/*

 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 pod

import (
	appsv1 "k8s.io/api/apps/v1"
	"k8s.io/client-go/informers"
	"kubesphere.io/kubesphere/pkg/constants"
	"kubesphere.io/kubesphere/pkg/models/resources/v1alpha2"

	"kubesphere.io/kubesphere/pkg/server/params"
	"kubesphere.io/kubesphere/pkg/utils/sliceutil"
	"sort"
	"strings"

	"k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/labels"
)

type podSearcher struct {
	informers informers.SharedInformerFactory
}

func NewPodSearcher(informers informers.SharedInformerFactory) v1alpha2.Interface {
	return &podSearcher{informers: informers}
}

func (s *podSearcher) Get(namespace, name string) (interface{}, error) {
	return s.informers.Core().V1().Pods().Lister().Pods(namespace).Get(name)
}

func (s *podSearcher) podBelongTo(item *v1.Pod, kind string, name string) bool {
	switch kind {
	case "Deployment":
		if s.podBelongToDeployment(item, name) {
			return true
		}
	case "ReplicaSet":
		if podBelongToReplicaSet(item, name) {
			return true
		}
	case "DaemonSet":
		if podBelongToDaemonSet(item, name) {
			return true
		}
	case "StatefulSet":
		if podBelongToStatefulSet(item, name) {
			return true
		}
	case "Job":
		if podBelongToJob(item, name) {
			return true
		}
	}
	return false
}

func replicaSetBelongToDeployment(replicaSet *appsv1.ReplicaSet, deploymentName string) bool {
	for _, owner := range replicaSet.OwnerReferences {
		if owner.Kind == "Deployment" && owner.Name == deploymentName {
			return true
		}
	}
	return false
}

func podBelongToDaemonSet(item *v1.Pod, name string) bool {
	for _, owner := range item.OwnerReferences {
		if owner.Kind == "DaemonSet" && owner.Name == name {
			return true
		}
	}
	return false
}

func podBelongToJob(item *v1.Pod, name string) bool {
	for _, owner := range item.OwnerReferences {
		if owner.Kind == "Job" && owner.Name == name {
			return true
		}
	}
	return false
}

func podBelongToReplicaSet(item *v1.Pod, replicaSetName string) bool {
	for _, owner := range item.OwnerReferences {
		if owner.Kind == "ReplicaSet" && owner.Name == replicaSetName {
			return true
		}
	}
	return false
}

func podBelongToStatefulSet(item *v1.Pod, statefulSetName string) bool {
	for _, owner := range item.OwnerReferences {
		if owner.Kind == "StatefulSet" && owner.Name == statefulSetName {
			return true
		}
	}
	return false
}

func (s *podSearcher) podBelongToDeployment(item *v1.Pod, deploymentName string) bool {
	replicas, err := s.informers.Apps().V1().ReplicaSets().Lister().ReplicaSets(item.Namespace).List(labels.Everything())
	if err != nil {
		return false
	}

	for _, r := range replicas {
		if replicaSetBelongToDeployment(r, deploymentName) && podBelongToReplicaSet(item, r.Name) {
			return true
		}
	}

	return false
}

func podBindPVC(item *v1.Pod, pvcName string) bool {
	for _, v := range item.Spec.Volumes {
		if v.VolumeSource.PersistentVolumeClaim != nil &&
			v.VolumeSource.PersistentVolumeClaim.ClaimName == pvcName {
			return true
		}
	}
	return false
}

func (s *podSearcher) podBelongToService(item *v1.Pod, serviceName string) bool {
	service, err := s.informers.Core().V1().Services().Lister().Services(item.Namespace).Get(serviceName)
	if err != nil {
		return false
	}

	selector := labels.Set(service.Spec.Selector).AsSelectorPreValidated()
	if selector.Empty() || !selector.Matches(labels.Set(item.Labels)) {
		return false
	}
	return true
}

// exactly Match
func (s *podSearcher) match(match map[string]string, item *v1.Pod) bool {
	for k, v := range match {
		switch k {
		case v1alpha2.OwnerKind:
			fallthrough
		case v1alpha2.OwnerName:
			kind := match[v1alpha2.OwnerKind]
			name := match[v1alpha2.OwnerName]
			if !s.podBelongTo(item, kind, name) {
				return false
			}
		case "nodeName":
			if item.Spec.NodeName != v {
				return false
			}
		case "pvcName":
			if !podBindPVC(item, v) {
				return false
			}
		case "serviceName":
			if !s.podBelongToService(item, v) {
				return false
			}
		case v1alpha2.Name:
			names := strings.Split(v, "|")
			if !sliceutil.HasString(names, item.Name) {
				return false
			}
		case v1alpha2.Keyword:
			if !strings.Contains(item.Name, v) && !v1alpha2.SearchFuzzy(item.Labels, "", v) && !v1alpha2.SearchFuzzy(item.Annotations, "", v) {
				return false
			}
		default:
			// label not exist or value not equal
			if val, ok := item.Labels[k]; !ok || val != v {
				return false
			}
		}
	}
	return true
}

// Fuzzy searchInNamespace
func (*podSearcher) fuzzy(fuzzy map[string]string, item *v1.Pod) bool {
	for k, v := range fuzzy {
		switch k {
		case v1alpha2.Name:
			if !strings.Contains(item.Name, v) && !strings.Contains(item.Annotations[constants.DisplayNameAnnotationKey], v) {
				return false
			}
		case v1alpha2.Label:
			if !v1alpha2.SearchFuzzy(item.Labels, "", v) {
				return false
			}
		case v1alpha2.Annotation:
			if !v1alpha2.SearchFuzzy(item.Annotations, "", v) {
				return false
			}
			return false
		case v1alpha2.App:
			if !strings.Contains(item.Labels[v1alpha2.Chart], v) && !strings.Contains(item.Labels[v1alpha2.Release], v) {
				return false
			}
		default:
			if !v1alpha2.SearchFuzzy(item.Labels, k, v) {
				return false
			}
		}
	}
	return true
}

func (*podSearcher) compare(a, b *v1.Pod, orderBy string) bool {
	switch orderBy {
	case v1alpha2.StartTime:
		if a.Status.StartTime == nil {
			return false
		}
		if b.Status.StartTime == nil {
			return true
		}
		return a.Status.StartTime.Before(b.Status.StartTime)
	case v1alpha2.CreateTime:
		return a.CreationTimestamp.Time.Before(b.CreationTimestamp.Time)
	case v1alpha2.Name:
		fallthrough
	default:
		return strings.Compare(a.Name, b.Name) <= 0
	}
}

func (s *podSearcher) Search(namespace string, conditions *params.Conditions, orderBy string, reverse bool) ([]interface{}, error) {

	pods, err := s.informers.Core().V1().Pods().Lister().Pods(namespace).List(labels.Everything())

	if err != nil {
		return nil, err
	}

	result := make([]*v1.Pod, 0)

	if len(conditions.Match) == 0 && len(conditions.Fuzzy) == 0 {
		result = pods
	} else {
		for _, item := range pods {
			if s.match(conditions.Match, item) && s.fuzzy(conditions.Fuzzy, item) {
				result = append(result, item)
			}
		}
	}
	sort.Slice(result, func(i, j int) bool {
		if reverse {
			tmp := i
			i = j
			j = tmp
		}
		return s.compare(result[i], result[j], orderBy)
	})

	r := make([]interface{}, 0)
	for _, i := range result {
		r = append(r, i)
	}
	return r, nil
}
