import json
from pathlib import Path

DEFAULT_SAVE_ROOT = "/mnt/svr-01/storage/records"
SETTINGS_FILE = Path("/mnt/storage/document-processor/settings/storage.json")


def _ensure_parent() -> None:
    SETTINGS_FILE.parent.mkdir(parents=True, exist_ok=True)


def get_default_save_root() -> str:
    try:
        if SETTINGS_FILE.exists():
            data = json.loads(SETTINGS_FILE.read_text())
            value = str(data.get("default_save_root") or "").strip()
            if value:
                return value
    except Exception:
        pass
    return DEFAULT_SAVE_ROOT


def set_default_save_root(path_str: str) -> str:
    value = str(path_str or "").strip() or DEFAULT_SAVE_ROOT
    _ensure_parent()
    SETTINGS_FILE.write_text(json.dumps({"default_save_root": value}, indent=2))
    return value


def reset_default_save_root() -> str:
    _ensure_parent()
    SETTINGS_FILE.write_text(json.dumps({"default_save_root": DEFAULT_SAVE_ROOT}, indent=2))
    return DEFAULT_SAVE_ROOT