"""图片上传与 OCR 提取触发。"""
from fastapi import (
    APIRouter,
    BackgroundTasks,
    Depends,
    HTTPException,
    Request,
    UploadFile,
    status,
)
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.db import get_db
from app.deps import get_current_user
from app.models.image import Image
from app.models.job import ProcessingJob
from app.models.user import User
from app.ratelimit import AI_LIMIT, UPLOAD_LIMIT, limiter, user_key
from app.schemas.job import ImageOut, JobOut
from app.services import storage
from app.services.extract_pipeline import run_extract_job

router = APIRouter(prefix="/api/images", tags=["images"])


@router.post("", response_model=ImageOut, status_code=status.HTTP_201_CREATED)
@limiter.limit(UPLOAD_LIMIT, key_func=user_key)
async def upload(
    request: Request,
    file: UploadFile,
    db: AsyncSession = Depends(get_db),
    current: User = Depends(get_current_user),
):
    data = await file.read()
    try:
        mime, ext = storage.validate_image(data)
    except storage.ImageValidationError as e:
        raise HTTPException(status.HTTP_400_BAD_REQUEST, detail=str(e))

    sha = storage.sha256_hex(data)
    # 去重：同用户同图直接复用
    existing = await db.scalar(
        select(Image).where(Image.user_id == current.id, Image.sha256 == sha)
    )
    if existing:
        return existing

    try:
        key = await storage.upload_image_async(current.id, data, ext, mime)
    except storage.StorageError as e:
        raise HTTPException(status.HTTP_503_SERVICE_UNAVAILABLE, detail=str(e))

    image = Image(
        user_id=current.id,
        object_key=key,
        mime=mime,
        size_bytes=len(data),
        sha256=sha,
    )
    db.add(image)
    await db.commit()
    await db.refresh(image)
    return image


@router.post(
    "/{image_id}/extract",
    response_model=JobOut,
    status_code=status.HTTP_202_ACCEPTED,
)
@limiter.limit(AI_LIMIT, key_func=user_key)
async def extract(
    request: Request,
    image_id: str,
    background: BackgroundTasks,
    db: AsyncSession = Depends(get_db),
    current: User = Depends(get_current_user),
):
    image = await db.scalar(
        select(Image).where(Image.id == image_id, Image.user_id == current.id)
    )
    if image is None:
        raise HTTPException(status.HTTP_404_NOT_FOUND, detail="图片不存在")

    job = ProcessingJob(user_id=current.id, image_id=image.id, kind="ocr_extract")
    db.add(job)
    await db.commit()
    await db.refresh(job)

    background.add_task(
        run_extract_job, job.id, current.id, image.object_key, image.mime
    )
    return job