#!/usr/bin/env python3
import os
import smtplib
import ssl
import sys
from email.message import EmailMessage


def main() -> int:
    subject = sys.argv[1] if len(sys.argv) > 1 else "Kaotings production alert"
    body = sys.stdin.read() or "No details provided."
    recipients = [item.strip() for item in os.environ.get("ALERT_RECIPIENTS", "").split(",") if item.strip()]
    if not recipients:
        raise SystemExit("ALERT_RECIPIENTS is required")
    message = EmailMessage()
    message["From"] = os.environ["SMTP_FROM"]
    message["To"] = ", ".join(recipients)
    message["Subject"] = subject
    message.set_content(body)
    context = ssl.create_default_context()
    with smtplib.SMTP_SSL(os.environ["SMTP_HOST"], int(os.environ.get("SMTP_PORT", "465")), context=context, timeout=20) as smtp:
        smtp.login(os.environ["SMTP_USER"], os.environ["SMTP_PASSWORD"])
        smtp.send_message(message)
    return 0


if __name__ == "__main__":
    sys.exit(main())