"""模型信息与运行时配置路由。"""

from __future__ import annotations

import asyncio

from fastapi import APIRouter, HTTPException

import config
from agents import agent_factory, agent_registry, model_factory
from api.models import ThinkingUpdateRequest
from obs import get_logger

logger = get_logger(__name__)

router = APIRouter(tags=["模型"])


@router.get("/model")
async def get_model_info():
    """当前模型配置、工具清单与组装摘要。"""
    return {
        **model_factory.describe(),
        "agent": agent_factory.describe(),
        "generation": agent_registry.generation(),
    }


@router.get("/model/tools")
async def get_tools():
    """工具清单（按分组），用于前端展示「agent 会什么」。"""
    from tools import registry

    registry.load_builtin_tools()
    return registry.describe()


@router.post("/model/thinking")
async def set_thinking(payload: ThinkingUpdateRequest):
    """切换思考级别。

    思考级别烧在模型实例里，改它必须**重建 agent**——所以这里调
    ``invalidate()`` 让下次请求重新编译，而不是原地改配置。重建期间
    (百毫秒级) 的在途请求继续用旧实例，不受影响。
    """
    level = payload.level.strip().lower()
    if level not in model_factory.VALID_THINKING_LEVELS:
        raise HTTPException(
            status_code=400,
            detail={
                "code": "invalid_level",
                "message": f"level 只能是 {' | '.join(model_factory.VALID_THINKING_LEVELS)}",
            },
        )
    if level == model_factory.normalize_thinking(None):
        return {"changed": False, "thinking": level, "message": "级别未变化"}

    # 级别来自环境变量，运行时改只能改进程内状态 + 失效重建
    config.THINKING_LEVEL = level
    generation = await asyncio.to_thread(agent_registry.invalidate)
    logger.info("思考级别切换为 %s，agent 将于下次请求重建（generation=%d）", level, generation)
    return {
        "changed": True,
        "thinking": level,
        "generation": generation,
        "message": "已生效，下一个请求会使用新的模型实例",
    }


@router.post("/model/reload")
async def reload_agent():
    """强制重建 agent。改完 .env 里的模型/窗口配置后用这个让改动生效。"""
    generation = await asyncio.to_thread(agent_registry.invalidate)
    return {"reloaded": True, "generation": generation}