# LDAP is case-insensitive hence no need to normalize username here

def authenticate_ldap(username, password):
    username = ldap.filter.escape_filter_chars(username)
    password = ldap.filter.escape_filter_chars(password)  # May cause problem with some passwords. Please test this.
    base_dn = settings.LDAP_CURRENT_YEAR_DN
    user_filter = "uid=" + username
    user_dn = ",".join([user_filter, base_dn])
    connect = ldap.initialize(settings.LDAP_URI)
    try:
        # if authentication successful, return the full user data
        connect.bind_s(user_dn, password)
        result = connect.search_s(base_dn, ldap.SCOPE_SUBTREE, user_filter)
        connect.unbind_s()
        if len(result) == 1:
            return result[0]
        else:
            return False
    except ldap.LDAPError:
        connect.unbind_s()
        return False


chs = ['q','w','e','r','t','y','u','i','o','p','a','s','d','f','g','h','j','k','l','z','x','c','v','b','n','m']
chl = ['Q','W','E','R','T','Y','U','I','O','P','A','S','D','F','G','H','J','K','L','Z','X','C','V','B','N','M']
chn = ['0','1','2','3','4','5','6','7','8','9']
chsp = ['!','(',')','-','.','_','`','~','@','#']