import json
import ldap
import ldap.modlist
import random

from datetime import datetime

from mandaye import config
from mandaye.log import logger
from mandaye.backends.default import storage_conn

def cmp_reverse_last_connection_date(x, y):
        return -cmp(x[1]['lastConnectionDate'][0], y[1]['lastConnectionDate'][0])

class Association(object):
    """
    association dictionary return by the following methods:
    {
        'id': '', # identifier of your association (must be unique)
        'sp_name': '', # name of the service provider (defined in the mappers)
        'sp_login': '', # login on the service provider
        'sp_post_values': '', # the post values for sp login form
        'idp_unique_id:': '', # the unique identifier of the identity provider (ex.: a saml NameID)
        'idp_name':  '', # identity provide name
        'last_connection':  datetime.datetime, # last connection with this association
        'creation_date':  datetime.datetime, # creation date of this association
    }
    """

    @staticmethod
    def ldap2association(ldap_object):
        return {
                'id': ldap_object['uniqueID'][0],
                'sp_name': ldap_object['spName'][0],
                'sp_login': ldap_object['spLogin'][0],
                'sp_post_values': json.loads(ldap_object['spPostValues'][0]),
                'idp_unique_id': ldap_object['idpUniqueID'][0],
                'idp_name': ldap_object['idpName'][0],
                'last_connection': datetime.strptime(
                    ldap_object['lastConnectionDate'][0][:14],
                    '%Y%m%d%H%M%S'),
                'creation_date': datetime.strptime(
                    ldap_object['creationDate'][0][:14],
                    '%Y%m%d%H%M%S'),
                }

    @staticmethod
    def get(sp_name, idp_unique_id, idp_name='default'):
        """ return a list of dict with associations matching all of this options """
        associations = []
        results = storage_conn.search_s(config.ldap_base_dn, ldap.SCOPE_ONELEVEL,
                filterstr='(&(objectClass=MandayeUser)(spName=%s)(idpUniqueID=%s)(idpName=%s))' % (sp_name, idp_unique_id, idp_name))
        for result in results:
            associations.append(Association.ldap2association(result[1]))
        return associations


    @staticmethod
    def get_by_id(asso_id):
        """ return a dict of the association with the id or None if it doesn't exist """
        results = storage_conn.search_s(config.ldap_base_dn, ldap.SCOPE_ONELEVEL,
                filterstr='(&(objectClass=MandayeUser)(uniqueID=%s))' %\
                        (asso_id))
        if results:
            return Association.ldap2association(results[0][1])
        return None

    @staticmethod
    def has_id(asso_id):
        """ check the given user is present in the directory """
        results = storage_conn.search_s(config.ldap_base_dn, ldap.SCOPE_ONELEVEL,
                filterstr='(&(objectClass=MandayeUser)(uniqueID=%s))' %\
                        (asso_id))
        if results:
            return True
        return False

    @staticmethod
    def update_or_create(sp_name, sp_login, sp_post_values, idp_unique_id,
            idp_name='default', creation_date=None, last_connection_date=None):
        """ update or create an associtaion which match the following values
        return the association id
        """
        results = storage_conn.search_s(config.ldap_base_dn, ldap.SCOPE_ONELEVEL,
                filterstr='(&(objectClass=MandayeUser)(spName=%s)(spLogin=%s)(idpUniqueID=%s)(idpName=%s))' %\
                        (sp_name, sp_login, idp_unique_id, idp_name))
        if not results:
            creation_date = creation_date or datetime.utcnow()
            last_connection_date = last_connection_date or datetime.utcnow()
            association = {'spName': str(sp_name),
                    'spLogin': str(sp_login),
                    'spPostValues': json.dumps(sp_post_values),
                    'idpUniqueID': str(idp_unique_id),
                    'idpName': str(idp_name),
                    'creationDate': creation_date.strftime('%Y%m%d%H%M%SZ'),
                    'lastConnectionDate': last_connection_date.strftime('%Y%m%d%H%M%SZ'),
                    'objectClass': 'MandayeUser'
                    }
            mod_list = ldap.modlist.addModlist(association)
            while True:
                unique_id = random.randint(1, 5000000)
                dn = "uniqueID=%s,%s" % (unique_id, config.ldap_base_dn)
                try:
                    result = storage_conn.add_s(dn, mod_list)
                except ldap.ALREADY_EXISTS:
                    continue
                break
            logger.info("New association %r with %r", sp_login, idp_unique_id)
            return unique_id
        else:
            results.sort(cmp_reverse_last_connection_date)
            dn = results[0][0]
            mod_list = [(ldap.MOD_REPLACE, 'spPostValues', json.dumps(sp_post_values))]
            storage_conn.modify_s(dn, mod_list)
            logger.info("Update post values for %r (%r)", sp_login, idp_unique_id)
            return results[0][1]['uniqueID'][0]

    @staticmethod
    def delete(asso_id):
        """ delete the association which has the following asso_id """
        dn = "uniqueID=%s,%s" % (asso_id, config.ldap_base_dn)
        storage_conn.delete_s(dn)
        logger.info('Delete %r association', dn)

    @staticmethod
    def get_last_connected(sp_name, idp_unique_id, idp_name='default'):
        """ get the last connecting association which match the parameters
        return a dict of the association
        """
        results = storage_conn.search_s(config.ldap_base_dn, ldap.SCOPE_ONELEVEL,
                filterstr='(&(objectClass=MandayeUser)(spName=%s)(idpUniqueID=%s)(idpName=%s))' % (sp_name, idp_unique_id, idp_name))
        if results:
            results.sort(cmp_reverse_last_connection_date)
            return Association.ldap2association(results[0][1])
        return None

    @staticmethod
    def update_last_connection(asso_id):
        """ update the association last connection time with the current time
        return a dict of the association
        """
        last_connection = datetime.utcnow().strftime("%Y%m%d%H%M%SZ")
        dn = "uniqueID=%s,%s" % (asso_id, config.ldap_base_dn)
        mod_list = [(ldap.MOD_REPLACE, 'lastConnectionDate', last_connection)]
        storage_conn.modify_s(dn, mod_list)

    @staticmethod
    def has_sp_login(sp_login, sp_name):
        results = storage_conn.search_s(config.ldap_base_dn, ldap.SCOPE_ONELEVEL,
                filterstr='(&(objectClass=MandayeUser)(spName=%s)(spLogin=%s))' %\
                        (sp_name, sp_login))
        if results:
            return True
        return False