/*
Copyright 2023 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 options

import (
	"context"
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"encoding/pem"
	"fmt"
	"os"
	"reflect"
	"testing"
	"time"

	"github.com/google/go-cmp/cmp"
	"github.com/google/go-cmp/cmp/cmpopts"
	"github.com/spf13/pflag"
	noopoteltrace "go.opentelemetry.io/otel/trace/noop"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	"k8s.io/apiserver/pkg/admission"
	apiserveroptions "k8s.io/apiserver/pkg/server/options"
	"k8s.io/apiserver/pkg/storage/etcd3"
	"k8s.io/apiserver/pkg/storage/storagebackend"
	auditbuffered "k8s.io/apiserver/plugin/pkg/audit/buffered"
	audittruncate "k8s.io/apiserver/plugin/pkg/audit/truncate"
	cliflag "k8s.io/component-base/cli/flag"
	basecompatibility "k8s.io/component-base/compatibility"
	"k8s.io/component-base/featuregate"
	"k8s.io/component-base/logs"
	"k8s.io/component-base/metrics"
	kubeoptions "k8s.io/kubernetes/pkg/kubeapiserver/options"
	"k8s.io/kubernetes/pkg/serviceaccount"
	v1alpha1testing "k8s.io/kubernetes/pkg/serviceaccount/externaljwt/plugin/testing/v1alpha1"
	netutils "k8s.io/utils/net"
)

func TestAddFlags(t *testing.T) {
	componentGlobalsRegistry := basecompatibility.NewComponentGlobalsRegistry()
	fs := pflag.NewFlagSet("addflagstest", pflag.PanicOnError)
	utilruntime.Must(componentGlobalsRegistry.Register("test", basecompatibility.NewEffectiveVersionFromString("1.32", "1.31", "1.31"), featuregate.NewFeatureGate()))
	s := NewOptions()
	s.GenericServerRunOptions.ComponentGlobalsRegistry = componentGlobalsRegistry
	var fss cliflag.NamedFlagSets
	s.AddFlags(&fss)
	for _, f := range fss.FlagSets {
		fs.AddFlagSet(f)
	}

	args := []string{
		"--enable-admission-plugins=AlwaysDeny",
		"--admission-control-config-file=/admission-control-config",
		"--advertise-address=192.168.10.10",
		"--anonymous-auth=false",
		"--audit-log-maxage=11",
		"--audit-log-maxbackup=12",
		"--audit-log-maxsize=13",
		"--audit-log-path=/var/log",
		"--audit-log-mode=blocking",
		"--audit-log-batch-buffer-size=46",
		"--audit-log-batch-max-size=47",
		"--audit-log-batch-max-wait=48s",
		"--audit-log-batch-throttle-enable=true",
		"--audit-log-batch-throttle-qps=49.5",
		"--audit-log-batch-throttle-burst=50",
		"--audit-log-truncate-enabled=true",
		"--audit-log-truncate-max-batch-size=45",
		"--audit-log-truncate-max-event-size=44",
		"--audit-log-version=audit.k8s.io/v1",
		"--audit-policy-file=/policy",
		"--audit-webhook-config-file=/webhook-config",
		"--audit-webhook-mode=blocking",
		"--audit-webhook-batch-buffer-size=42",
		"--audit-webhook-batch-max-size=43",
		"--audit-webhook-batch-max-wait=1s",
		"--audit-webhook-batch-throttle-enable=false",
		"--audit-webhook-batch-throttle-qps=43.5",
		"--audit-webhook-batch-throttle-burst=44",
		"--audit-webhook-truncate-enabled=true",
		"--audit-webhook-truncate-max-batch-size=43",
		"--audit-webhook-truncate-max-event-size=42",
		"--audit-webhook-initial-backoff=2s",
		"--audit-webhook-version=audit.k8s.io/v1",
		"--authentication-token-webhook-cache-ttl=3m",
		"--authentication-token-webhook-config-file=/token-webhook-config",
		"--authorization-mode=AlwaysDeny,RBAC",
		"--authorization-policy-file=/policy",
		"--authorization-webhook-cache-authorized-ttl=3m",
		"--authorization-webhook-cache-unauthorized-ttl=1m",
		"--authorization-webhook-config-file=/webhook-config",
		"--bind-address=192.168.10.20",
		"--client-ca-file=/client-ca",
		"--cors-allowed-origins=10.10.10.100,10.10.10.200",
		"--contention-profiling=true",
		"--egress-selector-config-file=/var/run/kubernetes/egress-selector/connectivity.yaml",
		"--enable-aggregator-routing=true",
		"--enable-priority-and-fairness=false",
		"--enable-logs-handler=false",
		"--etcd-keyfile=/var/run/kubernetes/etcd.key",
		"--etcd-certfile=/var/run/kubernetes/etcdce.crt",
		"--etcd-cafile=/var/run/kubernetes/etcdca.crt",
		"--http2-max-streams-per-connection=42",
		"--tracing-config-file=/var/run/kubernetes/tracing_config.yaml",
		"--proxy-client-cert-file=/var/run/kubernetes/proxy.crt",
		"--proxy-client-key-file=/var/run/kubernetes/proxy.key",
		"--request-timeout=2m",
		"--storage-backend=etcd3",
		"--lease-reuse-duration-seconds=100",
		"--emulated-version=test=1.31",
	}
	fs.Parse(args)
	utilruntime.Must(componentGlobalsRegistry.Set())

	// This is a snapshot of expected options parsed by args.
	expected := &Options{
		GenericServerRunOptions: &apiserveroptions.ServerRunOptions{
			AdvertiseAddress:             netutils.ParseIPSloppy("192.168.10.10"),
			CorsAllowedOriginList:        []string{"10.10.10.100", "10.10.10.200"},
			MaxRequestsInFlight:          400,
			MaxMutatingRequestsInFlight:  200,
			RequestTimeout:               time.Duration(2) * time.Minute,
			MinRequestTimeout:            1800,
			StorageInitializationTimeout: time.Minute,
			JSONPatchMaxCopyBytes:        int64(3 * 1024 * 1024),
			MaxRequestBodyBytes:          int64(3 * 1024 * 1024),
			ComponentGlobalsRegistry:     componentGlobalsRegistry,
			ComponentName:                basecompatibility.DefaultKubeComponent,
		},
		Admission: &kubeoptions.AdmissionOptions{
			GenericAdmission: &apiserveroptions.AdmissionOptions{
				RecommendedPluginOrder: s.Admission.GenericAdmission.RecommendedPluginOrder,
				DefaultOffPlugins:      s.Admission.GenericAdmission.DefaultOffPlugins,
				EnablePlugins:          []string{"AlwaysDeny"},
				ConfigFile:             "/admission-control-config",
				Plugins:                s.Admission.GenericAdmission.Plugins,
				Decorators:             s.Admission.GenericAdmission.Decorators,
			},
		},
		Etcd: &apiserveroptions.EtcdOptions{
			StorageConfig: storagebackend.Config{
				Type: "etcd3",
				Transport: storagebackend.TransportConfig{
					ServerList:     nil,
					KeyFile:        "/var/run/kubernetes/etcd.key",
					TrustedCAFile:  "/var/run/kubernetes/etcdca.crt",
					CertFile:       "/var/run/kubernetes/etcdce.crt",
					TracerProvider: noopoteltrace.NewTracerProvider(),
				},
				Prefix:                "/registry",
				CompactionInterval:    storagebackend.DefaultCompactInterval,
				CountMetricPollPeriod: time.Minute,
				DBMetricPollInterval:  storagebackend.DefaultDBMetricPollInterval,
				EventsHistoryWindow:   storagebackend.DefaultEventsHistoryWindow,
				HealthcheckTimeout:    storagebackend.DefaultHealthcheckTimeout,
				ReadycheckTimeout:     storagebackend.DefaultReadinessTimeout,
				LeaseManagerConfig: etcd3.LeaseManagerConfig{
					ReuseDurationSeconds: 100,
					MaxObjectCount:       1000,
				},
			},
			DefaultStorageMediaType: "application/vnd.kubernetes.protobuf",
			DeleteCollectionWorkers: 1,
			EnableGarbageCollection: true,
			EnableWatchCache:        true,
			DefaultWatchCacheSize:   100,
		},
		SecureServing: (&apiserveroptions.SecureServingOptions{
			BindAddress: netutils.ParseIPSloppy("192.168.10.20"),
			BindPort:    6443,
			ServerCert: apiserveroptions.GeneratableKeyCert{
				CertDirectory: "/var/run/kubernetes",
				PairName:      "apiserver",
			},
			HTTP2MaxStreamsPerConnection: 42,
			Required:                     true,
		}).WithLoopback(),
		EventTTL: 1 * time.Hour,
		Audit: &apiserveroptions.AuditOptions{
			LogOptions: apiserveroptions.AuditLogOptions{
				Path:       "/var/log",
				MaxAge:     11,
				MaxBackups: 12,
				MaxSize:    13,
				Format:     "json",
				BatchOptions: apiserveroptions.AuditBatchOptions{
					Mode: "blocking",
					BatchConfig: auditbuffered.BatchConfig{
						BufferSize:     46,
						MaxBatchSize:   47,
						MaxBatchWait:   48 * time.Second,
						ThrottleEnable: true,
						ThrottleQPS:    49.5,
						ThrottleBurst:  50,
					},
				},
				TruncateOptions: apiserveroptions.AuditTruncateOptions{
					Enabled: true,
					TruncateConfig: audittruncate.Config{
						MaxBatchSize: 45,
						MaxEventSize: 44,
					},
				},
				GroupVersionString: "audit.k8s.io/v1",
			},
			WebhookOptions: apiserveroptions.AuditWebhookOptions{
				ConfigFile: "/webhook-config",
				BatchOptions: apiserveroptions.AuditBatchOptions{
					Mode: "blocking",
					BatchConfig: auditbuffered.BatchConfig{
						BufferSize:     42,
						MaxBatchSize:   43,
						MaxBatchWait:   1 * time.Second,
						ThrottleEnable: false,
						ThrottleQPS:    43.5,
						ThrottleBurst:  44,
						AsyncDelegate:  true,
					},
				},
				TruncateOptions: apiserveroptions.AuditTruncateOptions{
					Enabled: true,
					TruncateConfig: audittruncate.Config{
						MaxBatchSize: 43,
						MaxEventSize: 42,
					},
				},
				InitialBackoff:     2 * time.Second,
				GroupVersionString: "audit.k8s.io/v1",
			},
			PolicyFile: "/policy",
		},
		Features: &apiserveroptions.FeatureOptions{
			EnableProfiling:           true,
			EnableContentionProfiling: true,
		},
		Authentication: &kubeoptions.BuiltInAuthenticationOptions{
			Anonymous: s.Authentication.Anonymous,
			ClientCert: &apiserveroptions.ClientCertAuthenticationOptions{
				ClientCA: "/client-ca",
			},
			WebHook: &kubeoptions.WebHookAuthenticationOptions{
				CacheTTL:     180000000000,
				ConfigFile:   "/token-webhook-config",
				Version:      "v1beta1",
				RetryBackoff: apiserveroptions.DefaultAuthWebhookRetryBackoff(),
			},
			BootstrapToken: &kubeoptions.BootstrapTokenAuthenticationOptions{},
			OIDC:           s.Authentication.OIDC,
			RequestHeader:  &apiserveroptions.RequestHeaderAuthenticationOptions{},
			ServiceAccounts: &kubeoptions.ServiceAccountAuthenticationOptions{
				Lookup:                true,
				ExtendExpiration:      true,
				MaxExtendedExpiration: serviceaccount.ExpirationExtensionSeconds * time.Second,
			},
			TokenFile:            &kubeoptions.TokenFileAuthenticationOptions{},
			TokenSuccessCacheTTL: 10 * time.Second,
			TokenFailureCacheTTL: 0,
		},
		Authorization: &kubeoptions.BuiltInAuthorizationOptions{
			Modes:                       []string{"AlwaysDeny", "RBAC"},
			PolicyFile:                  "/policy",
			WebhookConfigFile:           "/webhook-config",
			WebhookCacheAuthorizedTTL:   180000000000,
			WebhookCacheUnauthorizedTTL: 60000000000,
			WebhookVersion:              "v1beta1",
			WebhookRetryBackoff:         apiserveroptions.DefaultAuthWebhookRetryBackoff(),
		},
		APIEnablement: &apiserveroptions.APIEnablementOptions{
			RuntimeConfig: cliflag.ConfigurationMap{},
		},
		EgressSelector: &apiserveroptions.EgressSelectorOptions{
			ConfigFile: "/var/run/kubernetes/egress-selector/connectivity.yaml",
		},
		EnableLogsHandler:       false,
		EnableAggregatorRouting: true,
		ProxyClientKeyFile:      "/var/run/kubernetes/proxy.key",
		ProxyClientCertFile:     "/var/run/kubernetes/proxy.crt",
		Metrics:                 &metrics.Options{},
		Logs:                    logs.NewOptions(),
		Traces: &apiserveroptions.TracingOptions{
			ConfigFile: "/var/run/kubernetes/tracing_config.yaml",
		},
		AggregatorRejectForwardingRedirects: true,
		SystemNamespaces:                    []string{"kube-system", "kube-public", "default"},
	}

	expected.Authentication.OIDC.UsernameClaim = "sub"
	expected.Authentication.OIDC.SigningAlgs = []string{"RS256"}

	if !s.Authorization.AreLegacyFlagsSet() {
		t.Errorf("expected legacy authorization flags to be set")
	}
	// setting the method to nil since methods can't be compared with reflect.DeepEqual
	s.Authorization.AreLegacyFlagsSet = nil

	if !reflect.DeepEqual(expected, s) {
		t.Errorf("Got different run options than expected.\nDifference detected on:\n%s", cmp.Diff(expected, s, cmpopts.IgnoreFields(apiserveroptions.ServerRunOptions{}, "ComponentGlobalsRegistry"), cmpopts.IgnoreUnexported(admission.Plugins{}, kubeoptions.OIDCAuthenticationOptions{}, kubeoptions.AnonymousAuthenticationOptions{})))
	}

	testEffectiveVersion := s.GenericServerRunOptions.ComponentGlobalsRegistry.EffectiveVersionFor("test")
	if testEffectiveVersion.EmulationVersion().String() != "1.31" {
		t.Errorf("Got emulation version %s, wanted %s", testEffectiveVersion.EmulationVersion().String(), "1.31")
	}
}

func TestCompleteForServiceAccount(t *testing.T) {

	key, err := rsa.GenerateKey(rand.Reader, 2048)
	if err != nil {
		panic("Error while generating first RSA key")
	}

	// Marshal the private key into PEM format
	privateKeyPEM := &pem.Block{
		Type:  "RSA PRIVATE KEY",
		Bytes: x509.MarshalPKCS1PrivateKey(key),
	}

	// Open a file to write the private key
	privateKeyFile, err := os.Create("private_key.pem")
	if err != nil {
		t.Fatalf("Failed to create private key file: %v", err)
	}
	t.Cleanup(func() {
		_ = privateKeyFile.Close()
		_ = os.Remove("private_key.pem")
	})

	// Write the PEM-encoded private key to the file
	if err := pem.Encode(privateKeyFile, privateKeyPEM); err != nil {
		t.Fatalf("Failed to encode private key: %v", err)
	}

	testCases := []struct {
		desc                     string
		issuers                  []string
		externalSigner           bool
		signingKeyFiles          string
		maxExpiration            time.Duration
		maxExtendedExpiration    time.Duration
		externalMaxExpirationSec int64
		fetchError               error
		metadataError            error

		wantError                      error
		expectedMaxtokenExp            time.Duration
		expectedExtendedMaxTokenExp    time.Duration
		externalPublicKeyGetterPresent bool
	}{
		{
			desc: "endpoint and key file",
			issuers: []string{
				"iss",
			},
			externalSigner:  true,
			signingKeyFiles: "private_key.pem",
			maxExpiration:   time.Second * 3600,

			wantError: fmt.Errorf("service-account-signing-key-file and service-account-signing-endpoint are mutually exclusive and cannot be set at the same time"),
		},
		{
			desc: "max token expiration breaching acceptable values",
			issuers: []string{
				"iss",
			},
			externalSigner:  true,
			signingKeyFiles: "private_key.pem",
			maxExpiration:   time.Second * 10,

			wantError: fmt.Errorf("the service-account-max-token-expiration must be between 1 hour and 2^32 seconds"),
		},
		{
			desc: "path to a signing key provided",
			issuers: []string{
				"iss",
			},
			externalSigner:  false,
			signingKeyFiles: "private_key.pem",
			maxExpiration:   time.Second * 3600,

			externalPublicKeyGetterPresent: false,
			expectedMaxtokenExp:            time.Second * 3600,
		},
		{
			desc: "signing endpoint provided, use endpoint expiration",
			issuers: []string{
				"iss",
			},
			externalSigner:           true,
			signingKeyFiles:          "",
			maxExpiration:            0,
			maxExtendedExpiration:    365 * 24 * time.Hour,
			externalMaxExpirationSec: 600, // 10m

			expectedMaxtokenExp:            10 * time.Minute,
			expectedExtendedMaxTokenExp:    10 * time.Minute,
			externalPublicKeyGetterPresent: true,
		},
		{
			desc: "signing endpoint provided, use local smaller expirations",
			issuers: []string{
				"iss",
			},
			externalSigner:           true,
			signingKeyFiles:          "",
			maxExpiration:            1 * time.Hour,
			maxExtendedExpiration:    24 * time.Hour,
			externalMaxExpirationSec: 31556952, // 1 year

			expectedMaxtokenExp:            1 * time.Hour,
			expectedExtendedMaxTokenExp:    24 * time.Hour,
			externalPublicKeyGetterPresent: true,
		},
		{
			desc: "signing endpoint provided and want larger than signer can provide",
			issuers: []string{
				"iss",
			},
			externalSigner:           true,
			signingKeyFiles:          "",
			maxExpiration:            1 * time.Hour, // want 1hr
			externalMaxExpirationSec: 600,           // signer can only sign 10m

			wantError: fmt.Errorf("service-account-max-token-expiration cannot be set longer than the token expiration supported by service-account-signing-endpoint: 1h0m0s > 10m0s"),
		},
		{
			desc: "signing endpoint provided but return smaller than accaptable max token exp",
			issuers: []string{
				"iss",
			},
			externalSigner:           true,
			signingKeyFiles:          "",
			maxExpiration:            0,
			externalMaxExpirationSec: 300, // 5m

			wantError: fmt.Errorf("max token life supported by external-jwt-signer (300s) is less than acceptable (min 600s)"),
		},
		{
			desc: "signing endpoint provided and error when getting metadata",
			issuers: []string{
				"iss",
			},
			externalSigner:           true,
			signingKeyFiles:          "",
			maxExpiration:            0,
			externalMaxExpirationSec: 900, // 15m
			metadataError:            fmt.Errorf("metadata error"),

			wantError: fmt.Errorf("while setting up external-jwt-signer: rpc error: code = Unknown desc = metadata error"),
		},
		{
			desc: "signing endpoint provided and error when creating plugin (during initial fetch)",
			issuers: []string{
				"iss",
			},
			externalSigner:           true,
			signingKeyFiles:          "",
			maxExpiration:            0,
			externalMaxExpirationSec: 900, // 15m
			fetchError:               fmt.Errorf("keys fetch error"),

			wantError: fmt.Errorf("while setting up external-jwt-signer: while initially filling key cache: while performing initial cache fill: while fetching token verification keys: while getting externally supported jwt signing keys: rpc error: code = Unknown desc = keys fetch error"),
		},
	}

	for _, tc := range testCases {
		t.Run(tc.desc, func(t *testing.T) {

			options := NewOptions()
			if tc.externalSigner {
				// create and start mock signer.
				socketPath := fmt.Sprintf("@mock-external-jwt-signer-%d.sock", time.Now().Nanosecond())
				mockSigner := v1alpha1testing.NewMockSigner(t, socketPath)
				defer mockSigner.CleanUp()

				mockSigner.MaxTokenExpirationSeconds = tc.externalMaxExpirationSec
				mockSigner.MetadataError = tc.metadataError
				mockSigner.FetchError = tc.fetchError

				options.ServiceAccountSigningEndpoint = socketPath
			}
			options.ServiceAccountSigningKeyFile = tc.signingKeyFiles
			options.Authentication = &kubeoptions.BuiltInAuthenticationOptions{
				ServiceAccounts: &kubeoptions.ServiceAccountAuthenticationOptions{
					Issuers:               tc.issuers,
					MaxExpiration:         tc.maxExpiration,
					MaxExtendedExpiration: tc.maxExtendedExpiration,
				},
			}

			co := completedOptions{
				Options: *options,
			}

			ctx, cancel := context.WithCancel(context.Background())
			defer cancel()
			err := options.completeServiceAccountOptions(ctx, &co)

			if tc.wantError != nil {
				if err == nil || tc.wantError.Error() != err.Error() {
					t.Errorf("Expected error: %v, got: %v", tc.wantError, err)
				}
				return
			}

			if err != nil {
				t.Errorf("Didn't expect any error but got: %v", err)
			}
			if tc.externalPublicKeyGetterPresent != (co.Authentication.ServiceAccounts.ExternalPublicKeysGetter != nil) {
				t.Errorf("Unexpected value of ExternalPublicKeysGetter: %v", co.Authentication.ServiceAccounts.ExternalPublicKeysGetter)
			}
			if tc.expectedExtendedMaxTokenExp != co.Authentication.ServiceAccounts.MaxExtendedExpiration {
				t.Errorf("Expected MaxExtendedExpiration %v, found %v", tc.expectedExtendedMaxTokenExp, co.Authentication.ServiceAccounts.MaxExtendedExpiration)
			}
			if tc.expectedMaxtokenExp.Seconds() != co.Authentication.ServiceAccounts.MaxExpiration.Seconds() {
				t.Errorf("Expected MaxExpiration to be %v, found %v", tc.expectedMaxtokenExp, co.Authentication.ServiceAccounts.MaxExpiration)
			}
		})
	}
}