import express, { Request, Response } from "express";
import { container } from "tsyringe";
import { Counter, Gauge, collectDefaultMetrics, register } from "prom-client";
import { LocationService } from "../services/locationService";
import { WifiLocationService } from "../services/wifiLocationService";

const router = express.Router();
const locationService = container.resolve(LocationService);
const wifiLocationService = container.resolve(WifiLocationService);

// Collect default system metrics (e.g., CPU, memory usage)
const prefix = 'locationhub_';
collectDefaultMetrics({ prefix });

// Define a custom Counter metric
const requestCounter = new Counter({
  name: `${prefix}http_requests_total`,
  help: "Total number of HTTP requests",
  labelNames: ["method", "route", "status"],
});

const locationsTotal = new Gauge({
  name: `${prefix}locations_total`,
  help: "Total number of location entries in database",
  labelNames: ["database"],
});

const wifiLocationTotal = new Gauge({
  name: `${prefix}wifi_locations_total`,
  help: "Total number of wifi location entries in database",
  labelNames: ["database"],
});

const wifiLocationNotResolvable = new Gauge({
  name: `${prefix}wifi_locations_not_resolvable`,
  help: "Unresolved number of wifi location entries in database",
  labelNames: ["database"],
});

const wifiLocationRequestLimitExceeded = new Gauge({
  name: `${prefix}wifi_locations_request_limit_exceeded`,
  help: "Unresolved number of wifi location because request limit exceeded entries in database",
  labelNames: ["database"],
});


// Define the metrics endpoint
router.get("/", async (req: Request, res: Response) => {
  try {
    console.log("Metric Endpoint triggered");

    locationsTotal.set((await locationService.getAllLocations()).length);
    wifiLocationTotal.set((await wifiLocationService.getAllWifiLocations()).length);
    wifiLocationNotResolvable.set((await wifiLocationService.getAllWifiLocationsByNotResolvable).length);
    wifiLocationRequestLimitExceeded.set((await wifiLocationService.getAllWifiLocationsByRequestLimitExceeded).length);

    // Increment the counter with labels
    requestCounter.inc({ method: req.method, route: req.route.path, status: 200 });

    // Expose metrics in Prometheus format
    res.set("Content-Type", register.contentType);
    res.send(await register.metrics());
  } catch (error) {
    // Increment the counter for errors
    requestCounter.inc({ method: req.method, route: req.route.path, status: 500 });

    console.error("Error running metrics endpoint:", error);
    res.status(500).json({ error: "Error running metrics endpoint" });
  }
});

export default router;