#!/usr/bin/env python3
"""Silent attended creation of a password-free telemetry SMTP KV entry.

Never overwrite an existing version, including a password subsequently added by
its owner. Run inside warden's attended OpenBao platform-admin login envelope.
"""
import json
import os
import subprocess
import sys

PATH = 'platform/workloads/railiance-telemetry/smtp'
FIELDS = {'SMTP_HOST': 'smtp.ionos.de', 'SMTP_PORT': '587',
          'SMTP_USERNAME': 'platform@coulomb.social',
          'SMTP_FROM': 'platform@coulomb.social', 'SMTP_STARTTLS': 'true'}


def command(args):
    return subprocess.run(['bao', *args], capture_output=True, timeout=30)


def run(invoke=command):
    # Read only metadata before CAS=0 creation. No existing credential value is
    # needed to refuse an overwrite. The owner can safely rerun after adding it.
    before = invoke(['kv', 'metadata', 'get', '-format=json', PATH])
    if before.returncode == 0:
        metadata = json.loads(before.stdout)['data']
        if type(metadata.get('current_version')) is int and metadata['current_version'] >= 1:
            return 0
        return 20
    # Never infer absence from arbitrary errors or an unauthenticated connection.
    if b'No value found at ' not in before.stderr + before.stdout:
        return 21
    created = invoke(['kv', 'put', '-format=json', '-cas=0', PATH,
                      *[key + '=' + value for key, value in FIELDS.items()]])
    if created.returncode:
        return 22
    if json.loads(created.stdout).get('data', {}).get('version') != 1:
        return 23
    after = invoke(['kv', 'metadata', 'get', '-format=json', PATH])
    if after.returncode or json.loads(after.stdout)['data'].get('current_version') != 1:
        return 24
    return 0


if __name__ == '__main__':
    # The attended lane refuses all child output, including exceptions.
    with open(os.devnull, 'w') as sink:
        os.dup2(sink.fileno(), 1)
        os.dup2(sink.fileno(), 2)
        try:
            status = run()
        except Exception:
            status = 25
    sys.exit(status)