"""에이전트 런타임 — 발화 → 도구 선택 → 실행 → 응답."""

import uuid

import httpx

from common.category_schema.loader import get_schema
from common.enums import DBWRType, ErrorType, PlaceCategory
from common.database.db_session_manager import DB_SESSION_MNG
from common.database.model.models import places
from common.models.gmodel import UserInfo
from config import agent_config as config
from config.server_configs import external_api_config
from crud.fact_crud import FactCRUD
from crud.place_crud import PlaceCRUD
from services.agent import tools as registry
from services.agent.tools import ToolContext, ToolGrade, ToolRejected
from services.fact_service import FactService
from services.llm import provider
from services.llm.errors import LlmError
from services.prompts import agent as prompt
from common.logger import LOG

# 발화 길이 상한.
MAX_MESSAGE = 500
# 도구 선택은 짧은 프롬프트라 빠르다.
REQUEST_TIMEOUT = httpx.Timeout(20.0, connect=5.0)


class AgentError(RuntimeError):
    """라우터가 HTTP 로 옮길 도메인 예외."""


def is_configured() -> bool:
    """대화창을 열 수 있나 — 스위치와 LLM 키를 **둘 다** 본다."""
    return config.chat_enabled() and provider.active().is_configured()


async def _load_place(user: UserInfo, place_id: str):
    """소유자 범위."""
    err, place = await DB_SESSION_MNG.execute_lambda(
        places.DBType(),
        DBWRType.DB_READ.value,
        lambda s: PlaceCRUD().get_place(s, uuid.UUID(user.user_id), uuid.UUID(place_id)),
    )
    if err != ErrorType.SUCCESS or place is None:
        raise AgentError("PLACE_NOT_FOUND")
    return place


async def _context_facts(user: UserInfo, place_id: str, place) -> list[dict]:
    """모델에게 줄 '지금 값'."""
    res = await FactService(FactCRUD(), PlaceCRUD()).list_facts(user, place_id, publishable_only=True)
    schema = get_schema(PlaceCategory(place.category))
    out = []
    for f in (res.facts or []):
        spec = schema.get(f.key)
        if spec and spec.scope == "place" and (f.value or "").strip():
            # label 은 싣지 않는다 — 아래 '항목 목록' 에 이미 key↔label 이 있다.
            out.append({f.key: f.value})
    # 상한을 둔다.
    return out[:30]


async def _choose(place, fields, facts, message) -> dict:
    """LLM 한 번."""
    active = provider.active()
    async with httpx.AsyncClient(timeout=REQUEST_TIMEOUT) as client:
        result = await active.generate(
            client,
            external_api_config.gemini_text_model if active.__name__.endswith("gemini") else external_api_config.openai_text_model,
            prompt=prompt.build_prompt(
                place_name=place.name,
                tools=registry.describe(),
                fields=fields,
                facts=facts,
                message=message,
            ),
            response_schema=prompt.RESPONSE_SCHEMA,
            temperature=0.0,
        )
    return result.json or {}


async def chat(user: UserInfo, place_id: str, message: str, confirm: dict | None = None) -> dict:
    """대화 한 번."""
    message = (message or "").strip()
    if confirm is None and not message:
        raise AgentError("AGENT_EMPTY_MESSAGE")
    if len(message) > MAX_MESSAGE:
        raise AgentError("AGENT_MESSAGE_TOO_LONG")

    place = await _load_place(user, place_id)
    ctx = ToolContext(user=user, place_id=place_id, place=place)

    if confirm is not None:
        tool = registry.REGISTRY.get(confirm.get("tool") or "")
        if tool is None or tool.grade == ToolGrade.READ:
            raise AgentError("AGENT_UNKNOWN_TOOL")
        return await _execute(ctx, tool, confirm.get("args") or {})

    if not is_configured():
        raise AgentError("AGENT_NOT_CONFIGURED")

    fields = registry.fields_of(place)
    facts = await _context_facts(user, place_id, place)
    # 사이트 상태는 프롬프트에 싣지 않는다.

    try:
        choice = await _choose(place, fields, facts, message)
    except LlmError as ex:
        LOG.w(f"[agent] 도구 선택 실패: {type(ex).__name__}")
        raise AgentError("AGENT_CALL_FAILED") from ex

    name = (choice.get("tool") or "").strip()
    tool = registry.REGISTRY.get(name)
    if tool is None:
        return {
            "reply": (choice.get("message") or "").strip() or "무엇을 도와드릴까요?",
            "tool": None,
            "needs_confirm": False,
        }

    args = choice.get("args") or {}
    if tool.grade == ToolGrade.SEMI:
        # 실행하지 않는다.
        return {"reply": tool.confirm, "tool": tool.name, "args": args, "needs_confirm": True}

    return await _execute(ctx, tool, args)


async def _execute(ctx: ToolContext, tool, args: dict) -> dict:
    try:
        reply = await tool.run(ctx, args)
    except ToolRejected as ex:
        # 도구가 거절한 이유는 사장님께 그대로 보여 준다 — 실패를 숨기면 다시 시도한다.
        return {"reply": str(ex), "tool": tool.name, "needs_confirm": False, "rejected": True}
    return {"reply": reply, "tool": tool.name, "needs_confirm": False, "done": tool.grade != ToolGrade.READ}