package web

import (
	"context"
	"errors"
	"fmt"
	"net/http"
	"time"
)

type ServerConfig struct {
	Host              string
	Port              int
	ReadHeaderTimeout time.Duration
	ShutdownTimeout   time.Duration
}

func Run(ctx context.Context, cfg ServerConfig, handler http.Handler) error {
	server := &http.Server{
		Addr:              fmt.Sprintf("%s:%d", cfg.Host, cfg.Port),
		Handler:           handler,
		ReadHeaderTimeout: cfg.ReadHeaderTimeout,
	}
	serveErr := make(chan error, 1)
	go func() { serveErr <- server.ListenAndServe() }()

	select {
	case err := <-serveErr:
		if errors.Is(err, http.ErrServerClosed) {
			return nil
		}
		return fmt.Errorf("serve explorer: %w", err)
	case <-ctx.Done():
	}

	shutdownCtx, cancel := context.WithTimeout(context.Background(), cfg.ShutdownTimeout)
	defer cancel()
	if err := server.Shutdown(shutdownCtx); err != nil {
		_ = server.Close()
		return fmt.Errorf("shut down explorer: %w", err)
	}
	err := <-serveErr
	if err != nil && !errors.Is(err, http.ErrServerClosed) {
		return fmt.Errorf("serve explorer: %w", err)
	}
	return nil
}