/*
Copyright 2023.

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"

	"github.com/iwanhae/nodb/internal/templates"
	"k8s.io/apimachinery/pkg/runtime"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/log"

	databasev1 "github.com/iwanhae/nodb/api/v1"
	corev1 "k8s.io/api/core/v1"
	podutil "k8s.io/kubernetes/pkg/api/v1/pod"
)

// PostgreSQLReconciler reconciles a PostgreSQL object
type PostgreSQLPodReconciler struct {
	client.Client
	Scheme *runtime.Scheme
}

//+kubebuilder:rbac:groups="",resources=pods,verbs=watch;get
//+kubebuilder:rbac:groups=database.iwanhae.kr,resources=postgresqls/status,verbs=get;update;patch

func (r *PostgreSQLPodReconciler) Reconcile(ctx context.Context, req ctrl.Request) (result ctrl.Result, err error) {
	logger := log.FromContext(ctx)

	// Find PostgreSQL
	obj := databasev1.PostgreSQL{}
	if err := r.Get(ctx, req.NamespacedName, &obj); err != nil {
		if client.IgnoreNotFound(err) == nil {
			return ctrl.Result{}, nil
		}
		logger.Error(err, "resource not found")
		return ctrl.Result{}, err
	}
	original := obj.DeepCopy()

	// will update Status anyway
	defer func() {
		err = r.Status().Patch(ctx, &obj, client.MergeFrom(original))
		if err != nil {
			logger.Error(err, "failed to update status")
		}
	}()

	// Find Pod
	pod := corev1.Pod{}
	if err := r.Get(ctx, req.NamespacedName, &pod); err != nil {
		if client.IgnoreNotFound(err) == nil {
			// Have PostgreSQL, but no pod
			obj.Status.Status = databasev1.Status_Error
			return ctrl.Result{}, nil
		}
		logger.Error(err, "resource not found")
		return ctrl.Result{}, err
	}

	if pod.Labels[templates.LabelKeyType] != templates.LabelValuePostgreSQL {
		// This pod is not for PostgreSQL
		return ctrl.Result{}, nil
	}

	logger.Info("reconcile", "namespace", pod.Namespace, "name", pod.Name)

	cond := podutil.GetPodReadyCondition(pod.Status)
	if cond == nil {
		obj.Status.Conditions.Pod = databasev1.Status_Initializing
	} else if cond.Status == corev1.ConditionTrue {
		obj.Status.Conditions.Pod = databasev1.Status_Ready
	} else {
		obj.Status.Conditions.Pod = databasev1.Status_NotReady
	}

	if pod.Spec.NodeName != "" {
		obj.Status.ListenOn.Node = pod.Spec.NodeName
		obj.Status.ListenOn.Host = pod.Status.HostIP
	}

	return ctrl.Result{}, nil
}

// SetupWithManager sets up the controller with the Manager.
func (r *PostgreSQLPodReconciler) SetupWithManager(mgr ctrl.Manager) error {
	return ctrl.NewControllerManagedBy(mgr).
		For(&corev1.Pod{}).
		Complete(r)
}