"""持久化后台任务：AI 套图、单张编辑共用的父任务与逐图子任务。"""
from __future__ import annotations

import uuid
from datetime import datetime

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

from db import Base
from models.types import JSONType


class BackgroundJob(Base):
    """一个用户可见的后台操作：套图、单张编辑或批量水印。"""

    __tablename__ = "background_jobs"

    id: Mapped[uuid.UUID] = mapped_column(Uuid(as_uuid=True), primary_key=True, default=uuid.uuid4)
    # 商品删除后保留任务诊断记录，但 Worker 不会再把结果回写到不存在的商品。
    product_id: Mapped[uuid.UUID | None] = mapped_column(
        Uuid(as_uuid=True), ForeignKey("products.id", ondelete="SET NULL"), nullable=True, index=True
    )
    kind: Mapped[str] = mapped_column(String(32), index=True)  # image_suite | image_edit | watermark_batch
    status: Mapped[str] = mapped_column(String(24), default="queued", index=True)
    priority: Mapped[int] = mapped_column(Integer, default=0, index=True)
    provider: Mapped[str] = mapped_column(String(32), default="")
    model: Mapped[str | None] = mapped_column(String(128), nullable=True)
    platform: Mapped[str] = mapped_column(String(16), default="ozon")
    lang: Mapped[str] = mapped_column(String(16), default="ru")
    ratio: Mapped[str] = mapped_column(String(16), default="3:4")
    style_set: Mapped[int] = mapped_column(Integer, default=1)
    # 原始请求的不可变快照：商品上下文、参考图池、风格、要求、水印等。
    request_payload: Mapped[dict] = mapped_column(JSONType, default=dict)
    total: Mapped[int] = mapped_column(Integer, default=0)
    completed: Mapped[int] = mapped_column(Integer, default=0)
    failed: Mapped[int] = mapped_column(Integer, default=0)
    cancel_requested: Mapped[bool] = mapped_column(Boolean, default=False, index=True)
    error: Mapped[str | None] = mapped_column(Text, nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), index=True)
    started_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    completed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), index=True
    )


class BackgroundJobItem(Base):
    """任务中的一个可调度工作单元：套图的一张图或单张编辑。"""

    __tablename__ = "background_job_items"

    id: Mapped[uuid.UUID] = mapped_column(Uuid(as_uuid=True), primary_key=True, default=uuid.uuid4)
    job_id: Mapped[uuid.UUID] = mapped_column(
        Uuid(as_uuid=True), ForeignKey("background_jobs.id", ondelete="CASCADE"), index=True
    )
    position: Mapped[int] = mapped_column(Integer, default=0)
    status: Mapped[str] = mapped_column(String(24), default="queued", index=True)
    payload: Mapped[dict] = mapped_column(JSONType, default=dict)
    # 供应商异步任务 ID 与类型（pcore 还需 edits/generations）；重启后继续轮询，不重新提交。
    provider_task_id: Mapped[str | None] = mapped_column(String(512), nullable=True, index=True)
    provider_task_kind: Mapped[str | None] = mapped_column(String(64), nullable=True)
    attempts: Mapped[int] = mapped_column(Integer, default=0)
    max_attempts: Mapped[int] = mapped_column(Integer, default=3)
    result_url: Mapped[str | None] = mapped_column(Text, nullable=True)
    source_url: Mapped[str | None] = mapped_column(Text, nullable=True)
    watermark_config: Mapped[dict | None] = mapped_column(JSONType, nullable=True)
    generated_asset_id: Mapped[uuid.UUID | None] = mapped_column(Uuid(as_uuid=True), nullable=True)
    error: Mapped[str | None] = mapped_column(Text, nullable=True)
    next_run_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)
    lease_owner: Mapped[str | None] = mapped_column(String(128), nullable=True)
    lease_expires_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True, index=True)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
    started_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    completed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), index=True
    )