package server

import (
	"context"
	"net"
	"testing"

	"git.eeqj.de/sneak/routewatch/internal/config"
	"git.eeqj.de/sneak/routewatch/internal/logger"
	"git.eeqj.de/sneak/routewatch/internal/metrics"
	"git.eeqj.de/sneak/routewatch/internal/streamer"
)

// TestStartFailsWhenPortIsHeld holds a port with a listener of its own and
// checks that Start on that port returns an error. Before the fix Start
// listened in a goroutine, only logged the failure and returned nil, so the
// daemon kept running without its web server.
func TestStartFailsWhenPortIsHeld(t *testing.T) {
	held, err := net.Listen("tcp", ":0")
	if err != nil {
		t.Fatalf("failed to open the test listener: %v", err)
	}
	defer func() { _ = held.Close() }()

	port := held.Addr().(*net.TCPAddr).Port
	log := logger.New()
	s := New(nil, streamer.New(log, metrics.New()), log, &config.Config{Port: port})
	defer func() { _ = s.Stop(context.Background()) }()

	if err := s.Start(); err == nil {
		t.Fatalf("Start returned nil while port %d was held by another listener", port)
	}
}