"""Fixed root-owned locations shared by installer and runtime bootstrap."""

import json
import os
from pathlib import Path

CODE = Path("/usr/lib/mission-core-node/insta360")
SHARE = Path("/usr/share/mission-core-node/insta360")
STATE = Path("/var/lib/mission-core-insta360")
CONTROL = Path("/run/mission-core-x4-control")


def trusted(path, directory=False):
    info = path.lstat()
    if path.is_symlink() or info.st_uid != 0 or info.st_mode & 0o022:
        raise RuntimeError("Untrusted camera installation path")
    if path.is_dir() != directory:
        raise RuntimeError("Unexpected camera installation entry")
    return path


def manifest():
    trusted(SHARE, True)
    return json.loads(trusted(SHARE / "bundle.json").read_text())


def active():
    trusted(STATE, True)
    ident = trusted(STATE / "active.path").read_text().strip()
    if len(ident) != 24 or any(c not in "0123456789abcdef" for c in ident):
        raise RuntimeError("Invalid installed runtime revision")
    return trusted(STATE / "runtime", True) / ident


def directory(path, mode=0o755):
    path.mkdir(mode=mode, exist_ok=True)
    trusted(path, True)


def write(path, data, mode=0o644):
    import tempfile

    if path.exists() or path.is_symlink():
        trusted(path)
    fd, temporary = tempfile.mkstemp(prefix=".x4-", dir=path.parent)
    try:
        with os.fdopen(fd, "wb") as stream:
            os.fchmod(stream.fileno(), mode)
            stream.write(data)
            stream.flush()
            os.fsync(stream.fileno())
        os.replace(temporary, path)
        folder = os.open(path.parent, os.O_RDONLY)
        try:
            os.fsync(folder)
        finally:
            os.close(folder)
    finally:
        if os.path.exists(temporary):
            os.unlink(temporary)