package main

import (
	"context"
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"os"
	"syscall"
	"time"

	"github.com/kamilsk/breaker"
	"github.com/kamilsk/retry/v5"
)

func main() {
	const (
		header  = "X-Message"
		timeout = time.Minute
	)

	server := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
		time.Sleep(timeout / 10)
		_, _ = rw.Write([]byte(req.Header.Get(header)))
	}))
	defer server.Close()

	interrupter := breaker.Multiplex(
		breaker.BreakBySignal(os.Interrupt, syscall.SIGINT, syscall.SIGTERM),
		breaker.BreakByTimeout(timeout),
	)
	defer interrupter.Close()

	ctx := breaker.ToContext(interrupter)
	ctx = context.WithValue(ctx, header, "flexible mechanism to make execution flow interruptible")

	req, err := http.NewRequestWithContext(ctx, http.MethodGet, server.URL, nil)
	if err != nil {
		panic(err)
	}

	var resp *http.Response
	action := func(ctx context.Context) (err error) {
		req = req.Clone(ctx)

		source := ctx.Value(header).(string)
		req.Header.Set(header, source)

		resp, err = http.DefaultClient.Do(req)
		return err
	}

	if err := retry.Do(ctx, action); err != nil {
		fmt.Println("error:", err)
		return
	}
	_, _ = io.Copy(os.Stdout, resp.Body)
}

package main

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

	"github.com/kamilsk/breaker"
)

func main() {
	const timeout = time.Minute

	interrupter := breaker.Multiplex(
		breaker.BreakBySignal(os.Interrupt, syscall.SIGINT, syscall.SIGTERM),
		breaker.BreakByTimeout(timeout),
	)
	defer interrupter.Close()

	server := http.Server{
		Addr:    ":8080",
		Handler: http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {}),
		BaseContext: func(net.Listener) context.Context {
			return breaker.ToContext(interrupter)
		},
	}
	go func() {
		if err := server.ListenAndServe(); !errors.Is(err, http.ErrServerClosed) {
			log.Fatal(err)
		}
	}()

	<-interrupter.Done()
	if err := interrupter.Err(); errors.Is(err, breaker.Interrupted) {
		if err := server.Shutdown(context.TODO()); err != nil {
			panic(err)
		}
	}
	fmt.Println("graceful shutdown")
}