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

from pathlib import Path
import asyncio
import psutil

from fastapi import APIRouter, Depends, WebSocket, WebSocketDisconnect
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"]
    }

@router.websocket("/stream")
async def system_stream(websocket: WebSocket):
    await websocket.accept()
    try:
        while True:
            # Sende Live-Daten alle 500ms
            data = system_status()
            await websocket.send_json(data)
            await asyncio.sleep(0.5)
    except WebSocketDisconnect:
        pass