package main

import (
	"log"
	"net/http"
	"net/http/httputil"
	"net/url"
	"os"
	"path/filepath"
	"strings"
	"time"
)

func main() {
	gateway, err := url.Parse(env("DOCKER_GATEWAY_URL", "http://127.0.0.1:8081"))
	if err != nil {
		log.Fatal(err)
	}

	proxy := httputil.NewSingleHostReverseProxy(gateway)
	originalDirector := proxy.Director
	proxy.Director = func(request *http.Request) {
		originalDirector(request)
		request.URL.Path = "/v1/browsers" + strings.TrimPrefix(request.URL.Path, "/api/browsers")
		request.Host = gateway.Host
	}

	mux := http.NewServeMux()
	mux.Handle("/api/browsers", proxy)
	mux.Handle("/api/browsers/", proxy)
	mux.HandleFunc("GET /healthz", func(response http.ResponseWriter, _ *http.Request) {
		response.WriteHeader(http.StatusNoContent)
	})
	mux.Handle("/", spaHandler(env("WEB_DIR", "web/dist")))

	server := &http.Server{
		Addr:              env("LISTEN_ADDR", ":8080"),
		Handler:           mux,
		ReadHeaderTimeout: 5 * time.Second,
		IdleTimeout:       60 * time.Second,
	}
	log.Printf("CreatorHub control plane listening on %s", server.Addr)
	log.Fatal(server.ListenAndServe())
}

func spaHandler(directory string) http.Handler {
	files := http.FileServer(http.Dir(directory))
	return http.HandlerFunc(func(response http.ResponseWriter, request *http.Request) {
		name := filepath.Join(directory, filepath.Clean(strings.TrimPrefix(request.URL.Path, "/")))
		if info, err := os.Stat(name); err == nil && !info.IsDir() {
			files.ServeHTTP(response, request)
			return
		}
		http.ServeFile(response, request, filepath.Join(directory, "index.html"))
	})
}

func env(name, fallback string) string {
	if value := os.Getenv(name); value != "" {
		return value
	}
	return fallback
}