/*
Copyright 2024.

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 controller

import (
	"context"
	"fmt"
	"time"

	zitadelv1alpha1 "gitea.corredorconect.com/software-engineering/zitadel-k8s-operator/api/v1alpha1"
	condition "gitea.corredorconect.com/software-engineering/zitadel-k8s-operator/pkg/condition"
	"gitea.corredorconect.com/software-engineering/zitadel-k8s-operator/pkg/controller/service"
	"gitea.corredorconect.com/software-engineering/zitadel-k8s-operator/pkg/controller/system"
	"gitea.corredorconect.com/software-engineering/zitadel-k8s-operator/pkg/deployment"
	zitadelresourcesv1alpha1 "gitea.corredorconect.com/software-engineering/zitadel-resources-operator/api/v1alpha1"
	corev1 "k8s.io/api/core/v1"
	ctrlClient "sigs.k8s.io/controller-runtime/pkg/client"

	systemClient "github.com/zitadel/zitadel-go/v3/pkg/client/system"
	authn "github.com/zitadel/zitadel-go/v3/pkg/client/zitadel/authn"
	pb "github.com/zitadel/zitadel-go/v3/pkg/client/zitadel/system"
	appsv1 "k8s.io/api/apps/v1"
	"k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/client-go/util/workqueue"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/controller"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"

	"gitea.corredorconect.com/software-engineering/zitadel-k8s-operator/pkg/builder"
)

// InstanceReconciler reconciles a Instance object
type InstanceReconciler struct {
	client.Client
	RefResolver       *zitadelv1alpha1.RefResolver
	ConditionReady    *condition.Ready
	RequeueInterval   time.Duration
	Builder           *builder.Builder
	ServiceReconciler *service.ServiceReconciler
}

func NewInstanceReconciler(client client.Client, refResolver *zitadelv1alpha1.RefResolver,
	builder *builder.Builder,
	conditionReady *condition.Ready,
	serviceReconciler *service.ServiceReconciler,
	requeueInterval time.Duration) *InstanceReconciler {
	return &InstanceReconciler{
		Client:            client,
		RefResolver:       refResolver,
		ConditionReady:    conditionReady,
		RequeueInterval:   requeueInterval,
		ServiceReconciler: serviceReconciler,
		Builder:           builder,
	}
}

//+kubebuilder:rbac:groups=zitadel.topmanage.com,resources=instances,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=zitadel.topmanage.com,resources=instances/status,verbs=get;update;patch
//+kubebuilder:rbac:groups=zitadel.topmanage.com,resources=instances/finalizers,verbs=update
// +kubebuilder:rbac:groups=zitadel.github.com,resources=machineusers,verbs=get;list;watch;create;update;patch;delete
// +kubebuilder:rbac:groups=zitadel.github.com,resources=machineusers/status,verbs=get;update;patch
// +kubebuilder:rbac:groups=zitadel.github.com,resources=machineusers/finalizers,verbs=update
// +kubebuilder:rbac:groups=zitadel.github.com,resources=connections,verbs=get;list;watch;create;update;patch;delete
// +kubebuilder:rbac:groups=zitadel.github.com,resources=connections/status,verbs=get;update;patch
// +kubebuilder:rbac:groups=zitadel.github.com,resources=connections/finalizers,verbs=update
// +kubebuilder:rbac:groups=zitadel.github.com,resources=organizations,verbs=get;list;watch;create;update;patch;delete
// +kubebuilder:rbac:groups=zitadel.github.com,resources=organizations/status,verbs=get;update;patch
// +kubebuilder:rbac:groups=zitadel.github.com,resources=organizations/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.
func (r *InstanceReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
	var instance zitadelv1alpha1.Instance
	if err := r.Get(ctx, req.NamespacedName, &instance); err != nil {
		return ctrl.Result{}, client.IgnoreNotFound(err)
	}
	wr := newWrappedInstanceReconciler(r.Client, r.RefResolver, r.Builder, r.ServiceReconciler, &instance)
	wf := newWrappedInstanceFinalizer(r.Client, &instance)
	tf := system.NewSystemFinalizer(r.Client, wf)
	tr := system.NewSystemReconciler(r.Client, r.ConditionReady, wr, tf, r.RequeueInterval)

	result, err := tr.Reconcile(ctx, &instance)
	if err != nil {
		return result, fmt.Errorf("error reconciling in InstanceReconciler: %v", err)
	}
	return result, nil
}

type wrappedInstanceReconciler struct {
	client.Client
	refResolver       *zitadelv1alpha1.RefResolver
	instance          *zitadelv1alpha1.Instance
	Builder           *builder.Builder
	ServiceReconciler *service.ServiceReconciler
}

func newWrappedInstanceReconciler(client client.Client, refResolver *zitadelv1alpha1.RefResolver, builder *builder.Builder,
	serviceReconciler *service.ServiceReconciler,
	instance *zitadelv1alpha1.Instance) system.WrappedSystemReconciler {
	return &wrappedInstanceReconciler{
		Client:            client,
		refResolver:       refResolver,
		instance:          instance,
		Builder:           builder,
		ServiceReconciler: serviceReconciler,
	}
}

type instanceReconcilePhase struct {
	Name      string
	Reconcile func(context.Context, *systemClient.Client) error
}

func (wr *wrappedInstanceReconciler) Reconcile(ctx context.Context, ztdClient *systemClient.Client) error {
	phases := []instanceReconcilePhase{
		{
			Name:      "instance",
			Reconcile: wr.reconcileInstance,
		},
		{
			Name:      "connection",
			Reconcile: wr.reconcileConnection,
		},
		{
			Name:      "organization",
			Reconcile: wr.reconcileFirstOrganization,
		},
		{
			Name:      "loginUIMachineUser",
			Reconcile: wr.reconcileLoginUIMachineUser,
		},
		{
			Name:      "loginUIDeployment",
			Reconcile: wr.reconcileLoginUIDeployment,
		},
		{
			Name:      "loginUIService",
			Reconcile: wr.reconcileLoginUIService,
		},
	}
	for _, p := range phases {
		err := p.Reconcile(ctx, ztdClient)
		if err != nil {
			return err
		}
	}
	return nil
}

func (wr *wrappedInstanceReconciler) reconcileInstance(ctx context.Context, ztdClient *systemClient.Client) error {
	var instanceId *string
	if wr.instance.Status.InstanceId != nil {
		getInstanceRes, err := ztdClient.GetInstance(ctx, &pb.GetInstanceRequest{InstanceId: *wr.instance.Status.InstanceId})
		if err != nil {
			return fmt.Errorf("Error getting Instance: %v", err)
		}
		if getInstanceRes.Instance != nil {
			instanceId = &getInstanceRes.Instance.Id
		}
	}
	if instanceId == nil {
		createInstanceRes, err := ztdClient.CreateInstance(ctx, &pb.CreateInstanceRequest{
			InstanceName:    wr.instance.Spec.InstanceName,
			FirstOrgName:    wr.instance.Spec.Org.Name,
			CustomDomain:    wr.instance.Spec.CustomDomain,
			DefaultLanguage: wr.instance.Spec.DefaultLanguage,
			Owner: &pb.CreateInstanceRequest_Machine_{
				Machine: &pb.CreateInstanceRequest_Machine{
					UserName: wr.instance.MachineUserName(),
					Name:     wr.instance.MachineName(),
					PersonalAccessToken: &pb.CreateInstanceRequest_PersonalAccessToken{
						ExpirationDate: nil,
					},
					MachineKey: &pb.CreateInstanceRequest_MachineKey{
						ExpirationDate: nil,
						Type:           authn.KeyType_KEY_TYPE_JSON,
					},
				},
			},
		})
		if err != nil {
			return fmt.Errorf("Error creating Instance: %v", err)
		}

		key := types.NamespacedName{
			Name:      wr.instance.MachineSecretName(),
			Namespace: wr.instance.Namespace,
		}
		secretData := map[string][]byte{
			"pat":        []byte(createInstanceRes.Pat),
			"machinekey": createInstanceRes.MachineKey,
		}
		secret, err := wr.Builder.BuildSecret(builder.SecretOpts{Key: key, Data: secretData}, wr.instance)
		if err != nil {
			return fmt.Errorf("error building instance machine Secret: %v", err)
		}

		if err := wr.Create(ctx, secret); err != nil {
			return fmt.Errorf("error creating machinekey Secret: %v", err)
		}
		instanceId = &createInstanceRes.InstanceId
	}
	patch := ctrlClient.MergeFrom(wr.instance.DeepCopy())
	wr.instance.Status.InstanceId = instanceId
	return wr.Client.Status().Patch(ctx, wr.instance, patch)
}

func (wr *wrappedInstanceReconciler) reconcileConnection(ctx context.Context, ztdClient *systemClient.Client) error {
	key := types.NamespacedName{
		Name:      wr.instance.ConnectionObjectName(),
		Namespace: wr.instance.Namespace,
	}
	desiredConnection, err := wr.Builder.BuildConnection(key, wr.instance)
	if err != nil {
		return fmt.Errorf("error building Initial Connectionanization: %v", err)
	}

	var existingConnection zitadelresourcesv1alpha1.Connection
	if err := wr.Get(ctx, key, &existingConnection); err != nil {
		if !errors.IsNotFound(err) {
			return fmt.Errorf("error getting Initial Connectionanization: %v", err)
		}
		if err := wr.Create(ctx, desiredConnection); err != nil {
			return fmt.Errorf("error creating Initial Connectionanization: %v", err)
		}
		return nil
	}

	patch := client.MergeFrom(existingConnection.DeepCopy())
	existingConnection.Spec.Host = desiredConnection.Spec.Host
	existingConnection.Spec.Authentication = desiredConnection.Spec.Authentication
	return wr.Patch(ctx, &existingConnection, patch)
}

func (wr *wrappedInstanceReconciler) reconcileFirstOrganization(ctx context.Context, ztdClient *systemClient.Client) error {
	key := types.NamespacedName{
		Name:      wr.instance.FirstOrgObjectName(),
		Namespace: wr.instance.Namespace,
	}
	desiredOrg, err := wr.Builder.BuildOrganization(builder.OrganizationOpts{Key: key, Zitadel: wr.instance, OrganizationName: wr.instance.Spec.Org.Name}, wr.instance)
	if err != nil {
		return fmt.Errorf("error building Initial Organization: %v", err)
	}

	var existingOrg zitadelresourcesv1alpha1.Organization
	if err := wr.Get(ctx, key, &existingOrg); err != nil {
		if !errors.IsNotFound(err) {
			return fmt.Errorf("error getting Initial Organization: %v", err)
		}
		if err := wr.Create(ctx, desiredOrg); err != nil {
			return fmt.Errorf("error creating Initial Organization: %v", err)
		}
		return nil
	}

	patch := client.MergeFrom(existingOrg.DeepCopy())
	existingOrg.Spec.OrganzationName = desiredOrg.Spec.OrganzationName
	return wr.Patch(ctx, &existingOrg, patch)
}

func (wr *wrappedInstanceReconciler) reconcileLoginUIMachineUser(ctx context.Context, ztdClient *systemClient.Client) error {
	key := types.NamespacedName{
		Name:      wr.instance.LoginMachineUserName(),
		Namespace: wr.instance.Namespace,
	}

	desiredMachineUser, err := wr.Builder.BuildMachineUser(key, builder.MachineUserOpts{Instance: wr.instance,
		InternalPermissions: []zitadelresourcesv1alpha1.InternalPermissions{
			{

				Resource: zitadelresourcesv1alpha1.Resource{
					Instance: &zitadelresourcesv1alpha1.InstanceResource{},
				},
				Roles: []string{
					"IAM_LOGIN_CLIENT",
				},
			},
		},
		Username: "login-ui",
	}, wr.instance)
	if err != nil {
		return fmt.Errorf("error building LoginUI MachineUser: %v", err)
	}

	var existingMachineUser zitadelresourcesv1alpha1.MachineUser
	if err := wr.Get(ctx, key, &existingMachineUser); err != nil {
		if !errors.IsNotFound(err) {
			return fmt.Errorf("error getting MachineUser: %v", err)
		}
		if err := wr.Create(ctx, desiredMachineUser); err != nil {
			return fmt.Errorf("error creating MachineUser: %v", err)
		}
		return nil
	}

	patch := client.MergeFrom(existingMachineUser.DeepCopy())
	existingMachineUser.Spec.Authorizations = desiredMachineUser.Spec.Authorizations
	existingMachineUser.Spec.InternalPermissions = desiredMachineUser.Spec.InternalPermissions
	existingMachineUser.Spec.Metadata = desiredMachineUser.Spec.Metadata
	return wr.Patch(ctx, &existingMachineUser, patch)
}

func (wr *wrappedInstanceReconciler) reconcileLoginUIDeployment(ctx context.Context, ztdClient *systemClient.Client) error {
	if wr.instance.Status.InstanceId == nil {
		return fmt.Errorf("Instance not ready...")
	}
	cluster, err := wr.refResolver.Cluster(ctx, &wr.instance.Spec.ClusterRef, wr.instance.Namespace)
	if err != nil {
		return err
	}
	key := client.ObjectKeyFromObject(wr.instance)
	key.Name = key.Name + "-login-ui"

	instanceRes, err := ztdClient.GetInstance(ctx, &pb.GetInstanceRequest{InstanceId: *wr.instance.Status.InstanceId})
	if err != nil {
		return err
	}
	var customDomain string
	for _, d := range instanceRes.Instance.Domains {
		if d.Primary {
			customDomain = d.Domain
			break
		}
	}
	desiredSts, err := wr.Builder.BuildLoginDeployment(cluster, wr.instance, customDomain, key)
	if err != nil {
		return fmt.Errorf("error building Login UI Deployment: %v", err)
	}
	var existingDep appsv1.Deployment
	if err := wr.Get(ctx, key, &existingDep); err != nil {
		if !errors.IsNotFound(err) {
			return fmt.Errorf("error getting Login UI Deployment: %v", err)
		}
		if err := wr.Create(ctx, desiredSts); err != nil {
			return fmt.Errorf("error creating Login UI Deployment: %v", err)
		}
		return nil
	}

	patch := client.MergeFrom(existingDep.DeepCopy())
	existingDep.Spec.Template = desiredSts.Spec.Template
	existingDep.Spec.Replicas = desiredSts.Spec.Replicas
	return wr.Patch(ctx, &existingDep, patch)
}

func (wr *wrappedInstanceReconciler) reconcileLoginUIService(ctx context.Context, ztdClient *systemClient.Client) error {
	key := client.ObjectKeyFromObject(wr.instance)
	key.Name = key.Name + "-login-ui"
	opts := builder.ServiceOpts{
		Ports: []corev1.ServicePort{
			{
				Name: deployment.LoginName,
				Port: deployment.LoginPort,
			},
		},
	}
	desiredSvc, err := wr.Builder.BuildLoginService(wr.instance, key, opts)
	if err != nil {
		return fmt.Errorf("error building Service: %v", err)
	}
	return wr.ServiceReconciler.Reconcile(ctx, desiredSvc)
}

func (wr *wrappedInstanceReconciler) PatchStatus(ctx context.Context, patcher condition.Patcher) error {
	patch := client.MergeFrom(wr.instance.DeepCopy())
	patcher(&wr.instance.Status)

	if err := wr.Client.Status().Patch(ctx, wr.instance, patch); err != nil {
		return fmt.Errorf("error patching Instance status: %v", err)
	}
	return nil
}

// SetupWithManager sets up the controller with the Manager.
func (r *InstanceReconciler) SetupWithManager(mgr ctrl.Manager) error {
	return ctrl.NewControllerManagedBy(mgr).
		For(&zitadelv1alpha1.Instance{}).
		Owns(&corev1.Secret{}).
		Owns(&appsv1.Deployment{}).
		Owns(&corev1.Service{}).
		Owns(&zitadelresourcesv1alpha1.Connection{}).
		Owns(&zitadelresourcesv1alpha1.Organization{}).
		Owns(&zitadelresourcesv1alpha1.MachineUser{}).
		WithOptions(controller.Options{RateLimiter: workqueue.NewTypedItemExponentialFailureRateLimiter[reconcile.Request](time.Millisecond*500, time.Minute*3)}).
		Complete(r)
}