#!/usr/bin/env python3
# Copyright 2022 David Garcia
# See LICENSE file for licensing details.
#
# Learn more at: https://juju.is/docs/sdk

import json
import logging
from typing import Tuple

from ops.charm import CharmBase
from ops.main import main
from ops.model import ActiveStatus, BlockedStatus

from ldap3 import Server, Connection, ALL, SUBTREE, ALL_ATTRIBUTES

logger = logging.getLogger(__name__)


USER = "cn=admin,dc=example,dc=org"
PASSWORD = "admin"


class Service:
    def __init__(self, service_info):
        self._service_info = service_info

    @property
    def ip(self):
        return self._service_info["ip"][0]

    def get_port(self, port_name):
        return self._service_info["ports"][port_name]["port"]


class OsmConfig:
    def __init__(self, charm: CharmBase) -> None:
        self._charm = charm

    def get_service(self, service_name: str) -> Service:
        osm_config = json.loads(self._charm.config["osm-config"])
        services = [
            s_values
            for s_name, s_values in osm_config["v0"]["k8s"]["services"].items()
            if service_name in s_name
        ]
        return Service(services[0])


class Ldap:
    def __init__(self, ldap_uri: str) -> None:
        self.ldap_uri = ldap_uri
        self.connection = None

    def _connect(self):
        server = Server(self.ldap_uri, get_info=ALL, connect_timeout=10)
        self.connection = Connection(
            server, user="cn=admin,dc=example,dc=org", password="admin"
        )
        if not self.connection.bind():
            raise Exception("cannot connect to ldap server")

    def _disconnect(self):
        if not self.connection or self.connection.closed:
            return
        self.connection.unbind()

    def get_user_info(self, cn, dc):
        self._connect()
        try:
            if self.connection.search(
                search_base=f"{cn},{dc}",
                search_filter="(objectclass=*)",
                search_scope=SUBTREE,
                attributes=ALL_ATTRIBUTES,
            ):
                return self.connection.entries
        finally:
            self._disconnect()


class OpenldapOperatorCharm(CharmBase):
    """Charm the service."""

    def __init__(self, *args):
        super().__init__(*args)
        self.osm_config = OsmConfig(self)
        self.framework.observe(self.on.config_changed, self._on_config_changed)
        self.framework.observe(
            self.on.get_user_info_action, self._on_get_user_info_action
        )

    def _on_config_changed(self, _):
        """Handler for config-changed event."""
        osm_config = self.config.get("osm-config")
        if not osm_config:
            self.unit.status = BlockedStatus("osm-config missing")
            return
        logger.info(f"osm-config={osm_config}")
        self.unit.status = ActiveStatus()

    def _on_get_user_info_action(self, event):
        """Handler for get-user-info action."""
        cn_param = event.params["cn"]
        dc_param = event.params["dc"]
        cn = f"cn={cn_param}"
        dc = ",".join([f"dc={dc_component}" for dc_component in dc_param.split(".")])
        result = ""
        try:
            openldap_service = self.osm_config.get_service("stable-openldap")
            ldap_uri = (
                f'ldap://{openldap_service.ip}:{openldap_service.get_port("ldap-port")}'
            )
            ldap = Ldap(ldap_uri)
            result = ldap.get_user_info(cn, dc)
        except Exception as e:
            result = e
            logger.error(e)
            event.fail(f"Failed getting user info: {e}")

        event.set_results({"output": result})


if __name__ == "__main__":
    main(OpenldapOperatorCharm)