#!/usr/bin/python
"""
This code makes it easier to look up information in Wake Forest
University's LDAP.  Some of it, notably "search_by_name", should be
readily portable to other environments.

This code looks funny because it rates around 9/10 in pylint.
"""

import ldap
import sys


__revision__ = 1

class NoUniqueResultException(Exception):
    """
    Whatever it was couldn't find a unique result.
    """
    pass

class WFULDAP(object):
    """
    This class makes it a little easier to search in LDAP.
    """
    BASE_DN = 'dc=wfu,dc=edu'
    DEFAULT_HOST = 'ldap.wfu.edu'
    
    def __init__(self, ldap_conn=None):
        if ldap_conn == None:
            ldap_conn = ldap.open( self.DEFAULT_HOST )
        self.ldap_conn = ldap_conn

    def search(self,
               baseDN=BASE_DN,
               searchScope=ldap.SCOPE_SUBTREE,
               searchFilter='objectclass=*',
               retrieveAttributes=None):
        """Returns the expanded result set"""
        search_id = self.ldap_conn.search( baseDN,
                                           searchScope,
                                           searchFilter,
                                           retrieveAttributes)
        results = []
        while 1:
            result_type, result_data = self.ldap_conn.result( search_id, 0)
            if (result_data == []):
                break
            results.append( (result_type, result_data) )
        return results

    def search_by_cn( self, canonical_name ):
        "Searches by canonical name.  Don't pass 'cn='"
        return self.search( searchFilter='cn=%s' % canonical_name )

    def search_by_sn( self, surname ):
        "Searches by last name.  Don't pass 'sn='"
        return self.search( searchFilter='sn=%s' % surname )

    def search_by_unique_name( self, unique_name ):
        "Tries to find a unique name."
        # try searching by exact name
        results = self.search_by_cn( unique_name )
        if len(results)==1:
            return results[0][1] # return just the data

        # try searching by last name
        name_pieces = unique_name.split()
        results = self.search_by_sn( name_pieces[-1])
        if len(results)==1:
            return results[0][1]
        
        # try searching by first and last name
        results = self.search_by_cn( '%s*%s' % ( name_pieces[0],
                                                 name_pieces[-1],
                                                 ))
        if len(results)==1:
            return results[0][1]

        raise NoUniqueResultException

def name_to_userid( unique_name, wfuldap=WFULDAP() ):
    """
    Try to find a userid for a name.  Raises NoUniqueResultException
    if one couldn't be found.
    """
    unique_name = unique_name.strip()
    ldap_entry = wfuldap.search_by_unique_name( unique_name )
    userid = ldap_entry[0][1]['uid'][0]
    return userid
    
if __name__ == '__main__':
    for name in sys.stdin:
        name = name.strip()
        print "%8s: %s" % ( name_to_userid( name ), name )