package clustercache

import (
	"sync"
	"time"

	"github.com/opencost/opencost/core/pkg/log"
	"github.com/opencost/opencost/pkg/env"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/utils/ptr"

	appsv1 "k8s.io/api/apps/v1"
	batchv1 "k8s.io/api/batch/v1"
	v1 "k8s.io/api/core/v1"
	policyv1 "k8s.io/api/policy/v1"
	stv1 "k8s.io/api/storage/v1"
	"k8s.io/apimachinery/pkg/fields"
	"k8s.io/client-go/kubernetes"
)

type Namespace struct {
	Name        string
	Labels      map[string]string
	Annotations map[string]string
}

type Pod struct {
	UID               types.UID
	Name              string
	Namespace         string
	Labels            map[string]string
	Annotations       map[string]string
	OwnerReferences   []metav1.OwnerReference
	Status            PodStatus
	Spec              PodSpec
	DeletionTimestamp *time.Time
}

type PodStatus struct {
	Phase             v1.PodPhase
	ContainerStatuses []v1.ContainerStatus
}

type PodSpec struct {
	NodeName      string
	Containers    []Container
	Volumes       []v1.Volume
	RestartPolicy v1.RestartPolicy
}

type Container struct {
	Name      string
	Resources v1.ResourceRequirements
}

type Node struct {
	Name           string
	Labels         map[string]string
	Annotations    map[string]string
	Status         v1.NodeStatus
	SpecProviderID string
}

type Service struct {
	Name         string
	Namespace    string
	SpecSelector map[string]string
	Type         v1.ServiceType
	Status       v1.ServiceStatus
}

type DaemonSet struct {
	Name           string
	Namespace      string
	Labels         map[string]string
	SpecContainers []v1.Container
}

type Deployment struct {
	Name                    string
	Namespace               string
	Labels                  map[string]string
	Annotations             map[string]string
	MatchLabels             map[string]string
	SpecSelector            *metav1.LabelSelector
	SpecReplicas            *int32
	SpecStrategy            appsv1.DeploymentStrategy
	StatusAvailableReplicas int32
	PodSpec                 PodSpec
}

type StatefulSet struct {
	Name         string
	Namespace    string
	Labels       map[string]string
	Annotations  map[string]string
	SpecSelector *metav1.LabelSelector
	SpecReplicas *int32
	PodSpec      PodSpec
}

type PersistentVolumeClaim struct {
	Name        string
	Namespace   string
	Spec        v1.PersistentVolumeClaimSpec
	Labels      map[string]string
	Annotations map[string]string
}

type StorageClass struct {
	Name        string
	Labels      map[string]string
	Annotations map[string]string
	Parameters  map[string]string
	Provisioner string
	TypeMeta    metav1.TypeMeta
	Size        int
}

type Job struct {
	Name      string
	Namespace string
	Status    batchv1.JobStatus
}

type PersistentVolume struct {
	Name        string
	Namespace   string
	Labels      map[string]string
	Annotations map[string]string
	Spec        v1.PersistentVolumeSpec
	Status      v1.PersistentVolumeStatus
}

type ReplicationController struct {
	Name      string
	Namespace string
	Spec      v1.ReplicationControllerSpec
}

type PodDisruptionBudget struct {
	Name      string
	Namespace string
	Spec      policyv1.PodDisruptionBudgetSpec
	Status    policyv1.PodDisruptionBudgetStatus
}

type ReplicaSet struct {
	Name         string
	Namespace    string
	SpecSelector *metav1.LabelSelector
	Spec         appsv1.ReplicaSetSpec
}

type Volume struct {
}

// GetControllerOf returns a pointer to a copy of the controllerRef if controllee has a controller
func GetControllerOf(pod *Pod) *metav1.OwnerReference {
	ref := GetControllerOfNoCopy(pod)
	if ref == nil {
		return nil
	}
	cp := *ref
	cp.Controller = ptr.To(*ref.Controller)
	if ref.BlockOwnerDeletion != nil {
		cp.BlockOwnerDeletion = ptr.To(*ref.BlockOwnerDeletion)
	}
	return &cp
}

// GetControllerOfNoCopy returns a pointer to the controllerRef if controllee has a controller
func GetControllerOfNoCopy(pod *Pod) *metav1.OwnerReference {
	refs := pod.OwnerReferences
	for i := range refs {
		if refs[i].Controller != nil && *refs[i].Controller {
			return &refs[i]
		}
	}
	return nil
}

func transformNamespace(input *v1.Namespace) *Namespace {
	return &Namespace{
		Name:        input.Name,
		Annotations: input.Annotations,
		Labels:      input.Labels,
	}
}

func transformPodContainer(input v1.Container) Container {
	return Container{
		Name:      input.Name,
		Resources: input.Resources,
	}
}

func transformPodStatus(input v1.PodStatus) PodStatus {
	return PodStatus{
		Phase:             input.Phase,
		ContainerStatuses: input.ContainerStatuses,
	}
}

func transformPodSpec(input v1.PodSpec) PodSpec {
	containers := make([]Container, len(input.Containers))
	for i, container := range input.Containers {
		containers[i] = transformPodContainer(container)
	}
	return PodSpec{
		NodeName:      input.NodeName,
		Containers:    containers,
		Volumes:       input.Volumes,
		RestartPolicy: input.RestartPolicy,
	}

}

func transformTimestamp(input *metav1.Time) *time.Time {
	if input == nil {
		return nil
	}

	t := input.Time
	return &t
}

func transformPod(input *v1.Pod) *Pod {
	return &Pod{
		UID:               input.UID,
		Name:              input.Name,
		Namespace:         input.Namespace,
		Labels:            input.Labels,
		Annotations:       input.Annotations,
		OwnerReferences:   input.OwnerReferences,
		Spec:              transformPodSpec(input.Spec),
		Status:            transformPodStatus(input.Status),
		DeletionTimestamp: transformTimestamp(input.DeletionTimestamp),
	}
}

func transformNode(input *v1.Node) *Node {
	return &Node{
		Name:           input.Name,
		Labels:         input.Labels,
		Annotations:    input.Annotations,
		Status:         input.Status,
		SpecProviderID: input.Spec.ProviderID,
	}
}

func transformService(input *v1.Service) *Service {
	return &Service{
		Name:         input.Name,
		Namespace:    input.Namespace,
		SpecSelector: input.Spec.Selector,
		Type:         input.Spec.Type,
		Status:       input.Status,
	}
}

func transformDaemonSet(input *appsv1.DaemonSet) *DaemonSet {
	return &DaemonSet{
		Name:           input.Name,
		Namespace:      input.Namespace,
		Labels:         input.Labels,
		SpecContainers: input.Spec.Template.Spec.Containers,
	}
}

func transformDeployment(input *appsv1.Deployment) *Deployment {
	return &Deployment{
		Name:                    input.Name,
		Namespace:               input.Namespace,
		Labels:                  input.Labels,
		MatchLabels:             input.Spec.Selector.MatchLabels,
		SpecReplicas:            input.Spec.Replicas,
		SpecSelector:            input.Spec.Selector,
		SpecStrategy:            input.Spec.Strategy,
		StatusAvailableReplicas: input.Status.AvailableReplicas,
		PodSpec:                 transformPodSpec(input.Spec.Template.Spec),
	}
}

func transformStatefulSet(input *appsv1.StatefulSet) *StatefulSet {
	return &StatefulSet{
		Name:         input.Name,
		Namespace:    input.Namespace,
		SpecSelector: input.Spec.Selector,
		SpecReplicas: input.Spec.Replicas,
		PodSpec:      transformPodSpec(input.Spec.Template.Spec),
	}
}

func transformPersistentVolume(input *v1.PersistentVolume) *PersistentVolume {
	return &PersistentVolume{
		Name:        input.Name,
		Namespace:   input.Namespace,
		Labels:      input.Labels,
		Annotations: input.Annotations,
		Spec:        input.Spec,
		Status:      input.Status,
	}
}

func transformPersistentVolumeClaim(input *v1.PersistentVolumeClaim) *PersistentVolumeClaim {
	return &PersistentVolumeClaim{
		Name:        input.Name,
		Namespace:   input.Namespace,
		Spec:        input.Spec,
		Labels:      input.Labels,
		Annotations: input.Annotations,
	}
}

func transformStorageClass(input *stv1.StorageClass) *StorageClass {
	return &StorageClass{
		Name:        input.Name,
		Annotations: input.Annotations,
		Labels:      input.Labels,
		Parameters:  input.Parameters,
		Provisioner: input.Provisioner,
		TypeMeta:    input.TypeMeta,
		Size:        input.Size(),
	}
}

func transformJob(input *batchv1.Job) *Job {
	return &Job{
		Name:      input.Name,
		Namespace: input.Namespace,
		Status:    input.Status,
	}
}

func transformReplicationController(input *v1.ReplicationController) *ReplicationController {
	return &ReplicationController{
		Name:      input.Name,
		Namespace: input.Namespace,
		Spec:      input.Spec,
	}
}

func transformPodDisruptionBudget(input *policyv1.PodDisruptionBudget) *PodDisruptionBudget {
	return &PodDisruptionBudget{
		Name:      input.Name,
		Namespace: input.Namespace,
		Spec:      input.Spec,
		Status:    input.Status,
	}
}

func transformReplicaSet(input *appsv1.ReplicaSet) *ReplicaSet {
	return &ReplicaSet{
		Name:         input.Name,
		Namespace:    input.Namespace,
		Spec:         input.Spec,
		SpecSelector: input.Spec.Selector,
	}
}

// ClusterCache defines an contract for an object which caches components within a cluster, ensuring
// up to date resources using watchers
type ClusterCache interface {
	// Run starts the watcher processes
	Run()

	// Stops the watcher processes
	Stop()

	// GetAllNamespaces returns all the cached namespaces
	GetAllNamespaces() []*Namespace

	// GetAllNodes returns all the cached nodes
	GetAllNodes() []*Node

	// GetAllPods returns all the cached pods
	GetAllPods() []*Pod

	// GetAllServices returns all the cached services
	GetAllServices() []*Service

	// GetAllDaemonSets returns all the cached DaemonSets
	GetAllDaemonSets() []*DaemonSet

	// GetAllDeployments returns all the cached deployments
	GetAllDeployments() []*Deployment

	// GetAllStatfulSets returns all the cached StatefulSets
	GetAllStatefulSets() []*StatefulSet

	// GetAllReplicaSets returns all the cached ReplicaSets
	GetAllReplicaSets() []*ReplicaSet

	// GetAllPersistentVolumes returns all the cached persistent volumes
	GetAllPersistentVolumes() []*PersistentVolume

	// GetAllPersistentVolumeClaims returns all the cached persistent volume claims
	GetAllPersistentVolumeClaims() []*PersistentVolumeClaim

	// GetAllStorageClasses returns all the cached storage classes
	GetAllStorageClasses() []*StorageClass

	// GetAllJobs returns all the cached jobs
	GetAllJobs() []*Job

	// GetAllPodDisruptionBudgets returns all cached pod disruption budgets
	GetAllPodDisruptionBudgets() []*PodDisruptionBudget

	// GetAllReplicationControllers returns all cached replication controllers
	GetAllReplicationControllers() []*ReplicationController
}

// KubernetesClusterCache is the implementation of ClusterCache
type KubernetesClusterCache struct {
	client kubernetes.Interface

	namespaceWatch             WatchController
	nodeWatch                  WatchController
	podWatch                   WatchController
	serviceWatch               WatchController
	daemonsetsWatch            WatchController
	deploymentsWatch           WatchController
	statefulsetWatch           WatchController
	replicasetWatch            WatchController
	pvWatch                    WatchController
	pvcWatch                   WatchController
	storageClassWatch          WatchController
	jobsWatch                  WatchController
	pdbWatch                   WatchController
	replicationControllerWatch WatchController
	stop                       chan struct{}
}

func initializeCache(wc WatchController, wg *sync.WaitGroup, cancel chan struct{}) {
	defer wg.Done()
	wc.WarmUp(cancel)
}

func NewKubernetesClusterCache(client kubernetes.Interface) ClusterCache {
	if env.GetUseCacheV1() {
		return NewKubernetesClusterCacheV1(client)
	}
	return NewKubernetesClusterCacheV2(client)
}

func NewKubernetesClusterCacheV1(client kubernetes.Interface) ClusterCache {
	coreRestClient := client.CoreV1().RESTClient()
	appsRestClient := client.AppsV1().RESTClient()
	storageRestClient := client.StorageV1().RESTClient()
	batchClient := client.BatchV1().RESTClient()
	pdbClient := client.PolicyV1().RESTClient()

	kubecostNamespace := env.GetKubecostNamespace()
	log.Infof("NAMESPACE: %s", kubecostNamespace)

	kcc := &KubernetesClusterCache{
		client:                     client,
		namespaceWatch:             NewCachingWatcher(coreRestClient, "namespaces", &v1.Namespace{}, "", fields.Everything()),
		nodeWatch:                  NewCachingWatcher(coreRestClient, "nodes", &v1.Node{}, "", fields.Everything()),
		podWatch:                   NewCachingWatcher(coreRestClient, "pods", &v1.Pod{}, "", fields.Everything()),
		serviceWatch:               NewCachingWatcher(coreRestClient, "services", &v1.Service{}, "", fields.Everything()),
		daemonsetsWatch:            NewCachingWatcher(appsRestClient, "daemonsets", &appsv1.DaemonSet{}, "", fields.Everything()),
		deploymentsWatch:           NewCachingWatcher(appsRestClient, "deployments", &appsv1.Deployment{}, "", fields.Everything()),
		statefulsetWatch:           NewCachingWatcher(appsRestClient, "statefulsets", &appsv1.StatefulSet{}, "", fields.Everything()),
		replicasetWatch:            NewCachingWatcher(appsRestClient, "replicasets", &appsv1.ReplicaSet{}, "", fields.Everything()),
		pvWatch:                    NewCachingWatcher(coreRestClient, "persistentvolumes", &v1.PersistentVolume{}, "", fields.Everything()),
		pvcWatch:                   NewCachingWatcher(coreRestClient, "persistentvolumeclaims", &v1.PersistentVolumeClaim{}, "", fields.Everything()),
		storageClassWatch:          NewCachingWatcher(storageRestClient, "storageclasses", &stv1.StorageClass{}, "", fields.Everything()),
		jobsWatch:                  NewCachingWatcher(batchClient, "jobs", &batchv1.Job{}, "", fields.Everything()),
		pdbWatch:                   NewCachingWatcher(pdbClient, "poddisruptionbudgets", &policyv1.PodDisruptionBudget{}, "", fields.Everything()),
		replicationControllerWatch: NewCachingWatcher(coreRestClient, "replicationcontrollers", &v1.ReplicationController{}, "", fields.Everything()),
	}

	// Wait for each caching watcher to initialize
	cancel := make(chan struct{})
	var wg sync.WaitGroup
	if !env.IsETLReadOnlyMode() {
		wg.Add(14)
		go initializeCache(kcc.namespaceWatch, &wg, cancel)
		go initializeCache(kcc.nodeWatch, &wg, cancel)
		go initializeCache(kcc.podWatch, &wg, cancel)
		go initializeCache(kcc.serviceWatch, &wg, cancel)
		go initializeCache(kcc.daemonsetsWatch, &wg, cancel)
		go initializeCache(kcc.deploymentsWatch, &wg, cancel)
		go initializeCache(kcc.statefulsetWatch, &wg, cancel)
		go initializeCache(kcc.replicasetWatch, &wg, cancel)
		go initializeCache(kcc.pvWatch, &wg, cancel)
		go initializeCache(kcc.pvcWatch, &wg, cancel)
		go initializeCache(kcc.storageClassWatch, &wg, cancel)
		go initializeCache(kcc.jobsWatch, &wg, cancel)
		go initializeCache(kcc.pdbWatch, &wg, cancel)
		go initializeCache(kcc.replicationControllerWatch, &wg, cancel)
	}

	wg.Wait()

	log.Infof("Done waiting")

	return kcc
}

func (kcc *KubernetesClusterCache) Run() {
	if kcc.stop != nil {
		return
	}
	stopCh := make(chan struct{})

	go kcc.namespaceWatch.Run(1, stopCh)
	go kcc.nodeWatch.Run(1, stopCh)
	go kcc.podWatch.Run(1, stopCh)
	go kcc.serviceWatch.Run(1, stopCh)
	go kcc.daemonsetsWatch.Run(1, stopCh)
	go kcc.deploymentsWatch.Run(1, stopCh)
	go kcc.statefulsetWatch.Run(1, stopCh)
	go kcc.replicasetWatch.Run(1, stopCh)
	go kcc.pvWatch.Run(1, stopCh)
	go kcc.pvcWatch.Run(1, stopCh)
	go kcc.storageClassWatch.Run(1, stopCh)
	go kcc.jobsWatch.Run(1, stopCh)
	go kcc.pdbWatch.Run(1, stopCh)
	go kcc.replicationControllerWatch.Run(1, stopCh)

	kcc.stop = stopCh
}

func (kcc *KubernetesClusterCache) Stop() {
	if kcc.stop == nil {
		return
	}

	close(kcc.stop)
	kcc.stop = nil
}

func (kcc *KubernetesClusterCache) GetAllNamespaces() []*Namespace {
	var namespaces []*Namespace
	items := kcc.namespaceWatch.GetAll()
	for _, ns := range items {
		namespaces = append(namespaces, transformNamespace(ns.(*v1.Namespace)))
	}
	return namespaces
}

func (kcc *KubernetesClusterCache) GetAllNodes() []*Node {
	var nodes []*Node
	items := kcc.nodeWatch.GetAll()
	for _, node := range items {
		nodes = append(nodes, transformNode(node.(*v1.Node)))
	}
	return nodes
}

func (kcc *KubernetesClusterCache) GetAllPods() []*Pod {
	var pods []*Pod
	items := kcc.podWatch.GetAll()
	for _, pod := range items {
		pods = append(pods, transformPod(pod.(*v1.Pod)))
	}
	return pods
}

func (kcc *KubernetesClusterCache) GetAllServices() []*Service {
	var services []*Service
	items := kcc.serviceWatch.GetAll()
	for _, service := range items {
		services = append(services, transformService(service.(*v1.Service)))
	}
	return services
}

func (kcc *KubernetesClusterCache) GetAllDaemonSets() []*DaemonSet {
	var daemonsets []*DaemonSet
	items := kcc.daemonsetsWatch.GetAll()
	for _, daemonset := range items {
		daemonsets = append(daemonsets, transformDaemonSet(daemonset.(*appsv1.DaemonSet)))
	}
	return daemonsets
}

func (kcc *KubernetesClusterCache) GetAllDeployments() []*Deployment {
	var deployments []*Deployment
	items := kcc.deploymentsWatch.GetAll()
	for _, deployment := range items {
		deployments = append(deployments, transformDeployment(deployment.(*appsv1.Deployment)))
	}
	return deployments
}

func (kcc *KubernetesClusterCache) GetAllStatefulSets() []*StatefulSet {
	var statefulsets []*StatefulSet
	items := kcc.statefulsetWatch.GetAll()
	for _, statefulset := range items {
		statefulsets = append(statefulsets, transformStatefulSet(statefulset.(*appsv1.StatefulSet)))
	}
	return statefulsets
}

func (kcc *KubernetesClusterCache) GetAllReplicaSets() []*ReplicaSet {
	var replicasets []*ReplicaSet
	items := kcc.replicasetWatch.GetAll()
	for _, replicaset := range items {
		replicasets = append(replicasets, transformReplicaSet(replicaset.(*appsv1.ReplicaSet)))
	}
	return replicasets
}

func (kcc *KubernetesClusterCache) GetAllPersistentVolumes() []*PersistentVolume {
	var pvs []*PersistentVolume
	items := kcc.pvWatch.GetAll()
	for _, pv := range items {
		pvs = append(pvs, transformPersistentVolume(pv.(*v1.PersistentVolume)))
	}
	return pvs
}

func (kcc *KubernetesClusterCache) GetAllPersistentVolumeClaims() []*PersistentVolumeClaim {
	var pvcs []*PersistentVolumeClaim
	items := kcc.pvcWatch.GetAll()
	for _, pvc := range items {
		pvcs = append(pvcs, transformPersistentVolumeClaim(pvc.(*v1.PersistentVolumeClaim)))
	}
	return pvcs
}

func (kcc *KubernetesClusterCache) GetAllStorageClasses() []*StorageClass {
	var storageClasses []*StorageClass
	items := kcc.storageClassWatch.GetAll()
	for _, stc := range items {
		storageClasses = append(storageClasses, transformStorageClass(stc.(*stv1.StorageClass)))
	}
	return storageClasses
}

func (kcc *KubernetesClusterCache) GetAllJobs() []*Job {
	var jobs []*Job
	items := kcc.jobsWatch.GetAll()
	for _, job := range items {
		jobs = append(jobs, transformJob(job.(*batchv1.Job)))
	}
	return jobs
}

func (kcc *KubernetesClusterCache) GetAllPodDisruptionBudgets() []*PodDisruptionBudget {
	var pdbs []*PodDisruptionBudget
	items := kcc.pdbWatch.GetAll()
	for _, pdb := range items {
		pdbs = append(pdbs, transformPodDisruptionBudget(pdb.(*policyv1.PodDisruptionBudget)))
	}
	return pdbs
}

func (kcc *KubernetesClusterCache) GetAllReplicationControllers() []*ReplicationController {
	var rcs []*ReplicationController
	items := kcc.replicationControllerWatch.GetAll()
	for _, rc := range items {
		rcs = append(rcs, transformReplicationController(rc.(*v1.ReplicationController)))
	}
	return rcs
}