"""
modules/bt_devices.py — Phase 4: Bluetooth disconnect by device name (best-effort).

Windows Bluetooth pairing/unpairing is not stable without additional tooling.
We provide a real "disconnect" approximation by disabling the matching Bluetooth PnP device.
This often requires admin.
"""

from __future__ import annotations

import subprocess
from dataclasses import dataclass


@dataclass(frozen=True, slots=True)
class BTResult:
    ok: bool
    message: str


def _ps(cmd: str) -> subprocess.CompletedProcess[str]:
    return subprocess.run(
        ["powershell", "-NoProfile", "-ExecutionPolicy", "Bypass", "-Command", cmd],
        capture_output=True,
        text=True,
        shell=False,
    )


def disconnect(name_substring: str) -> BTResult:
    s = (name_substring or "").strip()
    if not s:
        return BTResult(False, "Missing device name.")
    cmd = (
        "try { "
        f"$d = Get-PnpDevice -Class Bluetooth -ErrorAction SilentlyContinue | Where-Object {{$_.FriendlyName -like '*{s}*'}} | Select-Object -First 1; "
        "if($null -eq $d){ 'NOTFOUND' } else { Disable-PnpDevice -InstanceId $d.InstanceId -Confirm:$false -ErrorAction Stop; 'OK' }"
        "} catch { 'FAIL:' + $_.Exception.Message }"
    )
    r = _ps(cmd)
    out = (r.stdout or "").strip()
    if out == "OK":
        return BTResult(True, "Bluetooth device disconnected (disabled).")
    if out == "NOTFOUND":
        return BTResult(False, "Bluetooth device not found.")
    if "access is denied" in out.lower():
        return BTResult(False, "Bluetooth disconnect needs admin permission.")
    return BTResult(False, f"Bluetooth disconnect failed: {out[:160]}")