package mock

import (
	"net"
	"strconv"
	"testing"
)

func TestAcquireProxy_sharedAcrossAcquires(t *testing.T) {
	t.Parallel()
	port := freePort(t)
	addr := net.JoinHostPort(mockProxyIP, strconv.Itoa(int(port)))

	release1, err := acquireProxy(port)
	if err != nil {
		t.Fatalf("acquireProxy() #1 error = %v", err)
	}
	// A second acquire for the same port must join the existing listener
	// rather than fail trying to bind it again — this is the whole point
	// of sharing by port instead of by IP.
	release2, err := acquireProxy(port)
	if err != nil {
		t.Fatalf("acquireProxy() #2 error = %v, want nil (should share the existing listener)", err)
	}

	release1()
	// One reference remains; the port must still be in use.
	if ln, err := net.Listen("tcp", addr); err == nil {
		ln.Close()
		t.Fatal("port became bindable after releasing only one of two references")
	}

	release2()
	// Last reference released: the port must now be free.
	ln, err := net.Listen("tcp", addr)
	if err != nil {
		t.Fatalf("port not released after last reference: %v", err)
	}
	ln.Close()
}

func TestAcquireProxy_releaseIsIdempotent(t *testing.T) {
	t.Parallel()
	port := freePort(t)
	release, err := acquireProxy(port)
	if err != nil {
		t.Fatalf("acquireProxy() error = %v", err)
	}
	release()
	release() // must not panic or double-decrement into a negative refcount
}