/*
Copyright 2015 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package deletion

import (
	"context"
	"fmt"
	"net/http"
	"net/http/httptest"
	"path"
	"strings"
	"sync"
	"testing"

	v1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/client-go/discovery"
	"k8s.io/client-go/dynamic"
	"k8s.io/client-go/kubernetes/fake"
	"k8s.io/client-go/metadata"
	metadatafake "k8s.io/client-go/metadata/fake"
	restclient "k8s.io/client-go/rest"
	core "k8s.io/client-go/testing"
	"k8s.io/klog/v2/ktesting"
	api "k8s.io/kubernetes/pkg/apis/core"
)

func TestFinalized(t *testing.T) {
	testNamespace := &v1.Namespace{
		Spec: v1.NamespaceSpec{
			Finalizers: []v1.FinalizerName{"a", "b"},
		},
	}
	if finalized(testNamespace) {
		t.Errorf("Unexpected result, namespace is not finalized")
	}
	testNamespace.Spec.Finalizers = []v1.FinalizerName{}
	if !finalized(testNamespace) {
		t.Errorf("Expected object to be finalized")
	}
}

func TestFinalizeNamespaceFunc(t *testing.T) {
	mockClient := &fake.Clientset{}
	testNamespace := &v1.Namespace{
		ObjectMeta: metav1.ObjectMeta{
			Name:            "test",
			ResourceVersion: "1",
		},
		Spec: v1.NamespaceSpec{
			Finalizers: []v1.FinalizerName{"kubernetes", "other"},
		},
	}
	d := namespacedResourcesDeleter{
		nsClient:       mockClient.CoreV1().Namespaces(),
		finalizerToken: v1.FinalizerKubernetes,
	}
	d.finalizeNamespace(context.Background(), testNamespace)
	actions := mockClient.Actions()
	if len(actions) != 1 {
		t.Errorf("Expected 1 mock client action, but got %v", len(actions))
	}
	if !actions[0].Matches("create", "namespaces") || actions[0].GetSubresource() != "finalize" {
		t.Errorf("Expected finalize-namespace action %v", actions[0])
	}
	finalizers := actions[0].(core.CreateAction).GetObject().(*v1.Namespace).Spec.Finalizers
	if len(finalizers) != 1 {
		t.Errorf("There should be a single finalizer remaining")
	}
	if string(finalizers[0]) != "other" {
		t.Errorf("Unexpected finalizer value, %v", finalizers[0])
	}
}

func testSyncNamespaceThatIsTerminating(t *testing.T, versions *metav1.APIVersions) {
	now := metav1.Now()
	namespaceName := "test"
	testNamespacePendingFinalize := &v1.Namespace{
		ObjectMeta: metav1.ObjectMeta{
			Name:              namespaceName,
			ResourceVersion:   "1",
			DeletionTimestamp: &now,
		},
		Spec: v1.NamespaceSpec{
			Finalizers: []v1.FinalizerName{"kubernetes"},
		},
		Status: v1.NamespaceStatus{
			Phase: v1.NamespaceTerminating,
		},
	}
	testNamespaceFinalizeComplete := &v1.Namespace{
		ObjectMeta: metav1.ObjectMeta{
			Name:              namespaceName,
			ResourceVersion:   "1",
			DeletionTimestamp: &now,
		},
		Spec: v1.NamespaceSpec{},
		Status: v1.NamespaceStatus{
			Phase: v1.NamespaceTerminating,
		},
	}

	// when doing a delete all of content, we will do a GET of a collection, and DELETE of a collection by default
	metadataClientActionSet := sets.NewString()
	resources := testResources()
	groupVersionResources, _ := discovery.GroupVersionResources(resources)
	for groupVersionResource := range groupVersionResources {
		urlPath := path.Join([]string{
			dynamic.LegacyAPIPathResolverFunc(schema.GroupVersionKind{Group: groupVersionResource.Group, Version: groupVersionResource.Version}),
			groupVersionResource.Group,
			groupVersionResource.Version,
			"namespaces",
			namespaceName,
			groupVersionResource.Resource,
		}...)
		metadataClientActionSet.Insert((&fakeAction{method: "GET", path: urlPath}).String())
		metadataClientActionSet.Insert((&fakeAction{method: "DELETE", path: urlPath}).String())
	}

	scenarios := map[string]struct {
		testNamespace           *v1.Namespace
		kubeClientActionSet     sets.String
		metadataClientActionSet sets.String
		gvrError                error
		expectErrorOnDelete     error
		expectStatus            *v1.NamespaceStatus
	}{
		"pending-finalize": {
			testNamespace: testNamespacePendingFinalize,
			kubeClientActionSet: sets.NewString(
				strings.Join([]string{"get", "namespaces", ""}, "-"),
				strings.Join([]string{"create", "namespaces", "finalize"}, "-"),
				strings.Join([]string{"list", "pods", ""}, "-"),
				strings.Join([]string{"update", "namespaces", "status"}, "-"),
			),
			metadataClientActionSet: metadataClientActionSet,
		},
		"complete-finalize": {
			testNamespace: testNamespaceFinalizeComplete,
			kubeClientActionSet: sets.NewString(
				strings.Join([]string{"get", "namespaces", ""}, "-"),
			),
			metadataClientActionSet: sets.NewString(),
		},
		"groupVersionResourceErr": {
			testNamespace: testNamespaceFinalizeComplete,
			kubeClientActionSet: sets.NewString(
				strings.Join([]string{"get", "namespaces", ""}, "-"),
			),
			metadataClientActionSet: sets.NewString(),
			gvrError:                fmt.Errorf("test error"),
		},
		"groupVersionResourceErr-finalize": {
			testNamespace: testNamespacePendingFinalize,
			kubeClientActionSet: sets.NewString(
				strings.Join([]string{"get", "namespaces", ""}, "-"),
				strings.Join([]string{"list", "pods", ""}, "-"),
				strings.Join([]string{"update", "namespaces", "status"}, "-"),
			),
			metadataClientActionSet: metadataClientActionSet,
			gvrError:                fmt.Errorf("test error"),
			expectErrorOnDelete:     fmt.Errorf("test error"),
			expectStatus: &v1.NamespaceStatus{
				Phase: v1.NamespaceTerminating,
				Conditions: []v1.NamespaceCondition{
					{Type: v1.NamespaceDeletionDiscoveryFailure},
				},
			},
		},
	}

	for scenario, testInput := range scenarios {
		t.Run(scenario, func(t *testing.T) {
			testHandler := &fakeActionHandler{statusCode: 200}
			srv, clientConfig := testServerAndClientConfig(testHandler.ServeHTTP)
			defer srv.Close()

			mockClient := fake.NewSimpleClientset(testInput.testNamespace)
			metadataClient, err := metadata.NewForConfig(clientConfig)
			if err != nil {
				t.Fatal(err)
			}

			fn := func() ([]*metav1.APIResourceList, error) {
				return resources, testInput.gvrError
			}
			_, ctx := ktesting.NewTestContext(t)
			d := NewNamespacedResourcesDeleter(ctx, mockClient.CoreV1().Namespaces(), metadataClient, mockClient.CoreV1(), fn, v1.FinalizerKubernetes)
			if err := d.Delete(ctx, testInput.testNamespace.Name); !matchErrors(err, testInput.expectErrorOnDelete) {
				t.Errorf("expected error %q when syncing namespace, got %q, %v", testInput.expectErrorOnDelete, err, testInput.expectErrorOnDelete == err)
			}

			// validate traffic from kube client
			actionSet := sets.NewString()
			for _, action := range mockClient.Actions() {
				actionSet.Insert(strings.Join([]string{action.GetVerb(), action.GetResource().Resource, action.GetSubresource()}, "-"))
			}
			if !actionSet.Equal(testInput.kubeClientActionSet) {
				t.Errorf("mock client expected actions:\n%v\n but got:\n%v\nDifference:\n%v",
					testInput.kubeClientActionSet, actionSet, testInput.kubeClientActionSet.Difference(actionSet))
			}

			// validate traffic from metadata client
			actionSet = sets.NewString()
			for _, action := range testHandler.actions {
				actionSet.Insert(action.String())
			}
			if !actionSet.Equal(testInput.metadataClientActionSet) {
				t.Errorf(" metadata client expected actions:\n%v\n but got:\n%v\nDifference:\n%v",
					testInput.metadataClientActionSet, actionSet, testInput.metadataClientActionSet.Difference(actionSet))
			}

			// validate status conditions
			if testInput.expectStatus != nil {
				obj, err := mockClient.Tracker().Get(schema.GroupVersionResource{Version: "v1", Resource: "namespaces"}, testInput.testNamespace.Namespace, testInput.testNamespace.Name)
				if err != nil {
					t.Fatalf("Unexpected error in getting the namespace: %v", err)
				}
				ns, ok := obj.(*v1.Namespace)
				if !ok {
					t.Fatalf("Expected a namespace but received %v", obj)
				}
				if ns.Status.Phase != testInput.expectStatus.Phase {
					t.Fatalf("Expected namespace status phase %v but received %v", testInput.expectStatus.Phase, ns.Status.Phase)
				}
				for _, expCondition := range testInput.expectStatus.Conditions {
					nsCondition := getCondition(ns.Status.Conditions, expCondition.Type)
					if nsCondition == nil {
						t.Fatalf("Missing namespace status condition %v", expCondition.Type)
					}
				}
			}
		})
	}
}

func TestRetryOnConflictError(t *testing.T) {
	mockClient := &fake.Clientset{}
	numTries := 0
	retryOnce := func(ctx context.Context, namespace *v1.Namespace) (*v1.Namespace, error) {
		numTries++
		if numTries <= 1 {
			return namespace, errors.NewConflict(api.Resource("namespaces"), namespace.Name, fmt.Errorf("ERROR"))
		}
		return namespace, nil
	}
	namespace := &v1.Namespace{}
	d := namespacedResourcesDeleter{
		nsClient: mockClient.CoreV1().Namespaces(),
	}
	_, err := d.retryOnConflictError(context.Background(), namespace, retryOnce)
	if err != nil {
		t.Errorf("Unexpected error %v", err)
	}
	if numTries != 2 {
		t.Errorf("Expected %v, but got %v", 2, numTries)
	}
}

func TestSyncNamespaceThatIsTerminatingNonExperimental(t *testing.T) {
	testSyncNamespaceThatIsTerminating(t, &metav1.APIVersions{})
}

func TestSyncNamespaceThatIsTerminatingV1(t *testing.T) {
	testSyncNamespaceThatIsTerminating(t, &metav1.APIVersions{Versions: []string{"apps/v1"}})
}

func TestSyncNamespaceThatIsActive(t *testing.T) {
	mockClient := &fake.Clientset{}
	testNamespace := &v1.Namespace{
		ObjectMeta: metav1.ObjectMeta{
			Name:            "test",
			ResourceVersion: "1",
		},
		Spec: v1.NamespaceSpec{
			Finalizers: []v1.FinalizerName{"kubernetes"},
		},
		Status: v1.NamespaceStatus{
			Phase: v1.NamespaceActive,
		},
	}
	fn := func() ([]*metav1.APIResourceList, error) {
		return testResources(), nil
	}
	_, ctx := ktesting.NewTestContext(t)
	d := NewNamespacedResourcesDeleter(ctx, mockClient.CoreV1().Namespaces(), nil, mockClient.CoreV1(),
		fn, v1.FinalizerKubernetes)
	err := d.Delete(ctx, testNamespace.Name)
	if err != nil {
		t.Errorf("Unexpected error when synching namespace %v", err)
	}
	if len(mockClient.Actions()) != 1 {
		t.Errorf("Expected only one action from controller, but got: %d %v", len(mockClient.Actions()), mockClient.Actions())
	}
	action := mockClient.Actions()[0]
	if !action.Matches("get", "namespaces") {
		t.Errorf("Expected get namespaces, got: %v", action)
	}
}

// matchError returns true if errors match, false if they don't, compares by error message only for convenience which should be sufficient for these tests
func matchErrors(e1, e2 error) bool {
	if e1 == nil && e2 == nil {
		return true
	}
	if e1 != nil && e2 != nil {
		return e1.Error() == e2.Error()
	}
	return false
}

// testServerAndClientConfig returns a server that listens and a config that can reference it
func testServerAndClientConfig(handler func(http.ResponseWriter, *http.Request)) (*httptest.Server, *restclient.Config) {
	srv := httptest.NewServer(http.HandlerFunc(handler))
	config := &restclient.Config{
		Host: srv.URL,
	}
	return srv, config
}

// fakeAction records information about requests to aid in testing.
type fakeAction struct {
	method string
	path   string
}

// String returns method=path to aid in testing
func (f *fakeAction) String() string {
	return strings.Join([]string{f.method, f.path}, "=")
}

// fakeActionHandler holds a list of fakeActions received
type fakeActionHandler struct {
	// statusCode returned by this handler
	statusCode int

	lock    sync.Mutex
	actions []fakeAction
}

// ServeHTTP logs the action that occurred and always returns the associated status code
func (f *fakeActionHandler) ServeHTTP(response http.ResponseWriter, request *http.Request) {
	f.lock.Lock()
	defer f.lock.Unlock()

	f.actions = append(f.actions, fakeAction{method: request.Method, path: request.URL.Path})
	response.Header().Set("Content-Type", runtime.ContentTypeJSON)
	response.WriteHeader(f.statusCode)
	response.Write([]byte("{\"apiVersion\": \"v1\", \"kind\": \"List\",\"items\":null}"))
}

// testResources returns a mocked up set of resources across different api groups for testing namespace controller.
func testResources() []*metav1.APIResourceList {
	results := []*metav1.APIResourceList{
		{
			GroupVersion: "v1",
			APIResources: []metav1.APIResource{
				{
					Name:       "pods",
					Namespaced: true,
					Kind:       "Pod",
					Verbs:      []string{"get", "list", "delete", "deletecollection", "create", "update"},
				},
				{
					Name:       "services",
					Namespaced: true,
					Kind:       "Service",
					Verbs:      []string{"get", "list", "delete", "deletecollection", "create", "update"},
				},
			},
		},
		{
			GroupVersion: "apps/v1",
			APIResources: []metav1.APIResource{
				{
					Name:       "deployments",
					Namespaced: true,
					Kind:       "Deployment",
					Verbs:      []string{"get", "list", "delete", "deletecollection", "create", "update"},
				},
			},
		},
	}
	return results
}

func TestDeleteEncounters404(t *testing.T) {
	now := metav1.Now()
	ns1 := &v1.Namespace{
		ObjectMeta: metav1.ObjectMeta{Name: "ns1", ResourceVersion: "1", DeletionTimestamp: &now},
		Spec:       v1.NamespaceSpec{Finalizers: []v1.FinalizerName{"kubernetes"}},
		Status:     v1.NamespaceStatus{Phase: v1.NamespaceActive},
	}
	ns2 := &v1.Namespace{
		ObjectMeta: metav1.ObjectMeta{Name: "ns2", ResourceVersion: "1", DeletionTimestamp: &now},
		Spec:       v1.NamespaceSpec{Finalizers: []v1.FinalizerName{"kubernetes"}},
		Status:     v1.NamespaceStatus{Phase: v1.NamespaceActive},
	}
	mockClient := fake.NewSimpleClientset(ns1, ns2)

	ns1FlakesNotFound := func(action core.Action) (handled bool, ret runtime.Object, err error) {
		if action.GetNamespace() == "ns1" {
			// simulate the flakes resource not existing when ns1 is processed
			return true, nil, errors.NewNotFound(schema.GroupResource{}, "")
		}
		return false, nil, nil
	}
	mockMetadataClient := metadatafake.NewSimpleMetadataClient(metadatafake.NewTestScheme())
	mockMetadataClient.PrependReactor("delete-collection", "flakes", ns1FlakesNotFound)
	mockMetadataClient.PrependReactor("list", "flakes", ns1FlakesNotFound)

	resourcesFn := func() ([]*metav1.APIResourceList, error) {
		return []*metav1.APIResourceList{{
			GroupVersion: "example.com/v1",
			APIResources: []metav1.APIResource{{Name: "flakes", Namespaced: true, Kind: "Flake", Verbs: []string{"get", "list", "delete", "deletecollection", "create", "update"}}},
		}}, nil
	}
	_, ctx := ktesting.NewTestContext(t)
	d := NewNamespacedResourcesDeleter(ctx, mockClient.CoreV1().Namespaces(), mockMetadataClient, mockClient.CoreV1(), resourcesFn, v1.FinalizerKubernetes)

	// Delete ns1 and get NotFound errors for the flakes resource
	mockMetadataClient.ClearActions()
	if err := d.Delete(ctx, ns1.Name); err != nil {
		t.Fatal(err)
	}
	if len(mockMetadataClient.Actions()) != 3 ||
		!mockMetadataClient.Actions()[0].Matches("delete-collection", "flakes") ||
		!mockMetadataClient.Actions()[1].Matches("list", "flakes") ||
		!mockMetadataClient.Actions()[2].Matches("list", "flakes") {
		for _, action := range mockMetadataClient.Actions() {
			t.Log("ns1", action)
		}
		t.Error("ns1: expected delete-collection -> fallback to list -> list to verify 0 items")
	}

	// Delete ns2
	mockMetadataClient.ClearActions()
	if err := d.Delete(ctx, ns2.Name); err != nil {
		t.Fatal(err)
	}
	if len(mockMetadataClient.Actions()) != 2 ||
		!mockMetadataClient.Actions()[0].Matches("delete-collection", "flakes") ||
		!mockMetadataClient.Actions()[1].Matches("list", "flakes") {
		for _, action := range mockMetadataClient.Actions() {
			t.Log("ns2", action)
		}
		t.Error("ns2: expected delete-collection -> list to verify 0 items")
	}
}
