const (
	// PodOSSelectorNodeLabelDoesNotMatch is used to denote that the pod was
	// rejected admission to the node because the pod's node selector
	// corresponding to kubernetes.io/os label didn't match the node label.
	PodOSSelectorNodeLabelDoesNotMatch = "PodOSSelectorNodeLabelDoesNotMatch"

	// PodOSNotSupported is used to denote that the pod was rejected admission
	// to the node because the pod's OS field didn't match the node OS.
	PodOSNotSupported = "PodOSNotSupported"

	// InvalidNodeInfo is used to denote that the pod was rejected admission
	// to the node because the kubelet was unable to retrieve the node info.
	InvalidNodeInfo = "InvalidNodeInfo"

	// InitContainerRestartPolicyForbidden is used to denote that the pod was
	// rejected admission to the node because it uses a restart policy other
	// than Always for some of its init containers.
	InitContainerRestartPolicyForbidden = "InitContainerRestartPolicyForbidden"

	// SupplementalGroupsPolicyNotSupported is used to denote that the pod was
	// rejected admission to the node because the node does not support
	// the pod's SupplementalGroupsPolicy.
	SupplementalGroupsPolicyNotSupported = "SupplementalGroupsPolicyNotSupported"

	// UnexpectedAdmissionError is used to denote that the pod was rejected
	// admission to the node because of an error during admission that could not
	// be categorized.
	UnexpectedAdmissionError = "UnexpectedAdmissionError"

	// UnknownReason is used to denote that the pod was rejected admission to
	// the node because a predicate failed for a reason that could not be
	// determined.
	UnknownReason = "UnknownReason"

	// UnexpectedPredicateFailureType is used to denote that the pod was
	// rejected admission to the node because a predicate returned a reason
	// object that was not an InsufficientResourceError or a PredicateFailureError.
	UnexpectedPredicateFailureType = "UnexpectedPredicateFailureType"

	// Prefix for admission reason when kubelet rejects a pod due to insufficient
	// resources available.
	InsufficientResourcePrefix = "OutOf"

	// These reasons are used to denote that the pod has reject admission
	// to the node because there's not enough resources to run the pod.
	OutOfCPU              = "OutOfcpu"
	OutOfMemory           = "OutOfmemory"
	OutOfEphemeralStorage = "OutOfephemeral-storage"
	OutOfPods             = "OutOfpods"
)

const (
	AppArmorNotAdmittedReason = "AppArmor"
)

type AdmissionFailureHandler interface {
	HandleAdmissionFailure(admitPod *v1.Pod, failureReasons []PredicateFailureReason) ([]PredicateFailureReason, error)
}

type AdmissionFailureHandlerStub struct{}

type InsufficientResourceError struct {
	ResourceName v1.ResourceName
	Requested    int64
	Used         int64
	Capacity     int64
}

type PodAdmitAttributes struct {
	// the pod to evaluate for admission
	Pod *v1.Pod
	// all pods bound to the kubelet excluding the pod being evaluated
	OtherPods []*v1.Pod
}

type PodAdmitHandler interface {
	// Admit evaluates if a pod can be admitted.
	Admit(attrs *PodAdmitAttributes) PodAdmitResult
}

type PodAdmitHandlers []PodAdmitHandler

type PodAdmitResult struct {
	// if true, the pod should be admitted.
	Admit bool
	// a brief single-word reason why the pod could not be admitted.
	Reason string
	// a brief message explaining why the pod could not be admitted.
	Message string
}

type PodAdmitTarget interface {
	// AddPodAdmitHandler adds the specified handler.
	AddPodAdmitHandler(a PodAdmitHandler)
}

type PodLifecycleTarget interface {
	PodAdmitTarget
	PodSyncLoopTarget
	PodSyncTarget
}

type PodSyncHandler interface {
	// ShouldEvict is invoked during each sync pod operation to determine
	// if the pod should be evicted from the kubelet.  If so, the pod status
	// is updated to mark its phase as failed with the provided reason and message,
	// and the pod is immediately killed.
	// This operation must return immediately as its called for each sync pod.
	// The provided pod should never be modified.
	ShouldEvict(pod *v1.Pod) ShouldEvictResponse
}

type PodSyncHandlers []PodSyncHandler

type PodSyncLoopHandler interface {
	// ShouldSync returns true if the pod needs to be synced.
	// This operation must return immediately as its called for each pod.
	// The provided pod should never be modified.
	ShouldSync(pod *v1.Pod) bool
}

type PodSyncLoopHandlers []PodSyncLoopHandler

type PodSyncLoopTarget interface {
	// AddPodSyncLoopHandler adds the specified handler.
	AddPodSyncLoopHandler(a PodSyncLoopHandler)
}

type PodSyncTarget interface {
	// AddPodSyncHandler adds the specified handler
	AddPodSyncHandler(a PodSyncHandler)
}

type PredicateFailureError struct {
	PredicateName string
	PredicateDesc string
}

type PredicateFailureReason interface {
	GetReason() string
}

type ShouldEvictResponse struct {
	// if true, the pod should be evicted.
	Evict bool
	// a brief CamelCase reason why the pod should be evicted.
	Reason string
	// a brief message why the pod should be evicted.
	Message string
}