"""Probe OS facts on first connect; cache in-memory so we only run uname once."""
from __future__ import annotations

from .models import Host, OSFamily

# In-memory cache. For production, persist to DB so facts survive restarts.
_FACTS_CACHE: dict[str, dict] = {}


def get_cached_facts(host: Host) -> dict | None:
    return _FACTS_CACHE.get(host.name)


def set_cached_facts(host: Host, facts: dict) -> None:
    _FACTS_CACHE[host.name] = facts


async def probe_facts(host: Host, connector) -> dict:
    """Run a tiny shell snippet to discover OS family + distribution.

    `connector` is an already-open connector instance for this host.
    Returns a facts dict and caches it.
    """
    cached = get_cached_facts(host)
    if cached:
        return cached

    facts: dict = {"os_family": host.os_family.value}

    # If we already know it from inventory, trust it.
    if host.os_family != OSFamily.UNKNOWN:
        set_cached_facts(host, facts)
        return facts

    # Heuristic: try Linux/Unix first, then Windows.
    # Note: on Windows hosts with Git-Bash installed, `uname -s` may return
    # MINGW/MSYS/CYGWIN — those still mean the underlying OS is Windows.
    try:
        res = await connector.run("uname -s", timeout=5)
        if res.exit_code == 0 and res.stdout.strip():
            kernel = res.stdout.strip().lower()
            if any(tok in kernel for tok in ("mingw", "msys", "cygwin")):
                facts["os_family"] = OSFamily.WINDOWS.value
            elif "linux" in kernel:
                facts["os_family"] = OSFamily.LINUX.value
            elif "darwin" in kernel:
                facts["os_family"] = OSFamily.DARWIN.value
            elif "aix" in kernel:
                facts["os_family"] = OSFamily.AIX.value

        if facts["os_family"] == OSFamily.UNKNOWN.value:
            # Try Windows PowerShell as last resort.
            res = await connector.run(
                "(Get-CimInstance Win32_OperatingSystem).Caption", timeout=5
            )
            if res.exit_code == 0 and res.stdout.strip():
                facts["os_family"] = OSFamily.WINDOWS.value
                facts["os_caption"] = res.stdout.strip()
    except Exception as e:  # noqa: BLE001 — probing is best-effort
        facts["probe_error"] = str(e)

    set_cached_facts(host, facts)
    return facts