/*
Copyright © contributors to CloudNativePG, established as
CloudNativePG a Series of LF Projects, LLC.

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.

SPDX-License-Identifier: Apache-2.0
*/

package instance

import (
	"context"
	"path"

	cnpgv1 "github.com/cloudnative-pg/cloudnative-pg/api/v1"
	"github.com/cloudnative-pg/machinery/pkg/log"
	"github.com/spf13/viper"
	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	"k8s.io/apimachinery/pkg/types"
	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/client"
	"sigs.k8s.io/controller-runtime/pkg/scheme"

	barmancloudv1 "github.com/cloudnative-pg/plugin-barman-cloud/api/v1"
	extendedclient "github.com/cloudnative-pg/plugin-barman-cloud/internal/cnpgi/instance/internal/client"
)

// Start starts the sidecar informers and CNPG-i server
func Start(ctx context.Context) error {
	scheme := generateScheme(ctx)

	setupLog := log.FromContext(ctx)
	setupLog.Info("Starting barman cloud instance plugin")

	podName := viper.GetString("pod-name")
	clusterName := viper.GetString("cluster-name")
	namespace := viper.GetString("namespace")

	controllerOptions := ctrl.Options{
		Scheme: scheme,
		Client: client.Options{
			// Important: the caching options below are used by
			// controller-runtime only.
			// The plugin code uses an enhanced client with a
			// custom caching strategy specifically for ObjectStores
			// and Clusters.
			//
			// This custom strategy is necessary because we lack
			// permission to list these resources at the namespace
			// level. Additionally, controller-runtime does not
			// support caching a closed (explicit) set of objects
			// within a namespace - it can only cache either individual
			// objects or all objects in a namespace.
			Cache: &client.CacheOptions{
				DisableFor: []client.Object{
					&corev1.Secret{},
					&barmancloudv1.ObjectStore{},
					&cnpgv1.Cluster{},
					&cnpgv1.Backup{},
				},
			},
		},
	}

	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), controllerOptions)
	if err != nil {
		setupLog.Error(err, "unable to start manager")
		return err
	}

	customCacheClient := extendedclient.NewExtendedClient(mgr.GetClient())

	if err := mgr.Add(&CNPGI{
		Client:         customCacheClient,
		InstanceName:   podName,
		PGDataPath:     viper.GetString("pgdata"),
		PGWALPath:      path.Join(viper.GetString("pgdata"), "pg_wal"),
		SpoolDirectory: viper.GetString("spool-directory"),
		PluginPath:     viper.GetString("plugin-path"),
	}); err != nil {
		setupLog.Error(err, "unable to create CNPGI runnable")
		return err
	}

	if err := mgr.Add(&CatalogMaintenanceRunnable{
		Client:   customCacheClient,
		Recorder: mgr.GetEventRecorderFor("policy-runnable"),
		ClusterKey: types.NamespacedName{
			Namespace: namespace,
			Name:      clusterName,
		},
		CurrentPodName: podName,
	}); err != nil {
		setupLog.Error(err, "unable to policy enforcement runnable")
		return err
	}

	if err := mgr.Start(ctx); err != nil {
		return err
	}

	return nil
}

// generateScheme creates a runtime.Scheme object with all the
// definition needed to support the sidecar. This allows
// the plugin to be used in every CNPG-based operator.
func generateScheme(ctx context.Context) *runtime.Scheme {
	result := runtime.NewScheme()

	utilruntime.Must(barmancloudv1.AddToScheme(result))
	utilruntime.Must(clientgoscheme.AddToScheme(result))

	cnpgGroup := viper.GetString("custom-cnpg-group")
	cnpgVersion := viper.GetString("custom-cnpg-version")
	if len(cnpgGroup) == 0 {
		cnpgGroup = cnpgv1.SchemeGroupVersion.Group
	}
	if len(cnpgVersion) == 0 {
		cnpgVersion = cnpgv1.SchemeGroupVersion.Version
	}

	// Proceed with custom registration of the CNPG scheme
	schemeGroupVersion := schema.GroupVersion{Group: cnpgGroup, Version: cnpgVersion}
	schemeBuilder := &scheme.Builder{GroupVersion: schemeGroupVersion}
	schemeBuilder.Register(&cnpgv1.Cluster{}, &cnpgv1.ClusterList{})
	schemeBuilder.Register(&cnpgv1.Backup{}, &cnpgv1.BackupList{})
	schemeBuilder.Register(&cnpgv1.ScheduledBackup{}, &cnpgv1.ScheduledBackupList{})
	utilruntime.Must(schemeBuilder.AddToScheme(result))

	schemeLog := log.FromContext(ctx)
	schemeLog.Info("CNPG types registration", "schemeGroupVersion", schemeGroupVersion)

	return result
}
