/*

 Copyright 2019 The KubeSphere Authors.

 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 quotas

import (
	"github.com/golang/glog"
	"k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/resource"
	"k8s.io/apimachinery/pkg/labels"
	"kubesphere.io/kubesphere/pkg/informers"
	"kubesphere.io/kubesphere/pkg/models"
	"kubesphere.io/kubesphere/pkg/models/resources"
	"kubesphere.io/kubesphere/pkg/params"
)

const (
	podsKey                   = "count/pods"
	daemonsetsKey             = "count/daemonsets.apps"
	deploymentsKey            = "count/deployments.apps"
	ingressKey                = "count/ingresses.extensions"
	servicesKey               = "count/services"
	statefulsetsKey           = "count/statefulsets.apps"
	persistentvolumeclaimsKey = "persistentvolumeclaims"
	jobsKey                   = "count/jobs.batch"
	cronJobsKey               = "count/cronjobs.batch"
)

type NamespacedResourceQuota struct {
	Namespace string `json:"namespace,omitempty"`

	Data struct {
		v1.ResourceQuotaStatus

		// quota left status, do the math on the side, cause it's
		// a lot easier with go-client library
		Left v1.ResourceList `json:"left,omitempty"`
	} `json:"data,omitempty"`
}

var (
	resourceMap = map[string]string{
		daemonsetsKey:             resources.DaemonSets,
		deploymentsKey:            resources.Deployments,
		ingressKey:                resources.Ingresses,
		servicesKey:               resources.Services,
		statefulsetsKey:           resources.StatefulSets,
		persistentvolumeclaimsKey: resources.PersistentVolumeClaims,
		podsKey:                   resources.Pods,
		jobsKey:                   resources.Jobs,
		cronJobsKey:               resources.CronJobs}
)

func getUsage(namespace, resource string) (int, error) {
	var result *models.PageableResponse
	var err error
	if resource == resources.Namespaces || resource == resources.StorageClasses {
		result, err = resources.ListResources("", resource, &params.Conditions{}, "", false, 1, 0)
	} else {
		result, err = resources.ListResources(namespace, resource, &params.Conditions{}, "", false, 1, 0)
	}

	if err != nil {
		glog.Error(err)
		return 0, err
	}

	return result.TotalCount, nil
}

// no one use this api anymore， marked as deprecated
func GetClusterQuotas() (*models.ResourceQuota, error) {

	quota := v1.ResourceQuotaStatus{Hard: make(v1.ResourceList), Used: make(v1.ResourceList)}

	for k, v := range resourceMap {
		used, err := getUsage("", v)
		if err != nil {
			return nil, err
		}
		var quantity resource.Quantity
		quantity.Set(int64(used))
		quota.Used[v1.ResourceName(k)] = quantity
	}

	return &models.ResourceQuota{Namespace: "\"\"", Data: quota}, nil

}

func GetNamespaceQuotas(namespace string) (*NamespacedResourceQuota, error) {
	quota, err := getNamespaceResourceQuota(namespace)
	if err != nil {
		glog.Error(err)
		return nil, err
	}
	if quota == nil {
		quota = &v1.ResourceQuotaStatus{Hard: make(v1.ResourceList), Used: make(v1.ResourceList)}
	}

	var resourceQuotaLeft = v1.ResourceList{}

	for key, hardLimit := range quota.Hard {
		if used, ok := quota.Used[key]; ok {
			left := hardLimit.DeepCopy()
			left.Sub(used)
			if hardLimit.Cmp(used) < 0 {
				left = resource.MustParse("0")
			}

			resourceQuotaLeft[key] = left
		}
	}

	// add extra quota usage, cause user may not specify them
	for key, val := range resourceMap {
		// only add them when they don't exist in quotastatus
		if _, ok := quota.Used[v1.ResourceName(key)]; !ok {
			used, err := getUsage(namespace, val)
			if err != nil {
				glog.Error(err)
				return nil, err
			}

			quota.Used[v1.ResourceName(key)] = *(resource.NewQuantity(int64(used), resource.DecimalSI))
		}
	}

	var result = NamespacedResourceQuota{
		Namespace: namespace,
	}
	result.Data.Hard = quota.Hard
	result.Data.Used = quota.Used
	result.Data.Left = resourceQuotaLeft

	return &result, nil

}

func updateNamespaceQuota(tmpResourceList, resourceList v1.ResourceList) {
	if tmpResourceList == nil {
		tmpResourceList = resourceList
	}
	for res, usage := range resourceList {
		tmpUsage, exist := tmpResourceList[res]
		if !exist {
			tmpResourceList[res] = usage
		}
		if tmpUsage.Cmp(usage) == 1 {
			tmpResourceList[res] = usage
		}
	}
}

func getNamespaceResourceQuota(namespace string) (*v1.ResourceQuotaStatus, error) {
	resourceQuotaLister := informers.SharedInformerFactory().Core().V1().ResourceQuotas().Lister()
	quotaList, err := resourceQuotaLister.ResourceQuotas(namespace).List(labels.Everything())
	if err != nil {
		glog.Error(err)
		return nil, err
	} else if len(quotaList) == 0 {
		return nil, nil
	}

	quotaStatus := v1.ResourceQuotaStatus{Hard: make(v1.ResourceList), Used: make(v1.ResourceList)}

	for _, quota := range quotaList {
		updateNamespaceQuota(quotaStatus.Hard, quota.Status.Hard)
		updateNamespaceQuota(quotaStatus.Used, quota.Status.Used)
	}

	return &quotaStatus, nil
}