/*
Copyright 2022.

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"

	"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"

	demov1 "mashibing.com/demo/app/api/v1"
)

// Reconciler对象，里面封装了我们调和函数需要的资源
// AppReconciler reconciles a App object
type AppReconciler struct {
	client.Client
	Scheme *runtime.Scheme
}

//+kubebuilder:rbac:groups=demo.mashibing.com,resources=apps,verbs=get;list;watch;create;update;patch;delete
//+kubebuilder:rbac:groups=demo.mashibing.com,resources=apps/status,verbs=get;update;patch
//+kubebuilder:rbac:groups=demo.mashibing.com,resources=apps/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 App 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@v0.13.0/pkg/reconcile
func (r *AppReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
	_ = log.FromContext(ctx)

	// 获取对象的惯例写法
	app := new(demov1.App)

	// Get（） 会调用实现了 Reader Interface 的对象。
	// 找到了实现的对象为  `delegatingReader` ，它只实现了 Reader 接口
	if err := r.Client.Get(ctx, req.NamespacedName, app); err != nil {
		return ctrl.Result{}, client.IgnoreNotFound(err)
	}

	// create() 会调用实现了 Writer Interface 的对象
	//r.Client.Create()
	return ctrl.Result{}, nil
}

// 完成了将 reconciler 加入 controller中，之后将controller加入manager中
// SetupWithManager sets up the controller with the Manager.
func (r *AppReconciler) SetupWithManager(mgr ctrl.Manager) error {
	return ctrl.NewControllerManagedBy(mgr). // 创建 controller
		For(&demov1.App{}). // 将我们当前的crd加入“过滤器”可以让controller订阅到crd的变化
		Complete(r) // 最终将 controller 加入，完成创建过程
}