"""
sn_basis/functions/os_wrapper.py – Betriebssystem-Abstraktion
"""

from pathlib import Path
import platform
from typing import Union


# ---------------------------------------------------------
# OS-Erkennung
# ---------------------------------------------------------

_SYSTEM = platform.system().lower()

if _SYSTEM.startswith("win"):
    OS_NAME = "windows"
elif _SYSTEM.startswith("darwin"):
    OS_NAME = "macos"
else:
    OS_NAME = "linux"

IS_WINDOWS = OS_NAME == "windows"
IS_LINUX = OS_NAME == "linux"
IS_MACOS = OS_NAME == "macos"


# ---------------------------------------------------------
# OS-Eigenschaften
# ---------------------------------------------------------

PATH_SEPARATOR = "\\" if IS_WINDOWS else "/"
LINE_SEPARATOR = "\r\n" if IS_WINDOWS else "\n"


# ---------------------------------------------------------
# Pfad-Utilities
# ---------------------------------------------------------

_PathLike = Union[str, Path]


def normalize_path(path: _PathLike) -> Path:
    """
    Normalisiert einen Pfad OS-unabhängig.
    """
    try:
        return Path(path).expanduser().resolve()
    except Exception:
        return Path(path)


def get_home_dir() -> Path:
    """
    Liefert das Home-Verzeichnis des aktuellen Users.
    """
    return Path.home()


# ---------------------------------------------------------
# Dateisystem-Eigenschaften
# ---------------------------------------------------------

def is_case_sensitive_fs() -> bool:
    """
    Gibt zurück, ob das Dateisystem case-sensitiv ist.
    """
    # Windows ist immer case-insensitive
    if IS_WINDOWS:
        return False

    # macOS meist case-insensitive, aber nicht garantiert
    if IS_MACOS:
        return False

    # Linux praktisch immer case-sensitiv
    return True