"""交易信号 API（M8.1）：提交/查询信号（落库可复现）。

POST /api/signals      body: {query: SelectionQuery, rules?: SignalRules}
GET  /api/signals/{id} 读回某次信号
GET  /api/signals      历史信号元数据（可过滤 as_of）
"""

from __future__ import annotations

from datetime import date
from typing import Annotated

from fastapi import APIRouter, HTTPException, Query
from pydantic import BaseModel

from app.api.deps import DbSession, SignalRepoDep, SignalServiceDep
from app.application.services.job_executor import new_id
from app.domain.entities.selection import SelectionQuery
from app.domain.entities.signal import SignalMeta, SignalResult, SignalRules

router = APIRouter(prefix="/signals", tags=["signals"])

_AsOfQuery = Annotated[date | None, Query(description="按信号时点过滤")]
_LimitQuery = Annotated[int, Query(ge=1, le=200)]


class SignalRequest(BaseModel):
    query: SelectionQuery
    rules: SignalRules = SignalRules()


class SignalRun(BaseModel):
    signal_id: str
    result: SignalResult


@router.post("", response_model=SignalRun, summary="生成一次交易信号（同步）并落库")
def run_signal(
    req: SignalRequest,
    service: SignalServiceDep,
    signal_repo: SignalRepoDep,
    session: DbSession,
) -> SignalRun:
    result = service.signal(req.query, req.rules)
    signal_id = new_id("SIG")
    signal_repo.save(signal_id, result)
    session.commit()
    return SignalRun(signal_id=signal_id, result=result)


@router.get("/{signal_id}", response_model=SignalResult, summary="读回一次信号结果")
def get_signal(signal_id: str, signal_repo: SignalRepoDep) -> SignalResult:
    result = signal_repo.get(signal_id)
    if result is None:
        raise HTTPException(status_code=404, detail=f"信号记录 {signal_id} 不存在")
    return result


@router.get("", response_model=list[SignalMeta], summary="历史信号元数据列表")
def list_signals(
    signal_repo: SignalRepoDep,
    as_of: _AsOfQuery = None,
    limit: _LimitQuery = 20,
) -> list[SignalMeta]:
    return signal_repo.list_recent(as_of=as_of, limit=limit)