"""分析任务队列：持久化到 SQLite，断电可恢复。"""
from __future__ import annotations

from datetime import datetime
from enum import Enum

from sqlalchemy import DateTime, ForeignKey, Index, Integer, String, Text, func
from sqlalchemy.orm import Mapped, mapped_column

from app.core.db import Base


class JobKind(str, Enum):
    """任务种类。"""

    OCR = "ocr"
    VLM = "vlm"
    FULL = "full"  # OCR + VLM 一条龙


class JobStatus(str, Enum):
    """任务运行状态。"""

    PENDING = "pending"
    RUNNING = "running"
    DONE = "done"
    FAILED = "failed"


class Job(Base):
    """单条分析任务记录。"""

    __tablename__ = "jobs"
    __table_args__ = (
        Index("ix_jobs_status", "status"),
        Index("ix_jobs_kind_status", "kind", "status"),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    screenshot_id: Mapped[int] = mapped_column(
        Integer,
        ForeignKey("screenshots.id", ondelete="CASCADE"),
        nullable=False,
    )
    kind: Mapped[str] = mapped_column(String(16), default=JobKind.FULL.value)
    status: Mapped[str] = mapped_column(String(16), default=JobStatus.PENDING.value)
    retries: Mapped[int] = mapped_column(Integer, default=0)
    last_error: Mapped[str | None] = mapped_column(Text, nullable=True)

    created_at: Mapped[datetime] = mapped_column(
        DateTime, server_default=func.now(), nullable=False
    )
    started_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
    finished_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)