from pathlib import Path

from .config import DEFAULT_BACKUP_DIR, read_env_value


def backup_dir() -> Path:
    return Path(read_env_value("BACKUP_DIR", DEFAULT_BACKUP_DIR))


def list_backups():
    path = backup_dir()
    if not path.exists():
        return []

    return sorted(
        path.glob("*.tar.gz"),
        key=lambda p: p.stat().st_mtime,
        reverse=True,
    )


def is_backup_path(path: Path) -> bool:
    target = path.resolve()
    root = backup_dir().resolve()
    return root in target.parents and target.suffixes[-2:] == [".tar", ".gz"]