/*
Copyright 2022.

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 controllers

import (
	"context"
	"fmt"
	"time"

	ffsv1alpha1 "github.com/tidbcloud/ffs-operator/api/v1alpha1"
	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/types"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/log"
)

// FFSClusterReconciler reconciles a FFSCluster object
type FFSClusterReconciler struct {
	client.Client
	Scheme *runtime.Scheme
}

//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=ffsclusters,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=ffsclusters/status,verbs=get;update;patch
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=ffsclusters/finalizers,verbs=update
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=etcds,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=etcds/status,verbs=get;update;patch
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=etcds/finalizers,verbs=update
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=universes,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=universes/status,verbs=get;update;patch
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=universes/finalizers,verbs=update
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=zones,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=zones/status,verbs=get;update;patch
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=zones/finalizers,verbs=update
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=realms,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=realms/status,verbs=get;update;patch
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=realms/finalizers,verbs=update
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=clients,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=clients/status,verbs=get;update;patch
//+kubebuilder:rbac:groups=ffs.tidbcloud,resources=clients/finalizers,verbs=update

// Reconcile is part of the main kubernetes reconciliation loop which aims to
// move the current state of the cluster closer to the desired state.
// TODO(user): Modify the Reconcile function to compare the state specified by
// the FFSCluster object against the actual cluster state, and then
// perform operations to make the cluster state reflect the state specified by
// the user.
//
// For more details, check Reconcile and its Result here:
// - https://pkg.go.dev/sigs.k8s.io/controller-runtime@v0.11.0/pkg/reconcile
func (r *FFSClusterReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
	logs := log.FromContext(ctx)

	var cluster ffsv1alpha1.FFSCluster
	if err := r.Get(ctx, req.NamespacedName, &cluster); err != nil {
		return ctrl.Result{}, client.IgnoreNotFound(err)
	}

	// CreateOrUpdate Etcd
	var etcds ffsv1alpha1.Etcd
	etcds.Name = "etcd"
	etcds.Namespace = cluster.Namespace
	or, err := ctrl.CreateOrUpdate(ctx, r.Client, &etcds, func() error {
		r.MutateEtcd(&cluster, &etcds)
		return ctrl.SetControllerReference(&cluster, &etcds, r.Scheme)
	})
	if err != nil {
		return ctrl.Result{}, err
	}
	logs.Info("CreateOrUpdate", "Etcd", or)

	var etcdSvc corev1.Service
	var etcdSvcEndpoints string
	for {
		err := r.Client.Get(context.TODO(), types.NamespacedName{
			Name:      "etcd-svc",
			Namespace: cluster.Namespace,
		}, &etcdSvc)
		if err != nil && errors.IsNotFound(err) {
			logs.Info("Etcd Service not found")
			time.Sleep(time.Millisecond * 300)
			continue
		} else if err != nil {
			logs.Error(err, "Failed to get Etcd Service")
			return ctrl.Result{}, err
		}
		etcdSvcEndpoints = fmt.Sprintf("%s.%s:%d", etcdSvc.Name, etcdSvc.Namespace, etcdSvc.Spec.Ports[0].Port)
		logs.Info("CreateOrUpdate", "EtcdService", etcdSvcEndpoints)
		break
	}

	// CreateOrUpdate Universe
	var universes ffsv1alpha1.Universe
	universes.Name = "universe"
	universes.Namespace = cluster.Namespace
	or, err = ctrl.CreateOrUpdate(ctx, r.Client, &universes, func() error {
		r.MutateUniverse(&cluster, &universes, etcdSvcEndpoints)
		return ctrl.SetControllerReference(&cluster, &universes, r.Scheme)
	})
	if err != nil {
		return ctrl.Result{}, err
	}
	logs.Info("CreateOrUpdate", "Universe", or)

	var universeSvc corev1.Service
	var universeSvcEndpoints string
	for {
		err := r.Client.Get(context.TODO(), types.NamespacedName{
			Name:      "universe-svc",
			Namespace: cluster.Namespace,
		}, &universeSvc)
		if err != nil && errors.IsNotFound(err) {
			logs.Info("Universe Service not found")
			time.Sleep(time.Millisecond * 300)
			continue
		} else if err != nil {
			logs.Error(err, "Failed to get Universe Service")
			return ctrl.Result{}, err
		}
		universeSvcEndpoints = fmt.Sprintf("%s.%s:%d", universeSvc.Name, universeSvc.Namespace, universeSvc.Spec.Ports[0].Port)
		logs.Info("CreateOrUpdate", "UniverseService", universeSvcEndpoints)
		break
	}

	if cluster.Spec.Zone != nil {
		// CreateOrUpdate Zone
		var zone ffsv1alpha1.Zone
		zone.Name = "zone"
		zone.Namespace = cluster.Namespace
		or, err = ctrl.CreateOrUpdate(ctx, r.Client, &zone, func() error {
			r.MutateZone(&cluster, &zone, universeSvcEndpoints, etcdSvcEndpoints)
			return ctrl.SetControllerReference(&cluster, &zone, r.Scheme)
		})
		if err != nil {
			return ctrl.Result{}, err
		}
		logs.Info("CreateOrUpdate", "Zone", or)
	}

	var zoneSvc corev1.Service
	for {
		err := r.Client.Get(context.TODO(), types.NamespacedName{
			Name:      "zone-svc",
			Namespace: cluster.Namespace,
		}, &zoneSvc)
		if err != nil && errors.IsNotFound(err) {
			logs.Info("Zone Service not found")
			time.Sleep(time.Millisecond * 300)
			continue
		} else if err != nil {
			logs.Error(err, "Failed to get Zone Service")
			return ctrl.Result{}, err
		}
		universeSvcEndpoints = fmt.Sprintf("%s:%d", zoneSvc.Spec.ClusterIP, zoneSvc.Spec.Ports[0].Port)
		logs.Info("CreateOrUpdate", "ZoneService", universeSvcEndpoints)
		break
	}

	if cluster.Spec.Realm != nil {
		// CreateOrUpdate Realm
		var realm ffsv1alpha1.Realm
		realm.Name = "realm"
		realm.Namespace = cluster.Namespace
		or, err = ctrl.CreateOrUpdate(ctx, r.Client, &realm, func() error {
			r.MutateRealm(&cluster, &realm, universeSvcEndpoints)
			return ctrl.SetControllerReference(&cluster, &realm, r.Scheme)
		})
		if err != nil {
			return ctrl.Result{}, err
		}
		logs.Info("CreateOrUpdate", "Realm", or)
	}

	return ctrl.Result{}, nil
}

// SetupWithManager sets up the controller with the Manager.
func (r *FFSClusterReconciler) SetupWithManager(mgr ctrl.Manager) error {
	return ctrl.NewControllerManagedBy(mgr).
		For(&ffsv1alpha1.FFSCluster{}).
		Owns(&ffsv1alpha1.Etcd{}).
		Owns(&ffsv1alpha1.Universe{}).
		Owns(&ffsv1alpha1.Zone{}).
		Owns(&ffsv1alpha1.Realm{}).
		Complete(r)
}

var (
	FFSLabelKey       = "ffs.tidbcloud"
	FFSCommonLabelKey = "app"
)

// MutateEtcd
func (r *FFSClusterReconciler) MutateEtcd(cluster *ffsv1alpha1.FFSCluster, etcds *ffsv1alpha1.Etcd) {
	etcds.Labels = map[string]string{
		FFSCommonLabelKey: "ffscluster",
	}
	etcds.Spec = ffsv1alpha1.EtcdSpec{
		Size:             cluster.Spec.Etcd.Size,
		Image:            cluster.Spec.Etcd.Image,
		StorageClassName: cluster.Spec.Etcd.StorageClassName,
	}
	if etcds.Spec.StorageClassName == nil {
		etcds.Spec.StorageClassName = cluster.Spec.StorageClassName
	}
}

// MutateUniverse
func (r *FFSClusterReconciler) MutateUniverse(cluster *ffsv1alpha1.FFSCluster, universes *ffsv1alpha1.Universe, endpoints string) {
	universes.Labels = map[string]string{
		FFSCommonLabelKey: "ffscluster",
	}
	universes.Spec = ffsv1alpha1.UniverseSpec{
		Size:      cluster.Spec.Universe.Size,
		Image:     cluster.Spec.Universe.Image,
		Endpoints: endpoints,
	}
}

// MutateZone
func (r *FFSClusterReconciler) MutateZone(cluster *ffsv1alpha1.FFSCluster, universes *ffsv1alpha1.Zone, universe, endpoints string) {
	universes.Labels = map[string]string{
		FFSCommonLabelKey: "ffscluster",
	}
	universes.Spec = ffsv1alpha1.ZoneSpec{
		Size:      cluster.Spec.Zone.Size,
		Image:     cluster.Spec.Zone.Image,
		Name:      cluster.Spec.Zone.Name,
		Universe:  universe,
		Endpoints: endpoints,
	}
}

// MutateRealm
func (r *FFSClusterReconciler) MutateRealm(cluster *ffsv1alpha1.FFSCluster, realms *ffsv1alpha1.Realm, universe string) {
	realms.Labels = map[string]string{
		FFSCommonLabelKey: "ffscluster",
	}
	realms.Spec = ffsv1alpha1.RealmSpec{
		Size:             cluster.Spec.Realm.Size,
		Image:            cluster.Spec.Realm.Image,
		StorageClassName: cluster.Spec.Realm.StorageClassName,
		Zone:             cluster.Spec.Realm.Zone,
		Universe:         universe,
	}
	if realms.Spec.StorageClassName == nil {
		realms.Spec.StorageClassName = cluster.Spec.StorageClassName
	}
}