"""Durable jobs, their per-item progress, and their event history.

A job is a unit of long-running work whose lifecycle survives browser, API, and
worker interruption. Progress is derived from ``job_items`` (the durable source of
truth), never from browser memory. ``job_events`` is an append-only activity log.
Leases (owner + expiry + heartbeat) and a monotonic ``fencing_token`` let a
recovered worker be fenced out after a newer worker takes ownership.
"""

from __future__ import annotations

from datetime import datetime

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

from photo_pipeline.db import Base


class Job(Base):
    __tablename__ = "jobs"

    id: Mapped[str] = mapped_column(String, primary_key=True)
    job_type: Mapped[str] = mapped_column(String, nullable=False)
    state: Mapped[str] = mapped_column(String, nullable=False)
    lock_key: Mapped[str | None] = mapped_column(String)
    idempotency_key: Mapped[str | None] = mapped_column(String, unique=True)

    lease_owner: Mapped[str | None] = mapped_column(String)
    lease_expires_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    heartbeat_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    fencing_token: Mapped[int] = mapped_column(Integer, nullable=False, default=0)

    error_code: Mapped[str | None] = mapped_column(String)
    error_message: Mapped[str | None] = mapped_column(String)

    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now()
    )
    started_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    finished_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    version: Mapped[int] = mapped_column(Integer, nullable=False, default=1)


class JobItem(Base):
    __tablename__ = "job_items"

    job_id: Mapped[str] = mapped_column(ForeignKey("jobs.id"), primary_key=True)
    item_key: Mapped[str] = mapped_column(String, primary_key=True)
    state: Mapped[str] = mapped_column(String, nullable=False)
    attempt_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
    error_code: Mapped[str | None] = mapped_column(String)
    error_message: Mapped[str | None] = mapped_column(String)
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now()
    )


class JobEvent(Base):
    __tablename__ = "job_events"

    id: Mapped[str] = mapped_column(String, primary_key=True)
    job_id: Mapped[str] = mapped_column(ForeignKey("jobs.id"), nullable=False)
    event_type: Mapped[str] = mapped_column(String, nullable=False)
    message: Mapped[str | None] = mapped_column(String)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), nullable=False, server_default=func.now()
    )