package main

import (
	"io/fs"
	"log"
	"net/http"
	"os"

	"countrygame/web"
)

func main() {
	port := os.Getenv("PORT")
	if port == "" {
		port = "8080"
	}

	// Used by the compose healthcheck: the distroless image has no curl.
	if len(os.Args) > 1 && os.Args[1] == "-healthcheck" {
		resp, err := http.Get("http://127.0.0.1:" + port + "/healthz")
		if err != nil || resp.StatusCode != http.StatusOK {
			os.Exit(1)
		}
		os.Exit(0)
	}

	root, err := fs.Sub(web.Files, ".")
	if err != nil {
		log.Fatal(err)
	}

	mux := http.NewServeMux()
	mux.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte("ok"))
	})
	mux.Handle("/", noCache(http.FileServer(http.FS(root))))

	log.Printf("country game listening on :%s", port)
	log.Fatal(http.ListenAndServe(":"+port, mux))
}

// noCache keeps iteration simple: data and scripts are always revalidated.
func noCache(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Cache-Control", "no-cache")
		next.ServeHTTP(w, r)
	})
}