"""Проверки живости и готовности."""

from __future__ import annotations

from typing import Literal

import redis.asyncio as aioredis
from fastapi import APIRouter, Response, status
from pydantic import BaseModel
from sqlalchemy import text

from app.api.deps import SessionDep
from app.core.config import settings
from app.core.logging import get_logger

router = APIRouter(tags=["health"])
log = get_logger(__name__)


class HealthResponse(BaseModel):
    status: Literal["ok", "degraded"]
    environment: str
    database: bool
    redis: bool


@router.get("/health", response_model=HealthResponse)
async def health() -> HealthResponse:
    """Liveness: процесс жив. Внешние зависимости не проверяются.

    Оркестратор не должен перезапускать контейнер из-за недоступного Postgres —
    перезапуск приложения проблему БД не решает.
    """
    return HealthResponse(
        status="ok", environment=settings.environment, database=True, redis=True
    )


@router.get("/health/ready", response_model=HealthResponse)
async def readiness(session: SessionDep, response: Response) -> HealthResponse:
    """Readiness: приложение способно обслуживать запросы."""
    db_ok = True
    redis_ok = True

    try:
        await session.execute(text("SELECT 1"))
    except Exception as exc:  # noqa: BLE001 — health-check не должен падать сам
        db_ok = False
        log.warning("readiness_db_failed", error=str(exc))

    client = aioredis.from_url(settings.redis_url)
    try:
        await client.ping()
    except Exception as exc:  # noqa: BLE001
        redis_ok = False
        log.warning("readiness_redis_failed", error=str(exc))
    finally:
        await client.aclose()

    healthy = db_ok and redis_ok
    if not healthy:
        response.status_code = status.HTTP_503_SERVICE_UNAVAILABLE

    return HealthResponse(
        status="ok" if healthy else "degraded",
        environment=settings.environment,
        database=db_ok,
        redis=redis_ok,
    )