#! /usr/bin/python2

"""Copy the IPA schema to the CA directory server instance

You need to run this script to prepare a 2.2 or 3.0 IPA master for
installation of a 3.1 replica.

Once a 3.1 replica is in the domain, every older CA master will emit schema
replication errors until this script is run on it.

"""

# DO NOT TOUCH THIS CODE, IT MUST BE COMPATIBLE WITH RHEL6
# disable pylint because current codebase didn't match RHEL6 code
# pylint: disable=all

import os
import sys
import pwd
import shutil

from hashlib import sha1

from ipapython import ipautil
from ipapython.ipa_log_manager import root_logger, standard_logging_setup
from ipaserver.install.dsinstance import schema_dirname
from ipalib import api

# oh dear, this is an old IPA (3.0+)
from ipaserver.install.dsinstance import DS_USER
from ipaserver.install.cainstance import PKI_USER
from ipapython import services

SERVERID = "PKI-IPA"
SCHEMA_FILENAMES = (
    "60kerberos.ldif",
    "60samba.ldif",
    "60ipaconfig.ldif",
    "60basev2.ldif",
    "60basev3.ldif",
    "60ipadns.ldif",
    "61kerberos-ipav3.ldif",
    "65ipacertstore.ldif",
    "65ipasudo.ldif",
    "70ipaotp.ldif",
    "05rfc2247.ldif",
)


def _sha1_file(filename):
    with open(filename, 'rb') as f:
        return sha1(f.read()).hexdigest()


def add_ca_schema():
    """Copy IPA schema files into the CA DS instance
    """
    pki_pent = pwd.getpwnam(PKI_USER)
    ds_pent = pwd.getpwnam(DS_USER)
    for schema_fname in SCHEMA_FILENAMES:
        source_fname = os.path.join(ipautil.SHARE_DIR, schema_fname)
        target_fname = os.path.join(schema_dirname(SERVERID), schema_fname)
        if not os.path.exists(source_fname):
            root_logger.debug('File does not exist: %s', source_fname)
            continue
        if os.path.exists(target_fname):
            target_sha1 = _sha1_file(target_fname)
            source_sha1 = _sha1_file(source_fname)
            if target_sha1 != source_sha1:
                target_size = os.stat(target_fname).st_size
                source_size = os.stat(source_fname).st_size
                root_logger.info('Target file %s exists but the content is '
                                 'different', target_fname)
                root_logger.info('\tTarget file: sha1: %s, size: %s B',
                                 target_sha1, target_size)
                root_logger.info('\tSource file: sha1: %s, size: %s B',
                                 source_sha1, source_size)
                if not ipautil.user_input("Do you want replace %s file?" %
                                          target_fname, True):
                    continue

            else:
                root_logger.info(
                    'Target exists, not overwriting: %s', target_fname)
                continue
        try:
            shutil.copyfile(source_fname, target_fname)
        except IOError as e:
            root_logger.warning('Could not install %s: %s', target_fname, e)
        else:
            root_logger.info('Installed %s', target_fname)
        os.chmod(target_fname, 0o440)    # read access for dirsrv user/group
        os.chown(target_fname, pki_pent.pw_uid, ds_pent.pw_gid)


def restart_pki_ds():
    """Restart the CA DS instance to pick up schema changes
    """
    root_logger.info('Restarting CA DS')
    services.service('dirsrv').restart(SERVERID)


def main():
    if os.getegid() != 0:
        sys.exit("Must be root to run this script")
    standard_logging_setup(verbose=True)

    # In 3.0, restarting needs access to api.env
    api.bootstrap_with_global_options(context='server')

    add_ca_schema()
    restart_pki_ds()

    root_logger.info('Schema updated successfully')


if __name__ == '__main__':
    main()