package activator

import (
	"context"
	"errors"
	"testing"
	"time"
)

func TestFenceInitialAdmissionTimeoutHasNoFence(t *testing.T) {
	t.Parallel()
	a := &Service{}
	a.mu.Lock()
	ctx, cancel := context.WithTimeout(context.Background(), 20*time.Millisecond)
	proof, err := a.FenceAndStop(ctx, "timeout.example.com", 1)
	cancel()
	if proof != nil || !errors.Is(err, ErrFenceNotInstalled) {
		a.mu.Unlock()
		t.Fatalf("uninstalled fence reported as installed: proof=%v err=%v", proof != nil, err)
	}
	if a.fences["timeout.example.com"] != 0 {
		a.mu.Unlock()
		t.Fatal("fence installed while mutex held")
	}
	a.mu.Unlock()
	if !a.wakeAllowed("timeout.example.com") {
		t.Fatal("unexpected admission state")
	}
}

func TestScheduledTokenSlowHostDoesNotBlockSiblingFence(t *testing.T) {
	a := &Service{}
	entered, release := make(chan struct{}), make(chan struct{})
	done := make(chan error, 1)
	go func() {
		_, e := a.PrepareScheduledToken("slow.example.com", func() (string, error) { close(entered); <-release; return "token", nil })
		done <- e
	}()
	<-entered
	defer func() { close(release); <-done }()
	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
	defer cancel()
	proof, err := a.FenceAndStop(ctx, "sibling.example.com", 1)
	if proof != nil || !errors.Is(err, ErrStopUnproven) {
		t.Fatalf("sibling fence blocked by unrelated IO: %v", err)
	}
	callback := make(chan error, 1)
	go func() {
		_, e := a.PrepareScheduledToken("fast.example.com", func() (string, error) { return "fast", nil })
		callback <- e
	}()
	select {
	case e := <-callback:
		if e != nil {
			t.Fatal(e)
		}
	case <-time.After(time.Second):
		t.Fatal("sibling token callback blocked")
	}
	// A separate goroutine detects the former global mutex hold without hanging the test.
	result := make(chan bool, 1)
	go func() { result <- a.wakeAllowed("third.example.com") }()
	select {
	case allowed := <-result:
		if !allowed {
			t.Fatal("unrelated admission refused")
		}
	case <-time.After(time.Second):
		t.Fatal("unrelated admission blocked")
	}
}