# Authors:
#   Petr Viktorin <pviktori@redhat.com>
#
# Copyright (C) 2013  Red Hat
# see file 'COPYING' for use and warranty information
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""Common tasks for FreeIPA integration tests"""

import os
import textwrap
import re
import collections
import itertools
import time
import StringIO

from ldif import LDIFWriter

from ipapython import ipautil
from ipapython.dn import DN
from ipapython.ipa_log_manager import log_mgr
from ipatests.test_integration import util
from ipatests.test_integration.config import env_to_script
from ipatests.test_integration.host import Host

log = log_mgr.get_logger(__name__)


def prepare_host(host):
    if isinstance(host, Host):
        env_filename = os.path.join(host.config.test_dir, 'env.sh')
        host.collect_log(env_filename)
        host.transport.mkdir_recursive(host.config.test_dir)
        host.put_file_contents(env_filename, env_to_script(host.to_env()))


def apply_common_fixes(host):
    fix_etc_hosts(host)
    fix_hostname(host)
    fix_resolv_conf(host)


def backup_file(host, filename):
    if host.transport.file_exists(filename):
        backupname = os.path.join(host.config.test_dir, 'file_backup',
                                  filename.lstrip('/'))
        host.transport.mkdir_recursive(os.path.dirname(backupname))
        host.run_command(['cp', '-af', filename, backupname])
        return True
    else:
        rmname = os.path.join(host.config.test_dir, 'file_remove')
        host.run_command('echo %s >> %s' % (
            ipautil.shell_quote(filename),
            ipautil.shell_quote(rmname)))
        contents = host.get_file_contents(rmname)
        host.transport.mkdir_recursive(os.path.dirname(rmname))
        return False


def fix_etc_hosts(host):
    backup_file(host, '/etc/hosts')
    contents = host.get_file_contents('/etc/hosts')
    # Remove existing mentions of the host's FQDN, short name, and IP
    contents = re.sub('\s%s(\s|$)' % re.escape(host.hostname), ' ', contents,
                      flags=re.MULTILINE)
    contents = re.sub('\s%s(\s|$)' % re.escape(host.shortname), ' ', contents,
                      flags=re.MULTILINE)
    contents = re.sub('^%s.*' % re.escape(host.ip), '', contents,
                      flags=re.MULTILINE)
    # Add the host's info again
    contents += '\n%s %s %s\n' % (host.ip, host.hostname, host.shortname)
    log.debug('Writing the following to /etc/hosts:\n%s', contents)
    host.put_file_contents('/etc/hosts', contents)


def fix_hostname(host):
    backup_file(host, '/etc/hostname')
    host.put_file_contents('/etc/hostname', host.hostname + '\n')
    host.run_command(['hostname', host.hostname])

    backupname = os.path.join(host.config.test_dir, 'backup_hostname')
    host.run_command('hostname > %s' % ipautil.shell_quote(backupname))


def fix_resolv_conf(host):
    backup_file(host, '/etc/resolv.conf')
    lines = host.get_file_contents('/etc/resolv.conf').splitlines()
    lines = ['#' + l if l.startswith('nameserver') else l for l in lines]
    for other_host in host.domain.hosts:
        if other_host.role in ('master', 'replica'):
            lines.append('nameserver %s' % other_host.ip)
    contents = '\n'.join(lines)
    log.debug('Writing the following to /etc/resolv.conf:\n%s', contents)
    host.put_file_contents('/etc/resolv.conf', contents)


def unapply_fixes(host):
    restore_files(host)
    restore_hostname(host)

    # Clean up the test directory
    host.run_command(['rm', '-rvf', host.config.test_dir])


def restore_files(host):
    backupname = os.path.join(host.config.test_dir, 'file_backup')
    rmname = os.path.join(host.config.test_dir, 'file_remove')

    # Restore the backed up files
    host.run_command('cp -arvf %s/* /' % ipautil.shell_quote(backupname),
                     raiseonerr=False)

    # Restore context of the backed-up files
    sed_remove_backupdir = 's/%s//g' % backupname.replace('/', '\/')
    host.run_command("find %s | "
                     "sed '%s' | "
                     "sed '/^$/d' | "
                     "xargs -d '\n' "
                     "/sbin/restorecon -v" % (backupname, sed_remove_backupdir))

    # Remove all the files that did not exist and were 'backed up'
    host.run_command(['xargs', '-d', r'\n', '-a', rmname, 'rm', '-vf'],
                     raiseonerr=False)
    host.run_command(['rm', '-rvf', backupname, rmname], raiseonerr=False)


def restore_hostname(host):
    backupname = os.path.join(host.config.test_dir, 'backup_hostname')
    try:
        hostname = host.get_file_contents(backupname)
    except IOError:
        log.debug('No hostname backed up on %s' % host.hostname)
    else:
        host.run_command(['hostname', hostname.strip()])
        host.run_command(['rm', backupname])


def enable_replication_debugging(host):
    log.info('Enable LDAP replication logging')
    logging_ldif = textwrap.dedent("""
        dn: cn=config
        changetype: modify
        replace: nsslapd-errorlog-level
        nsslapd-errorlog-level: 8192
        """)
    host.run_command(['ldapmodify', '-x',
                      '-D', str(host.config.dirman_dn),
                      '-w', host.config.dirman_password],
                     stdin_text=logging_ldif)


def install_master(host):
    host.collect_log('/var/log/ipaserver-install.log')
    host.collect_log('/var/log/ipaclient-install.log')
    inst = host.domain.realm.replace('.', '-')
    host.collect_log('/var/log/dirsrv/slapd-%s/errors' % inst)
    host.collect_log('/var/log/dirsrv/slapd-%s/access' % inst)

    apply_common_fixes(host)

    host.run_command(['ipa-server-install', '-U',
                      '-r', host.domain.name,
                      '-p', host.config.dirman_password,
                      '-a', host.config.admin_password,
                      '--setup-dns',
                      '--forwarder', host.config.dns_forwarder])

    enable_replication_debugging(host)

    kinit_admin(host)


def install_replica(master, replica, setup_ca=True):
    replica.collect_log('/var/log/ipareplica-install.log')
    replica.collect_log('/var/log/ipareplica-conncheck.log')

    apply_common_fixes(replica)

    master.run_command(['ipa-replica-prepare',
                        '-p', replica.config.dirman_password,
                        '--ip-address', replica.ip,
                        replica.hostname])
    replica_bundle = master.get_file_contents(
        '/var/lib/ipa/replica-info-%s.gpg' % replica.hostname)
    replica_filename = os.path.join(replica.config.test_dir,
                                    'replica-info.gpg')
    replica.put_file_contents(replica_filename, replica_bundle)
    args = ['ipa-replica-install', '-U',
            '--setup-ca',
            '-p', replica.config.dirman_password,
            '-w', replica.config.admin_password,
            '--ip-address', replica.ip,
            replica_filename]
    if setup_ca:
        args.append('--setup-ca')
    replica.run_command(args)

    enable_replication_debugging(replica)

    kinit_admin(replica)


def install_client(master, client):
    client.collect_log('/var/log/ipaclient-install.log')

    apply_common_fixes(client)

    client.run_command(['ipa-client-install', '-U',
                        '--domain', client.domain.name,
                        '--realm', client.domain.realm,
                        '-p', client.config.admin_name,
                        '-w', client.config.admin_password,
                        '--server', master.hostname])

    kinit_admin(client)


def install_adtrust(host):
    """
    Runs ipa-adtrust-install on the client and generates SIDs for the entries.
    Configures the compat tree for the legacy clients.
    """

    # ipa-adtrust-install appends to ipaserver-install.log
    host.collect_log('/var/log/ipaserver-install.log')

    inst = host.domain.realm.replace('.', '-')
    host.collect_log('/var/log/dirsrv/slapd-%s/errors' % inst)
    host.collect_log('/var/log/dirsrv/slapd-%s/access' % inst)

    kinit_admin(host)
    host.run_command(['ipa-adtrust-install', '-U',
                      '--enable-compat',
                      '--netbios-name', host.netbios,
                      '-a', host.config.admin_password,
                      '--add-sids'])

    # Restart named because it lost connection to dirsrv
    # (Directory server restarts during the ipa-adtrust-install)
    host.run_command(['systemctl', 'restart', 'named'])

    # Check that named is running and has loaded the information from LDAP
    dig_command = ['dig', 'SRV', '+short', '@localhost',
               '_ldap._tcp.%s' % host.domain.name]
    dig_output = '0 100 389 %s.' % host.hostname
    dig_test = lambda x: re.search(re.escape(dig_output), x)

    util.run_repeatedly(host, dig_command, test=dig_test)


def configure_dns_for_trust(master, ad):
    """
    This configures DNS on IPA master according to the relationship of the
    IPA's and AD's domains.
    """

    def is_subdomain(subdomain, domain):
        subdomain_unpacked = subdomain.split('.')
        domain_unpacked = domain.split('.')

        subdomain_unpacked.reverse()
        domain_unpacked.reverse()

        subdomain = False

        if len(subdomain_unpacked) > len(domain_unpacked):
            subdomain = True

            for subdomain_segment, domain_segment in zip(subdomain_unpacked,
                                                         domain_unpacked):
                subdomain = subdomain and subdomain_segment == domain_segment

        return subdomain

    kinit_admin(master)

    if is_subdomain(master.domain.name, ad.domain.name):
        master.run_command(['ipa', 'dnszone-add', ad.domain.name,
                            '--name-server', ad.hostname,
                            '--admin-email', 'hostmaster@%s' % ad.domain.name,
                            '--forwarder', ad.ip,
                            '--forward-policy', 'only',
                            '--ip-address', ad.ip,
                            '--force'])
    elif is_subdomain(ad.domain.name, master.domain.name):
        master.run_command(['ipa', 'dnsrecord-add', master.domain.name,
                            '%s.%s' % (ad.shortname, ad.netbios),
                            '--a-ip-address', ad.ip])

        master.run_command(['ipa', 'dnsrecord-add', master.domain.name,
                            ad.netbios,
                            '--ns-hostname',
                            '%s.%s' % (ad.shortname, ad.netbios)])

        master.run_command(['ipa', 'dnszone-mod', master.domain.name,
                            '--allow-transfer', ad.ip])
    else:
        master.run_command(['ipa', 'dnszone-add', ad.domain.name,
                            '--name-server', ad.hostname,
                            '--admin-email', 'hostmaster@%s' % ad.domain.name,
                            '--forwarder', ad.ip,
                            '--forward-policy', 'only',
                            '--ip-address', ad.ip,
                            '--force'])


def establish_trust_with_ad(master, ad, extra_args=()):
    """
    Establishes trust with Active Directory. Trust type is detected depending
    on the presence of SfU (Services for Unix) support on the AD.

    Use extra arguments to pass extra arguments to the trust-add command, such
    as --range-type="ipa-ad-trust" to enfroce a particular range type.
    """

    # Force KDC to reload MS-PAC info by trying to get TGT for HTTP
    master.run_command(['kinit', '-kt', '/etc/httpd/conf/ipa.keytab',
                        'HTTP/%s' % master.hostname])
    master.run_command(['systemctl', 'restart', 'krb5kdc.service'])
    master.run_command(['kdestroy', '-A'])

    kinit_admin(master)
    master.run_command(['klist'])
    master.run_command(['smbcontrol', 'all', 'debug', '100'])
    util.run_repeatedly(master,
                        ['ipa', 'trust-add',
                        '--type', 'ad', ad.domain.name,
                        '--admin', 'Administrator',
                        '--password'] + list(extra_args),
                        stdin_text=master.config.ad_admin_password)
    master.run_command(['smbcontrol', 'all', 'debug', '1'])
    clear_sssd_cache(master)


def remove_trust_with_ad(master, ad):
    """
    Removes trust with Active Directory. Also removes the associated ID range.
    """

    kinit_admin(master)

    # Remove the trust
    master.run_command(['ipa', 'trust-del', ad.domain.name])

    # Remove the range
    range_name = ad.domain.name.upper() + '_id_range'
    master.run_command(['ipa', 'idrange-del', range_name])


def configure_auth_to_local_rule(master, ad):
    """
    Configures auth_to_local rule in /etc/krb5.conf
    """

    section_identifier = " %s = {" % master.domain.realm
    line1 = ("  auth_to_local = RULE:[1:$1@$0](^.*@%s$)s/@%s/@%s/"
             % (ad.domain.realm, ad.domain.realm, ad.domain.name))
    line2 = "  auth_to_local = DEFAULT"

    krb5_conf_content = master.get_file_contents('/etc/krb5.conf')
    krb5_lines = [line.rstrip() for line in krb5_conf_content.split('\n')]
    realm_section_index = krb5_lines.index(section_identifier)

    krb5_lines.insert(realm_section_index + 1, line1)
    krb5_lines.insert(realm_section_index + 2, line2)

    krb5_conf_new_content = '\n'.join(krb5_lines)
    master.put_file_contents('/etc/krb5.conf', krb5_conf_new_content)

    master.run_command(['systemctl', 'restart', 'sssd'])


def clear_sssd_cache(host):
    """
    Clears SSSD cache by removing the cache files. Restarts SSSD.
    """

    systemd_available = host.transport.file_exists('/bin/systemctl')

    if systemd_available:
        host.run_command(['systemctl', 'start', 'sssd'])
    else:
        host.run_command(['/sbin/service', 'sssd', 'start'])

    host.run_command("find /var/lib/sss/db -name '*.ldb' | "
                     "xargs rm -fv")
    host.run_command(['rm', '-fv', '/var/lib/sss/mc/group'])
    host.run_command(['rm', '-fv', '/var/lib/sss/mc/passwd'])

    if systemd_available:
        host.run_command(['systemctl', 'start', 'sssd'])
    else:
        host.run_command(['/sbin/service', 'sssd', 'start'])


def sync_time(host, server):
    """
    Syncs the time with the remote server. Please note that this function
    leaves ntpd stopped.
    """

    host.run_command(['systemctl', 'stop', 'ntpd'])
    host.run_command(['ntpdate', server.hostname])


def connect_replica(master, replica):
    kinit_admin(replica)
    replica.run_command(['ipa-replica-manage', 'connect', master.hostname])


def disconnect_replica(master, replica):
    kinit_admin(replica)
    replica.run_command(['ipa-replica-manage', 'disconnect', master.hostname])


def kinit_admin(host):
    host.run_command(['kinit', 'admin'],
                      stdin_text=host.config.admin_password)


def uninstall_master(host):
    host.collect_log('/var/log/ipaserver-uninstall.log')

    host.run_command(['ipa-server-install', '--uninstall', '-U'],
                     raiseonerr=False)
    unapply_fixes(host)


def uninstall_client(host):
    host.collect_log('/var/log/ipaclient-uninstall.log')

    host.run_command(['ipa-client-install', '--uninstall', '-U'],
                     raiseonerr=False)
    unapply_fixes(host)


def get_topo(name_or_func):
    """Get a topology function by name

    A topology function receives a master and list of replicas, and yields
    (parent, child) pairs, where "child" should be installed from "parent"
    (or just connected if already installed)

    If a callable is given instead of name, it is returned directly
    """
    if callable(name_or_func):
        return name_or_func
    return topologies[name_or_func]


def _topo(name):
    """Decorator that registers a function in topologies under a given name"""
    def add_topo(func):
        topologies[name] = func
        return func
    return add_topo
topologies = collections.OrderedDict()


@_topo('star')
def star_topo(master, replicas):
    r"""All replicas are connected to the master

          Rn R1 R2
           \ | /
        R7-- M -- R3
           / | \
          R6 R5 R4
    """
    for replica in replicas:
        yield master, replica


@_topo('line')
def line_topo(master, replicas):
    r"""Line topology

          M
           \
           R1
            \
            R2
             \
             R3
              \
              ...
    """
    for replica in replicas:
        yield master, replica
        master = replica


@_topo('complete')
def complete_topo(master, replicas):
    r"""Each host connected to each other host

          M--R1
          |\/|
          |/\|
         R2-R3
    """
    for replica in replicas:
        yield master, replica
    for replica1, replica2 in itertools.combinations(replicas, 2):
        yield replica1, replica2


@_topo('tree')
def tree_topo(master, replicas):
    r"""Binary tree topology

             M
            / \
           /   \
          R1   R2
         /  \  / \
        R3 R4 R5 R6
       /
      R7 ...

    """
    replicas = list(replicas)

    def _masters():
        for host in [master] + replicas:
            yield host
            yield host

    for parent, child in zip(_masters(), replicas):
        yield parent, child


@_topo('tree2')
def tree2_topo(master, replicas):
    r"""First replica connected directly to master, the rest in a line

          M
         / \
        R1 R2
            \
            R3
             \
             R4
              \
              ...

    """
    if replicas:
        yield master, replicas[0]
    for replica in replicas[1:]:
        yield master, replica
        master = replica


def install_topo(topo, master, replicas, clients,
                 skip_master=False, setup_replica_cas=True):
    """Install IPA servers and clients in the given topology"""
    replicas = list(replicas)
    installed = {master}
    if not skip_master:
        install_master(master)

    add_a_records_for_hosts_in_master_domain(master)

    for parent, child in get_topo(topo)(master, replicas):
        if child in installed:
            log.info('Connecting replica %s to %s' % (parent, child))
            connect_replica(parent, child)
        else:
            log.info('Installing replica %s from %s' % (parent, child))
            install_replica(parent, child, setup_ca=setup_replica_cas)
        installed.add(child)
    install_clients([master] + replicas, clients)


def install_clients(servers, clients):
    """Install IPA clients, distributing them among the given servers"""
    for server, client in itertools.izip(itertools.cycle(servers), clients):
        log.info('Installing client %s on %s' % (server, client))
        install_client(server, client)


def _entries_to_ldif(entries):
    """Format LDAP entries as LDIF"""
    lines = []
    io = StringIO.StringIO()
    writer = LDIFWriter(io)
    for entry in entries:
        writer.unparse(str(entry.dn), dict(entry))
    return io.getvalue()


def wait_for_replication(ldap, timeout=30):
    """Wait until updates on all replication agreements are done (or failed)

    :param ldap: LDAP client
        autenticated with necessary rights to read the mapping tree
    :param timeout: Maximum time to wait, in seconds

    Note that this waits for updates originating on this host, not those
    coming from other hosts.
    """
    log.debug('Waiting for replication to finish')
    for i in range(timeout):
        time.sleep(1)
        status_attr = 'nsds5replicaLastUpdateStatus'
        progress_attr = 'nsds5replicaUpdateInProgress'
        entries = ldap.get_entries(
            DN(('cn', 'mapping tree'), ('cn', 'config')),
            filter='(objectclass=nsds5replicationagreement)',
            attrs_list=[status_attr, progress_attr])
        log.debug('Replication agreements: \n%s', _entries_to_ldif(entries))
        if any(not e.single_value[status_attr].startswith('0 ')
               for e in entries):
            log.error('Replication error')
            continue
        if any(e.single_value[progress_attr] == 'TRUE' for e in entries):
            log.debug('Replication in progress (waited %s/%ss)',
                      i, timeout)
        else:
            log.debug('Replication finished')
            break
    else:
        log.error('Giving up wait for replication to finish')


def add_a_records_for_hosts_in_master_domain(master):
    for host in master.domain.hosts:
        # We don't need to take care of the zone creation since it is master
        # domain
        add_a_record(master, host)


def add_a_record(master, host):
    # Find out if the record is already there
    cmd = master.run_command(['ipa',
                              'dnsrecord-find',
                              master.domain.name,
                              host.hostname,
                              '--a-rec', host.ip],
                             raiseonerr=False)

    # If not, add it
    if cmd.returncode != 0:
        master.run_command(['ipa',
                            'dnsrecord-add',
                            master.domain.name,
                            host.hostname,
                            '--a-rec', host.ip])