"""Liveness and readiness endpoints.

- ``/health``       — liveness: the process is up. No dependencies touched.
- ``/health/ready`` — readiness: dependencies (Postgres) are reachable.

Orchestrators and Caddy probe these; they are intentionally outside the
versioned ``/api`` surface.
"""

from fastapi import APIRouter, Response, status
from sqlalchemy import text

from app.core.config import get_settings
from app.core.db import get_engine
from app.core.schema_version import schema_is_current

router = APIRouter(tags=["health"])


@router.get("/health")
async def health() -> dict:
    settings = get_settings()
    return {
        "status": "ok",
        "service": settings.app_name,
        "version": settings.version,
        "env": settings.app_env,
    }


@router.get("/health/ready")
async def ready(response: Response) -> dict:
    checks: dict[str, str] = {}
    try:
        async with get_engine().connect() as conn:
            await conn.execute(text("SELECT 1"))
            checks["database"] = "ok"
            # Schema drift = code ahead of the DB; queries would 500. Fail
            # readiness loudly rather than serve a broken surface.
            ok, db, expected = await schema_is_current(conn)
            if not ok:
                checks["schema"] = (
                    f"drift: db={sorted(db) or ['none']} expected={sorted(expected)} "
                    "— run 'alembic upgrade head'"
                )
                response.status_code = status.HTTP_503_SERVICE_UNAVAILABLE
                return {"status": "not ready", "checks": checks}
            checks["schema"] = "ok"
        return {"status": "ready", "checks": checks}
    except Exception as exc:  # noqa: BLE001 — surface any failure as "not ready"
        checks.setdefault("database", "error")
        response.status_code = status.HTTP_503_SERVICE_UNAVAILABLE
        return {"status": "not ready", "checks": checks, "detail": str(exc)}