life-echo/api/app/agents/memoir/narrative_agent.py

"""
NarrativeAgent：生成创意标题和叙事改写。
叙事正文走 `get_narrative_json_prompt` / `get_narrative_merge_json_prompt`（传记作家式书面语 + 事实边界）。
"""

from __future__ import annotations

import json
from typing import Any, Dict, Optional

from app.agents.memoir.prompts import (
    get_creative_title_json_prompt,
    get_narrative_json_prompt,
    get_narrative_merge_json_prompt,
)
from app.core.langchain_llm import invoke_json_object
from app.core.logging import get_logger
from app.features.memoir.memoir_images.json_payload import extract_json_payload

logger = get_logger(__name__)


class NarrativeAgent:
    """生成章节标题和叙事正文"""

    def generate_title(
        self,
        stage: str,
        emotion: str,
        slots: Dict[str, str],
        user_profile: str = "",
        birth_year: Optional[int] = None,
        llm: Any = None,
    ) -> str:
        """生成创意标题。若无 LLM 则返回默认标题"""
        if not llm:
            return f"{stage} 回忆"
        try:
            prompt = get_creative_title_json_prompt(
                stage=stage,
                emotion=emotion,
                slots=slots,
                user_profile=user_profile,
                birth_year=birth_year,
            )
            raw = invoke_json_object(
                llm,
                prompt,
                max_tokens=256,
                agent="NarrativeAgent.generate_title",
            )
            data = json.loads(extract_json_payload(raw))
            title = (data.get("title") or "").strip() if isinstance(data, dict) else ""
            if title:
                return title.strip('"')
            return f"{stage} 回忆"
        except Exception as e:
            logger.warning("NarrativeAgent 生成标题失败: {}", e)
            return f"{stage} 回忆"

    def generate_narrative(
        self,
        stage: str,
        slots: Dict[str, str],
        new_content: str,
        existing_content: str = "",
        user_profile: str = "",
        birth_year: Optional[int] = None,
        llm: Any = None,
        background_voice: str = "default",
    ) -> str:
        """将新对话改写为叙述。若无 LLM 则直接拼接。

        若 `existing_content` 非空（append 路径），使用整篇合并提示，输出覆盖全篇的有序段落。
        """
        if not llm:
            if existing_content:
                return f"{existing_content}\n\n{new_content}"
            return new_content
        try:
            merge_mode = bool((existing_content or "").strip())
            if merge_mode:
                prompt = get_narrative_merge_json_prompt(
                    stage=stage,
                    slots=slots,
                    new_content=new_content,
                    existing_content=existing_content,
                    user_profile=user_profile,
                    birth_year=birth_year,
                    background_voice=background_voice,
                )
                max_tokens = 8192
                agent_name = "NarrativeAgent.generate_narrative_merge"
            else:
                prompt = get_narrative_json_prompt(
                    stage=stage,
                    slots=slots,
                    new_content=new_content,
                    existing_content=existing_content,
                    user_profile=user_profile,
                    birth_year=birth_year,
                    background_voice=background_voice,
                )
                max_tokens = 4096
                agent_name = "NarrativeAgent.generate_narrative"
            return invoke_json_object(
                llm,
                prompt,
                max_tokens=max_tokens,
                agent=agent_name,
            ).strip()
        except Exception as e:
            logger.warning("NarrativeAgent 生成叙事失败: {}", e)
            if existing_content:
                return f"{existing_content}\n\n{new_content}"
            return new_content