package actionsgithubcom

import (
	"fmt"
	"strings"
	"testing"

	"github.com/actions/actions-runner-controller/apis/actions.github.com/v1alpha1"
	"github.com/actions/scaleset"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

func TestMetadataPropagation(t *testing.T) {
	autoscalingRunnerSet := v1alpha1.AutoscalingRunnerSet{
		ObjectMeta: metav1.ObjectMeta{
			Name:      "test-scale-set",
			Namespace: "test-ns",
			Labels: map[string]string{
				LabelKeyKubernetesPartOf:          labelValueKubernetesPartOf,
				LabelKeyKubernetesVersion:         "0.2.0",
				"arbitrary-label":                 "random-value",
				"example.com/label":               "example-value",
				"example.com/example":             "example-value",
				"directly.excluded.org/label":     "excluded-value",
				"directly.excluded.org/arbitrary": "not-excluded-value",
			},
			Annotations: map[string]string{
				runnerScaleSetIDAnnotationKey:         "1",
				AnnotationKeyGitHubRunnerGroupName:    "test-group",
				AnnotationKeyGitHubRunnerScaleSetName: "test-scale-set",
			},
		},
		Spec: v1alpha1.AutoscalingRunnerSetSpec{
			GitHubConfigUrl: "https://github.com/org/repo",
			AutoscalingListenerMetadata: &v1alpha1.ResourceMeta{
				Labels: map[string]string{
					"test.com/autoscaling-listener-label": "autoscaling-listener-label",
				},
				Annotations: map[string]string{
					"test.com/autoscaling-listener-annotation": "autoscaling-listener-annotation",
				},
			},
			ListenerServiceAccountMetadata: &v1alpha1.ResourceMeta{
				Labels: map[string]string{
					"test.com/listener-service-account-label": "listener-service-account-label",
				},
				Annotations: map[string]string{
					"test.com/listener-service-account-annotation": "listener-service-account-annotation",
				},
			},
			ListenerRoleMetadata: &v1alpha1.ResourceMeta{
				Labels: map[string]string{
					"test.com/listener-role-label": "listener-role-label",
				},
				Annotations: map[string]string{
					"test.com/listener-role-annotation": "listener-role-annotation",
				},
			},
			ListenerRoleBindingMetadata: &v1alpha1.ResourceMeta{
				Labels: map[string]string{
					"test.com/listener-role-binding-label": "listener-role-binding-label",
				},
				Annotations: map[string]string{
					"test.com/listener-role-binding-annotation": "listener-role-binding-annotation",
				},
			},
			ListenerConfigSecretMetadata: &v1alpha1.ResourceMeta{
				Labels: map[string]string{
					"test.com/listener-config-secret-label": "listener-config-secret-label",
				},
				Annotations: map[string]string{
					"test.com/listener-config-secret-annotation": "listener-config-secret-annotation",
				},
			},
			EphemeralRunnerSetMetadata: &v1alpha1.ResourceMeta{
				Labels: map[string]string{
					"test.com/ephemeral-runner-set-label": "ephemeral-runner-set-label",
				},
				Annotations: map[string]string{
					"test.com/ephemeral-runner-set-annotation": "ephemeral-runner-set-annotation",
				},
			},
			EphemeralRunnerMetadata: &v1alpha1.ResourceMeta{
				Labels: map[string]string{
					"test.com/ephemeral-runner-label": "ephemeral-runner-label",
				},
				Annotations: map[string]string{
					"test.com/ephemeral-runner-annotation": "ephemeral-runner-annotation",
				},
			},
			EphemeralRunnerConfigSecretMetadata: &v1alpha1.ResourceMeta{
				Labels: map[string]string{
					"test.com/ephemeral-runner-config-secret-label": "ephemeral-runner-config-secret-label",
				},
				Annotations: map[string]string{
					"test.com/ephemeral-runner-config-secret-annotation": "ephemeral-runner-config-secret-annotation",
				},
			},
		},
	}

	b := ResourceBuilder{
		ExcludeLabelPropagationPrefixes: []string{
			"example.com/",
			"directly.excluded.org/label",
		},
	}
	ephemeralRunnerSet, err := b.newEphemeralRunnerSet(&autoscalingRunnerSet)
	require.NoError(t, err)
	assert.Equal(t, labelValueKubernetesPartOf, ephemeralRunnerSet.Labels[LabelKeyKubernetesPartOf])
	assert.Equal(t, "runner-set", ephemeralRunnerSet.Labels[LabelKeyKubernetesComponent])
	assert.Equal(t, autoscalingRunnerSet.Labels[LabelKeyKubernetesVersion], ephemeralRunnerSet.Labels[LabelKeyKubernetesVersion])
	assert.NotEmpty(t, ephemeralRunnerSet.Annotations[annotationKeyRunnerSpecHash])
	assert.Equal(t, autoscalingRunnerSet.Name, ephemeralRunnerSet.Labels[LabelKeyGitHubScaleSetName])
	assert.Equal(t, autoscalingRunnerSet.Namespace, ephemeralRunnerSet.Labels[LabelKeyGitHubScaleSetNamespace])
	assert.Equal(t, "", ephemeralRunnerSet.Labels[LabelKeyGitHubEnterprise])
	assert.Equal(t, "org", ephemeralRunnerSet.Labels[LabelKeyGitHubOrganization])
	assert.Equal(t, "repo", ephemeralRunnerSet.Labels[LabelKeyGitHubRepository])
	assert.Equal(t, autoscalingRunnerSet.Annotations[AnnotationKeyGitHubRunnerGroupName], ephemeralRunnerSet.Annotations[AnnotationKeyGitHubRunnerGroupName])
	assert.Equal(t, autoscalingRunnerSet.Annotations[AnnotationKeyGitHubRunnerScaleSetName], ephemeralRunnerSet.Annotations[AnnotationKeyGitHubRunnerScaleSetName])
	assert.Equal(t, autoscalingRunnerSet.Labels["arbitrary-label"], ephemeralRunnerSet.Labels["arbitrary-label"])
	assert.Equal(t, "ephemeral-runner-set-label", ephemeralRunnerSet.Labels["test.com/ephemeral-runner-set-label"])
	assert.Equal(t, "ephemeral-runner-set-annotation", ephemeralRunnerSet.Annotations["test.com/ephemeral-runner-set-annotation"])

	listener, err := b.newAutoScalingListener(&autoscalingRunnerSet, ephemeralRunnerSet, autoscalingRunnerSet.Namespace, "test:latest", nil)
	require.NoError(t, err)
	assert.Equal(t, labelValueKubernetesPartOf, listener.Labels[LabelKeyKubernetesPartOf])
	assert.Equal(t, "runner-scale-set-listener", listener.Labels[LabelKeyKubernetesComponent])
	assert.Equal(t, autoscalingRunnerSet.Labels[LabelKeyKubernetesVersion], listener.Labels[LabelKeyKubernetesVersion])
	assert.NotEmpty(t, ephemeralRunnerSet.Annotations[annotationKeyRunnerSpecHash])
	assert.Equal(t, autoscalingRunnerSet.Name, listener.Labels[LabelKeyGitHubScaleSetName])
	assert.Equal(t, autoscalingRunnerSet.Namespace, listener.Labels[LabelKeyGitHubScaleSetNamespace])
	assert.Equal(t, "", listener.Labels[LabelKeyGitHubEnterprise])
	assert.Equal(t, "org", listener.Labels[LabelKeyGitHubOrganization])
	assert.Equal(t, "repo", listener.Labels[LabelKeyGitHubRepository])
	assert.Equal(t, autoscalingRunnerSet.Labels["arbitrary-label"], listener.Labels["arbitrary-label"])
	assert.Equal(t, "autoscaling-listener-label", listener.Labels["test.com/autoscaling-listener-label"])
	assert.Equal(t, "autoscaling-listener-annotation", listener.Annotations["test.com/autoscaling-listener-annotation"])

	assert.NotContains(t, listener.Labels, "example.com/label")
	assert.NotContains(t, listener.Labels, "example.com/example")
	assert.NotContains(t, listener.Labels, "directly.excluded.org/label")
	assert.Equal(t, "not-excluded-value", listener.Labels["directly.excluded.org/arbitrary"])

	listenerServiceAccount := b.newScaleSetListenerServiceAccount(listener)
	assert.Equal(t, "listener-service-account-label", listenerServiceAccount.Labels["test.com/listener-service-account-label"])
	assert.Equal(t, "listener-service-account-annotation", listenerServiceAccount.Annotations["test.com/listener-service-account-annotation"])

	listenerRole := b.newScaleSetListenerRole(listener)
	assert.Equal(t, "listener-role-label", listenerRole.Labels["test.com/listener-role-label"])
	assert.Equal(t, "listener-role-annotation", listenerRole.Annotations["test.com/listener-role-annotation"])

	listenerRoleBinding := b.newScaleSetListenerRoleBinding(listener, listenerRole, listenerServiceAccount)
	assert.Equal(t, "listener-role-binding-label", listenerRoleBinding.Labels["test.com/listener-role-binding-label"])
	assert.Equal(t, "listener-role-binding-annotation", listenerRoleBinding.Annotations["test.com/listener-role-binding-annotation"])

	listenerPod, err := b.newScaleSetListenerPod(listener, &corev1.Secret{}, listenerServiceAccount, nil)
	require.NoError(t, err)
	assert.Equal(t, listenerPod.Labels, listener.Labels)

	ephemeralRunner := b.newEphemeralRunner(ephemeralRunnerSet)
	require.NoError(t, err)

	for _, key := range commonLabelKeys {
		if key == LabelKeyKubernetesComponent {
			continue
		}
		assert.Equal(t, ephemeralRunnerSet.Labels[key], ephemeralRunner.Labels[key])
	}
	assert.Equal(t, "runner", ephemeralRunner.Labels[LabelKeyKubernetesComponent])
	assert.Equal(t, autoscalingRunnerSet.Annotations[AnnotationKeyGitHubRunnerGroupName], ephemeralRunner.Annotations[AnnotationKeyGitHubRunnerGroupName])
	assert.Equal(t, autoscalingRunnerSet.Annotations[AnnotationKeyGitHubRunnerScaleSetName], ephemeralRunnerSet.Annotations[AnnotationKeyGitHubRunnerScaleSetName])
	assert.Equal(t, "ephemeral-runner-label", ephemeralRunner.Labels["test.com/ephemeral-runner-label"])
	assert.Equal(t, "ephemeral-runner-annotation", ephemeralRunner.Annotations["test.com/ephemeral-runner-annotation"])

	runnerSecret := b.newEphemeralRunnerJitSecret(ephemeralRunner, &scaleset.RunnerScaleSetJitRunnerConfig{
		Runner: &scaleset.RunnerReference{
			ID:               1,
			Name:             "test",
			RunnerScaleSetID: 1,
		},
		EncodedJITConfig: "",
	})
	assert.Equal(t, "ephemeral-runner-config-secret-label", runnerSecret.Labels["test.com/ephemeral-runner-config-secret-label"])
	assert.Equal(t, "ephemeral-runner-config-secret-annotation", runnerSecret.Annotations["test.com/ephemeral-runner-config-secret-annotation"])

	pod := b.newEphemeralRunnerPod(ephemeralRunner, runnerSecret)
	for key := range ephemeralRunner.Labels {
		assert.Equal(t, ephemeralRunner.Labels[key], pod.Labels[key])
	}
}

func TestGitHubURLTrimLabelValues(t *testing.T) {
	enterprise := strings.Repeat("a", 64)
	organization := strings.Repeat("b", 64)
	repository := strings.Repeat("c", 64)

	autoscalingRunnerSet := v1alpha1.AutoscalingRunnerSet{
		ObjectMeta: metav1.ObjectMeta{
			Name:      "test-scale-set",
			Namespace: "test-ns",
			Labels: map[string]string{
				LabelKeyKubernetesPartOf:  labelValueKubernetesPartOf,
				LabelKeyKubernetesVersion: "0.2.0",
			},
			Annotations: map[string]string{
				runnerScaleSetIDAnnotationKey:         "1",
				AnnotationKeyGitHubRunnerGroupName:    "test-group",
				AnnotationKeyGitHubRunnerScaleSetName: "test-scale-set",
			},
		},
	}

	t.Run("org/repo", func(t *testing.T) {
		autoscalingRunnerSet := autoscalingRunnerSet.DeepCopy()
		autoscalingRunnerSet.Spec = v1alpha1.AutoscalingRunnerSetSpec{
			GitHubConfigUrl: fmt.Sprintf("https://github.com/%s/%s", organization, repository),
		}

		var b ResourceBuilder
		ephemeralRunnerSet, err := b.newEphemeralRunnerSet(autoscalingRunnerSet)
		require.NoError(t, err)
		assert.Len(t, ephemeralRunnerSet.Labels[LabelKeyGitHubEnterprise], 0)
		assert.Len(t, ephemeralRunnerSet.Labels[LabelKeyGitHubOrganization], 63)
		assert.Len(t, ephemeralRunnerSet.Labels[LabelKeyGitHubRepository], 63)
		assert.True(t, strings.HasSuffix(ephemeralRunnerSet.Labels[LabelKeyGitHubOrganization], trimLabelVauleSuffix))
		assert.True(t, strings.HasSuffix(ephemeralRunnerSet.Labels[LabelKeyGitHubRepository], trimLabelVauleSuffix))

		listener, err := b.newAutoScalingListener(autoscalingRunnerSet, ephemeralRunnerSet, autoscalingRunnerSet.Namespace, "test:latest", nil)
		require.NoError(t, err)
		assert.Len(t, listener.Labels[LabelKeyGitHubEnterprise], 0)
		assert.Len(t, listener.Labels[LabelKeyGitHubOrganization], 63)
		assert.Len(t, listener.Labels[LabelKeyGitHubRepository], 63)
		assert.True(t, strings.HasSuffix(ephemeralRunnerSet.Labels[LabelKeyGitHubOrganization], trimLabelVauleSuffix))
		assert.True(t, strings.HasSuffix(ephemeralRunnerSet.Labels[LabelKeyGitHubRepository], trimLabelVauleSuffix))
	})

	t.Run("enterprise", func(t *testing.T) {
		autoscalingRunnerSet := autoscalingRunnerSet.DeepCopy()
		autoscalingRunnerSet.Spec = v1alpha1.AutoscalingRunnerSetSpec{
			GitHubConfigUrl: fmt.Sprintf("https://github.com/enterprises/%s", enterprise),
		}

		var b ResourceBuilder
		ephemeralRunnerSet, err := b.newEphemeralRunnerSet(autoscalingRunnerSet)
		require.NoError(t, err)
		assert.Len(t, ephemeralRunnerSet.Labels[LabelKeyGitHubEnterprise], 63)
		assert.True(t, strings.HasSuffix(ephemeralRunnerSet.Labels[LabelKeyGitHubEnterprise], trimLabelVauleSuffix))
		assert.Len(t, ephemeralRunnerSet.Labels[LabelKeyGitHubOrganization], 0)
		assert.Len(t, ephemeralRunnerSet.Labels[LabelKeyGitHubRepository], 0)

		listener, err := b.newAutoScalingListener(autoscalingRunnerSet, ephemeralRunnerSet, autoscalingRunnerSet.Namespace, "test:latest", nil)
		require.NoError(t, err)
		assert.Len(t, listener.Labels[LabelKeyGitHubEnterprise], 63)
		assert.True(t, strings.HasSuffix(ephemeralRunnerSet.Labels[LabelKeyGitHubEnterprise], trimLabelVauleSuffix))
		assert.Len(t, listener.Labels[LabelKeyGitHubOrganization], 0)
		assert.Len(t, listener.Labels[LabelKeyGitHubRepository], 0)
	})
}

func TestOwnershipRelationships(t *testing.T) {
	// Create an AutoscalingRunnerSet
	autoscalingRunnerSet := v1alpha1.AutoscalingRunnerSet{
		ObjectMeta: metav1.ObjectMeta{
			Name:      "test-scale-set",
			Namespace: "test-ns",
			UID:       "test-autoscaling-runner-set-uid",
			Labels: map[string]string{
				LabelKeyKubernetesPartOf:  labelValueKubernetesPartOf,
				LabelKeyKubernetesVersion: "0.2.0",
			},
			Annotations: map[string]string{
				runnerScaleSetIDAnnotationKey:         "1",
				AnnotationKeyGitHubRunnerGroupName:    "test-group",
				AnnotationKeyGitHubRunnerScaleSetName: "test-scale-set",
				annotationKeyValuesHash:               "test-hash",
			},
		},
		Spec: v1alpha1.AutoscalingRunnerSetSpec{
			GitHubConfigUrl: "https://github.com/org/repo",
		},
	}

	// Initialize ResourceBuilder
	b := ResourceBuilder{}

	// Create EphemeralRunnerSet
	ephemeralRunnerSet, err := b.newEphemeralRunnerSet(&autoscalingRunnerSet)
	require.NoError(t, err)

	// Create and test Listener Pod ownership
	listener, err := b.newAutoScalingListener(&autoscalingRunnerSet, ephemeralRunnerSet, autoscalingRunnerSet.Namespace, "test:latest", nil)
	require.NoError(t, err)
	listener.UID = "test-listener-uid"
	listenerServiceAccount := &corev1.ServiceAccount{
		ObjectMeta: metav1.ObjectMeta{Name: "test-sa"},
	}
	listenerPod, err := b.newScaleSetListenerPod(listener, &corev1.Secret{}, listenerServiceAccount, nil)
	require.NoError(t, err)

	require.Len(t, listenerPod.OwnerReferences, 1, "Listener Pod should have exactly one owner reference")
	ownerRef := listenerPod.OwnerReferences[0]
	assert.Equal(t, v1alpha1.GroupVersion.String(), ownerRef.APIVersion, "Owner reference APIVersion should match GroupVersion")
	assert.Equal(t, "AutoscalingListener", ownerRef.Kind, "Owner reference Kind should be AutoscalingListener")
	assert.Equal(t, listener.GetName(), ownerRef.Name, "Owner reference name should match AutoscalingListener name")
	assert.Equal(t, listener.GetUID(), ownerRef.UID, "Owner reference UID should match AutoscalingListener UID")
	assert.Equal(t, true, *ownerRef.Controller, "Controller flag should be true")
	assert.Equal(t, true, *ownerRef.BlockOwnerDeletion, "BlockOwnerDeletion flag should be true")

	// Test EphemeralRunnerSet ownership
	require.Len(t, ephemeralRunnerSet.OwnerReferences, 1, "EphemeralRunnerSet should have exactly one owner reference")
	ownerRef = ephemeralRunnerSet.OwnerReferences[0]
	assert.Equal(t, v1alpha1.GroupVersion.String(), ownerRef.APIVersion, "Owner reference APIVersion should match GroupVersion")
	assert.Equal(t, "AutoscalingRunnerSet", ownerRef.Kind, "Owner reference Kind should be AutoscalingRunnerSet")
	assert.Equal(t, autoscalingRunnerSet.GetName(), ownerRef.Name, "Owner reference name should match AutoscalingRunnerSet name")
	assert.Equal(t, autoscalingRunnerSet.GetUID(), ownerRef.UID, "Owner reference UID should match AutoscalingRunnerSet UID")
	assert.Equal(t, true, *ownerRef.Controller, "Controller flag should be true")
	assert.Equal(t, true, *ownerRef.BlockOwnerDeletion, "BlockOwnerDeletion flag should be true")

	// Create EphemeralRunner
	ephemeralRunner := b.newEphemeralRunner(ephemeralRunnerSet)

	// Test EphemeralRunner ownership
	require.Len(t, ephemeralRunner.OwnerReferences, 1, "EphemeralRunner should have exactly one owner reference")
	ownerRef = ephemeralRunner.OwnerReferences[0]
	assert.Equal(t, v1alpha1.GroupVersion.String(), ownerRef.APIVersion, "Owner reference APIVersion should match GroupVersion")
	assert.Equal(t, "EphemeralRunnerSet", ownerRef.Kind, "Owner reference Kind should be EphemeralRunnerSet")
	assert.Equal(t, ephemeralRunnerSet.GetName(), ownerRef.Name, "Owner reference name should match EphemeralRunnerSet name")
	assert.Equal(t, ephemeralRunnerSet.GetUID(), ownerRef.UID, "Owner reference UID should match EphemeralRunnerSet UID")
	assert.Equal(t, true, *ownerRef.Controller, "Controller flag should be true")
	assert.Equal(t, true, *ownerRef.BlockOwnerDeletion, "BlockOwnerDeletion flag should be true")

	// Create EphemeralRunnerPod
	runnerSecret := &corev1.Secret{
		ObjectMeta: metav1.ObjectMeta{
			Name: "test-secret",
		},
	}
	pod := b.newEphemeralRunnerPod(ephemeralRunner, runnerSecret)

	// Test EphemeralRunnerPod ownership
	require.Len(t, pod.OwnerReferences, 1, "EphemeralRunnerPod should have exactly one owner reference")
	ownerRef = pod.OwnerReferences[0]
	assert.Equal(t, v1alpha1.GroupVersion.String(), ownerRef.APIVersion, "Owner reference APIVersion should match GroupVersion")
	assert.Equal(t, "EphemeralRunner", ownerRef.Kind, "Owner reference Kind should be EphemeralRunner")
	assert.Equal(t, ephemeralRunner.GetName(), ownerRef.Name, "Owner reference name should match EphemeralRunner name")
	assert.Equal(t, ephemeralRunner.GetUID(), ownerRef.UID, "Owner reference UID should match EphemeralRunner UID")
	assert.Equal(t, true, *ownerRef.Controller, "Controller flag should be true")
	assert.Equal(t, true, *ownerRef.BlockOwnerDeletion, "BlockOwnerDeletion flag should be true")
}

func TestListenerPodNodeSelector(t *testing.T) {
	autoscalingRunnerSet := v1alpha1.AutoscalingRunnerSet{
		ObjectMeta: metav1.ObjectMeta{
			Name:      "test-scale-set",
			Namespace: "test-ns",
			Labels: map[string]string{
				LabelKeyKubernetesPartOf:  labelValueKubernetesPartOf,
				LabelKeyKubernetesVersion: "0.2.0",
			},
			Annotations: map[string]string{
				runnerScaleSetIDAnnotationKey:         "1",
				AnnotationKeyGitHubRunnerGroupName:    "test-group",
				AnnotationKeyGitHubRunnerScaleSetName: "test-scale-set",
			},
		},
		Spec: v1alpha1.AutoscalingRunnerSetSpec{
			GitHubConfigUrl: "https://github.com/org/repo",
		},
	}

	b := ResourceBuilder{}
	ephemeralRunnerSet, err := b.newEphemeralRunnerSet(&autoscalingRunnerSet)
	require.NoError(t, err)

	listener, err := b.newAutoScalingListener(&autoscalingRunnerSet, ephemeralRunnerSet, autoscalingRunnerSet.Namespace, "test:latest", nil)
	require.NoError(t, err)

	listenerServiceAccount := &corev1.ServiceAccount{
		ObjectMeta: metav1.ObjectMeta{
			Name: "test",
		},
	}

	t.Run("default listener pod has linux nodeSelector", func(t *testing.T) {
		pod, err := b.newScaleSetListenerPod(listener, &corev1.Secret{}, listenerServiceAccount, nil)
		require.NoError(t, err)
		require.NotNil(t, pod.Spec.NodeSelector)
		assert.Equal(t, "linux", pod.Spec.NodeSelector[LabelKeyKubernetesOS],
			"listener pod should default to linux nodeSelector")
	})

	t.Run("nil listenerTemplate preserves linux nodeSelector", func(t *testing.T) {
		listenerNoTemplate := listener.DeepCopy()
		listenerNoTemplate.Spec.Template = nil

		pod, err := b.newScaleSetListenerPod(listenerNoTemplate, &corev1.Secret{}, listenerServiceAccount, nil)
		require.NoError(t, err)
		require.NotNil(t, pod.Spec.NodeSelector)
		assert.Equal(t, "linux", pod.Spec.NodeSelector[LabelKeyKubernetesOS],
			"listener pod should keep linux nodeSelector when no template is provided")
	})

	t.Run("listenerTemplate with nil nodeSelector preserves linux default", func(t *testing.T) {
		listenerWithTemplate := listener.DeepCopy()
		listenerWithTemplate.Spec.Template = &corev1.PodTemplateSpec{
			Spec: corev1.PodSpec{
				// NodeSelector intentionally nil
				Tolerations: []corev1.Toleration{
					{Key: "example.com/test", Operator: corev1.TolerationOpExists},
				},
			},
		}

		pod, err := b.newScaleSetListenerPod(listenerWithTemplate, &corev1.Secret{}, listenerServiceAccount, nil)
		require.NoError(t, err)
		require.NotNil(t, pod.Spec.NodeSelector,
			"linux nodeSelector should not be cleared by template with nil nodeSelector")
		assert.Equal(t, "linux", pod.Spec.NodeSelector[LabelKeyKubernetesOS])
		assert.Len(t, pod.Spec.Tolerations, 1, "other template fields should still be applied")
	})

	t.Run("listenerTemplate with explicit nodeSelector overrides default", func(t *testing.T) {
		listenerWithTemplate := listener.DeepCopy()
		listenerWithTemplate.Spec.Template = &corev1.PodTemplateSpec{
			Spec: corev1.PodSpec{
				NodeSelector: map[string]string{
					LabelKeyKubernetesOS: "linux",
					"custom-label/pool":  "listeners",
				},
			},
		}

		pod, err := b.newScaleSetListenerPod(listenerWithTemplate, &corev1.Secret{}, listenerServiceAccount, nil)
		require.NoError(t, err)
		require.NotNil(t, pod.Spec.NodeSelector)
		assert.Equal(t, "linux", pod.Spec.NodeSelector[LabelKeyKubernetesOS])
		assert.Equal(t, "listeners", pod.Spec.NodeSelector["custom-label/pool"],
			"explicit template nodeSelector should be applied")
	})

	t.Run("listenerTemplate with empty nodeSelector overrides default", func(t *testing.T) {
		listenerWithTemplate := listener.DeepCopy()
		listenerWithTemplate.Spec.Template = &corev1.PodTemplateSpec{
			Spec: corev1.PodSpec{
				NodeSelector: map[string]string{},
			},
		}

		pod, err := b.newScaleSetListenerPod(listenerWithTemplate, &corev1.Secret{}, listenerServiceAccount, nil)
		require.NoError(t, err)
		// An explicitly set empty map is non-nil, so it overrides the default.
		// This is intentional: the user explicitly opted out of nodeSelector constraints.
		assert.NotNil(t, pod.Spec.NodeSelector)
		assert.Empty(t, pod.Spec.NodeSelector,
			"explicitly empty nodeSelector should override the linux default")
	})
}