# This Source Code Form is subject to the terms of the Mozilla Public

# License, v. 2.0. If a copy of the MPL was not distributed with this

# file, You can obtain one at https://mozilla.org/MPL/2.0/.

# SPDX-License-Identifier: MPL-2.0

# Copyright (c) 2026 Den Rozhnovskiy

from __future__ import annotations

import hashlib

import hmac

from collections.abc import Mapping

from pathlib import Path

from ._json_io import (

json_text as _json_text,

)

from ._json_io import (

read_json_document as _read_json_document,

)

from ._json_io import (

write_json_document_atomically as _write_json_document_atomically,

)

def as_str_or_none(value: object) -> str | None:

return value if isinstance(value, str) else None

def as_int_or_none(value: object) -> int | None:

return value if isinstance(value, int) else None

def as_object_list(value: object) -> list[object] | None:

return value if isinstance(value, list) else None

def as_str_dict(value: object) -> dict[str, object] | None:

if not isinstance(value, dict):

return None

if not all(isinstance(key, str) for key in value):

return None

return value

def canonical_json(data: object) -> str:

return _json_text(data, sort_keys=True)

def sign_cache_payload(data: Mapping[str, object]) -> str:

canonical = canonical_json(data)

return hashlib.sha256(canonical.encode("utf-8")).hexdigest()

def verify_cache_payload_signature(

payload: Mapping[str, object],

signature: str,

) -> bool:

return hmac.compare_digest(signature, sign_cache_payload(payload))

def read_json_document(path: Path) -> object:

return _read_json_document(path)

def write_json_document_atomically(path: Path, document: object) -> None:

_write_json_document_atomically(path, document, sort_keys=True)