from datetime import datetime
from typing import Any

from sqlalchemy import DateTime, Enum, Index, String, Text, func
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.orm import Mapped, mapped_column

from app.models.base import Base, TimestampMixin, UUIDPrimaryKeyMixin
from app.models.enums import JobStatus


class Job(UUIDPrimaryKeyMixin, TimestampMixin, Base):
    """Postgres-backed background queue, claimed via FOR UPDATE SKIP LOCKED."""

    __tablename__ = "jobs"
    __table_args__ = (Index("ix_jobs_status_run_after", "status", "run_after"),)

    type: Mapped[str] = mapped_column(String(100))
    payload: Mapped[dict[str, Any]] = mapped_column(JSONB, default=dict)
    status: Mapped[JobStatus] = mapped_column(
        Enum(JobStatus, native_enum=False, length=32), default=JobStatus.pending
    )
    run_after: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now()
    )
    attempts: Mapped[int] = mapped_column(default=0)
    last_error: Mapped[str | None] = mapped_column(Text)