/*
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"

	"github.com/go-logr/logr"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"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/controller/controllerutil"

	esv1alpha1 "github.com/external-secrets/external-secrets/api/v1alpha1"
	"github.com/external-secrets/external-secrets/pkg/provider"
	_ "github.com/external-secrets/external-secrets/pkg/provider/register"
	"github.com/external-secrets/external-secrets/pkg/provider/schema"
)

const (
	requeueAfter = time.Second * 30
)

// ExternalSecretReconciler reconciles a ExternalSecret object.
type ExternalSecretReconciler struct {
	client.Client
	Log    logr.Logger
	Scheme *runtime.Scheme
}

// +kubebuilder:rbac:groups=external-secrets.io,resources=externalsecrets,verbs=get;list;watch;create;update;patch;delete
// +kubebuilder:rbac:groups=external-secrets.io,resources=externalsecrets/status,verbs=get;update;patch

func (r *ExternalSecretReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
	ctx := context.Background()
	log := r.Log.WithValues("external-secrets", req.NamespacedName)

	var externalSecret esv1alpha1.ExternalSecret

	err := r.Get(ctx, req.NamespacedName, &externalSecret)
	if err != nil {
		log.Error(err, "could not get ExternalSecret")
		return ctrl.Result{}, client.IgnoreNotFound(err)
	}

	secret := &corev1.Secret{
		ObjectMeta: metav1.ObjectMeta{
			Name:      externalSecret.Name,
			Namespace: externalSecret.Namespace,
		},
	}

	_, err = ctrl.CreateOrUpdate(ctx, r.Client, secret, func() error {
		store, err := r.getStore(ctx, &externalSecret)
		if err != nil {
			return fmt.Errorf("could not get store reference from ExternalSecret %q: %w", externalSecret.Name, err)
		}

		storeProvider, err := schema.GetProvider(store)
		if err != nil {
			// TODO: add SecretStore name to the log message
			return fmt.Errorf("could not get store provider: %w", err)
		}

		// TODO: Does the * work?
		// If not, should I change the Provider interface?
		providerClient, err := storeProvider.New(ctx, *store.GetProvider(), r.Client, req.Namespace)
		if err != nil {
			return fmt.Errorf("could not get provider client: %w", err)
		}

		err = controllerutil.SetControllerReference(&externalSecret, &secret.ObjectMeta, r.Scheme)
		if err != nil {
			return fmt.Errorf("could not set ExternalSecret controller reference: %w", err)
		}

		secret.Labels = externalSecret.Labels
		secret.Annotations = externalSecret.Annotations

		// TODO: Pass reference to the client (not a copy)?
		secret.Data, err = r.getProviderSecretData(ctx, providerClient, &externalSecret)
		if err != nil {
			return fmt.Errorf("could not get secret data from provider: %w", err)
		}

		return nil
	})

	if err != nil {
		log.Error(err, "could not reconcile ExternalSecret")

		// TODO: Set ExternalSecret.Status.Conditions
		return ctrl.Result{RequeueAfter: requeueAfter}, nil
	}

	return ctrl.Result{}, nil
}

func (r *ExternalSecretReconciler) getStore(ctx context.Context, externalSecret *esv1alpha1.ExternalSecret) (esv1alpha1.GenericStore, error) {
	// TODO: Implement getting ClusterSecretStore
	var secretStore esv1alpha1.SecretStore

	ref := types.NamespacedName{
		Name:      externalSecret.Spec.SecretStoreRef.Name,
		Namespace: externalSecret.Namespace,
	}

	err := r.Get(ctx, ref, &secretStore)
	if err != nil {
		return nil, fmt.Errorf("could not get SecretStore %q, %w", ref.Name, err)
	}

	return &secretStore, nil
}

func (r *ExternalSecretReconciler) getProviderSecretData(ctx context.Context, providerClient provider.Provider, externalSecret *esv1alpha1.ExternalSecret) (map[string][]byte, error) {
	providerData := make(map[string][]byte)

	for _, remoteRef := range externalSecret.Spec.DataFrom {
		secretMap, err := providerClient.GetSecretMap(ctx, remoteRef)
		if err != nil {
			return nil, fmt.Errorf("key %q from ExternalSecret %q: %w", remoteRef.Key, externalSecret.Name, err)
		}

		providerData = Merge(providerData, secretMap)
	}

	for _, secretRef := range externalSecret.Spec.Data {
		secretData, err := providerClient.GetSecret(ctx, secretRef.RemoteRef)
		if err != nil {
			return nil, fmt.Errorf("key %q from ExternalSecret %q: %w", secretRef.RemoteRef.Key, externalSecret.Name, err)
		}

		providerData[secretRef.SecretKey] = secretData
	}

	return providerData, nil
}

func (r *ExternalSecretReconciler) SetupWithManager(mgr ctrl.Manager) error {
	return ctrl.NewControllerManagedBy(mgr).
		For(&esv1alpha1.ExternalSecret{}).
		Complete(r)
}