import { Router } from "express";
import { hostname } from "node:os";
import type { Config } from "../lib/config.js";
import type { Db } from "../lib/db.js";
import type { Cache } from "../lib/redis.js";

export function rootRouter(deps: {
  config: Config;
  db?: Db;
  cache?: Cache;
}): Router {
  const router = Router();

  router.get("/", async (_req, res, next) => {
    try {
      const body: Record<string, unknown> = {
        service: deps.config.SERVICE_NAME,
        version: deps.config.GIT_SHA,
        pod: hostname(),
      };
      if (deps.db) {
        const r = await deps.db.query(
          "SELECT id, name, created_at FROM service_info ORDER BY id LIMIT 1",
        );
        body.db = r.rows[0] ?? null;
      }
      if (deps.cache) {
        body.cacheHits = await deps.cache.incr(
          `${deps.config.SERVICE_NAME}:hits`,
        );
      }
      res.json(body);
    } catch (err) {
      next(err);
    }
  });

  return router;
}