# backend/app/routers/ops.py — readiness + 메트릭 노출 (phase-15)
from fastapi import APIRouter, Depends
from fastapi.responses import PlainTextResponse
from sqlmodel import Session, text

from ..config import get_settings
from ..db import get_session
from ..observability import metrics
from ..schemas import ReadyOut

router = APIRouter()


def check_ollama() -> dict:
    """Ollama 도달성 점검(테스트에서 monkeypatch 가능)."""
    import httpx

    st = get_settings()
    try:
        r = httpx.get(f"{st.ollama_host}/api/tags", timeout=2.0)
        return {"reachable": r.status_code == 200, "model": st.ollama_model, "host": st.ollama_host}
    except Exception:
        return {"reachable": False, "model": st.ollama_model, "host": st.ollama_host}


@router.get("/ready", response_model=ReadyOut)
def ready(s: Session = Depends(get_session)):
    checks: dict[str, str] = {}
    db_ok = True
    try:
        s.exec(text("SELECT 1"))
        checks["db"] = "ok"
    except Exception as e:
        db_ok = False
        checks["db"] = f"error: {type(e).__name__}"
    checks["migrations"] = "ok"
    llm = check_ollama()
    # LLM 미가용은 차단하지 않음(heuristic 폴백)
    checks["llm"] = f"ok:{llm['model']}" if llm.get("reachable") else "fallback:heuristic"
    checks["worker"] = "scheduled" if get_settings().worker_enabled else "manual"
    return ReadyOut(ready=db_ok, checks=checks)


@router.get("/metrics", response_class=PlainTextResponse)
def prometheus_metrics():
    """Prometheus 텍스트. 운영에선 리버스 프록시(Caddy)가 외부 접근 차단."""
    return PlainTextResponse(metrics.render(), media_type="text/plain; version=0.0.4")