package main

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

func main() {
	mux := http.NewServeMux()
	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		time.Sleep(5 * time.Second) // Simulate a long-running request
		fmt.Fprintf(w, "Hello from a gracefully shutting down server!")
	})

	server := &http.Server{Addr: ":8080", Handler: mux}

	// Create a channel to listen for OS signals
	stop := make(chan os.Signal, 1)
	signal.Notify(stop, os.Interrupt, syscall.SIGTERM) // Capture Ctrl+C and Kubernetes/Docker termination signals

	go func() {
		fmt.Println("Server starting on :8080")
		if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalf("Could not listen on %s: %v
", server.Addr, err)
		}
	}()

	// Block until a signal is received
	<-stop

	fmt.Println("
Shutting down server...")

	// Create a context with a timeout for the shutdown
	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer cancel() // Ensure the context is cancelled to release resources

	// Attempt to gracefully shut down the server
	if err := server.Shutdown(ctx); err != nil {
		log.Fatalf("Server forced to shutdown: %v
", err)
	}

	fmt.Println("Server exited gracefully.")
}