#
# Copyright 2012 Canonical Ltd.
#
# Authors:
#  James Page <james.page@canonical.com>
#  Paul Collins <paul.collins@canonical.com>
#

import json
import subprocess
import time
import os

from socket import gethostname as get_unit_hostname

LEADER = 'leader'
PEON = 'peon'
QUORUM = [LEADER, PEON]


def is_quorum():
    asok = "/var/run/ceph/ceph-mon.{}.asok".format(get_unit_hostname())
    cmd = [
        "ceph",
        "--admin-daemon",
        asok,
        "mon_status"
    ]
    if os.path.exists(asok):
        try:
            result = json.loads(subprocess.check_output(cmd))
        except subprocess.CalledProcessError:
            return False
        except ValueError:
            # Non JSON response from mon_status
            return False
        if result['state'] in QUORUM:
            return True
        else:
            return False
    else:
        return False


def is_leader():
    asok = "/var/run/ceph/ceph-mon.{}.asok".format(get_unit_hostname())
    cmd = [
        "ceph",
        "--admin-daemon",
        asok,
        "mon_status"
    ]
    if os.path.exists(asok):
        try:
            result = json.loads(subprocess.check_output(cmd))
        except subprocess.CalledProcessError:
            return False
        except ValueError:
            # Non JSON response from mon_status
            return False
        if result['state'] == LEADER:
            return True
        else:
            return False
    else:
        return False


def wait_for_quorum():
    while not is_quorum():
        time.sleep(3)


def add_bootstrap_hint(peer):
    asok = "/var/run/ceph/ceph-mon.{}.asok".format(get_unit_hostname())
    cmd = [
        "ceph",
        "--admin-daemon",
        asok,
        "add_bootstrap_peer_hint",
        peer
    ]
    if os.path.exists(asok):
        # Ignore any errors for this call
        subprocess.call(cmd)

DISK_FORMATS = [
    'xfs',
    'ext4',
    'btrfs'
]


def is_osd_disk(dev):
    try:
        info = subprocess.check_output(['sgdisk', '-i', '1', dev])
        info = info.split("\n")  # IGNORE:E1103
        for line in info:
            if line.startswith(
                'Partition GUID code: 4FBD7E29-9D25-41B8-AFD0-062C0CEFF05D'
            ):
                return True
    except subprocess.CalledProcessError:
        pass
    return False


def rescan_osd_devices():
    cmd = [
        'udevadm', 'trigger',
        '--subsystem-match=block', '--action=add'
    ]

    subprocess.call(cmd)


def zap_disk(dev):
    cmd = ['sgdisk', '--zap-all', dev]
    subprocess.check_call(cmd)


_bootstrap_keyring = "/var/lib/ceph/bootstrap-osd/ceph.keyring"


def is_bootstrapped():
    return os.path.exists(_bootstrap_keyring)


def wait_for_bootstrap():
    while (not is_bootstrapped()):
        time.sleep(3)


def import_osd_bootstrap_key(key):
    if not os.path.exists(_bootstrap_keyring):
        cmd = [
            'ceph-authtool',
            _bootstrap_keyring,
            '--create-keyring',
            '--name=client.bootstrap-osd',
            '--add-key={}'.format(key)
        ]
        subprocess.check_call(cmd)

# OSD caps taken from ceph-create-keys
_osd_bootstrap_caps = {
    'mon': [
        'allow command osd create ...',
        'allow command osd crush set ...',
        r'allow command auth add * osd allow\ * mon allow\ rwx',
        'allow command mon getmap'
    ]
}


def get_osd_bootstrap_key():
    return get_named_key('bootstrap-osd', _osd_bootstrap_caps)


_radosgw_keyring = "/etc/ceph/keyring.rados.gateway"


def import_radosgw_key(key):
    if not os.path.exists(_radosgw_keyring):
        cmd = [
            'ceph-authtool',
            _radosgw_keyring,
            '--create-keyring',
            '--name=client.radosgw.gateway',
            '--add-key={}'.format(key)
        ]
        subprocess.check_call(cmd)

# OSD caps taken from ceph-create-keys
_radosgw_caps = {
    'mon': ['allow r'],
    'osd': ['allow rwx']
}


def get_radosgw_key():
    return get_named_key('radosgw.gateway', _radosgw_caps)


_default_caps = {
    'mon': ['allow r'],
    'osd': ['allow rwx']
}


def get_named_key(name, caps=None):
    caps = caps or _default_caps
    cmd = [
        'ceph',
        '--name', 'mon.',
        '--keyring',
        '/var/lib/ceph/mon/ceph-{}/keyring'.format(
            get_unit_hostname()
        ),
        'auth', 'get-or-create', 'client.{}'.format(name),
    ]
    # Add capabilities
    for subsystem, subcaps in caps.iteritems():
        cmd.extend([
            subsystem,
            '; '.join(subcaps),
        ])
    output = subprocess.check_output(cmd).strip()  # IGNORE:E1103
    # get-or-create appears to have different output depending
    # on whether its 'get' or 'create'
    # 'create' just returns the key, 'get' is more verbose and
    # needs parsing
    key = None
    if len(output.splitlines()) == 1:
        key = output
    else:
        for element in output.splitlines():
            if 'key' in element:
                key = element.split(' = ')[1].strip()  # IGNORE:E1103
    return key