"""SMTP email sending -- password resets and battery-threshold alerts.

Config lives in the server_settings singleton row (admin-configured via
/admin, see routers/pages.py), not env vars -- it's operator
infrastructure a household admin sets up once through the UI, same
spirit as the rest of this project's "no separate config file" stance
post-redesign. Uses stdlib smtplib; no new dependency.

send_email() never raises -- a broken mail server shouldn't 500 a
password-reset request or a battery report; callers get a bool and log
a warning on failure."""

from __future__ import annotations

import logging
import smtplib
from email.mime.text import MIMEText

from .models import ServerSettings

logger = logging.getLogger(__name__)

SMTP_TIMEOUT_S = 10


def send_email(settings: ServerSettings, to_address: str, subject: str, body: str) -> bool:
    if not settings.smtp_host or not to_address:
        return False

    msg = MIMEText(body)
    msg["Subject"] = subject
    msg["From"] = settings.smtp_from_address or settings.smtp_username or "noreply@localhost"
    msg["To"] = to_address

    try:
        with smtplib.SMTP(settings.smtp_host, settings.smtp_port, timeout=SMTP_TIMEOUT_S) as smtp:
            if settings.smtp_use_tls:
                smtp.starttls()
            if settings.smtp_username:
                smtp.login(settings.smtp_username, settings.smtp_password)
            smtp.send_message(msg)
        return True
    except (OSError, smtplib.SMTPException) as e:
        logger.warning("Failed to send email to %s: %s", to_address, e)
        return False