# Copyright (C) 2009-2010 Canonical Ltd.
# Copyright (C) 2012, 2013 Hewlett-Packard Development Company, L.P.
# Copyright (C) 2012 Yahoo! Inc.
#
# Author: Scott Moser <scott.moser@canonical.com>
# Author: Juerg Hafliger <juerg.haefliger@hp.com>
# Author: Joshua Harlow <harlowja@yahoo-inc.com>
#
# This file is part of cloud-init. See LICENSE file for license information.

import errno
import os

from cloudinit import log as logging
from cloudinit.net import eni
from cloudinit import sources
from cloudinit import util

LOG = logging.getLogger(__name__)


class DataSourceNoCloud(sources.DataSource):

    dsname = "NoCloud"

    def __init__(self, sys_cfg, distro, paths):
        sources.DataSource.__init__(self, sys_cfg, distro, paths)
        self.seed = None
        self.seed_dirs = [os.path.join(paths.seed_dir, 'nocloud'),
                          os.path.join(paths.seed_dir, 'nocloud-net')]
        self.seed_dir = None
        self.supported_seed_starts = ("/", "file://")

    def __str__(self):
        root = sources.DataSource.__str__(self)
        return "%s [seed=%s][dsmode=%s]" % (root, self.seed, self.dsmode)

    def _get_devices(self, label):
        fslist = util.find_devs_with("TYPE=vfat")
        fslist.extend(util.find_devs_with("TYPE=iso9660"))

        label_list = util.find_devs_with("LABEL=%s" % label.upper())
        label_list.extend(util.find_devs_with("LABEL=%s" % label.lower()))

        devlist = list(set(fslist) & set(label_list))
        devlist.sort(reverse=True)
        return devlist

    def _get_data(self):
        defaults = {
            "instance-id": "nocloud",
            "dsmode": self.dsmode,
        }

        found = []
        mydata = {'meta-data': {}, 'user-data': "", 'vendor-data': "",
                  'network-config': None}

        try:
            # Parse the system serial label from dmi. If not empty, try parsing
            # like the commandline
            md = {}
            serial = util.read_dmi_data('system-serial-number')
            if serial and load_cmdline_data(md, serial):
                found.append("dmi")
                mydata = _merge_new_seed(mydata, {'meta-data': md})
        except Exception:
            util.logexc(LOG, "Unable to parse dmi data")
            return False

        try:
            # Parse the kernel command line, getting data passed in
            md = {}
            if load_cmdline_data(md):
                found.append("cmdline")
                mydata = _merge_new_seed(mydata, {'meta-data': md})
        except Exception:
            util.logexc(LOG, "Unable to parse command line data")
            return False

        # Check to see if the seed dir has data.
        pp2d_kwargs = {'required': ['user-data', 'meta-data'],
                       'optional': ['vendor-data', 'network-config']}

        for path in self.seed_dirs:
            try:
                seeded = util.pathprefix2dict(path, **pp2d_kwargs)
                found.append(path)
                LOG.debug("Using seeded data from %s", path)
                mydata = _merge_new_seed(mydata, seeded)
                break
            except ValueError:
                pass

        # If the datasource config had a 'seedfrom' entry, then that takes
        # precedence over a 'seedfrom' that was found in a filesystem
        # but not over external media
        if self.ds_cfg.get('seedfrom'):
            found.append("ds_config_seedfrom")
            mydata['meta-data']["seedfrom"] = self.ds_cfg['seedfrom']

        # fields appropriately named can also just come from the datasource
        # config (ie, 'user-data', 'meta-data', 'vendor-data' there)
        if 'user-data' in self.ds_cfg and 'meta-data' in self.ds_cfg:
            mydata = _merge_new_seed(mydata, self.ds_cfg)
            found.append("ds_config")

        def _pp2d_callback(mp, data):
            return util.pathprefix2dict(mp, **data)

        label = self.ds_cfg.get('fs_label', "cidata")
        if label is not None:
            for dev in self._get_devices(label):
                try:
                    LOG.debug("Attempting to use data from %s", dev)

                    try:
                        seeded = util.mount_cb(dev, _pp2d_callback,
                                               pp2d_kwargs)
                    except ValueError:
                        LOG.warning("device %s with label=%s not a "
                                    "valid seed.", dev, label)
                        continue

                    mydata = _merge_new_seed(mydata, seeded)

                    LOG.debug("Using data from %s", dev)
                    found.append(dev)
                    break
                except OSError as e:
                    if e.errno != errno.ENOENT:
                        raise
                except util.MountFailedError:
                    util.logexc(LOG, "Failed to mount %s when looking for "
                                "data", dev)

        # There was no indication on kernel cmdline or data
        # in the seeddir suggesting this handler should be used.
        if len(found) == 0:
            return False

        # The special argument "seedfrom" indicates we should
        # attempt to seed the userdata / metadata from its value
        # its primarily value is in allowing the user to type less
        # on the command line, ie: ds=nocloud;s=http://bit.ly/abcdefg
        if "seedfrom" in mydata['meta-data']:
            seedfrom = mydata['meta-data']["seedfrom"]
            seedfound = False
            for proto in self.supported_seed_starts:
                if seedfrom.startswith(proto):
                    seedfound = proto
                    break
            if not seedfound:
                LOG.debug("Seed from %s not supported by %s", seedfrom, self)
                return False

            # This could throw errors, but the user told us to do it
            # so if errors are raised, let them raise
            (md_seed, ud) = util.read_seeded(seedfrom, timeout=None)
            LOG.debug("Using seeded cache data from %s", seedfrom)

            # Values in the command line override those from the seed
            mydata['meta-data'] = util.mergemanydict([mydata['meta-data'],
                                                      md_seed])
            mydata['user-data'] = ud
            found.append(seedfrom)

        # Now that we have exhausted any other places merge in the defaults
        mydata['meta-data'] = util.mergemanydict([mydata['meta-data'],
                                                  defaults])

        self.dsmode = self._determine_dsmode(
            [mydata['meta-data'].get('dsmode')])

        if self.dsmode == sources.DSMODE_DISABLED:
            LOG.debug("%s: not claiming datasource, dsmode=%s", self,
                      self.dsmode)
            return False

        self.seed = ",".join(found)
        self.metadata = mydata['meta-data']
        self.userdata_raw = mydata['user-data']
        self.vendordata_raw = mydata['vendor-data']
        self._network_config = mydata['network-config']
        self._network_eni = mydata['meta-data'].get('network-interfaces')
        return True

    @property
    def platform_type(self):
        # Handle upgrade path of pickled ds
        if not hasattr(self, '_platform_type'):
            self._platform_type = None
        if not self._platform_type:
            self._platform_type = 'lxd' if util.is_lxd() else 'nocloud'
        return self._platform_type

    def _get_cloud_name(self):
        """Return unknown when 'cloud-name' key is absent from metadata."""
        return sources.METADATA_UNKNOWN

    def _get_subplatform(self):
        """Return the subplatform metadata source details."""
        if self.seed.startswith('/dev'):
            subplatform_type = 'config-disk'
        else:
            subplatform_type = 'seed-dir'
        return '%s (%s)' % (subplatform_type, self.seed)

    def check_instance_id(self, sys_cfg):
        # quickly (local check only) if self.instance_id is still valid
        # we check kernel command line or files.
        current = self.get_instance_id()
        if not current:
            return None

        # LP: #1568150 need getattr in the case that an old class object
        # has been loaded from a pickled file and now executing new source.
        dirs = getattr(self, 'seed_dirs', [self.seed_dir])
        quick_id = _quick_read_instance_id(dirs=dirs)
        if not quick_id:
            return None
        return quick_id == current

    @property
    def network_config(self):
        if self._network_config is None:
            if self._network_eni is not None:
                self._network_config = eni.convert_eni_data(self._network_eni)
        return self._network_config


def _quick_read_instance_id(dirs=None):
    if dirs is None:
        dirs = []

    iid_key = 'instance-id'
    fill = {}
    if load_cmdline_data(fill) and iid_key in fill:
        return fill[iid_key]

    for d in dirs:
        if d is None:
            continue
        try:
            data = util.pathprefix2dict(d, required=['meta-data'])
            md = util.load_yaml(data['meta-data'])
            if iid_key in md:
                return md[iid_key]
        except ValueError:
            pass

    return None


def load_cmdline_data(fill, cmdline=None):
    pairs = [("ds=nocloud", sources.DSMODE_LOCAL),
             ("ds=nocloud-net", sources.DSMODE_NETWORK)]
    for idstr, dsmode in pairs:
        if parse_cmdline_data(idstr, fill, cmdline):
            # if dsmode was explicitly in the command line, then
            # prefer it to the dsmode based on the command line id
            if 'dsmode' not in fill:
                fill['dsmode'] = dsmode
            return True
    return False


# Returns true or false indicating if cmdline indicated
# that this module should be used.  Updates dictionary 'fill'
# with data that was found.
# Example cmdline:
#  root=LABEL=uec-rootfs ro ds=nocloud
def parse_cmdline_data(ds_id, fill, cmdline=None):
    if cmdline is None:
        cmdline = util.get_cmdline()
    cmdline = " %s " % cmdline

    if not (" %s " % ds_id in cmdline or " %s;" % ds_id in cmdline):
        return False

    argline = ""
    # cmdline can contain:
    # ds=nocloud[;key=val;key=val]
    for tok in cmdline.split():
        if tok.startswith(ds_id):
            argline = tok.split("=", 1)

    # argline array is now 'nocloud' followed optionally by
    # a ';' and then key=value pairs also terminated with ';'
    tmp = argline[1].split(";")
    if len(tmp) > 1:
        kvpairs = tmp[1:]
    else:
        kvpairs = ()

    # short2long mapping to save cmdline typing
    s2l = {"h": "local-hostname", "i": "instance-id", "s": "seedfrom"}
    for item in kvpairs:
        if item == "":
            continue
        try:
            (k, v) = item.split("=", 1)
        except Exception:
            k = item
            v = None
        if k in s2l:
            k = s2l[k]
        fill[k] = v

    return True


def _maybe_remove_top_network(cfg):
    """If network-config contains top level 'network' key, then remove it.

    Some providers of network configuration may provide a top level
    'network' key (LP: #1798117) even though it is not necessary.

    Be friendly and remove it if it really seems so.

    Return the original value if no change or the updated value if changed."""
    nullval = object()
    network_val = cfg.get('network', nullval)
    if network_val is nullval:
        return cfg
    bmsg = 'Top level network key in network-config %s: %s'
    if not isinstance(network_val, dict):
        LOG.debug(bmsg, "was not a dict", cfg)
        return cfg
    if len(list(cfg.keys())) != 1:
        LOG.debug(bmsg, "had multiple top level keys", cfg)
        return cfg
    if network_val.get('config') == "disabled":
        LOG.debug(bmsg, "was config/disabled", cfg)
    elif not all(('config' in network_val, 'version' in network_val)):
        LOG.debug(bmsg, "but missing 'config' or 'version'", cfg)
        return cfg
    LOG.debug(bmsg, "fixed by removing shifting network.", cfg)
    return network_val


def _merge_new_seed(cur, seeded):
    ret = cur.copy()

    newmd = seeded.get('meta-data', {})
    if not isinstance(seeded['meta-data'], dict):
        newmd = util.load_yaml(seeded['meta-data'])
    ret['meta-data'] = util.mergemanydict([cur['meta-data'], newmd])

    if seeded.get('network-config'):
        ret['network-config'] = _maybe_remove_top_network(
            util.load_yaml(seeded.get('network-config')))

    if 'user-data' in seeded:
        ret['user-data'] = seeded['user-data']
    if 'vendor-data' in seeded:
        ret['vendor-data'] = seeded['vendor-data']
    return ret


class DataSourceNoCloudNet(DataSourceNoCloud):
    def __init__(self, sys_cfg, distro, paths):
        DataSourceNoCloud.__init__(self, sys_cfg, distro, paths)
        self.supported_seed_starts = ("http://", "https://")


# Used to match classes to dependencies
datasources = [
    (DataSourceNoCloud, (sources.DEP_FILESYSTEM, )),
    (DataSourceNoCloudNet, (sources.DEP_FILESYSTEM, sources.DEP_NETWORK)),
]


# Return a list of data sources that match this set of dependencies
def get_datasource_list(depends):
    return sources.list_from_depends(depends, datasources)

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