"""ntfy.sh notifications.

Topic is loaded from settings (auto-generated on first run). The topic
is functionally a password — anyone subscribed to the topic URL
receives notifications. We use cryptographically-random topics
(secrets.token_urlsafe(12)) to make brute-force discovery impractical.

Notifications are best-effort: a failure to deliver (network down,
ntfy.sh outage) is logged but does NOT block the daemon's main loop.
"""

from __future__ import annotations

import logging

import requests

logger = logging.getLogger(__name__)

NTFY_BASE = "https://ntfy.sh"


def topic_url(topic: str) -> str:
    return f"{NTFY_BASE}/{topic}"


def notify(
    topic: str,
    title: str,
    message: str,
    *,
    priority: str = "default",
    tags: list[str] | None = None,
) -> bool:
    """Post one notification. Returns True on HTTP 200, False otherwise.

    Never raises on transport errors — this path runs from the daemon's
    main loop and a failed notification should not stop work.
    """
    if not topic:
        logger.warning("ntfy topic is empty; skipping notification: %s", title)
        return False
    headers = {
        "Title": title,
        "Priority": priority,
    }
    if tags:
        headers["Tags"] = ",".join(tags)
    try:
        resp = requests.post(
            topic_url(topic), data=message.encode("utf-8"), headers=headers, timeout=10
        )
    except requests.RequestException as exc:
        logger.warning("ntfy delivery failed for topic <redacted>: %s", exc)
        return False
    if resp.status_code != 200:
        logger.warning("ntfy non-200 (%s): %s", resp.status_code, resp.text[:200])
        return False
    return True