package main

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

func main() {
	ctx, can := signal.NotifyContext(context.Background(), syscall.SIGINT)
	defer can()

	cfg, err := newConfig()
	if err != nil {
		panic(err)
	}

	if err := run(ctx, cfg); err != nil && ctx.Err() == nil {
		panic(err)
	}
}

func run(ctx context.Context, cfg Config) error {
	select {
	case <-ctx.Done():
		return ctx.Err()
	case err := <-listenAndServe(ctx, cfg):
		return err
	}
}

func listenAndServe(ctx context.Context, cfg Config) chan error {
	s := http.Server{
		Addr: fmt.Sprintf(":%d", cfg.Port),
	}

	errc := make(chan error)
	go func() {
		defer close(errc)
		errc <- s.ListenAndServe()
	}()

	return errc
}