"""
回忆录后台处理器

负责：
- 分析用户对话内容，提取关键信息
- 更新回忆录状态（slots）
- 生成/更新章节内容
- 创建创意章节标题

使用 Celery 进行后台任务处理，支持可靠的任务队列和重试机制
"""
from __future__ import annotations

import json
import logging
from dataclasses import dataclass
from typing import Dict, List

from agents.state_schema import MemoirStateSchema
from services.llm_service import llm_service
from .prompts.memory_prompts import (
    get_creative_title_prompt,
    get_narrative_prompt,
    get_state_extraction_prompt,
)

logger = logging.getLogger(__name__)

STAGE_KEYWORDS = {
    "childhood": ["童年", "小时候", "出生", "家乡", "小镇"],
    "education": ["上学", "学校", "老师", "同学", "教育", "大学"],
    "career": ["工作", "职业", "事业", "公司", "同事", "创业"],
    "family": ["伴侣", "孩子", "家庭", "家人", "结婚", "父母"],
    "belief": ["信念", "价值观", "座右铭", "坚持", "原则"],
}


@dataclass
class AnalysisResult:
    detected_stage: str
    extracted_slots: Dict[str, str]
    emotion: str
    is_new_chapter: bool


class ContentAnalyzer:
    """对话内容分析（支持异步）"""

    def __init__(self) -> None:
        self.llm = llm_service.get_llm()

    def _detect_stage(self, user_message: str, fallback_stage: str) -> str:
        message = user_message.lower()
        for stage, keywords in STAGE_KEYWORDS.items():
            if any(word in message for word in keywords):
                return stage
        return fallback_stage

    def _fallback_slots(self, state: MemoirStateSchema, stage: str, user_message: str) -> Dict[str, str]:
        stage_slots = state.slots.get(stage, {})
        for key, value in stage_slots.items():
            if not value.snippet:
                return {key: user_message.strip()[:200]}
        return {}

    async def analyze_message(self, user_message: str, current_state: MemoirStateSchema) -> AnalysisResult:
        detected_stage = self._detect_stage(user_message, current_state.current_stage)
        extracted_slots: Dict[str, str] = {}
        emotion = "neutral"
        is_new_chapter = False

        if self.llm:
            try:
                prompt = get_state_extraction_prompt(
                    user_message=user_message,
                    current_stage=current_state.current_stage,
                    stage_slots=current_state.slots.get(detected_stage, {}),
                )
                # 使用异步调用
                response = await self.llm.ainvoke(prompt)
                content = response.content.strip()
                parsed = json.loads(content)
                detected_stage = parsed.get("detected_stage", detected_stage)
                extracted_slots = parsed.get("slots", {}) or {}
                emotion = parsed.get("emotion", emotion)
                is_new_chapter = bool(parsed.get("is_new_chapter", is_new_chapter))
            except json.JSONDecodeError:
                extracted_slots = self._fallback_slots(current_state, detected_stage, user_message)
            except Exception as e:
                logger.error(f"分析消息失败: {e}")
                extracted_slots = self._fallback_slots(current_state, detected_stage, user_message)
        else:
            extracted_slots = self._fallback_slots(current_state, detected_stage, user_message)

        return AnalysisResult(
            detected_stage=detected_stage,
            extracted_slots=extracted_slots,
            emotion=emotion,
            is_new_chapter=is_new_chapter,
        )


class MemoirGenerator:
    """回忆录生成与更新（支持异步）"""

    def __init__(self) -> None:
        self.llm = llm_service.get_llm()

    async def generate_chapter_title(self, stage: str, slots: Dict[str, str], emotion: str) -> str:
        if not self.llm:
            return f"{stage} 回忆"
        try:
            prompt = get_creative_title_prompt(stage=stage, emotion=emotion, slots=slots)
            # 使用异步调用
            response = await self.llm.ainvoke(prompt)
            return response.content.strip().strip('"')
        except Exception as e:
            logger.error(f"生成标题失败: {e}")
            return f"{stage} 回忆"

    async def generate_narrative(self, stage: str, slots: Dict[str, str], new_content: str, existing_content: str) -> str:
        if not self.llm:
            if existing_content:
                return f"{existing_content}\n\n{new_content}"
            return new_content
        try:
            prompt = get_narrative_prompt(stage=stage, slots=slots, new_content=new_content, existing_content=existing_content)
            # 使用异步调用
            response = await self.llm.ainvoke(prompt)
            return response.content.strip()
        except Exception as e:
            logger.error(f"生成叙事失败: {e}")
            if existing_content:
                return f"{existing_content}\n\n{new_content}"
            return new_content


class BackgroundTaskRunner:
    """后台任务调度器（使用 Celery）"""

    def __init__(self, debounce_seconds: int = 5) -> None:
        self.debounce_seconds = debounce_seconds
        # 内存中的待处理任务（用于去抖）
        self._pending: Dict[str, List[str]] = {}
        self._timers: Dict[str, object] = {}
        self.analyzer = ContentAnalyzer()
        self.generator = MemoirGenerator()

    async def _submit_task(self, user_id: str, segment_ids: List[str]) -> str | None:
        """
        提交 Celery 任务并记录
        
        Returns:
            任务 ID，失败返回 None
        """
        try:
            from tasks.memoir_tasks import process_memoir_segments
            from services.task_tracker import task_tracker
            
            # 提交到 Celery
            result = process_memoir_segments.delay(user_id, segment_ids)
            task_id = result.id
            
            # 记录任务
            await task_tracker.add_task(user_id, task_id, "memoir")
            
            logger.info(f"已提交 Celery 任务: user_id={user_id}, task_id={task_id}, segments={len(segment_ids)}")
            return task_id
        except Exception as e:
            logger.error(f"提交 Celery 任务失败: {e}")
            return None

    async def queue_message(self, user_id: str, segment_id: str) -> None:
        """
        将消息加入处理队列
        
        使用 Celery 延迟任务实现去抖效果
        """
        import asyncio
        
        # 收集待处理的 segment_ids
        self._pending.setdefault(user_id, []).append(segment_id)
        
        # 取消之前的定时器
        if user_id in self._timers:
            self._timers[user_id].cancel()
        
        # 创建新的定时器
        async def delayed_submit():
            try:
                await asyncio.sleep(self.debounce_seconds)
                segment_ids = self._pending.pop(user_id, [])
                if segment_ids:
                    await self._submit_task(user_id, segment_ids)
            except asyncio.CancelledError:
                pass
            except Exception as e:
                logger.error(f"延迟提交任务失败: {e}")
        
        self._timers[user_id] = asyncio.create_task(delayed_submit())

    async def flush_pending(self, user_id: str) -> str | None:
        """
        立即提交用户的待处理任务（用于对话结束时）
        
        Returns:
            任务 ID，无任务或失败返回 None
        """
        # 取消定时器
        if user_id in self._timers:
            self._timers[user_id].cancel()
            del self._timers[user_id]
        
        # 提交待处理任务
        segment_ids = self._pending.pop(user_id, [])
        if segment_ids:
            return await self._submit_task(user_id, segment_ids)
        return None