            (remote,) = ctx.cluster.only(client).remotes.keys()
            remote.run(
                args=[
                    'rmdir', '{tdir}/qemu'.format(tdir=testdir), run.Raw('||'), 'true',
                    ]
                )

@contextlib.contextmanager
def generate_iso(ctx, config):
    """Execute system commands to generate iso"""
    log.info('generating iso...')
    testdir = teuthology.get_testdir(ctx)
    for client, client_config in config.iteritems():
        assert 'test' in client_config, 'You must specify a test to run'
        src_dir = os.path.dirname(__file__)
        userdata_path = os.path.join(testdir, 'qemu', 'userdata.' + client)
        metadata_path = os.path.join(testdir, 'qemu', 'metadata.' + client)

        with file(os.path.join(src_dir, 'userdata_setup.yaml'), 'rb') as f:
            test_setup = ''.join(f.readlines())

        with file(os.path.join(src_dir, 'userdata_teardown.yaml'), 'rb') as f:
            test_teardown = ''.join(f.readlines())

        user_data = test_setup
        if client_config.get('type', 'filesystem') == 'filesystem':
            for i in xrange(0, client_config.get('num_rbd', DEFAULT_NUM_RBD)):
                dev_letter = chr(ord('b') + i)
                user_data += """
- |
  #!/bin/bash
  mkdir /mnt/test_{dev_letter}
  mkfs -t xfs /dev/vd{dev_letter}
  mount -t xfs /dev/vd{dev_letter} /mnt/test_{dev_letter}
""".format(dev_letter=dev_letter)

        # this may change later to pass the directories as args to the
        # script or something. xfstests needs that.
        user_data += """
- |
  #!/bin/bash
  test -d /mnt/test_b && cd /mnt/test_b
  /mnt/cdrom/test.sh > /mnt/log/test.log 2>&1 && touch /mnt/log/success
""" + test_teardown

        (remote,) = ctx.cluster.only(client).remotes.keys()
        teuthology.write_file(remote, userdata_path, StringIO(user_data))

        with file(os.path.join(src_dir, 'metadata.yaml'), 'rb') as f:
            teuthology.write_file(remote, metadata_path, f)

        test_file = '{tdir}/qemu/{client}.test.sh'.format(tdir=testdir, client=client)
        remote.run(
            args=[
                'wget', '-nv', '-O', test_file,
                client_config['test'],
                run.Raw('&&'),
                'chmod', '755', test_file,
                ],
            )
        remote.run(
            args=[
                'genisoimage', '-quiet', '-input-charset', 'utf-8',
                '-volid', 'cidata', '-joliet', '-rock',
                '-o', '{tdir}/qemu/{client}.iso'.format(tdir=testdir, client=client),
                '-graft-points',
                'user-data={userdata}'.format(userdata=userdata_path),
                'meta-data={metadata}'.format(metadata=metadata_path),
                'test.sh={file}'.format(file=test_file),
                ],
            )
    try:
        yield
    finally:
        for client in config.iterkeys():
            (remote,) = ctx.cluster.only(client).remotes.keys()
            remote.run(
                args=[
                    'rm', '-f',
                    '{tdir}/qemu/{client}.iso'.format(tdir=testdir, client=client),
                    os.path.join(testdir, 'qemu', 'userdata.' + client),
                    os.path.join(testdir, 'qemu', 'metadata.' + client),
                    '{tdir}/qemu/{client}.test.sh'.format(tdir=testdir, client=client),
                    ],
                )

@contextlib.contextmanager
def download_image(ctx, config):
    """Downland base image, remove image file when done"""
    log.info('downloading base image')
    testdir = teuthology.get_testdir(ctx)
    for client, client_config in config.iteritems():
        (remote,) = ctx.cluster.only(client).remotes.keys()
        base_file = '{tdir}/qemu/base.{client}.qcow2'.format(tdir=testdir, client=client)
        remote.run(
            args=[
                'wget', '-nv', '-O', base_file, DEFAULT_IMAGE_URL,
                ]
            )
    try:
        yield
    finally:
        log.debug('cleaning up base image files')
        for client in config.iterkeys():
            base_file = '{tdir}/qemu/base.{client}.qcow2'.format(
                tdir=testdir,
                client=client,
                )
            (remote,) = ctx.cluster.only(client).remotes.keys()
            remote.run(
                args=[
                    'rm', '-f', base_file,
                    ],
                )

@contextlib.contextmanager
def run_qemu(ctx, config):
    """Setup kvm environment and start qemu"""
    procs = []
    testdir = teuthology.get_testdir(ctx)
    for client, client_config in config.iteritems():
        (remote,) = ctx.cluster.only(client).remotes.keys()
        log_dir = '{tdir}/archive/qemu/{client}'.format(tdir=testdir, client=client)
        remote.run(
            args=[
                'mkdir', log_dir, run.Raw('&&'),
                'sudo', 'modprobe', 'kvm',
                ]
            )

        base_file = '{tdir}/qemu/base.{client}.qcow2'.format(tdir=testdir, client=client)
        args=[
            'adjust-ulimits',
            'ceph-coverage',
            '{tdir}/archive/coverage'.format(tdir=testdir),
            'daemon-helper',
            'term',
            'qemu-system-x86_64', '-enable-kvm', '-nographic',
            '-m', str(client_config.get('memory', DEFAULT_MEM)),
            # base OS device
            '-drive',
            'file={base},format=qcow2,if=virtio'.format(base=base_file),
            # cd holding metadata for cloud-init
            '-cdrom', '{tdir}/qemu/{client}.iso'.format(tdir=testdir, client=client),
            # virtio 9p fs for logging
            '-fsdev',
            'local,id=log,path={log},security_model=none'.format(log=log_dir),
            '-device',
            'virtio-9p-pci,fsdev=log,mount_tag=test_log',
            ]

        cachemode = 'none'
        ceph_config = ctx.ceph.conf.get('global', {})
        ceph_config.update(ctx.ceph.conf.get('client', {}))
        ceph_config.update(ctx.ceph.conf.get(client, {}))
        if ceph_config.get('rbd cache'):
            if ceph_config.get('rbd cache max dirty', 1) > 0:
                cachemode = 'writeback'
            else:
                cachemode = 'writethrough'

        for i in xrange(client_config.get('num_rbd', DEFAULT_NUM_RBD)):
            args.extend([
                '-drive',
                'file=rbd:rbd/{img}:id={id},format=raw,if=virtio,cache={cachemode}'.format(
                    img='{client}.{num}'.format(client=client, num=i),
                    id=client[len('client.'):],
                    cachemode=cachemode,
                    ),
                ])

        log.info('starting qemu...')
        procs.append(
            remote.run(
                args=args,
                logger=log.getChild(client),
                stdin=run.PIPE,
                wait=False,
                )
            )

    try:
        yield
    finally:
        log.info('waiting for qemu tests to finish...')
        run.wait(procs)

        log.debug('checking that qemu tests succeeded...')
        for client in config.iterkeys():
            (remote,) = ctx.cluster.only(client).remotes.keys()
            remote.run(
                args=[
                    'test', '-f',
                    '{tdir}/archive/qemu/{client}/success'.format(
                        tdir=testdir,
                        client=client
                        ),
                    ],
                )

@contextlib.contextmanager
def task(ctx, config):
    """
    Run a test inside of QEMU on top of rbd. Only one test
    is supported per client.

    For example, you can specify which clients to run on::

        tasks:
        - ceph:
        - qemu:
            client.0:
              test: http://ceph.com/qa/test.sh
            client.1:
              test: http://ceph.com/qa/test2.sh

    Or use the same settings on all clients:

        tasks:
        - ceph:
        - qemu:
            all:
              test: http://ceph.com/qa/test.sh

    For tests that don't need a filesystem, set type to block::

        tasks:
        - ceph:
        - qemu:
            client.0:
              test: http://ceph.com/qa/test.sh
              type: block

    The test should be configured to run on /dev/vdb and later
    devices.

    If you want to run a test that uses more than one rbd image,
    specify how many images to use::

        tasks:
        - ceph:
        - qemu:
            client.0:
              test: http://ceph.com/qa/test.sh
              type: block
              num_rbd: 2

    You can set the amount of memory the VM has (default is 1024 MB)::

        tasks:
        - ceph:
        - qemu:
            client.0:
              test: http://ceph.com/qa/test.sh
              memory: 512 # megabytes
    """
    assert isinstance(config, dict), \
           "task qemu only supports a dictionary for configuration"

    config = teuthology.replace_all_with_clients(ctx.cluster, config)

    managers = []
    for client, client_config in config.iteritems():
        num_rbd = client_config.get('num_rbd', 1)
        assert num_rbd > 0, 'at least one rbd device must be used'
        for i in xrange(num_rbd):
            create_config = {
                client: {
                    'image_name':
                    '{client}.{num}'.format(client=client, num=i),
                    }
                }
            managers.append(
                lambda create_config=create_config:
                rbd.create_image(ctx=ctx, config=create_config)
                )

    managers.extend([
        lambda: create_dirs(ctx=ctx, config=config),
        lambda: generate_iso(ctx=ctx, config=config),
        lambda: download_image(ctx=ctx, config=config),
        lambda: run_qemu(ctx=ctx, config=config),
        ])

    with contextutil.nested(*managers):
        yield