#!/usr/bin/env python3
"""Attended repair of one consumer field using an operator-held current password.

Never reads a Secret payload, changes a provider password, or copies a bundle.
"""
from __future__ import annotations

import argparse
import base64
import getpass
import json
import re
import subprocess
import sys

CLUSTER_UID = 'a553c742-0115-43d4-99a4-a5ca56fe0786'
KUBE = ['kubectl', '--kubeconfig', '/home/worsch/.kube/config-hosteurope',
        '--server', 'https://127.0.0.1:16444', '--request-timeout=20s']
NAMESPACE = 'sso'
SECRET = 'lldap-secrets'
KEY = 'LLDAP_LDAP_USER_PASS'
# The password and returned directory token remain in this child process only.
# Child stdin carries the operator input; no credential is a process argument.
VERIFY = '''import json,os,sys
from urllib.error import HTTPError
from provisioner import LLDAPProvisioner
try:
 assert os.environ['LLDAP_URL']=='http://lldap.sso.svc.cluster.local:17170'
 p=LLDAPProvisioner(base_url=os.environ['LLDAP_URL'],admin_password=json.load(sys.stdin)['password'])
 token=p._login()
 p._gql(token,'query { groups { id } }',{})
except Exception:
 print('directory-check-failed');sys.exit(1)
print('directory-check-passed')
'''
VERIFY_RELOADED = '''import os,sys
from provisioner import LLDAPProvisioner
try:
 p=LLDAPProvisioner(base_url=os.environ['LLDAP_URL'],admin_password=os.environ['LLDAP_ADMIN_PASSWORD'])
 token=p._login()
 p._gql(token,'query { groups { id } }',{})
except Exception:
 print('reloaded-check-failed');sys.exit(1)
print('reloaded-check-passed')
'''


class Refused(Exception):
    """Fixed safe code only; never carry child output or an exception repr."""


def run(arguments, *, data=None, timeout=30):
    try:
        result = subprocess.run(KUBE + arguments, input=data, text=True,
                                capture_output=True, timeout=timeout)
    except (OSError, subprocess.TimeoutExpired):
        raise Refused('command_unavailable') from None
    if result.returncode:
        raise Refused('command_refused') from None
    return result.stdout.strip()


def inspect():
    uid = run(['get', 'namespace', 'kube-system', '-o', 'jsonpath={.metadata.uid}'])
    if uid != CLUSTER_UID:
        raise Refused('wrong_cluster')
    # Do not include annotations: last-applied configuration can contain data.
    fields = run(['-n', NAMESPACE, 'get', 'secret', SECRET, '-o',
                  'go-template={{.metadata.uid}} {{.metadata.resourceVersion}} {{if .metadata.ownerReferences}}{{len .metadata.ownerReferences}}{{else}}0{{end}}']).split()
    if len(fields) != 3 or not re.fullmatch(r'[a-f0-9-]{36}', fields[0]) or not fields[1].isdigit():
        raise Refused('invalid_metadata')
    if fields[2] != '0':
        raise Refused('controller_owned_secret')
    return {'uid': fields[0], 'resource_version': fields[1]}


def patch(password, metadata):
    return [
        {'op': 'test', 'path': '/metadata/uid', 'value': metadata['uid']},
        {'op': 'test', 'path': '/metadata/resourceVersion', 'value': metadata['resource_version']},
        {'op': 'replace', 'path': '/data/' + KEY,
         'value': base64.b64encode(password.encode()).decode()},
    ]


def reconcile(password, *, mode, expected_uid=None, expected_resource_version=None):
    if not password or len(password) > 4096 or '\x00' in password:
        raise Refused('invalid_protected_input')
    metadata = inspect()
    if mode == 'apply' and metadata != {'uid': expected_uid, 'resource_version': expected_resource_version}:
        raise Refused('stale_metadata')
    result = run(['-n', NAMESPACE, 'exec', '-i', 'deployment/identity-provisioner',
                  '--', 'python', '-c', VERIFY], data=json.dumps({'password': password}))
    if result != 'directory-check-passed':
        raise Refused('current_provider_credential_unverified')
    if mode == 'check':
        return {'result': 'checked', 'provider_login': True, 'secret_written': False, **metadata}
    payload = json.dumps(patch(password, metadata))
    command = ['-n', NAMESPACE, 'patch', 'secret', SECRET, '--type=json',
               '--patch-file=/dev/stdin', '-o', 'name']
    run(command + ['--dry-run=server'], data=payload)
    run(command, data=payload)
    # Do not restore the known nonworking field on failure. Report partial repair.
    try:
        run(['-n', NAMESPACE, 'rollout', 'restart', 'deployment/identity-provisioner'])
        run(['-n', NAMESPACE, 'rollout', 'status', 'deployment/identity-provisioner',
             '--timeout=120s'], timeout=150)
        result = run(['-n', NAMESPACE, 'exec', 'deployment/identity-provisioner',
                      '--', 'python', '-c', VERIFY_RELOADED])
        if result != 'reloaded-check-passed':
            raise Refused('consumer_verification_failed')
    except Refused:
        raise Refused('field_updated_consumer_verification_incomplete') from None
    return {'result': 'reconciled', 'provider_login': True, 'consumer_login': True,
            'provider_password_changed': False, 'secret_field': KEY, **inspect()}


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('mode', choices=['inspect', 'check', 'apply'])
    parser.add_argument('--expected-uid')
    parser.add_argument('--expected-resource-version')
    args = parser.parse_args()
    try:
        if args.mode == 'inspect':
            result = {'result': 'inspected', **inspect()}
        else:
            if args.mode == 'apply' and not (args.expected_uid and args.expected_resource_version):
                raise Refused('exact_metadata_required')
            if not sys.stdin.isatty():
                raise Refused('attended_terminal_required')
            password = getpass.getpass('Current working LLDAP admin password (hidden): ')
            result = reconcile(password, mode=args.mode, expected_uid=args.expected_uid,
                               expected_resource_version=args.expected_resource_version)
            del password
        print(json.dumps(result, sort_keys=True))
        return 0
    except Refused as error:
        print(json.dumps({'result': 'refused', 'code': str(error)}))
        return 1


if __name__ == '__main__':
    raise SystemExit(main())