"""本机能力探测：GPU 等（供控制台 UI）。"""
from __future__ import annotations

import platform
import socket
import subprocess
import threading
import time
from typing import Any


def detect_nvidia_gpu() -> bool:
    if platform.system().lower() not in ("windows", "linux"):
        return False
    try:
        _kw: dict = {"capture_output": True, "timeout": 4}
        if platform.system().lower() == "windows":
            _kw["creationflags"] = subprocess.CREATE_NO_WINDOW
        r = subprocess.run(["nvidia-smi"], **_kw)
        return r.returncode == 0
    except Exception:
        return False


def detect_nvenc_available(nvidia_present: bool | None = None) -> bool:
    if nvidia_present is None:
        nvidia_present = detect_nvidia_gpu()
    if not nvidia_present:
        return False
    try:
        _kw = {"capture_output": True, "text": True, "timeout": 8}
        if platform.system().lower() == "windows":
            _kw["creationflags"] = subprocess.CREATE_NO_WINDOW
        r = subprocess.run(["ffmpeg", "-hide_banner", "-encoders"], **_kw)
        return r.returncode == 0 and "h264_nvenc" in (r.stdout or "")
    except Exception:
        return False


_GPU_STATUS_CACHE_TTL_SECONDS = 60.0
_gpu_status_lock = threading.Lock()
_gpu_status_cache: tuple[float, dict[str, Any]] | None = None


def gpu_status_payload(force_refresh: bool = False) -> dict[str, Any]:
    global _gpu_status_cache
    now = time.time()
    with _gpu_status_lock:
        if not force_refresh and _gpu_status_cache and (now - _gpu_status_cache[0]) < _GPU_STATUS_CACHE_TTL_SECONDS:
            return dict(_gpu_status_cache[1])

    nv = detect_nvidia_gpu()
    enc = detect_nvenc_available(nv)
    payload = {
        "nvidia_detected": nv,
        "nvenc_available": enc,
    }
    with _gpu_status_lock:
        _gpu_status_cache = (time.time(), payload)
    return dict(payload)


def machine_summary_payload() -> dict[str, Any]:
    """供远程 App 遥测：本机标识与系统信息。"""
    return {
        "hostname": socket.gethostname(),
        "os": platform.system(),
        "os_release": platform.release(),
        "machine": platform.machine(),
        "python": platform.python_version(),
    }