"""FastAPI entrypoint with dependency-free liveness and database readiness probes."""

from typing import Any

import psycopg
import uvicorn
from fastapi import FastAPI, Response, status

from app import __version__
from app.api.v1 import demo_router
from app.core.config import get_settings
from app.core.secrets import SecretFileError

app = FastAPI(title="Geological RAG API", version=__version__)
app.include_router(demo_router)

type HealthPayload = dict[str, str | dict[str, str]]


@app.get("/health/live", tags=["health"])
@app.get("/api/v1/health/live", tags=["health"])
def live() -> dict[str, str]:
    return {"status": "ok", "version": __version__}


@app.get(
    "/health/ready",
    tags=["health"],
    responses={status.HTTP_503_SERVICE_UNAVAILABLE: {"description": "Database unavailable"}},
)
@app.get("/api/v1/health/ready", tags=["health"])
def ready(response: Response) -> HealthPayload:
    settings = get_settings()
    try:
        dsn = settings.database_url().set(drivername="postgresql")
        with psycopg.connect(
            dsn.render_as_string(hide_password=False),
            connect_timeout=2,
            autocommit=True,
        ) as connection:
            result = connection.execute("SELECT 1").fetchone()
            if result != (1,):
                raise psycopg.DatabaseError("readiness query returned an unexpected result")
    except (OSError, SecretFileError, psycopg.Error):
        # Do not expose connection strings, secret paths, hostnames, or driver errors.
        response.status_code = status.HTTP_503_SERVICE_UNAVAILABLE
        return {"status": "not_ready", "checks": {"database": "unavailable"}}
    return {"status": "ready", "checks": {"database": "ok"}}


@app.get("/api/v1/meta", tags=["meta"])
def meta() -> dict[str, Any]:
    settings = get_settings()
    return {
        "name": settings.app_name,
        "environment": settings.app_env,
        "version": __version__,
        "models": {
            "embedding": settings.embedding_model,
            "rerank": settings.rerank_model,
            "generation": settings.llm_model,
        },
    }


if __name__ == "__main__":
    # Compose publishes this listener only on the host loopback interface.
    uvicorn.run("app.main:app", host="0.0.0.0", port=8000)  # noqa: S104