"""# Summary

Jobs domain — the worker's queue. Each job is a unit of pipeline work the
background worker claims and executes.
"""
from typing import Literal

from pydantic import BaseModel

from domain.parents.models import Metadata


class Job(BaseModel):
    """A unit of background work.

    Attributes:
        id (int | None): Server-assigned identifier. Defaults to None.
        name (str): Human label for the job.
        kind (str): Dispatch key — selects the pipeline (e.g.
            ``appointment_reminder``).
        status (str): Lifecycle status. Defaults to ``pending``.
        payload (dict | None): Job-specific input. Defaults to None.
        retry_count (int): Failed attempts so far. Defaults to 0.
        error_message (str | None): Last failure detail. Defaults to None.
        metadata (Metadata | None): Presentation metadata. Defaults to None.
    """

    id: int | None = None
    name: str
    kind: str
    status: Literal["pending", "processing", "done", "failed"] = "pending"
    payload: dict | None = None
    retry_count: int = 0
    error_message: str | None = None
    metadata: Metadata | None = None

    model_config = {"extra": "ignore"}