from pathlib import Path

ALLOWED_ROOTS = [
    "/data/adaptai",
]
PROTECTED_PATHS = [
    "/",
    "/bin",
    "/sbin",
    "/usr",
    "/etc",
    "/lib",
    "/lib64",
    "/boot",
    "/sys",
    "/proc",
    "/dev",
    "/root",
]

# Normalize and dedupe
PROTECTED_PATHS = sorted(set([str(Path(p).resolve()) for p in PROTECTED_PATHS]))
ALLOWED_ROOTS = sorted(set([str(Path(p).resolve()) for p in ALLOWED_ROOTS]))


def _real(p: str) -> str:
    try:
        return str(Path(p).resolve())
    except Exception:
        return p


def is_allowed_path(path: str) -> bool:
    rp = _real(path)
    # Allowed if under any allowlisted root
    for root in ALLOWED_ROOTS:
        if rp == root or rp.startswith(root + "/"):
            return True
    return False


def is_protected_path(path: str) -> bool:
    rp = _real(path)
    for prot in PROTECTED_PATHS:
        if rp == prot or rp.startswith(prot + "/"):
            return True
    return False


def guard_write_path(path: str) -> tuple[bool, str]:
    """
    Returns (ok, msg). ok=False when path is protected or not under allowed roots.
    """
    rp = _real(path)
    if is_protected_path(rp) and not is_allowed_path(rp):
        return False, f"write blocked: protected path {rp}"
    if not is_allowed_path(rp):
        return False, f"write blocked: outside allowed roots {rp}"
    return True, rp