package apps

import (
	"context"
	"fmt"
	"time"

	"github.com/Nerzal/gocloak/v11"
	"github.com/fluxcd/pkg/apis/meta"
	"github.com/fluxcd/pkg/runtime/conditions"
	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/runtime"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
	"sigs.k8s.io/controller-runtime/pkg/log"

	appsv1alpha1 "libre.sh/controller/apis/apps/v1alpha1"
	"libre.sh/controller/internal"
)

// OIDCClientReconciler reconciles a OIDCClient object
type OIDCClientReconciler struct {
	client.Client
	Scheme *runtime.Scheme
}

//+kubebuilder:rbac:groups=apps.libre.sh,resources=oidcclients,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=apps.libre.sh,resources=oidcclients/status,verbs=get;update;patch
//+kubebuilder:rbac:groups=apps.libre.sh,resources=oidcclients/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 OIDCClient 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@v0.12.1/pkg/reconcile
func (r *OIDCClientReconciler) Reconcile(ctx context.Context, req ctrl.Request) (result ctrl.Result, err error) {
	log := log.FromContext(ctx)

	log.Info("reconciling")

	var oidcClient appsv1alpha1.OIDCClient
	err = r.Client.Get(ctx, req.NamespacedName, &oidcClient)
	if err != nil {
		return ctrl.Result{}, client.IgnoreNotFound(err)
	}

	if oidcClient.Spec.Suspend {
		return ctrl.Result{}, nil
	}

	var kcErr error

	defer func() {
		if err != nil {
			return
		}
		if kcErr != nil {
			log.Error(kcErr, "Failed to provision oidcClient")
			result.RequeueAfter = 10 * time.Minute
			conditions.MarkStalled(&oidcClient, meta.FailedReason, kcErr.Error())
		} else {
			conditions.Delete(&oidcClient, meta.StalledCondition)
		}
		if conditions.IsStalled(&oidcClient) {
			conditions.MarkFalse(&oidcClient, meta.ReadyCondition, meta.FailedReason, "Is stalled")
		} else if conditions.IsReconciling(&oidcClient) {
			conditions.MarkUnknown(&oidcClient, meta.ReadyCondition, meta.ProgressingReason, "Is reconciling")
		} else {
			conditions.MarkTrue(&oidcClient, meta.ReadyCondition, meta.SucceededReason, "Is provisionned")
		}
		err = r.Client.Status().Update(ctx, &oidcClient)
	}()

	if oidcClient.Generation != conditions.GetObservedGeneration(&oidcClient, meta.ReadyCondition) {
		conditions.MarkReconciling(&oidcClient, meta.ProgressingReason, "Reconciliation in progress")
		err = r.Client.Status().Update(ctx, &oidcClient)
		if err != nil {
			return
		}
	}

	config, err := internal.GetConfig(ctx, r.Client, oidcClient.Namespace)
	if err != nil {
		return
	}

	provider, err := config.GetKeycloak(ctx, r.Client)
	if err != nil {
		return
	}

	oidcClient.SetDefaults()

	// TODO this only works for new keycloak version that do not use the auth subpath
	// TODO use system user not master
	keycloakClient := gocloak.NewClient(provider.Endpoint, gocloak.SetAuthAdminRealms("admin/realms"), gocloak.SetAuthRealms("realms"))
	token, kcErr := keycloakClient.LoginAdmin(ctx, provider.Username, provider.Password, "master")
	if kcErr != nil {
		return
	}

	getClientsParams := gocloak.GetClientsParams{
		ClientID: &oidcClient.Spec.ClientID,
	}

	var oidClientExists bool
	clientRepresentation := &gocloak.Client{}

	clientRepresentations, kcErr := keycloakClient.GetClients(ctx, token.AccessToken, oidcClient.Spec.Realm, getClientsParams)
	if kcErr != nil {
		return
	}

	// TODO manage it if returns multiple clients ?
	if len(clientRepresentations) == 1 {
		oidClientExists = true
		clientRepresentation = clientRepresentations[0]
	}

	internal.MutateOIDCClientRepresentation(oidcClient, clientRepresentation)

	if !oidClientExists {
		// Create Realm
		log.Info("creating oidc client")
		clientID, kcErr := keycloakClient.CreateClient(ctx, token.AccessToken, oidcClient.Spec.Realm, *clientRepresentation)
		if kcErr != nil {
			return
		}
		clientRepresentation.ID = &clientID
	} else {
		kcErr = keycloakClient.UpdateClient(ctx, token.AccessToken, oidcClient.Spec.Realm, *clientRepresentation)
		if kcErr != nil {
			return
		}
	}

	cred, kcErr := keycloakClient.GetClientSecret(ctx, token.AccessToken, oidcClient.Spec.Realm, *clientRepresentation.ID)
	if err != nil {
		return
	}

	secret := &corev1.Secret{}
	secret.Name = fmt.Sprintf("%s-%s-oidc", oidcClient.Name, oidcClient.Spec.Realm)
	secret.Namespace = oidcClient.Namespace

	_, err = controllerutil.CreateOrUpdate(context.TODO(), r.Client, secret, func() error {
		data := map[string][]byte{
			"client-id":     []byte(oidcClient.Spec.ClientID),
			"client-secret": []byte(*cred.Value),
		}

		secret.Data = data

		return controllerutil.SetOwnerReference(&oidcClient, secret, r.Scheme)
	})
	if err != nil {
		panic(err)
	}

	conditions.Delete(&oidcClient, meta.ReconcilingCondition)

	return
}

// SetupWithManager sets up the controller with the Manager.
func (r *OIDCClientReconciler) SetupWithManager(mgr ctrl.Manager) error {
	return ctrl.NewControllerManagedBy(mgr).
		For(&appsv1alpha1.OIDCClient{}).
		Complete(r)
}