"""USB-Block-Devices des Hosts auflisten (via lsblk, /dev + /run/udev gemountet)."""
import json
import subprocess


def list_usb_sticks():
    out = subprocess.run(
        ["lsblk", "-J", "-b", "-o", "NAME,SIZE,MODEL,VENDOR,TRAN,RM,TYPE,MOUNTPOINT"],
        capture_output=True,
        text=True,
        check=True,
    ).stdout
    data = json.loads(out)
    root = get_root_disk_name()
    sticks = []
    for dev in data.get("blockdevices", []):
        if dev.get("type") != "disk":
            continue
        is_removable = str(dev.get("rm")) in ("1", "True", "true")
        is_usb_tran = dev.get("tran") == "usb"
        if not (is_removable or is_usb_tran):
            continue
        name = dev["name"]
        mounted = bool(dev.get("mountpoint")) or any(
            c.get("mountpoint") for c in (dev.get("children") or [])
        )
        sticks.append(
            {
                "name": name,
                "path": f"/dev/{name}",
                "size_bytes": int(dev.get("size") or 0),
                "model": (dev.get("model") or "").strip(),
                "vendor": (dev.get("vendor") or "").strip(),
                "transport": dev.get("tran"),
                "mounted": mounted,
                "is_root_disk": name == root,
            }
        )
    return sticks


def get_root_disk_name():
    """Name (ohne /dev/) der Platte, auf der / liegt -- fuer Schutz vor Selbstzerstoerung."""
    try:
        src = subprocess.run(
            ["findmnt", "-n", "-o", "SOURCE", "/"], capture_output=True, text=True, check=True
        ).stdout.strip()
        pk = subprocess.run(
            ["lsblk", "-no", "PKNAME", src], capture_output=True, text=True
        ).stdout.strip()
        return pk or src.replace("/dev/", "")
    except Exception:  # noqa: BLE001
        return None