import ldap3
import random
from datetime import datetime

MAXENTRIES = 1000000
OBJECTCLASSES = ['top', 'person', 'organizationalPerson', 'inetOrgPerson', 'posixAccount', 'shadowAccount']
USERATTRIBUTES = ['cn' , 'sn', 'givenName', 'uid', 'uidNumber' , 'gidNumber', 'homeDirectory', 'loginShell', 'gecos' , 'shadowLastChange', 'shadowMax', 'userPassword', 'mail', 'description']


class logserver():
    def __init__(self, ldap_host: str, admin_user: str, admin_pass: str, base: str, ssl: bool = True ):

        self.ldap_host = ldap_host
        self.admin_user = admin_user
        self.admin_pass = admin_pass
        self.base = base
        self.ssl = ssl

        if ssl:
            server = ldap3.Server(self.ldap_host,use_ssl=True)
        else:
            server = ldap3.Server(self.ldap_host)

        self.conn = ldap3.Connection(server, admin_user, admin_pass, auto_bind=True)

        self.organization, self.dc, self.dcfull, self.domain = self.expandbase()

        self.logbase = f'ou=log,{self.dcfull}'

        # Unique id of the log branch
        self.id = self.getid()

        # How many changes we applied to the LDAP server
        self.loaded = self.getloaded()

        # How many changes are recoreded in total
        self.total = self.gettotal()
        self.refreshtotal()

    def expandbase(self, base: str = '')->(str,str,str,str):
        '''
            Extract orgnaization, name of dc object and full domain part with al
l dc values from base
        '''
        if base == '':
            base = self.base

        # Split base string with commas to find values of organization and dc
        baselist = base.split(",")
        
        organization = ''
        dc = ''
        dcfull = ''
        domain = ''

        # Find ou in base and set it as organization variable
        for i in baselist:
            if i.split('=')[0] == 'ou':
                organization = i.split('=')[1]

        # Find first dc and set it as dc variable        
        for i in baselist:
            if i.split('=')[0] == 'dc':
                dc = i.split('=')[1]
                break

        # Find full dc and set it as dcfull variable
        for i in baselist:
            if i.split('=')[0] == 'dc':
            # if first dc, add it from dc variable
                if dcfull == '' and domain == '':
                    dcfull = f'dc={dc}'
                    domain = dc
                else:
                    dcfull += ',dc=' + i.split('=')[1]
                    domain += f'.{i.split("=")[1]}'
 
        return organization, dc, dcfull, domain

    def getid(self, base: str = '')->int:
        if base == '':
            base = self.logbase

        self.conn.search(search_base=f'uid=id,{base}',search_filter='(objectClass=person)', attributes=['uidNumber'])
        response = self.conn.response
        if response == []:
            id = random.randint(10**12, 10**13-1)
            attributes = {'cn' : 'id', 'sn' : 'id', 'givenName' : 'id', 'uid' : 'id', 'uidNumber' : id, 'gidNumber' : id, 'homeDirectory' : f'/home/id', 'loginShell' : '/usr/bin/git-shell', 'gecos' : 'SystemUser', 'shadowLastChange' : self.lastpwchangenow(), 'shadowMax' : '45', 'userPassword' : 'id', 'mail' : f'id@{self.domain}' }
            self.conn.add(f'uid=id,{base}', OBJECTCLASSES, attributes)
            return id
        else:
            response = int(response[0]['attributes']['uidNumber'])

        return response

    def gettotal(self, base: str = '')->int:
        if base == '':
            base = self.logbase

        self.conn.search(search_base=f'uid=total,{base}',search_filter='(objectClass=person)', attributes=['uidNumber'])
        response = self.conn.response
        if response == []:
            response = 0
        else:
            response = int(response[0]['attributes']['uidNumber'])
        return response

    def settotal(self, newvalue: int, base: str = ''):
        if base == '':
            base = self.logbase

        newvalue = int(newvalue)

        # Check if total record already present
        self.conn.search(search_base=f'uid=total,{base}',search_filter='(objectClass=person)', attributes=['uidNumber'])
        response = self.conn.response
 
        attributes = {'cn' : 'total', 'sn' : 'total', 'givenName' : 'total', 'uid' : 'total', 'uidNumber' : newvalue, 'gidNumber' : newvalue, 'homeDirectory' : f'/home/total', 'loginShell' : '/usr/bin/git-shell', 'gecos' : 'SystemUser', 'shadowLastChange' : self.lastpwchangenow(), 'shadowMax' : '45', 'userPassword' : 'total', 'mail' : f'total@{self.domain}' }

        if response == []:
            self.conn.add(f'uid=total,{base}', OBJECTCLASSES, attributes)
        else:
            self.conn.modify(f'uid=total,{base}', {'uidNumber' : (ldap3.MODIFY_REPLACE, [newvalue])})

        return self.conn.response

    def getloaded(self, base: str = '')->int:
        if base == '':
            base = self.logbase

        self.conn.search(search_base=f'uid=loaded,{base}',search_filter='(objectClass=person)', attributes=['uidNumber'])
        response = self.conn.response
        if response == []:
            response = 0
        else:
            response = int(response[0]['attributes']['uidNumber'])
        return response

    def setloaded(self, newvalue: int, base: str = ''):
        if base == '':
            base = self.logbase

        newvalue = int(newvalue)

        # Check if loaded record already present
        self.conn.search(search_base=f'uid=loaded,{base}',search_filter='(objectClass=person)', attributes=['uidNumber'])
        response = self.conn.response
 
        attributes = {'cn' : 'loaded', 'sn' : 'loaded', 'givenName' : 'loaded', 'uid' : 'loaded', 'uidNumber' : newvalue, 'gidNumber' : newvalue, 'homeDirectory' : f'/home/loaded', 'loginShell' : '/usr/bin/git-shell', 'gecos' : 'SystemUser', 'shadowLastChange' : self.lastpwchangenow(), 'shadowMax' : '45', 'userPassword' : 'loaded', 'mail' : f'loaded@{self.domain}' }

        if response == []:
            self.conn.add(f'uid=loaded,{base}', OBJECTCLASSES, attributes)
        else:
            self.conn.modify(f'uid=loaded,{base}', {'uidNumber' : (ldap3.MODIFY_REPLACE, [newvalue])})

        return self.conn.response

    def refreshtotal(self, base: str = '')->int:
        if base == '':
            base = self.logbase

        self.settotal(self.findtotal(base), base)
        return self.gettotal(base)

    def findtotal(self, base: str = '')->int:
        if base == '':
            base = self.logbase

        for entry in range(self.gettotal(base) + 1, MAXENTRIES):
            self.conn.search(search_base=f'uid={entry},{base}',search_filter='(objectClass=person)', attributes=['uidNumber'])
            if self.conn.response == []:
                return entry - 1

    def applylogs(self, base: str = '')->int:
        if base == '':
            base = self.logbase

        self.refreshtotal(base)

        loaded = self.getloaded(base) + 1
        total = self.gettotal(base) + 1

        for log_number in range(loaded, total):
            self.applylog(log_number, base)

        return total - loaded

    def applylog(self, log_number: int, base: str = ''):
        if base == '':
            base = self.logbase

        log = self.getlog(log_number, base)

        if log == []:
            return -1
        
        attributes = log['attributes']

        for key in attributes:
            if isinstance(attributes[key], list):
                attributes[key] = attributes[key][0]

        uid = attributes['cn']
        action = attributes['description']
        del attributes['description']

        if action == 'ADD':
            self.conn.add(f'uid={uid},{self.base}', OBJECTCLASSES, attributes)
        elif action == 'DELETE':
            self.conn.delete(f'uid={uid},{self.base}')
        elif action == 'CHANGEPASS':
            self.conn.modify(f'uid={uid},{self.base}', {'userPassword': (ldap3.MODIFY_REPLACE,attributes['userPassword'])})
        else:
            return f'Error: Unrecognized action in log entry: {action}'

        self.setloaded(self.getloaded(base) + 1, base)
        return self.conn.response

    def getlog(self, log_number: int, base: str = ''):
        if base == '':
            base = self.logbase

        self.conn.search(search_base=f'uid={log_number},{base}',search_filter = '(objectClass=person)', attributes = USERATTRIBUTES)

        response = self.conn.response

        if response == []:
            return response
        else:
            return response[0]
        
    def setlog(self, attributes: dict, base: str = '', log_number: int = -1):
        if base == '':
            base = self.logbase

        if log_number == -1:
            self.refreshtotal(base)
            log_number = self.gettotal(base) + 1

        self.conn.add(f'uid={log_number},{base}', OBJECTCLASSES, attributes)
        return self.conn.response

    def getbasecopy(self, remote)->str:
        '''
            Gets the base of a log copy of remote server on the local server
        '''
        remoteid = remote.getid()
        localdcfull = self.dcfull

        basecopy = f'ou=sync-{remoteid},{localdcfull}'

        # Check if it exists and create it if not
        self.conn.search(search_base=basecopy,search_filter='(objectClass=organizationalUnit)', attributes=['ou'])
        if self.conn.response == []:
            self.conn.add(basecopy, ['top', 'organizationalUnit'], {'ou' : f'sync-{remoteid}'})

        return basecopy

    def pullfrom(self, source)->int:
        pulled = 0
        basecopy = self.getbasecopy(source)

        self.refreshtotal(basecopy)
        source.refreshtotal()

        total_dest = self.gettotal(basecopy)
        total_src = source.gettotal()

        for log_number in range(total_dest + 1, total_src + 1):
            log = source.getlog(log_number)
            if log == []:
                break
            attributes = log['attributes']

            self.setlog(attributes, basecopy)
            pulled += 1

        return pulled

    def applyfrom(self, source)->int:
        basecopy = self.getbasecopy(source)

        appliedlogs = self.applylogs(basecopy)

        return appliedlogs

    def lastpwchangenow(self):
        '''
            Return time of last password change for the user set to current time 
            messured in days from UNIX epoch
        '''

        return str((datetime.utcnow() - datetime(1970,1,1)).days)

class ldapsync():
    def __init__(self):
        self.servers = []

    def add(self, log_server: logserver)->list:
        self.servers.append(log_server)
        return self.servers

    def remove(self, log_server: logserver)->list:
        self.servers.remove(log_server)
        return self.servers

    def pullfromall(self, log_server: logserver)->int:
        pulledlogs = 0

        for source in self.servers:
            if source != log_server:
                pulledlogs += log_server.pullfrom(source)

        return pulledlogs

    def pull(self)->int:
        pulledlogs = 0

        for server in self.servers:
            pulledlogs += self.pullfromall(server)

        return pulledlogs

    def applyfromall(self, log_server: logserver)->int:
        appliedlogs = 0

        for source in self.servers:
            if source != log_server:
                appliedlogs += log_server.applyfrom(source)

        return appliedlogs

    def apply(self)->int:
        appliedlogs = 0

        for server in self.servers:
            appliedlogs += self.applyfromall(server)

        return appliedlogs

    def sync(self)->int:
        pulledlogs = self.pull()
        appliedlogs = self.apply()

        return appliedlogs