"""File-backed queue configuration."""

from __future__ import annotations

from dataclasses import dataclass
import os
from pathlib import Path

from python_utils import check_env

from python_repositories.config.dotenv_loader import load_dotenv

_DEFAULT_MAX_AGE_HOURS = 24


@dataclass(frozen=True)
class FileQueueConfig:
    """Configuration for a JSONL file-backed queue.

    Path and key schema are owned by the caller. This package does not assume
    any particular directory layout or item field names.
    """

    path: Path
    max_age_hours: int = _DEFAULT_MAX_AGE_HOURS
    dedup_keys: tuple[str, ...] = ()
    age_key: str | None = None

    @classmethod
    def from_env(
        cls,
        path_env_var_name: str = "FILE_QUEUE_PATH",
        *,
        max_age_hours_env_var_name: str = "FILE_QUEUE_MAX_AGE_HOURS",
        dedup_keys: tuple[str, ...] = (),
        age_key: str | None = None,
        use_dotenv: bool = True,
    ) -> FileQueueConfig:
        """Load path and optional max age from environment variables.

        ``dedup_keys`` and ``age_key`` are domain-specific and must be passed
        explicitly; they are not read from the environment.
        """
        if use_dotenv:
            load_dotenv()
        check_env(path_env_var_name)
        raw_max_age = os.getenv(max_age_hours_env_var_name)
        max_age_hours = (
            _DEFAULT_MAX_AGE_HOURS if raw_max_age is None else int(raw_max_age)
        )
        return cls(
            path=Path(str(os.getenv(path_env_var_name))),
            max_age_hours=max_age_hours,
            dedup_keys=dedup_keys,
            age_key=age_key,
        )