"""异步大模型任务执行器。"""
from __future__ import annotations

import json
import traceback
from datetime import datetime
from fastapi import HTTPException

from database import SessionLocal
from models import LlmTask


class _FakeUser:
    id = 0


def run_llm_task(task_id: int, kind: str, params: dict) -> None:
    db = SessionLocal()
    task = db.get(LlmTask, task_id)
    if task is None:
        db.close()
        return
    task.status = "running"
    task.progress = 10
    task.message = "任务已开始，正在调用模型…"
    db.commit()
    try:
        task.progress = 25
        db.commit()
        if kind == "generate_questions":
            from routers.question_bank import generate as execute
            from schemas import GenerateIn

            payload = GenerateIn.model_validate(params)
            task.progress = 40
            task.message = "正在生成题目并解析结构…"
            db.commit()
            result = execute(payload=payload, db=db, _=_FakeUser())
            count = len(result)
            ids = [item.id for item in result]
            task.progress = 100
            task.status = "success"
            task.message = f"成功生成 {count} 道题"
            task.result = json.dumps({"count": count, "ids": ids}, ensure_ascii=False)
        elif kind == "generate_chapters":
            from routers.catalog import generate_catalog_chapters
            from schemas import ChaptersGenerateIn

            payload = ChaptersGenerateIn.model_validate(params)
            task.progress = 40
            task.message = "正在生成章节目录…"
            db.commit()
            result = execute_generate_chapters(
                db, params["textbook_id"], payload
            )
            task.progress = 100
            task.status = "success"
            task.message = result.message
            task.result = json.dumps(
                {
                    "count": len(result.created),
                    "message": result.message,
                },
                ensure_ascii=False,
            )
        elif kind == "organize_chapters":
            from routers.catalog import organize_textbook_chapters
            from schemas import ChaptersOrganizeIn

            payload = ChaptersOrganizeIn.model_validate(params)
            task.progress = 40
            task.message = "正在解析目录素材并关联知识图谱…"
            db.commit()
            result = organize_textbook_chapters(
                textbook_id=params["textbook_id"],
                payload=payload,
                db=db,
                _=_FakeUser(),
            )
            task.progress = 100
            task.status = "success"
            task.message = result.message
            task.result = json.dumps(
                {
                    "count": len(result.created),
                    "message": result.message,
                },
                ensure_ascii=False,
            )
        else:
            raise ValueError(f"不支持的任务类型：{kind}")
    except Exception as exc:  # noqa: BLE001
        db.rollback()
        task = db.get(LlmTask, task_id)
        task.status = "failed"
        task.message = (
            str(exc.detail)[:500]
            if isinstance(exc, HTTPException)
            else (str(exc)[:500] or exc.__class__.__name__)
        )
        task.progress = 100
        task.result = json.dumps(
            {"trace": traceback.format_exc()[-2000:]}, ensure_ascii=False
        )
    finally:
        task.finished_at = datetime.utcnow()
        db.commit()
        db.close()


def execute_generate_chapters(db, textbook_id: int, payload):
    from routers.catalog import generate_catalog_chapters

    return generate_catalog_chapters(
        textbook_id=textbook_id,
        payload=payload,
        db=db,
        _=_FakeUser(),
    )