/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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"
	"reflect"
	"time"

	"github.com/apache/lucene-solr-operator/controllers/util"
	"github.com/go-logr/logr"
	"k8s.io/apimachinery/pkg/api/errors"
	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/reconcile"

	solrv1beta1 "github.com/apache/lucene-solr-operator/api/v1beta1"
)

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

// +kubebuilder:rbac:groups=solr.bloomberg.com,resources=solrcollectionaliases,verbs=get;list;watch;create;update;patch;delete
// +kubebuilder:rbac:groups=solr.bloomberg.com,resources=solrcollectionaliases/status,verbs=get;update;patch
// +kubebuilder:rbac:groups=solr.bloomberg.com,resources=solrcloud,verbs=get;list;watch
// +kubebuilder:rbac:groups=solr.bloomberg.com,resources=solrcloud/status,verbs=get

func (r *SolrCollectionAliasReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
	_ = context.Background()
	_ = r.Log.WithValues("solrcollectionalias", req.NamespacedName)

	alias := &solrv1beta1.SolrCollectionAlias{}
	aliasFinalizer := "alias.finalizers.bloomberg.com"

	err := r.Get(context.TODO(), req.NamespacedName, alias)
	if err != nil {
		if errors.IsNotFound(err) {
			// Object not found, return.  Created objects are automatically garbage collected.
			// For additional cleanup logic use finalizers.
			return reconcile.Result{}, nil
		}
		// Error reading the object - requeue the req.
		return reconcile.Result{}, err
	}

	oldStatus := alias.Status.DeepCopy()
	requeueOrNot := reconcile.Result{Requeue: true, RequeueAfter: time.Second * 5}

	aliasCreationStatus := reconcileSolrCollectionAlias(r, alias, alias.Spec.SolrCloud, alias.Name, alias.Spec.AliasType, alias.Spec.Collections, alias.Namespace)

	if err != nil {
		r.Log.Error(err, "Error while creating SolrCloud alias")
	}

	if alias.ObjectMeta.DeletionTimestamp.IsZero() {
		// The object is not being deleted, so if it does not have our finalizer,
		// then lets add the finalizer and update the object
		if !util.ContainsString(alias.ObjectMeta.Finalizers, aliasFinalizer) {
			alias.ObjectMeta.Finalizers = append(alias.ObjectMeta.Finalizers, aliasFinalizer)
			if err := r.Update(context.Background(), alias); err != nil {
				return reconcile.Result{}, err
			}
		}
	} else {
		// The object is being deleted, get associated SolrCloud
		solrCloud := &solrv1beta1.SolrCloud{}
		err = r.Get(context.TODO(), types.NamespacedName{Namespace: alias.Namespace, Name: alias.Spec.SolrCloud}, solrCloud)

		if util.ContainsString(alias.ObjectMeta.Finalizers, aliasFinalizer) && solrCloud != nil && aliasCreationStatus {
			r.Log.Info("Deleting Solr collection alias", "cloud", alias.Spec.SolrCloud, "namespace", alias.Namespace, "Collection Name", alias.Name)
			// our finalizer is present, along with the associated SolrCloud and alias lets delete alias
			delete, err := util.DeleteCollectionAlias(alias.Spec.SolrCloud, alias.Name, alias.Namespace)
			if err != nil {
				r.Log.Error(err, "Failed to delete Solr collection")
				return reconcile.Result{}, err
			}

			r.Log.Info("Deleted Solr collection", "cloud", alias.Spec.SolrCloud, "namespace", alias.Namespace, "Alias", alias.Name, "Deleted", delete)

		}

		// remove our finalizer from the list and update it.
		alias.ObjectMeta.Finalizers = util.RemoveString(alias.ObjectMeta.Finalizers, aliasFinalizer)
		if err := r.Update(context.Background(), alias); err != nil {
			return reconcile.Result{}, err
		}
	}

	if alias.Status.CreatedTime == nil {
		now := metav1.Now()
		alias.Status.CreatedTime = &now
		alias.Status.Created = aliasCreationStatus
	}

	if !reflect.DeepEqual(oldStatus, alias.Status) {
		r.Log.Info("Updating status for collection alias", "alias", alias, "namespace", alias.Namespace, "name", alias.Name)
		err = r.Status().Update(context.TODO(), alias)
	}

	if aliasCreationStatus {
		requeueOrNot = reconcile.Result{}
	}

	return requeueOrNot, nil
}

func reconcileSolrCollectionAlias(r *SolrCollectionAliasReconciler, alias *solrv1beta1.SolrCollectionAlias, solrCloudName string, aliasName string, aliasType string, collections []string, namespace string) (aliasCreationStatus bool) {
	success, aliasCollections := util.CurrentCollectionAliasDetails(solrCloudName, aliasName, namespace)

	// If not created, or if alias status differs from spec requirements create alias
	if !success || !reflect.DeepEqual(alias.Status.Collections, aliasCollections) {
		r.Log.Info("Applying collection alias", "alias", alias)
		err := util.CreateCollectionAlias(solrCloudName, aliasName, aliasType, collections, namespace)
		if err == nil {
			alias.Status.Created = true
			alias.Status.Collections = collections
			return alias.Status.Created
		}
	}

	return alias.Status.Created
}

func (r *SolrCollectionAliasReconciler) SetupWithManager(mgr ctrl.Manager) error {
	return ctrl.NewControllerManagedBy(mgr).
		For(&solrv1beta1.SolrCollectionAlias{}).
		Complete(r)
}