"""Platform-specific paths and tool resolution for meshbay-node."""

import asyncio
import os
import shutil
import sys
from pathlib import Path

# ── Console ──────────────────────────────────────────────────────────────────


def force_utf8_stdio() -> None:
    """
    Make stdout/stderr UTF-8. A Windows console is cp1252 by default, so any
    ``print()`` carrying a character outside it — the ``->`` arrows and em
    dashes the CLI help and messages are full of — raises UnicodeEncodeError
    and takes the command down with it. No effect where the streams are
    already UTF-8 or cannot be reconfigured.
    """
    for stream in (sys.stdout, sys.stderr):
        try:
            stream.reconfigure(encoding="utf-8")
        except (AttributeError, ValueError, OSError):
            pass


# ── Event loop ───────────────────────────────────────────────────────────────


def configure_event_loop() -> None:
    """
    The daemon runs on Windows' default ProactorEventLoop: verified end to end
    (a live browser peer connecting, an index sync, a file download and an
    ffmpeg-transcoded video stream). aiortc only ever hangs on it in the
    *same-process loopback* the tests use, which the test suite handles on its
    own (repo-root conftest).

    Escape hatch, opt-in only: MESHBAY_NODE_EVENT_LOOP=selector switches to the
    SelectorEventLoop. That fixes aiortc-in-one-process but breaks ffmpeg
    (SelectorEventLoop cannot spawn subprocesses on Windows), so it is not the
    default and probably never should be.
    """
    if sys.platform != "win32":
        return
    if os.environ.get("MESHBAY_NODE_EVENT_LOOP", "").lower() == "selector":
        asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())


# ── Directories ──────────────────────────────────────────────────────────────


def config_dir() -> Path:
    if sys.platform == "win32":
        return Path(os.environ.get("LOCALAPPDATA") or Path.home()) / "meshbay"
    return Path.home() / ".config" / "meshbay"


def data_dir() -> Path:
    if sys.platform == "win32":
        return Path(os.environ.get("LOCALAPPDATA") or Path.home()) / "meshbay" / "data"
    return Path.home() / ".local" / "share" / "meshbay"


def state_dir() -> Path:
    if sys.platform == "win32":
        return Path(os.environ.get("LOCALAPPDATA") or Path.home()) / "meshbay" / "state"
    return Path.home() / ".local" / "state" / "meshbay"


# ── File permissions ─────────────────────────────────────────────────────────


def chmod_private(path: Path, *, mode: int = 0o600) -> None:
    """Set restrictive permissions on a file. No-op on Windows (NTFS ignores mode bits)."""
    if sys.platform != "win32":
        path.chmod(mode)


# ── Media tools ──────────────────────────────────────────────────────────────

_ffmpeg_path: str = "ffmpeg"
_ffprobe_path: str = "ffprobe"


def check_media_tools(
    ffmpeg: str = "ffmpeg", ffprobe: str = "ffprobe",
) -> None:
    """Resolve ffmpeg/ffprobe at daemon startup. Raises RuntimeError if not found."""
    global _ffmpeg_path, _ffprobe_path
    resolved = shutil.which(ffmpeg)
    if not resolved:
        raise RuntimeError(
            f"{ffmpeg!r} not found in PATH. "
            "Install ffmpeg or set [node] ffmpeg_path in node.toml."
        )
    _ffmpeg_path = resolved
    resolved = shutil.which(ffprobe)
    if not resolved:
        raise RuntimeError(
            f"{ffprobe!r} not found in PATH. "
            "Install ffmpeg or set [node] ffprobe_path in node.toml."
        )
    _ffprobe_path = resolved


def ffmpeg_cmd() -> str:
    return _ffmpeg_path


def ffprobe_cmd() -> str:
    return _ffprobe_path