# Authors: Rob Crittenden <rcritten@redhat.com>
#
# Copyright (C) 2007  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; version 2 only
#
# 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, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#

import sys
sys.path.append("/usr/share/ipa")

import ldap
import ipaserver.dsinstance
import ipaserver.ipaldap
import ipaserver.util
import xmlrpclib
import ipa.config
from ipa import ipaerror

import string
from types import *
import os
import re

# Need a global to store this between requests
_LDAPPool = None

DefaultContainer = "ou=users,ou=default"

#
# Apache runs in multi-process mode so each process will have its own
# connection. This could theoretically drive the total number of connections
# very high but since this represents just the administrative interface
# this is not anticipated.
class IPAConnPool:
    def __init__(self):
        self.numentries = 0
        self.freelist = []

    def getConn(self, host, port, bindca, bindcert, bindkey, proxydn=None):
        self.numentries = self.numentries + 1
        if len(self.freelist) > 0:
            conn = self.freelist.pop()
        else:
            conn = ipaserver.ipaldap.IPAdmin(host,port,bindca,bindcert,bindkey)
        conn.set_proxydn(proxydn)
        return conn

    def releaseConn(self, conn):
        self.freelist.append(conn)

class IPAServer:

    def __init__(self):
        global _LDAPPool
        # FIXME, this needs to be auto-discovered
        self.host = 'localhost'
        self.port = 636
        self.bindcert = "/usr/share/ipa/cert.pem"
        self.bindkey = "/usr/share/ipa/key.pem"
        self.bindca = "/usr/share/ipa/cacert.asc"
    
        if _LDAPPool is None:
            _LDAPPool = IPAConnPool()
        ipa.config.init_config()
        self.basedn = ipaserver.util.realm_to_suffix(ipa.config.config.get_realm())
        self.scope = ldap.SCOPE_SUBTREE
        self.princ = None

    def set_principal(self, princ):
        self.princ = princ
    
    def get_dn_from_principal(self, princ):
        """Given a kerberls principal get the LDAP uid"""
        global _LDAPPool

        # FIXME: should we search for this in a specific area of the tree?
        filter = "(krbPrincipalName=" + princ + ")"
        # The only anonymous search we should have
        m1 = _LDAPPool.getConn(self.host,self.port,self.bindca,self.bindcert,self.bindkey,None)
        ent = m1.getEntry(self.basedn, self.scope, filter, ['dn'])
        _LDAPPool.releaseConn(m1)
    
        return "dn:" + ent.dn
    
    def convert_entry(self, ent):
    
        # Convert to LDIF
        entry = str(ent) 

        # Strip off any junk
        entry = entry.strip()

        # Don't need to identify binary fields and this breaks the parser so
        # remove double colons
        entry = entry.replace('::', ':')
        specs = [spec.split(':') for spec in entry.split('\n')]
    
        # Convert into a dict. We need to handle multi-valued attributes as well
        # so we'll convert those into lists.
        user={}
        for (k,v) in specs:
            k = k.lower()
            if user.get(k) is not None:
                if isinstance(user[k],list):
                    user[k].append(v.strip())
                else:
                    first = user[k]
                    user[k] = []
                    user[k].append(first)
                    user[k].append(v.strip())
            else:
                    user[k] = v.strip()
    
        return user
    
    def __get_user (self, base, filter, sattrs=None, opts=None):
        """Get a specific user's entry. Return as a dict of values.
           Multi-valued fields are represented as lists.
        """
        global _LDAPPool
        ent=""

        if opts:
            self.set_principal(opts['remoteuser'])
    
        dn = self.get_dn_from_principal(self.princ)
    
        m1 = _LDAPPool.getConn(self.host,self.port,self.bindca,self.bindcert,self.bindkey,dn)
        ent = m1.getEntry(base, self.scope, filter, sattrs)
        _LDAPPool.releaseConn(m1)
    
        return self.convert_entry(ent)
 
    def get_user_by_uid (self, uid, sattrs=None, opts=None):
        """Get a specific user's entry. Return as a dict of values.
           Multi-valued fields are represented as lists.
        """

        filter = "(uid=" + uid + ")"
        return self.__get_user(self.basedn, filter, sattrs, opts)
    
    def get_user_by_dn (self, dn, sattrs=None, opts=None):
        """Get a specific user's entry. Return as a dict of values.
           Multi-valued fields are represented as lists.
        """

        filter = "(objectClass=*)"
        return self.__get_user(dn, filter, sattrs, opts)
    
    def add_user (self, user, user_container=None, opts=None):
        """Add a user in LDAP. Takes as input a dict where the key is the
           attribute name and the value is either a string or in the case
           of a multi-valued field a list of values. user_container sets
           where in the tree the user is placed."""
        global _LDAPPool

        if user_container is None:
            user_container = DefaultContainer

        dn="uid=%s,%s,%s" % (user['uid'], user_container,self.basedn)
        entry = ipaserver.ipaldap.Entry(dn)

        # some required objectclasses
        entry.setValues('objectClass', 'top', 'posixAccount', 'shadowAccount', 'account', 'person', 'inetOrgPerson', 'organizationalPerson', 'krbPrincipalAux', 'krbTicketPolicyAux')
    
        # Fill in shadow fields
        entry.setValue('shadowMin', '0')
        entry.setValue('shadowMax', '99999')
        entry.setValue('shadowWarning', '7')
        entry.setValue('shadowExpire', '-1')
        entry.setValue('shadowInactive', '-1')
        entry.setValue('shadowFlag', '-1')
    
        # FIXME: calculate shadowLastChange
    
        # fill in our new entry with everything sent by the user
        for u in user:
            entry.setValues(u, user[u])

        if opts:
            self.set_principal(opts['remoteuser'])
    
        dn = self.get_dn_from_principal(self.princ)

        m1 = _LDAPPool.getConn(self.host,self.port,self.bindca,self.bindcert,self.bindkey,dn)
        res = m1.addEntry(entry)
        _LDAPPool.releaseConn(m1)
        return res
    
    def get_add_schema (self):
        """Get the list of fields to be used when adding users in the GUI."""
    
        # FIXME: this needs to be pulled from LDAP
        fields = []
    
        field1 = {
            "name":       "uid" ,
            "label":      "Login:",
            "type":       "text",
            "validator":  "text",
            "required":   "true"
        }
        fields.append(field1)
    
        field1 = {
            "name":       "givenName" ,
            "label":      "First name:",
            "type":       "text",
            "validator":  "string",
            "required":   "true"
        }
        fields.append(field1)
    
        field1 = {
            "name":       "sn" ,
            "label":      "Last name:",
            "type":       "text",
            "validator":  "string",
            "required":   "true"
        }
        fields.append(field1)
    
        field1 = {
            "name":       "mail" ,
            "label":      "E-mail address:",
            "type":       "text",
            "validator":  "email",
            "required":   "true"
        }
        fields.append(field1)
    
        return fields
    
    def get_all_users (self, args=None, opts=None):
        """Return a list containing a User object for each
        existing user.
        """
        global _LDAPPool
    
        if opts:
            self.set_principal(opts['remoteuser'])

        dn = self.get_dn_from_principal(self.princ)
    
        # FIXME: Is this the filter we want or should it be more specific?
        filter = "(objectclass=posixAccount)"

        m1 = _LDAPPool.getConn(self.host,self.port,self.bindca,self.bindcert,self.bindkey,dn)
        all_users = m1.getList(self.basedn, self.scope, filter, None)
        _LDAPPool.releaseConn(m1)
    
        users = []
        for u in all_users:
            users.append(self.convert_entry(u))
    
        return users

    def find_users (self, criteria, sattrs=None, user_container=None, opts=None):
        """Return a list containing a User object for each
        existing user that matches the criteria.
        """
        global _LDAPPool

        if user_container is None:
            user_container = DefaultContainer

        if opts:
            self.set_principal(opts['remoteuser'])

        dn = self.get_dn_from_principal(self.princ)

        # TODO: this escaper assumes the python-ldap library will error out
        #       on invalid codepoints.  we need to check malformed utf-8 input
        #       where the second byte in a multi-byte character
        #       is (illegally) ')' and make sure python-ldap
        #       bombs out.
        criteria = re.sub(r'[\(\)\\]', ldap_search_escape, criteria)

        # FIXME: Is this the filter we want or do we want to do searches of
        # cn as well? Or should the caller pass in the filter?
        filter = "(|(uid=%s)(cn=%s))" % (criteria, criteria)
        basedn = user_container + "," +  self.basedn
        try:
            m1 = _LDAPPool.getConn(self.host,self.port,self.bindca,self.bindcert,self.bindkey,dn)
            results = m1.getList(basedn, self.scope, filter, sattrs)
            _LDAPPool.releaseConn(m1)
        except ipaerror.exception_for(ipaerror.LDAP_NOT_FOUND):
            results = []

        users = []
        for u in results:
            users.append(self.convert_entry(u))
    
        return users

    def convert_scalar_values(self, orig_dict):
        """LDAP update dicts expect all values to be a list (except for dn).
           This method converts single entries to a list."""
        new_dict={}
        for (k,v) in orig_dict.iteritems():
            if not isinstance(v, list) and k != 'dn':
                v = [v]
            new_dict[k] = v

        return new_dict

    def update_user (self, olduser, newuser, opts=None):
        """Update a user in LDAP"""
        global _LDAPPool

        olduser = self.convert_scalar_values(olduser)
        newuser = self.convert_scalar_values(newuser)

        # Should be able to get this from either the old or new user
        # but just in case someone has decided to try changing it, use the
        # original
        try:
            moddn = olduser['dn']
        except KeyError, e:
            raise ipaerror.gen_exception(ipaerror.LDAP_MISSING_DN)

        if opts:
            self.set_principal(opts['remoteuser'])
    
        proxydn = self.get_dn_from_principal(self.princ)

        m1 = _LDAPPool.getConn(self.host,self.port,self.bindca,self.bindcert,self.bindkey,proxydn)
        res = m1.updateEntry(moddn, olduser, newuser)
        _LDAPPool.releaseConn(m1)
        return res

    def mark_user_deleted (self, uid, opts=None):
        """Mark a user as inactive in LDAP. We aren't actually deleting
           users here, just making it so they can't log in, etc."""
        global _LDAPPool

        if opts:
            self.set_principal(opts['remoteuser'])

        proxydn = self.get_dn_from_principal(self.princ)

        user = self.get_user_by_uid(uid, ['dn', 'uid', 'nsAccountlock'], opts)

        # Are we doing an add or replace operation?
        if user.has_key('nsaccountlock'):
            if user['nsaccountlock'] == "true":
                return "already marked as deleted"
            has_key = True
        else:
            has_key = False

        m1 = _LDAPPool.getConn(self.host,self.port,self.bindca,self.bindcert,self.bindkey,proxydn)
        res = m1.inactivateEntry(user['dn'], has_key)
        _LDAPPool.releaseConn(m1)
        return res


def ldap_search_escape(match):
    """Escapes out nasty characters from the ldap search.
    See RFC 2254."""
    value = match.group()
    if (len(value) != 1):
        return ""

    if value == "(":
        return "\\28"
    elif value == ")":
        return "\\29"
    elif value == "\\":
        return "\\5c"
    else:
        return value