router.go

package server

import (
	"net/http"
	"sync"

	"github.com/go-chi/chi"
	"github.com/markbates/pkger"
	"github.com/prometheus/client_golang/prometheus/promhttp"
)

var (
	displaysMu sync.Mutex
	displays   map[string]*Display = make(map[string]*Display)
)

// GetRouter gets the router for the server
func GetRouter(useHostNamespace bool) *chi.Mux {

	r := chi.NewRouter()

	r.Route("/twitch", func(r chi.Router) {
		r.With(monitoringMiddleware("/twitch/getTopGames")).Get("/getTopGames", twitchGetTopGamesHandler)
		r.With(monitoringMiddleware("/twitch/searchGames")).Get("/searchGames", twitchSearchGamesHandler)
		r.With(monitoringMiddleware("/twitch/getTopStreams")).Get("/getTopStreams", twitchGetTopStreamsHandler)
		r.With(monitoringMiddleware("/twitch/getFeaturedStreams")).Get("/getFeaturedStreams", twitchGetFeaturedStreamsHandler)
	})

	r.Get("/display", func(w http.ResponseWriter, r *http.Request) {
		namespace := "default"
		if useHostNamespace {
			namespace = r.Host
		}

		displaysMu.Lock()
		display, ok := displays[namespace]
		if !ok {
			display = NewDisplay(namespace)
			displays[namespace] = display
		}
		displaysMu.Unlock()

		// We had to create a namespace
		// Increase metric outside mutex for performance
		if !ok {
			namespacesMetric.Inc()
		}

		if r.Header.Get("Accept") == "text/event-stream" {
			displayListernersMetric.Inc()
			defer displayListernersMetric.Dec()
			monitoringMiddleware("/display(events)")(http.HandlerFunc(display.eventsHandler)).ServeHTTP(w, r)
		} else {
			monitoringMiddleware("/display(state)")(http.HandlerFunc(display.stateHandler)).ServeHTTP(w, r)
		}
	})

	// Export Prometheus metrics
	r.Handle("/metrics", promhttp.Handler())

	r.With(monitoringMiddleware("/")).Mount("/", http.FileServer(pkger.Dir("/internal/static")))

	return r
}