from __future__ import annotations

import json
from typing import Any

from .errors import MQConfigError


SUPPORTED_VALUE_FORMATS = {"json", "bytes"}


def encode_message_value(value: Any, value_format: str = "json") -> bytes | None:
    _validate_value_format(value_format)
    if value is None:
        return None
    if value_format == "bytes":
        if isinstance(value, bytes):
            return value
        raise TypeError("bytes mq value must be bytes")
    return json.dumps(value, ensure_ascii=False, separators=(",", ":")).encode("utf-8")


def decode_message_value(value: bytes | None, value_format: str = "json") -> Any:
    _validate_value_format(value_format)
    if value is None:
        return None
    if value_format == "bytes":
        return value
    return json.loads(value.decode("utf-8"))


def encode_message_key(key: str | bytes | None) -> bytes | None:
    if key is None or isinstance(key, bytes):
        return key
    return str(key).encode("utf-8")


def decode_message_key(key: bytes | None) -> str | None:
    if key is None:
        return None
    return key.decode("utf-8")


def _validate_value_format(value_format: str) -> None:
    if value_format not in SUPPORTED_VALUE_FORMATS:
        supported = ", ".join(sorted(SUPPORTED_VALUE_FORMATS))
        raise MQConfigError(f"unsupported mq value_format: {value_format!r}, supported: {supported}")