#!/usr/bin/python
#
# Helpers for provision stuff
# Copyright (C) Matthieu Patou <mat@matws.net> 2009-2010
#
# Based on provision a Samba4 server by
# Copyright (C) Jelmer Vernooij <jelmer@samba.org> 2007-2008
# Copyright (C) Andrew Bartlett <abartlet@samba.org> 2008
#
#
# 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/>.


import os
import sys
import string
import re

import samba
from samba import Ldb, DS_DOMAIN_FUNCTION_2000
from ldb import SCOPE_SUBTREE, SCOPE_ONELEVEL, SCOPE_BASE, LdbError
import ldb
from samba.provision import  ProvisionNames,provision_paths_from_lp,FILL_FULL,provision
from samba.provisionexceptions import ProvisioningError
from samba.dcerpc import misc, security
from samba.ndr import ndr_pack, ndr_unpack

def get_paths(param,targetdir=None,smbconf=None):
	"""Get paths to important provision objects (smb.conf, ldb files, ...)

	:param param: Param object
	:param targetdir: Directory where the provision is (or will be) stored
	:param smbconf: Path to the smb.conf file
	:return: A list with the path of important provision objects"""
	if targetdir is not None:
		if (not os.path.exists(os.path.join(targetdir, "etc"))):
			os.makedirs(os.path.join(targetdir, "etc"))
		smbconf = os.path.join(targetdir, "etc", "smb.conf")
	if smbconf is None:
			smbconf = param.default_path()

	if not os.path.exists(smbconf):
		raise ProvisioningError("Unable to find smb.conf ...")

	lp = param.LoadParm()
	lp.load(smbconf)
	paths = provision_paths_from_lp(lp,lp.get("realm"))
	return paths


def find_provision_key_parameters(param,credentials,session_info,paths,smbconf):
	"""Get key provision parameters (realm, domain, ...) from a given provision

	:param param: Param object
	:param credentials: Credentials for the authentification
	:param session_info: Session object
	:param paths: A list of path to provision object
	:param smbconf: Path to the smb.conf file
	:return: A list of key provision parameters"""

	lp = param.LoadParm()
	lp.load(paths.smbconf)
	names = ProvisionNames()
	names.adminpass = None
	# NT domain, kerberos realm, root dn, domain dn, domain dns name
	names.domain = string.upper(lp.get("workgroup"))
	names.realm = lp.get("realm")
	basedn = "DC=" + names.realm.replace(".",",DC=")
	names.dnsdomain = names.realm
	names.realm = string.upper(names.realm)
	# netbiosname
	secrets_ldb = Ldb(paths.secrets, session_info=session_info, credentials=credentials,lp=lp, options=["modules:samba_secrets"])
	# Get the netbiosname first (could be obtained from smb.conf in theory)
	attrs = ["sAMAccountName"]
	res = secrets_ldb.search(expression="(flatname=%s)"%names.domain,base="CN=Primary Domains", scope=SCOPE_SUBTREE, attrs=attrs)
	names.netbiosname = str(res[0]["sAMAccountName"]).replace("$","")

	names.smbconf = smbconf
	# It's important here to let ldb load with the old module or it's quite
	# certain that the LDB won't load ...
	samdb = Ldb(paths.samdb, session_info=session_info,
		    credentials=credentials, lp=lp, options=["modules:samba_dsdb"])

	# That's a bit simplistic but it's ok as long as we have only 3
	# partitions
	attrs2 = ["defaultNamingContext", "schemaNamingContext","configurationNamingContext","rootDomainNamingContext"]
	current = samdb.search(expression="(objectClass=*)",base="", scope=SCOPE_BASE, attrs=attrs2)

	names.configdn = current[0]["configurationNamingContext"]
	configdn = str(names.configdn)
	names.schemadn = current[0]["schemaNamingContext"]
	if not (ldb.Dn(samdb, basedn) == (ldb.Dn(samdb, current[0]["defaultNamingContext"][0]))):
		raise ProvisioningError(("basedn in %s (%s) and from %s (%s) is not the same ..." % (paths.samdb, str(current[0]["defaultNamingContext"][0]), paths.smbconf, basedn)))

	names.domaindn=current[0]["defaultNamingContext"]
	names.rootdn=current[0]["rootDomainNamingContext"]
	# default site name
	attrs3 = ["cn"]
	res3= samdb.search(expression="(objectClass=*)",base="CN=Sites,"+configdn, scope=SCOPE_ONELEVEL, attrs=attrs3)
	names.sitename = str(res3[0]["cn"])

	# dns hostname and server dn
	attrs4 = ["dNSHostName"]
	res4= samdb.search(expression="(CN=%s)"%names.netbiosname,base="OU=Domain Controllers,"+basedn, \
						scope=SCOPE_ONELEVEL, attrs=attrs4)
	names.hostname = str(res4[0]["dNSHostName"]).replace("."+names.dnsdomain,"")

	server_res = samdb.search(expression="serverReference=%s"%res4[0].dn, attrs=[], base=configdn)
	names.serverdn = server_res[0].dn

	# invocation id/objectguid
	res5 = samdb.search(expression="(objectClass=*)",base="CN=NTDS Settings,%s" % str(names.serverdn), scope=SCOPE_BASE, attrs=["invocationID","objectGUID"])
	names.invocation = str(ndr_unpack( misc.GUID,res5[0]["invocationId"][0]))
	names.ntdsguid = str(ndr_unpack( misc.GUID,res5[0]["objectGUID"][0]))

	# domain guid/sid
	attrs6 = ["objectGUID", "objectSid","msDS-Behavior-Version" ]
	res6 = samdb.search(expression="(objectClass=*)",base=basedn, scope=SCOPE_BASE, attrs=attrs6)
	names.domainguid = str(ndr_unpack( misc.GUID,res6[0]["objectGUID"][0]))
	names.domainsid = ndr_unpack( security.dom_sid,res6[0]["objectSid"][0])
	if res6[0].get("msDS-Behavior-Version") == None or int(res6[0]["msDS-Behavior-Version"][0]) < DS_DOMAIN_FUNCTION_2000:
		names.domainlevel = DS_DOMAIN_FUNCTION_2000
	else:
		names.domainlevel = int(res6[0]["msDS-Behavior-Version"][0])

	# policy guid
	attrs7 = ["cn","displayName"]
	res7 = samdb.search(expression="(displayName=Default Domain Policy)",base="CN=Policies,CN=System,"+basedn, \
							scope=SCOPE_ONELEVEL, attrs=attrs7)
	names.policyid = str(res7[0]["cn"]).replace("{","").replace("}","")
	# dc policy guid
	attrs8 = ["cn","displayName"]
	res8 = samdb.search(expression="(displayName=Default Domain Controllers Policy)",base="CN=Policies,CN=System,"+basedn, \
							scope=SCOPE_ONELEVEL, attrs=attrs7)
	if len(res8) == 1:
		names.policyid_dc = str(res8[0]["cn"]).replace("{","").replace("}","")
	else:
		names.policyid_dc = None

	return names


# Create a fresh new reference provision
# This provision will be the reference for knowing what has changed in the
# since the latest upgrade in the current provision
def newprovision(names,setup_dir,creds,session,smbconf,provdir,messagefunc):
	"""Create a new provision

	:param names: List of provision parameters
	:param setup_dis: Directory where the setup files are stored
	:param creds: Credentials for the authentification
	:param session: Session object
	:param smbconf: Path to the smb.conf file
	:param provdir: Directory where the provision will be stored
	:param messagefunc: A function for displaying the message of the provision"""
	if os.path.isdir(provdir):
		rmall(provdir)
	logstd=os.path.join(provdir,"log.std")
	os.chdir(os.path.join(setup_dir,".."))
	os.mkdir(provdir)
	#os.close(2)
	#sys.stderr = open("%s/provision.log"%provdir, "w")
	messagefunc("Provision stored in %s"%provdir)
	#messagefunc("STDERR message of provision will be logged in %s/provision.log"%provdir)
	#sys.stderr = open("/dev/stdout", "w")
	provision(setup_dir, messagefunc,
		session, creds, smbconf=smbconf, targetdir=provdir,
		samdb_fill=FILL_FULL, realm=names.realm, domain=names.domain,
		domainguid=names.domainguid, domainsid=str(names.domainsid),ntdsguid=names.ntdsguid,
		policyguid=names.policyid,policyguid_dc=names.policyid_dc,hostname=names.netbiosname,
		hostip=None, hostip6=None,
		invocationid=names.invocation, adminpass=names.adminpass,
		krbtgtpass=None, machinepass=None,
		dnspass=None, root=None, nobody=None,
		wheel=None, users=None,
		serverrole="domain controller",
		ldap_backend_extra_port=None,
		backend_type=None,
		ldapadminpass=None,
		ol_mmr_urls=None,
		slapd_path=None,
		setup_ds_path=None,
		nosync=None,
		dom_for_fun_level=names.domainlevel,
		ldap_dryrun_mode=None,useeadb=True)

def dn_sort(x,y):
	"""Sorts two DNs in the lexicographical order it and put higher level DN before.

	So given the dns cn=bar,cn=foo and cn=foo the later will be return as smaller
	:param x: First object to compare
	:param y: Second object to compare
	"""
	p = re.compile(r'(?<!\\),')
	tab1 = p.split(str(x))
	tab2 = p.split(str(y))
	min = 0
	if (len(tab1) > len(tab2)):
		min = len(tab2)
	elif (len(tab1) < len(tab2)):
		min = len(tab1)
	else:
		min = len(tab1)
	len1=len(tab1)-1
	len2=len(tab2)-1
	space = " "
	# Note: python range go up to upper limit but do not include it
	for i in range(0,min):
		ret=cmp(tab1[len1-i],tab2[len2-i])
		if(ret != 0):
			return ret
		else:
			if(i==min-1):
				assert len1!=len2,"PB PB PB"+space.join(tab1)+" / "+space.join(tab2)
				if(len1>len2):
					return 1
				else:
					return -1
	return ret


def rmall(topdir):
	"""Remove a directory its contents and all its subdirectory

	:param topdir: Directory to remove"""
	for root, dirs, files in os.walk(topdir, topdown=False):
		for name in files:
			os.remove(os.path.join(root, name))
		for name in dirs:
			os.rmdir(os.path.join(root, name))
	os.rmdir(topdir)