/*
Copyright © The ESO 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

    https://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 controller

import (
	"crypto/tls"
	"os"
	"time"

	"github.com/spf13/cobra"
	v1 "k8s.io/api/core/v1"
	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
	"k8s.io/apimachinery/pkg/runtime"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/cache"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/healthz"
	"sigs.k8s.io/controller-runtime/pkg/metrics/filters"
	"sigs.k8s.io/controller-runtime/pkg/metrics/server"
	"sigs.k8s.io/controller-runtime/pkg/webhook"

	esv1 "github.com/external-secrets/external-secrets/apis/externalsecrets/v1"
	esv1alpha1 "github.com/external-secrets/external-secrets/apis/externalsecrets/v1alpha1"
	genv1alpha1 "github.com/external-secrets/external-secrets/apis/generators/v1alpha1"
	"github.com/external-secrets/external-secrets/pkg/controllers/clusterexternalsecret"
	"github.com/external-secrets/external-secrets/pkg/controllers/clusterexternalsecret/cesmetrics"
	"github.com/external-secrets/external-secrets/pkg/controllers/clusterpushsecret"
	"github.com/external-secrets/external-secrets/pkg/controllers/clusterpushsecret/cpsmetrics"
	ctrlcommon "github.com/external-secrets/external-secrets/pkg/controllers/common"
	"github.com/external-secrets/external-secrets/pkg/controllers/externalsecret"
	"github.com/external-secrets/external-secrets/pkg/controllers/externalsecret/esmetrics"
	"github.com/external-secrets/external-secrets/pkg/controllers/generatorstate"
	ctrlmetrics "github.com/external-secrets/external-secrets/pkg/controllers/metrics"
	"github.com/external-secrets/external-secrets/pkg/controllers/pushsecret"
	"github.com/external-secrets/external-secrets/pkg/controllers/pushsecret/psmetrics"
	"github.com/external-secrets/external-secrets/pkg/controllers/secretstore"
	"github.com/external-secrets/external-secrets/pkg/controllers/secretstore/cssmetrics"
	"github.com/external-secrets/external-secrets/pkg/controllers/secretstore/ssmetrics"
	"github.com/external-secrets/external-secrets/runtime/feature"

	// To allow using gcp auth.
	_ "k8s.io/client-go/plugin/pkg/client/auth"
)

var (
	scheme                                = runtime.NewScheme()
	setupLog                              = ctrl.Log.WithName("setup")
	dnsName                               string
	certDir                               string
	liveAddr                              string
	metricsAddr                           string
	metricsSecure                         bool
	metricsAuth                           bool
	metricsCertDir                        string
	metricsCertName                       string
	metricsKeyName                        string
	healthzAddr                           string
	controllerClass                       string
	enableLeaderElection                  bool
	leaderElectionID                      string
	leaderElectionLeaseDuration           time.Duration
	leaderElectionRenewDeadline           time.Duration
	leaderElectionRetryPeriod             time.Duration
	enableSecretsCache                    bool
	enableConfigMapsCache                 bool
	enableManagedSecretsCache             bool
	enableSecretAPIReadOnCacheMismatch    bool
	enablePartialCache                    bool
	concurrent                            int
	port                                  int
	clientQPS                             float32
	clientBurst                           int
	loglevel                              string
	zapTimeEncoding                       string
	namespace                             string
	enableClusterStoreReconciler          bool
	enableSecretStoreReconciler           bool
	enableClusterExternalSecretReconciler bool
	enableClusterPushSecretReconciler     bool
	enablePushSecretReconciler            bool
	enableFloodGate                       bool
	enableGeneratorState                  bool
	enableExtendedMetricLabels            bool
	storeRequeueInterval                  time.Duration
	serviceName, serviceNamespace         string
	secretName, secretNamespace           string
	crdNames                              []string
	crdRequeueInterval                    time.Duration
	certCheckInterval                     time.Duration
	certLookaheadInterval                 time.Duration
	tlsCiphers                            string
	tlsMinVersion                         string
	enableHTTP2                           bool
	allowGenericTargets                   bool
)

const (
	errCreateController = "unable to create controller"
)

func init() {
	// kubernetes schemes
	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
	utilruntime.Must(apiextensionsv1.AddToScheme(scheme))

	// external-secrets schemes
	utilruntime.Must(esv1.AddToScheme(scheme))
	utilruntime.Must(esv1alpha1.AddToScheme(scheme))
	utilruntime.Must(genv1alpha1.AddToScheme(scheme))
}

var rootCmd = &cobra.Command{
	Use:   "external-secrets",
	Short: "operator that reconciles ExternalSecrets and SecretStores",
	Long:  `For more information visit https://external-secrets.io`,
	Run: func(cmd *cobra.Command, _ []string) {
		setupLogger()

		ctrlmetrics.SetUpLabelNames(enableExtendedMetricLabels)
		esmetrics.SetUpMetrics()
		config := ctrl.GetConfigOrDie()
		config.QPS = clientQPS
		config.Burst = clientBurst

		// the client creates a ListWatch for resources that are requested with .Get() or .List()
		// some users might want to completely disable caching of Secrets and ConfigMaps
		// to decrease memory usage at the expense of high Kubernetes API usage
		// see: https://github.com/external-secrets/external-secrets/issues/721
		clientCacheDisableFor := make([]client.Object, 0)
		if !enableSecretsCache {
			// dont cache any secrets
			clientCacheDisableFor = append(clientCacheDisableFor, &v1.Secret{})
		}
		if !enableConfigMapsCache {
			// dont cache any configmaps
			clientCacheDisableFor = append(clientCacheDisableFor, &v1.ConfigMap{})
		}
		metricsOpts := server.Options{
			BindAddress: metricsAddr,
		}
		if metricsSecure {
			metricsOpts.SecureServing = true
			metricsOpts.CertDir = metricsCertDir
			metricsOpts.CertName = metricsCertName
			metricsOpts.KeyName = metricsKeyName
		}
		if metricsAuth {
			metricsOpts.FilterProvider = filters.WithAuthenticationAndAuthorization
		}
		if metricsAuth && !metricsSecure {
			setupLog.Error(nil, "--metrics-auth requires --metrics-secure; bearer tokens over plaintext HTTP is not allowed")
			os.Exit(1)
		}
		// Disable HTTP/2 if not explicitly enabled
		if !enableHTTP2 {
			metricsOpts.TLSOpts = []func(*tls.Config){disableHTTP2}
		}
		mgrOpts := ctrl.Options{
			Scheme:                 scheme,
			Metrics:                metricsOpts,
			HealthProbeBindAddress: liveAddr,
			WebhookServer: webhook.NewServer(webhook.Options{
				Port: 9443,
			}),
			Client: client.Options{
				Cache: &client.CacheOptions{
					DisableFor: clientCacheDisableFor,
				},
			},
			LeaderElection:   enableLeaderElection,
			LeaderElectionID: leaderElectionID,
			LeaseDuration:    &leaderElectionLeaseDuration,
			RenewDeadline:    &leaderElectionRenewDeadline,
			RetryPeriod:      &leaderElectionRetryPeriod,
		}
		if namespace != "" {
			mgrOpts.Cache.DefaultNamespaces = map[string]cache.Config{
				namespace: {},
			}
		}
		mgr, err := ctrl.NewManager(config, mgrOpts)
		if err != nil {
			setupLog.Error(err, "unable to start manager")
			os.Exit(1)
		}

		// we create a special client for accessing secrets in the ExternalSecret reconcile loop.
		// by default, it is the same as the normal client, but if `--enable-managed-secrets-caching`
		// is set, we use a special client that only caches secrets managed by an ExternalSecret.
		// if we are already caching all secrets, we don't need to use the special client.
		secretClient := mgr.GetClient()
		if enableManagedSecretsCache && !enableSecretsCache {
			secretClient, err = ctrlcommon.BuildManagedSecretClient(mgr, namespace)
			if err != nil {
				setupLog.Error(err, "unable to create managed secret client")
				os.Exit(1)
			}
		}

		if enableSecretStoreReconciler {
			ssmetrics.SetUpMetrics()
			if err = (&secretstore.StoreReconciler{
				Client:            mgr.GetClient(),
				Log:               ctrl.Log.WithName("controllers").WithName("SecretStore"),
				Scheme:            mgr.GetScheme(),
				ControllerClass:   controllerClass,
				RequeueInterval:   storeRequeueInterval,
				PushSecretEnabled: enablePushSecretReconciler,
			}).SetupWithManager(mgr, ctrlcommon.BuildControllerOptions(concurrent)); err != nil {
				setupLog.Error(err, errCreateController, "controller", "SecretStore")
				os.Exit(1)
			}
		}

		if enableClusterStoreReconciler {
			cssmetrics.SetUpMetrics()
			if err = (&secretstore.ClusterStoreReconciler{
				Client:            mgr.GetClient(),
				Log:               ctrl.Log.WithName("controllers").WithName("ClusterSecretStore"),
				Scheme:            mgr.GetScheme(),
				ControllerClass:   controllerClass,
				RequeueInterval:   storeRequeueInterval,
				PushSecretEnabled: enablePushSecretReconciler,
			}).SetupWithManager(mgr, ctrlcommon.BuildControllerOptions(concurrent)); err != nil {
				setupLog.Error(err, errCreateController, "controller", "ClusterSecretStore")
				os.Exit(1)
			}
		}
		if err = (&generatorstate.Reconciler{
			Client:     mgr.GetClient(),
			Log:        ctrl.Log.WithName("controllers").WithName("GeneratorState"),
			Scheme:     mgr.GetScheme(),
			RestConfig: mgr.GetConfig(),
		}).SetupWithManager(mgr, ctrlcommon.BuildControllerOptions(concurrent)); err != nil {
			setupLog.Error(err, errCreateController, "controller", "GeneratorState")
			os.Exit(1)
		}
		if err = (&externalsecret.Reconciler{
			Client:                             mgr.GetClient(),
			SecretClient:                       secretClient,
			EnableSecretAPIReadOnCacheMismatch: enableSecretAPIReadOnCacheMismatch,
			Log:                                ctrl.Log.WithName("controllers").WithName("ExternalSecret"),
			Scheme:                             mgr.GetScheme(),
			RestConfig:                         mgr.GetConfig(),
			ControllerClass:                    controllerClass,
			RequeueInterval:                    time.Hour,
			ClusterSecretStoreEnabled:          enableClusterStoreReconciler,
			EnableFloodGate:                    enableFloodGate,
			EnableGeneratorState:               enableGeneratorState,
			AllowGenericTargets:                allowGenericTargets,
		}).SetupWithManager(cmd.Context(), mgr, ctrlcommon.BuildControllerOptions(concurrent)); err != nil {
			setupLog.Error(err, errCreateController, "controller", "ExternalSecret")
			os.Exit(1)
		}
		if enablePushSecretReconciler {
			psmetrics.SetUpMetrics()
			if err = (&pushsecret.Reconciler{
				Client:          mgr.GetClient(),
				Log:             ctrl.Log.WithName("controllers").WithName("PushSecret"),
				Scheme:          mgr.GetScheme(),
				ControllerClass: controllerClass,
				RestConfig:      mgr.GetConfig(),
				RequeueInterval: time.Hour,
			}).SetupWithManager(cmd.Context(), mgr, ctrlcommon.BuildControllerOptions(concurrent)); err != nil {
				setupLog.Error(err, errCreateController, "controller", "PushSecret")
				os.Exit(1)
			}
		}
		if enableClusterExternalSecretReconciler {
			cesmetrics.SetUpMetrics()

			if err = (&clusterexternalsecret.Reconciler{
				Client:          mgr.GetClient(),
				Log:             ctrl.Log.WithName("controllers").WithName("ClusterExternalSecret"),
				Scheme:          mgr.GetScheme(),
				RequeueInterval: time.Hour,
			}).SetupWithManager(mgr, ctrlcommon.BuildControllerOptions(concurrent)); err != nil {
				setupLog.Error(err, errCreateController, "controller", "ClusterExternalSecret")
				os.Exit(1)
			}
		}

		if enableClusterPushSecretReconciler {
			cpsmetrics.SetUpMetrics()

			if err = (&clusterpushsecret.Reconciler{
				Client:          mgr.GetClient(),
				Log:             ctrl.Log.WithName("controllers").WithName("ClusterPushSecret"),
				Scheme:          mgr.GetScheme(),
				RequeueInterval: time.Hour,
				Recorder:        mgr.GetEventRecorderFor("external-secrets-controller"),
			}).SetupWithManager(mgr, ctrlcommon.BuildControllerOptions(concurrent)); err != nil {
				setupLog.Error(err, errCreateController, "controller", "ClusterPushSecret")
				os.Exit(1)
			}
		}

		if err := mgr.AddHealthzCheck("healthz", healthz.Ping); err != nil {
			setupLog.Error(err, "unable to add controller healthz check")
			os.Exit(1)
		}
		if err := mgr.AddReadyzCheck("readyz", healthz.Ping); err != nil {
			setupLog.Error(err, "unable to add controller readyz check")
			os.Exit(1)
		}

		fs := feature.Features()
		for _, f := range fs {
			if f.Initialize == nil {
				continue
			}
			f.Initialize()
		}
		setupLog.Info("starting manager")
		if err := mgr.Start(ctrl.SetupSignalHandler()); err != nil {
			setupLog.Error(err, "problem running manager")
			os.Exit(1)
		}
	},
}

// Execute starts the command execution process.
func Execute() {
	cobra.CheckErr(rootCmd.Execute())
}

func init() {
	rootCmd.Flags().StringVar(&metricsAddr, "metrics-addr", ":8080", "The address the metric endpoint binds to.")
	rootCmd.Flags().BoolVar(&metricsAuth, "metrics-auth", false, "Enable Kubernetes RBAC-based authentication and authorization for the metrics endpoint.")
	rootCmd.Flags().BoolVar(&metricsSecure, "metrics-secure", false, "Enable HTTPS for the metrics endpoint.")
	rootCmd.Flags().StringVar(&metricsCertDir, "metrics-cert-dir", "", "Directory containing TLS certificate and key for metrics endpoint.")
	rootCmd.Flags().StringVar(&metricsCertName, "metrics-cert-name", "tls.crt", "TLS certificate filename for metrics endpoint.")
	rootCmd.Flags().StringVar(&metricsKeyName, "metrics-key-name", "tls.key", "TLS key filename for metrics endpoint.")
	rootCmd.Flags().StringVar(&controllerClass, "controller-class", "default", "The controller is instantiated with a specific controller name and filters ES based on this property")
	rootCmd.Flags().BoolVar(&enableLeaderElection, "enable-leader-election", false,
		"Enable leader election for controller manager. "+
			"Enabling this will ensure there is only one active controller manager.")
	rootCmd.Flags().StringVar(&leaderElectionID, "leader-election-id", "external-secrets-controller",
		"The ID of the lease object used for leader election. Set this to a unique value when running multiple deployments in the same namespace.")
	rootCmd.Flags().DurationVar(&leaderElectionLeaseDuration, "leader-election-lease-duration", 15*time.Second,
		"The duration that non-leader candidates will wait to force acquire leadership. This is measured against time of last observed ack.")
	rootCmd.Flags().DurationVar(&leaderElectionRenewDeadline, "leader-election-renew-deadline", 10*time.Second,
		"The interval between attempts by the acting leader to renew its leadership before it stops leading. This must be less than the lease duration.")
	rootCmd.Flags().DurationVar(&leaderElectionRetryPeriod, "leader-election-retry-period", 2*time.Second,
		"The duration the clients should wait between attempting acquisition and renewal of a leadership.")
	rootCmd.Flags().IntVar(&concurrent, "concurrent", 1, "The number of concurrent reconciles.")
	rootCmd.Flags().Float32Var(&clientQPS, "client-qps", 50, "QPS configuration to be passed to rest.Client")
	rootCmd.Flags().IntVar(&clientBurst, "client-burst", 100, "Maximum Burst allowed to be passed to rest.Client")
	rootCmd.Flags().StringVar(&liveAddr, "live-addr", ":8082", "The address the live endpoint binds to.")
	rootCmd.Flags().StringVar(&loglevel, "loglevel", "info", "loglevel to use, one of: debug, info, warn, error, dpanic, panic, fatal")
	rootCmd.Flags().StringVar(&zapTimeEncoding, "zap-time-encoding", "epoch", "Zap time encoding (one of 'epoch', 'millis', 'nano', 'iso8601', 'rfc3339' or 'rfc3339nano')")
	rootCmd.Flags().
		StringVar(&namespace, "namespace", "", "watch external secrets scoped in the provided namespace only. ClusterSecretStore can be used but only work if it doesn't reference resources from other namespaces")
	rootCmd.Flags().BoolVar(&enableClusterStoreReconciler, "enable-cluster-store-reconciler", true, "Enable cluster store reconciler.")
	rootCmd.Flags().BoolVar(&enableSecretStoreReconciler, "enable-secret-store-reconciler", true, "Enable secret store reconciler.")
	rootCmd.Flags().BoolVar(&enableClusterExternalSecretReconciler, "enable-cluster-external-secret-reconciler", true, "Enable cluster external secret reconciler.")
	rootCmd.Flags().BoolVar(&enableClusterPushSecretReconciler, "enable-cluster-push-secret-reconciler", true, "Enable cluster push secret reconciler.")
	rootCmd.Flags().BoolVar(&enablePushSecretReconciler, "enable-push-secret-reconciler", true, "Enable push secret reconciler.")
	rootCmd.Flags().BoolVar(&enableSecretsCache, "enable-secrets-caching", false, "Enable secrets caching for ALL secrets in the cluster (WARNING: can increase memory usage).")
	rootCmd.Flags().BoolVar(&enableConfigMapsCache, "enable-configmaps-caching", false, "Enable configmaps caching for ALL configmaps in the cluster (WARNING: can increase memory usage).")
	rootCmd.Flags().BoolVar(&enableManagedSecretsCache, "enable-managed-secrets-caching", true, "Enable secrets caching for secrets managed by an ExternalSecret")
	rootCmd.Flags().BoolVar(
		&enableSecretAPIReadOnCacheMismatch,
		"enable-secret-api-read-on-cache-mismatch",
		true,
		"Enable a direct API read when the partial Secret cache and managed Secret cache disagree. Disable to rely on cache retry only.",
	)
	rootCmd.Flags().DurationVar(&storeRequeueInterval, "store-requeue-interval", time.Minute*5, "Default Time duration between reconciling (Cluster)SecretStores")
	rootCmd.Flags().BoolVar(&enableFloodGate, "enable-flood-gate", true, "Enable flood gate. External secret will be reconciled only if the ClusterStore or Store have an healthy or unknown state.")
	rootCmd.Flags().BoolVar(&enableGeneratorState, "enable-generator-state", true, "Whether the Controller should manage GeneratorState")
	rootCmd.Flags().BoolVar(&enableExtendedMetricLabels, "enable-extended-metric-labels", false, "Enable recommended kubernetes annotations as labels in metrics.")
	rootCmd.Flags().BoolVar(&enableHTTP2, "enable-http2", false,
		"If set, HTTP/2 will be enabled for the metrics server")
	rootCmd.Flags().
		BoolVar(&allowGenericTargets, "unsafe-allow-generic-targets", false, "Enable support for creating generic resources (ConfigMaps, Custom Resources). WARNING: Using generic resources, please sure all policies are correctly configured.")
	fs := feature.Features()
	for _, f := range fs {
		rootCmd.Flags().AddFlagSet(f.Flags)
	}
}

// disableHTTP2 is a TLS configuration function that disables HTTP/2.
func disableHTTP2(cfg *tls.Config) {
	cfg.NextProtos = []string{"http/1.1"}
}
