import os
import shutil
from pathlib import Path


def is_btrfs(path):
    try:
        import subprocess
        out = subprocess.check_output(["stat", "-f", "-c", "%T", path]).decode()
        return "btrfs" in out.lower()
    except:
        return False


def store_reflink(src, dst):
    """
    Fast copy using CoW if supported
    """
    try:
        shutil.copy2(src, dst, follow_symlinks=True)
    except Exception:
        shutil.copy(src, dst)


def cas_path(config, key):
    base = Path(config["btrfs_path"])
    path = base / key

    path.parent.mkdir(parents=True, exist_ok=True)
    return str(path)