"""聊天滚动摘要：每轮后压缩历史，续聊只带摘要 + 当前消息。"""
from __future__ import annotations

from hub_ai.text_util import clip_text, is_ai_error_reply
from hub_ai.client import generate_text
from hub_ai.config import (
    CHAT_ROLLING_SUMMARY_GEN_MAX_TOKENS,
    CHAT_ROLLING_SUMMARY_MAX_CHARS,
    CHAT_ROLLING_SUMMARY_TEMPERATURE,
)
from hub_ai.prompts import (
    ROLLING_SUMMARY_GENERAL_SYSTEM,
    ROLLING_SUMMARY_TRADING_SYSTEM,
    build_rolling_summary_user_prompt,
)
from hub_ai.store import CHAT_BOT_GENERAL, update_session_rolling_summary


def refresh_session_rolling_summary(
    session_id: str,
    *,
    prior_summary: str,
    user_text: str,
    assistant_text: str,
    bot_mode: str,
) -> str:
    """合并旧摘要与本轮对话，生成新的短摘要并写入会话。"""
    user_clip = clip_text(user_text, 1200)
    assistant_clip = clip_text(assistant_text, 1800)
    if not user_clip and not assistant_clip:
        summary = clip_text(prior_summary, CHAT_ROLLING_SUMMARY_MAX_CHARS)
        update_session_rolling_summary(session_id, summary)
        return summary

    system = (
        ROLLING_SUMMARY_GENERAL_SYSTEM
        if (bot_mode or "").strip().lower() == CHAT_BOT_GENERAL
        else ROLLING_SUMMARY_TRADING_SYSTEM
    )
    raw = generate_text(
        system=system,
        user=build_rolling_summary_user_prompt(
            prior_summary=prior_summary,
            user_text=user_clip,
            assistant_text=assistant_clip,
        ),
        temperature=CHAT_ROLLING_SUMMARY_TEMPERATURE,
        max_tokens=CHAT_ROLLING_SUMMARY_GEN_MAX_TOKENS,
        max_continuations=1,
    )
    if is_ai_error_reply(raw):
        fallback = _fallback_summary(prior_summary, user_clip, assistant_clip)
        update_session_rolling_summary(session_id, fallback)
        return fallback

    summary = clip_text(raw, CHAT_ROLLING_SUMMARY_MAX_CHARS)
    update_session_rolling_summary(session_id, summary)
    return summary


def _fallback_summary(prior: str, user_text: str, assistant_text: str) -> str:
    parts: list[str] = []
    if prior.strip():
        parts.append(prior.strip())
    if user_text.strip():
        parts.append(f"用户：{clip_text(user_text, 200)}")
    if assistant_text.strip():
        parts.append(f"教练：{clip_text(assistant_text, 280)}")
    return clip_text("\n".join(parts), CHAT_ROLLING_SUMMARY_MAX_CHARS)