from __future__ import annotations

from datetime import datetime
from zoneinfo import ZoneInfo

from fastapi.templating import Jinja2Templates

from app.settings import APP_NAME, ROOT

templates = Jinja2Templates(directory=str(ROOT / "app" / "templates"))
BERLIN = ZoneInfo("Europe/Berlin")


def dt(value: datetime | None, fmt: str = "%d.%m.%Y %H:%M") -> str:
    if not value:
        return "–"
    if value.tzinfo is None:
        from datetime import timezone
        value = value.replace(tzinfo=timezone.utc)
    return value.astimezone(BERLIN).strftime(fmt)


templates.env.filters["dt"] = dt
templates.env.globals["APP_NAME"] = APP_NAME


def _live() -> bool:
    from app.services import deploy
    return deploy.live_enabled()


templates.env.globals["deploy_live"] = _live


def _static_v(name: str) -> str:
    """Cache-Busting: Änderungszeit der Datei als Query-Parameter, damit Browser nach einem Deploy nie veraltete JS/CSS-Dateien nutzen."""
    try:
        return str(int((ROOT / "app" / "static" / name).stat().st_mtime))
    except OSError:
        return "0"


templates.env.globals["static_v"] = _static_v