#!/usr/bin/env python3
"""Filesystem layout helpers shared by the web configurator and updater.

On the target device the layout is:

    /opt/buttontask/
        versions/<ver>/   (ButtonTask + webconfig/)
        current -> versions/<ver>
        config/  icons/    (shared, never replaced)
        run/               (heartbeat, update-status.json)
        scripts/           (privileged helpers, see scripts/)
"""
import os
from pathlib import Path


def install_root():
    """Resolve the ButtonTask install root (the directory holding
    versions/, current, config/, run/)."""
    env = os.environ.get("BUTTONTASK_ROOT")
    if env:
        return Path(env)
    return Path("/opt/buttontask")


def run_dir():
    p = install_root() / "run"
    try:
        p.mkdir(parents=True, exist_ok=True)
    except OSError:
        pass
    return p


def versions_dir():
    return install_root() / "versions"


def current_link():
    return install_root() / "current"


def scripts_dir():
    """Directory with the privileged helper scripts.

    Prefer the installed copy under <root>/scripts, fall back to the copy
    that ships next to this package (dev/source tree)."""
    installed = install_root() / "scripts"
    if installed.is_dir():
        return installed
    return Path(__file__).resolve().parent / "scripts"


QT_HEARTBEAT = "qt.alive"
UPDATE_STATUS = "update-status.json"
BUTTON_LOG = "button-log.jsonl"