"""中控 AI：单会话聊天（直到用户点击新开）。"""
from __future__ import annotations

from typing import Any

from hub_ai.client import generate_text, model_label
from hub_ai.config import CHAT_MAX_HISTORY_TURNS, CHAT_TEMPERATURE
from hub_ai.context import build_daily_context, format_chat_context_brief
from hub_ai.prompts import CHAT_SYSTEM, build_chat_user_prompt
from hub_ai.store import (
    append_chat_message,
    create_new_session,
    ensure_active_session,
    get_active_session,
    load_chat_store,
    summary_excerpt_for_chat,
)


def _history_lines(messages: list[dict], max_turns: int = CHAT_MAX_HISTORY_TURNS) -> str:
    rows = [m for m in (messages or []) if m.get("role") in ("user", "assistant")]
    rows = rows[-max_turns * 2 :]
    lines = []
    for m in rows:
        role = "用户" if m.get("role") == "user" else "搭档"
        lines.append(f"{role}：{m.get('content') or ''}")
    return "\n".join(lines)


def get_chat_state() -> dict[str, Any]:
    store = load_chat_store()
    session = get_active_session()
    return {
        "active_session_id": store.get("active_session_id"),
        "session": session,
        "model": model_label(),
    }


def start_new_chat(*, trading_day: str) -> dict:
    session = create_new_session(trading_day=trading_day)
    return {"ok": True, "session": session, "model": model_label()}


def send_chat_message(
    exchanges: list[dict],
    message: str,
    *,
    trading_day: str | None = None,
) -> dict[str, Any]:
    text = (message or "").strip()
    if not text:
        return {"ok": False, "msg": "消息不能为空"}

    ctx = build_daily_context(exchanges, trading_day=trading_day)
    day = ctx["trading_day"]
    session = ensure_active_session(trading_day=day)
    sid = session["id"]
    history = _history_lines(session.get("messages") or [])

    append_chat_message(sid, "user", text)

    brief_ctx = format_chat_context_brief(ctx)
    excerpt = summary_excerpt_for_chat(day)

    user_prompt = build_chat_user_prompt(
        context_text=brief_ctx,
        trading_day=day,
        summary_excerpt=excerpt,
        history_lines=history,
        user_message=text,
    )
    reply = generate_text(
        system=CHAT_SYSTEM,
        user=user_prompt,
        temperature=CHAT_TEMPERATURE,
    )
    if reply.startswith("AI 调用失败"):
        return {"ok": False, "msg": reply, "session_id": sid}

    session = append_chat_message(sid, "assistant", reply)
    return {
        "ok": True,
        "trading_day": day,
        "session": session,
        "reply": reply,
        "model": model_label(),
    }