src/ctp_slack_bot/utils/immutable.py

from types import MappingProxyType
from collections.abc import Iterable, Mapping, Sequence, Set
from typing import Any


def to_deep_immutable(obj: Any):
    """Recursively convert mutable containers to immutable equivalents."""

    # Handle mappings (dict-like).
    if isinstance(obj, Mapping):
        return MappingProxyType({to_deep_immutable(key): to_deep_immutable(value) for key, value in obj.items()})
    
    # Handle sets.
    if isinstance(obj, Set):
        return frozenset(to_deep_immutable(item) for item in obj)
    
    # Handle sequences (list/tuple-like).
    if isinstance(obj, (Iterable, Sequence)) and not isinstance(obj, (str, bytes)):
        return tuple(to_deep_immutable(item) for item in obj)
    
    # Return anything else as-is.
    return obj