package main

import (
	"context"
	"io"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"
)

const (
	defaultPort           = "9234"
	readTimeout           = 2 * time.Second
	readHeaderTimeout     = 2 * time.Second
	writeTimeout          = 2 * time.Second
	idleTimeout           = 2 * time.Second
	serverShutdownTimeout = 10 * time.Second
)

func main() {
	srv := newServer()

	go func(srv *http.Server) {
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalln("srv.ListenAndServe:", err)
		}
	}(srv)

	log.Println("Server is listening on the port", defaultPort)

	waitForSignal(context.Background())

	ctxShutdown, cancelShutdown := context.WithTimeout(context.Background(), serverShutdownTimeout)
	defer cancelShutdown()
	err := srv.Shutdown(ctxShutdown)
	if err != nil {
		log.Println("srv.Shutdown:", err)
	}
}

func newServer() *http.Server {
	return &http.Server{
		Addr: ":" + defaultPort,
		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			_, _ = io.Copy(os.Stdout, r.Body)
			w.WriteHeader(http.StatusOK)
		}),
		ReadTimeout:       readTimeout,
		ReadHeaderTimeout: readHeaderTimeout,
		WriteTimeout:      writeTimeout,
		IdleTimeout:       idleTimeout,
	}
}

func waitForSignal(ctx context.Context) {
	ctx, stop := signal.NotifyContext(ctx, os.Interrupt, syscall.SIGTERM)
	defer stop()
	<-ctx.Done()
}