"""Persistent RQ indexing jobs; scoring uses the same parser and file lock."""
from sqlalchemy import select

from .db import SessionLocal
from .models import IndexTask, SubmissionFile, now
from .scoring import parse_submission


def run_index_task(task_id: int, *, session_factory=SessionLocal, embedder=None):
    with session_factory() as db:
        task = db.get(IndexTask, task_id)
        if not task or task.status == "completed":
            return
        task.status, task.error = "running", ""
        db.commit()
        try:
            if task.kind == "project":
                file = db.get(SubmissionFile, task.submission_file_id)
                if not file or file.recognition_status != "recognized":
                    raise ValueError("材料已取消选择，请重新预览")
                kwargs = {"embedder": embedder} if embedder else {}
                parsed = parse_submission(db, file, **kwargs)
                task.result = {"file_id": file.id, "pages": len(parsed.get("pages", []))}
            elif task.kind == "course":
                from .services import ingest_course
                task.result = ingest_course(task.course_version_id, db)
                if task.result["errors"]:
                    raise ValueError("部分课程资料入库失败：" + ", ".join(task.result["errors"]))
            else:
                raise ValueError("未知索引任务类型")
            task.status = "completed"
        except Exception as exc:
            task.status, task.error = "failed", str(exc)[:1000]
        task.updated_at = now()
        db.commit()


def create_course_index_task(db, course_version_id: int):
    from .services import enqueue_index_task
    existing = db.scalar(select(IndexTask).where(IndexTask.course_version_id == course_version_id,
        IndexTask.kind == "course", IndexTask.status.in_(["queued", "running"])).order_by(IndexTask.id.desc()))
    task = existing or IndexTask(course_version_id=course_version_id, kind="course", status="queued")
    if not existing:
        db.add(task)
        db.commit()
    enqueue_index_task(db, task.id)
    return task