"""
System-Router: Liefert Live-Auslastung (CPU, RAM, Disk, GPU, Temp).
Greift lokal auf psutil und sysfs zu.
"""

from pathlib import Path
import psutil

from fastapi import APIRouter, Depends
from auth import auth

router = APIRouter(prefix="/api/system", dependencies=[Depends(auth)])

def _read_sysfs_int(path: Path) -> int | None:
    try:
        if path.exists():
            return int(path.read_text().strip())
    except Exception:
        pass
    return None

def _get_gpu_mem():
    # Suche in /sys/class/drm/ nach card*, die mem_info_* hat
    drm_dir = Path("/sys/class/drm")
    if not drm_dir.exists():
        return None
    
    for card in drm_dir.glob("card*"):
        dev_dir = card / "device"
        vram_total = _read_sysfs_int(dev_dir / "mem_info_vram_total")
        if vram_total is not None:
            return {
                "vram": {
                    "used": _read_sysfs_int(dev_dir / "mem_info_vram_used") or 0,
                    "total": vram_total,
                },
                "gtt": {
                    "used": _read_sysfs_int(dev_dir / "mem_info_gtt_used") or 0,
                    "total": _read_sysfs_int(dev_dir / "mem_info_gtt_total") or 0,
                }
            }
    return None

def _get_temperatures():
    temps = {"cpu": None, "gpu": None}
    hwmon_dir = Path("/sys/class/hwmon")
    if not hwmon_dir.exists():
        return temps

    for hw in hwmon_dir.glob("hwmon*"):
        try:
            name = (hw / "name").read_text().strip()
            temp_val = _read_sysfs_int(hw / "temp1_input")
            if temp_val is not None:
                if name == "k10temp":
                    temps["cpu"] = temp_val / 1000.0
                elif name == "amdgpu":
                    temps["gpu"] = temp_val / 1000.0
        except Exception:
            continue
    return temps

@router.get("/status")
def system_status():
    temps = _get_temperatures()
    
    cpu_percent = psutil.cpu_percent(interval=None)
    ram = psutil.virtual_memory()
    disk = psutil.disk_usage("/")
    
    return {
        "cpu": {
            "percent": cpu_percent,
            "temp": temps["cpu"]
        },
        "ram": {
            "used": ram.used,
            "total": ram.total,
            "percent": ram.percent
        },
        "disk": {
            "used": disk.used,
            "total": disk.total,
            "percent": disk.percent
        },
        "gpu": _get_gpu_mem() or {
            "vram": {"used": 0, "total": 0},
            "gtt": {"used": 0, "total": 0}
        },
        "gpu_temp": temps["gpu"]
    }