modules/audio_control.py

"""
modules/audio_control.py — Phase 4 (System Control): Audio controls (Windows).

Master volume:
  Uses nircmd.exe (already bundled) for reliable behavior.

Per-app volume:
  Optional (requires pycaw). If pycaw isn't installed, we return a clear message.
"""

from __future__ import annotations

import os
import re
import subprocess
from dataclasses import dataclass

from config import BASE_DIR

NIRCMD = os.path.join(BASE_DIR, "nircmd.exe")


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


def _run(cmd: list[str]) -> subprocess.CompletedProcess[str]:
    return subprocess.run(cmd, capture_output=True, text=True, shell=False)


def set_master_volume(percent: int) -> AudioResult:
    p = max(0, min(100, int(percent)))
    if not os.path.exists(NIRCMD):
        return AudioResult(False, "nircmd.exe missing; master volume unavailable.")
    # nircmd setsysvolume expects 0..65535
    val = int((p / 100.0) * 65535)
    r = _run([NIRCMD, "setsysvolume", str(val)])
    if r.returncode != 0:
        err = (r.stderr or r.stdout or "").strip()
        return AudioResult(False, f"Master volume failed: {err[:160]}")
    return AudioResult(True, f"Master volume set to {p}%.")


def change_master_volume(delta_percent: int) -> AudioResult:
    d = int(delta_percent)
    if not os.path.exists(NIRCMD):
        return AudioResult(False, "nircmd.exe missing; master volume unavailable.")
    val = int((d / 100.0) * 65535)
    r = _run([NIRCMD, "changesysvolume", str(val)])
    if r.returncode != 0:
        err = (r.stderr or r.stdout or "").strip()
        return AudioResult(False, f"Master volume change failed: {err[:160]}")
    return AudioResult(True, "Master volume changed.")


def mute(muted: bool = True) -> AudioResult:
    if not os.path.exists(NIRCMD):
        return AudioResult(False, "nircmd.exe missing; mute unavailable.")
    r = _run([NIRCMD, "mutesysvolume", "1" if muted else "0"])
    if r.returncode != 0:
        err = (r.stderr or r.stdout or "").strip()
        return AudioResult(False, f"Mute failed: {err[:160]}")
    return AudioResult(True, "Muted." if muted else "Unmuted.")


def set_app_volume(process_name: str, percent: int) -> AudioResult:
    """
    Set volume for an app by process name, e.g. 'chrome.exe' or 'discord.exe'.
    Requires pycaw; otherwise returns a clear message.
    """
    p = max(0, min(100, int(percent)))
    name = process_name.strip()
    if not name:
        return AudioResult(False, "Missing process name.")
    if not name.lower().endswith(".exe"):
        name += ".exe"

    try:
        from pycaw.pycaw import AudioUtilities  # type: ignore
        from comtypes import CLSCTX_ALL  # type: ignore
        from ctypes import POINTER, cast  # type: ignore
        from pycaw.pycaw import ISimpleAudioVolume  # type: ignore
    except Exception:
        return AudioResult(False, "Per-app volume requires pycaw (not installed).")

    sessions = AudioUtilities.GetAllSessions()
    found = False
    for s in sessions:
        try:
            if not s.Process:
                continue
            if s.Process.name().lower() != name.lower():
                continue
            found = True
            vol = s._ctl.QueryInterface(ISimpleAudioVolume)  # pylint: disable=protected-access
            vol.SetMasterVolume(p / 100.0, None)
        except Exception:
            continue
    if not found:
        return AudioResult(False, f"No active audio session for {name}.")
    return AudioResult(True, f"{name} volume set to {p}%.")