"""Async story title refinement after new story create (placeholder first)."""

import time

from celery import shared_task

from app.core.db import get_sync_db
from app.core.llm_gateway import LlmGateway, LlmUseCase
from app.core.logging import get_logger

logger = get_logger(__name__)


@shared_task(bind=True, max_retries=2, default_retry_delay=15)
def generate_story_title_after_create(
    self,
    story_id: str,
    chapter_category: str,
    oral_scope: str,
    user_id: str,
):
    """Replace placeholder title with LLM title when body is long enough."""
    from app.agents.chat.prompts_profile import format_user_profile_context
    from app.agents.memoir.narrative_agent import NarrativeAgent
    from app.features.memoir.state_service import get_or_create_state_sync
    from app.features.memoir.story_pipeline_sync import (
        _maybe_generate_title,
        _placeholder_title,
        _slot_snippets_for_narrative,
    )
    from app.features.story.models import Story
    from app.features.user.models import User

    t0 = time.perf_counter()
    logger.info(
        "event=story_title_task_start story_id={} user_id={} chapter_category={} "
        "msg=故事标题精修任务开始",
        story_id,
        user_id,
        chapter_category,
    )
    try:
        with get_sync_db() as db:
            st = db.get(Story, story_id)
            if not st or str(st.user_id) != str(user_id):
                ms = (time.perf_counter() - t0) * 1000
                logger.info(
                    "event=story_title_task_skip story_id={} reason=not_found duration_ms={:.1f} "
                    "msg=标题精修跳过（故事不存在或无权限）",
                    story_id,
                    ms,
                )
                return {"status": "skip_not_found"}
            user_obj_pre = db.get(User, user_id)
            user_language = (
                "en"
                if user_obj_pre is not None
                and str(getattr(user_obj_pre, "language_preference", "zh") or "zh").lower()
                == "en"
                else "zh"
            )
            expected_ph_zh = _placeholder_title(chapter_category, language="zh")
            expected_ph_en = _placeholder_title(chapter_category, language="en")
            expected_ph = _placeholder_title(chapter_category, language=user_language)
            current = (st.title or "").strip()
            if current and current not in (expected_ph_zh, expected_ph_en):
                ms = (time.perf_counter() - t0) * 1000
                logger.info(
                    "event=story_title_task_skip story_id={} reason=user_modified duration_ms={:.1f} "
                    "msg=标题精修跳过（用户已改标题）",
                    story_id,
                    ms,
                )
                return {"status": "skip_user_modified"}

            llm = LlmGateway().langchain_llm_for(LlmUseCase("story_title"))
            if not llm:
                ms = (time.perf_counter() - t0) * 1000
                logger.info(
                    "event=story_title_task_skip story_id={} reason=no_llm duration_ms={:.1f} "
                    "msg=标题精修跳过（无 LLM）",
                    story_id,
                    ms,
                )
                return {"status": "skip_no_llm"}

            user_obj = user_obj_pre
            user_profile = ""
            birth_year = None
            if user_obj:
                birth_year = user_obj.birth_year
                user_profile = format_user_profile_context(
                    birth_year=user_obj.birth_year,
                    birth_place=user_obj.birth_place,
                    grew_up_place=user_obj.grew_up_place,
                    occupation=user_obj.occupation,
                    language=user_language,
                )

            state = get_or_create_state_sync(user_id, db)
            slot_snippets = _slot_snippets_for_narrative(
                state=state,
                chapter_category=chapter_category,
                user_id=user_id,
            )
            md = (st.canonical_markdown or "").strip()
            new_title = _maybe_generate_title(
                NarrativeAgent(),
                chapter_category=chapter_category,
                md=md,
                slot_snippets=slot_snippets,
                user_profile=user_profile,
                user_birth_year=birth_year,
                llm=llm,
                oral_scope=oral_scope or "",
                language=user_language,
            )
            if not new_title.strip() or new_title.strip() in (
                expected_ph_zh,
                expected_ph_en,
                expected_ph,
            ):
                ms = (time.perf_counter() - t0) * 1000
                logger.info(
                    "event=story_title_task_skip story_id={} reason=placeholder duration_ms={:.1f} "
                    "msg=标题精修跳过（仍为占位）",
                    story_id,
                    ms,
                )
                return {"status": "skip_placeholder"}
            st.title = new_title
            db.commit()
            ms = (time.perf_counter() - t0) * 1000
            logger.info(
                "event=story_title_task_done story_id={} user_id={} duration_ms={:.1f} "
                "msg=故事标题精修完成",
                story_id,
                user_id,
                ms,
            )
            return {"status": "ok", "title": new_title}
    except Exception as exc:
        ms = (time.perf_counter() - t0) * 1000
        logger.warning(
            "event=generate_story_title_after_create_failed story_id={} duration_ms={:.1f} err={} "
            "msg=故事标题精修失败",
            story_id,
            ms,
            exc,
        )
        raise self.retry(exc=exc) from exc