import contextlib
import logging

from cStringIO import StringIO

from teuthology import misc
from teuthology.job_status import set_status
from teuthology.orchestra import run


log = logging.getLogger(__name__)


@contextlib.contextmanager
def syslog(ctx, config):
    """
    start syslog / stop syslog on exit.
    """
    if ctx.archive is None:
        # disable this whole feature if we're not going to archive the data
        # anyway
        yield
        return

    log.info('Starting syslog monitoring...')

    archive_dir = misc.get_archive_dir(ctx)
    log_dir = '{adir}/syslog'.format(adir=archive_dir)
    run.wait(
        ctx.cluster.run(
            args=['mkdir', '-p', '-m0755', '--', log_dir],
            wait=False,
        )
    )

    CONF = '/etc/rsyslog.d/80-cephtest.conf'
    kern_log = '{log_dir}/kern.log'.format(log_dir=log_dir)
    misc_log = '{log_dir}/misc.log'.format(log_dir=log_dir)
    conf_lines = [
        'kern.* -{kern_log};RSYSLOG_FileFormat'.format(kern_log=kern_log),
        '*.*;kern.none -{misc_log};RSYSLOG_FileFormat'.format(
            misc_log=misc_log),
    ]
    conf_fp = StringIO('\n'.join(conf_lines))
    try:
        for rem in ctx.cluster.remotes.iterkeys():
            log_context = 'system_u:object_r:var_log_t:s0'
            for log_path in (kern_log, misc_log):
                rem.run(args='touch %s' % log_path)
                rem.chcon(log_path, log_context)
            misc.sudo_write_file(
                remote=rem,
                path=CONF,
                data=conf_fp,
            )
            conf_fp.seek(0)
        run.wait(
            ctx.cluster.run(
                args=[
                    'sudo',
                    'service',
                    # a mere reload (SIGHUP) doesn't seem to make
                    # rsyslog open the files
                    'rsyslog',
                    'restart',
                ],
                wait=False,
            ),
        )

        yield
    finally:
        log.info('Shutting down syslog monitoring...')

        run.wait(
            ctx.cluster.run(
                args=[
                    'sudo',
                    'rm',
                    '-f',
                    '--',
                    CONF,
                    run.Raw('&&'),
                    'sudo',
                    'service',
                    'rsyslog',
                    'restart',
                ],
                wait=False,
            ),
        )
        # race condition: nothing actually says rsyslog had time to
        # flush the file fully. oh well.

        log.info('Checking logs for errors...')
        for rem in ctx.cluster.remotes.iterkeys():
            log.debug('Checking %s', rem.name)
            r = rem.run(
                args=[
                    'egrep', '--binary-files=text',
                    '\\bBUG\\b|\\bINFO\\b|\\bDEADLOCK\\b',
                    run.Raw('{adir}/syslog/*.log'.format(adir=archive_dir)),
                    run.Raw('|'),
                    'grep', '-v', 'task .* blocked for more than .* seconds',
                    run.Raw('|'),
                    'grep', '-v', 'lockdep is turned off',
                    run.Raw('|'),
                    'grep', '-v', 'trying to register non-static key',
                    run.Raw('|'),
                    'grep', '-v', 'DEBUG: fsize',  # xfs_fsr
                    run.Raw('|'),
                    'grep', '-v', 'CRON',  # ignore cron noise
                    run.Raw('|'),
                    'grep', '-v', 'BUG: bad unlock balance detected',  # #6097
                    run.Raw('|'),
                    'grep', '-v', 'inconsistent lock state',  # FIXME see #2523
                    run.Raw('|'),
                    'grep', '-v', '*** DEADLOCK ***',  # part of lockdep output
                    run.Raw('|'),
                    'grep', '-v',
                    # FIXME see #2590 and #147
                    'INFO: possible irq lock inversion dependency detected',
                    run.Raw('|'),
                    'grep', '-v',
                    'INFO: NMI handler (perf_event_nmi_handler) took too long to run',  # noqa
                    run.Raw('|'),
                    'grep', '-v', 'INFO: recovery required on readonly',
                    run.Raw('|'),
                    'grep', '-v', 'ceph-create-keys: INFO',
                    run.Raw('|'),
                    'egrep', '-v', '\\bsalt-master\\b|\\bsalt-minion\\b|\\bsalt-api\\b',
                    run.Raw('|'),
                    'head', '-n', '1',
                ],
                stdout=StringIO(),
            )
            stdout = r.stdout.getvalue()
            if stdout != '':
                log.error('Error in syslog on %s: %s', rem.name, stdout)
                set_status(ctx.summary, 'fail')
                if 'failure_reason' not in ctx.summary:
                    ctx.summary['failure_reason'] = \
                        "'{error}' in syslog".format(error=stdout)

        log.info('Compressing syslogs...')
        run.wait(
            ctx.cluster.run(
                args=[
                    'find',
                    '{adir}/syslog'.format(adir=archive_dir),
                    '-name',
                    '*.log',
                    '-print0',
                    run.Raw('|'),
                    'sudo',
                    'xargs',
                    '-0',
                    '--no-run-if-empty',
                    '--',
                    'gzip',
                    '--',
                ],
                wait=False,
            ),
        )
