import re

from ldap3 import BASE

from .krbldap import Konnection


ATTRIBUTE_MAP = {
    "cn": "username",
    "displayName": "display name",
    "givenName": "first name",
#    "mail": "email",
#    "sn": "last name"
}

ATTRIBUTES = [*ATTRIBUTE_MAP, "memberOf"]
COMMON_DN = "OU=users,OU=psi,DC=d,DC=psi,DC=ch"
PGROUP_PATTERN = re.compile(r"CN=(p\d{5}),")
SERVERS = [f"dc{i:02}.d.psi.ch" for i in range(3)]


def get_data(username, password):
    with Konnection(SERVERS, username, password) as conn:
        conn.search(
            make_search_base(username),
            search_filter="(objectClass=*)",
            search_scope=BASE,
            attributes=ATTRIBUTES
        )

        entries = conn.entries

    n_entries = len(entries)
    if n_entries != 1:
        raise RuntimeError(f"received ambiguous result ({n_entries} entries)")

    entry = entries[0]
    res = repack(entry)

    res_username = res["username"]
    if res_username != username:
        raise RuntimeError(f"username mismatch: {res_username} != {username}")

    return res


def make_search_base(cn):
    res = [f"CN={cn}"]
    if cn.startswith("ext-"):
        res.append("OU=external")
    elif cn.startswith("gac-"):
        res.append("OU=nonpersons")
    res.append(COMMON_DN)
    return ",".join(res)


def repack(entry):
    attrs = entry.entry_attributes_as_dict
    res = {ATTRIBUTE_MAP[old]: item[0] for old, item in attrs.items() if old in ATTRIBUTE_MAP if item}
    res["pgroups"] = sorted(m.group(1) for i in attrs["memberOf"] if (m := PGROUP_PATTERN.search(i)))
    return res