#!/usr/bin/python3

import sys
import ldap3
import syslog
import requests

from base64 import b64decode
from email.utils import parsedate_to_datetime
from requests.packages.urllib3.exceptions import SubjectAltNameWarning


URL = "https://adm01.home.foo.sh/facts"


def get_url(URL):
    return requests.get(
        URL,
        cert=(
            "/etc/pki/tls/certs/ldap01.home.foo.sh.crt",
            "/etc/pki/tls/private/ldap01.home.foo.sh.key",
        ),
        verify="/etc/pki/tls/certs/ca.crt",
    ).json()


def get_hostlist():
    for entry in get_url(URL):
        mtime = parsedate_to_datetime(entry["mtime"])
        yield (entry["name"], mtime)


def get_hostdata(hostname):
    return get_url("{}/{}".format(URL, hostname))


def ldap_connect():
    server = ldap3.Server("ldapi:///var/run/ldapi")
    conn = ldap3.Connection(
        server,
        authentication=ldap3.SASL,
        sasl_mechanism=ldap3.EXTERNAL,
        sasl_credentials="",
        client_strategy=ldap3.SYNC,
    )
    conn.bind()
    conn.search(
        search_base="",
        search_filter="(objectClass=*)",
        search_scope=ldap3.BASE,
        attributes=["namingContexts"],
    )
    basedn = conn.response[0]["attributes"]["namingContexts"][0]
    return (conn, basedn)


def parse_certificate(data):
    try:
        return b64decode(data["ansible_local"]["ansible_certificate"])
    except KeyError:
        return []


def parse_description(data):
    osinfo = "{} {} ({})".format(
        data["ansible_distribution"],
        data["ansible_distribution_version"],
        data["ansible_architecture"],
    )
    try:
        memory = data["ansible_memory_mb"]["real"]["total"]
    except KeyError:
        memory = data["ansible_memtotal_mb"]
    if memory < 1024:
        memory = "{} MB".format(memory)
    else:
        memory = "{} GB".format(round(memory / 1024, 1))
    sysinfo = "{} CPU(s), {} GB memory".format(data["ansible_processor_count"], memory,)
    if data["ansible_product_name"] == "KVM":
        devinfo = "KVM - Guest"
    else:
        devinfo = "{} - {}".format(
            data["ansible_system_vendor"], data["ansible_product_version"],
        )
    return "\n".join([devinfo, osinfo, sysinfo])


def parse_location(data):
    return "Home"


def parse_sshkey(data):
    try:
        return "ssh-ed25519 {}".format(data["ansible_ssh_host_key_ed25519_public"])
    except KeyError:
        return []


def parse_serial(data):
    try:
        serial = data["ansible_product_serial"]
        if serial in ["NA", "System Serial Number"]:
            return []
        return serial
    except KeyError:
        return []


def parse_objectclass(data):
    objclass = ["device"]
    if data["userCertificate;binary"] != []:
        objclass.append("strongAuthenticationUser")
    if data["sshPublicKey"] != []:
        objclass.append("ldapPublicKey")
    return objclass


def main(verbose):
    requests.packages.urllib3.disable_warnings(SubjectAltNameWarning)
    syslog.openlog(
        sys.argv[0].split("/")[-1], logoption=syslog.LOG_PID, facility=syslog.LOG_DAEMON
    )
    (conn, basedn) = ldap_connect()
    for (hostname, mtime) in get_hostlist():
        if hostname in ("localhost"):
            continue
        dn = f"cn={hostname},ou=Hosts,{basedn}"
        if verbose:
            print(f"Processing entry {dn}")
        result = conn.search(
            search_base=dn,
            search_scope=ldap3.BASE,
            search_filter=f"(&(objectClass=device)(cn={hostname}))",
            attributes=[ldap3.ALL_ATTRIBUTES, "modifyTimeStamp"],
        )
        if result and conn.response[0]["attributes"]["modifyTimestamp"] > mtime:
            continue
        facts = get_hostdata(hostname)

        # initialize data
        if result:
            ldap_data = dict(conn.response[0]["attributes"])
            del ldap_data["modifyTimestamp"]
        else:
            ldap_data = {"cn": hostname}

        ldap_data["userCertificate;binary"] = parse_certificate(facts)
        ldap_data["description"] = parse_description(facts)
        ldap_data["l"] = parse_location(facts)
        ldap_data["sshPublicKey"] = parse_sshkey(facts)
        ldap_data["serialNumber"] = parse_serial(facts)
        ldap_data["objectClass"] = parse_objectclass(ldap_data)
        if result:
            for key in ldap_data:
                ldap_data[key] = [(ldap3.MODIFY_REPLACE, ldap_data[key])]
            syslog.syslog(syslog.LOG_INFO, f"Updating netdb data for host '{dn}'")
            if not conn.modify(dn, ldap_data):
                print(dn, conn.result)
        else:
            ldap_data = dict(filter(lambda x: x[1] != [], ldap_data.items()))
            syslog.syslog(syslog.LOG_INFO, f"Adding netdb data for host '{dn}'")
            if not conn.add(dn, attributes=ldap_data):
                print(dn, conn.result)
    syslog.closelog()


if __name__ == "__main__":
    try:
        verbose = False
        if len(sys.argv) > 1:
            if sys.argv[1] == "-v":
                verbose = True
            else:
                print(f"Usage: {sys.argv[0]} [-v]", file=sys.stderr)
        main(verbose)
    except KeyboardInterrupt:
        sys.exit(1)