const (
	PreferClosestNUMANodes string = "prefer-closest-numa-nodes"
	MaxAllowableNUMANodes  string = "max-allowable-numa-nodes"
)

const (

	// ErrorTopologyAffinity represents the type for a TopologyAffinityError
	ErrorTopologyAffinity = "TopologyAffinityError"
)

const PolicyBestEffort string = "best-effort"

const PolicyNone string = "none"

const PolicyRestricted string = "restricted"

const PolicySingleNumaNode string = "single-numa-node"

type HintMerger struct {
	NUMAInfo *NUMAInfo
	Hints    [][]TopologyHint
	// Set bestNonPreferredAffinityCount to help decide which affinity mask is
	// preferred amongst all non-preferred hints. We calculate this value as
	// the maximum of the minimum affinity counts supplied for any given hint
	// provider. In other words, prefer a hint that has an affinity mask that
	// includes all of the NUMA nodes from the provider that requires the most
	// NUMA nodes to satisfy its allocation.
	BestNonPreferredAffinityCount int
	CompareNUMAAffinityMasks      func(candidate *TopologyHint, current *TopologyHint) (best *TopologyHint)
}

type HintProvider interface {
	// GetTopologyHints returns a map of resource names to a list of possible
	// concrete resource allocations in terms of NUMA locality hints. Each hint
	// is optionally marked "preferred" and indicates the set of NUMA nodes
	// involved in the hypothetical allocation. The topology manager calls
	// this function for each hint provider, and merges the hints to produce
	// a consensus "best" hint. The hint providers may subsequently query the
	// topology manager to influence actual resource assignment.
	GetTopologyHints(pod *v1.Pod, container *v1.Container) map[string][]TopologyHint
	// GetPodTopologyHints returns a map of resource names to a list of possible
	// concrete resource allocations per Pod in terms of NUMA locality hints.
	GetPodTopologyHints(pod *v1.Pod) map[string][]TopologyHint
	// Allocate triggers resource allocation to occur on the HintProvider after
	// all hints have been gathered and the aggregated Hint is available via a
	// call to Store.GetAffinity().
	Allocate(pod *v1.Pod, container *v1.Container) error
}

type Manager interface {
	// PodAdmitHandler is implemented by Manager
	lifecycle.PodAdmitHandler
	// AddHintProvider adds a hint provider to manager to indicate the hint provider
	// wants to be consulted with when making topology hints
	AddHintProvider(HintProvider)
	// AddContainer adds pod to Manager for tracking
	AddContainer(pod *v1.Pod, container *v1.Container, containerID string)
	// RemoveContainer removes pod from Manager tracking
	RemoveContainer(containerID string) error
	// Store is the interface for storing pod topology hints
	Store
}

type NUMADistances map[int][]uint64

type NUMAInfo struct {
	Nodes         []int
	NUMADistances NUMADistances
}

type Policy interface {
	// Returns Policy Name
	Name() string
	// Returns a merged TopologyHint based on input from hint providers
	// and a Pod Admit Handler Response based on hints and policy type
	Merge(providersHints []map[string][]TopologyHint) (TopologyHint, bool)
}

type PolicyOptions struct {
	PreferClosestNUMA     bool
	MaxAllowableNUMANodes int
}

type Scope interface {
	Name() string
	GetPolicy() Policy
	Admit(pod *v1.Pod) lifecycle.PodAdmitResult
	// AddHintProvider adds a hint provider to manager to indicate the hint provider
	// wants to be consoluted with when making topology hints
	AddHintProvider(h HintProvider)
	// AddContainer adds pod to Manager for tracking
	AddContainer(pod *v1.Pod, container *v1.Container, containerID string)
	// RemoveContainer removes pod from Manager tracking
	RemoveContainer(containerID string) error
	// Store is the interface for storing pod topology hints
	Store
}

type Store interface {
	GetAffinity(podUID string, containerName string) TopologyHint
	GetPolicy() Policy
}

type TopologyAffinityError struct{}

type TopologyHint struct {
	NUMANodeAffinity bitmask.BitMask
	// Preferred is set to true when the NUMANodeAffinity encodes a preferred
	// allocation for the Container. It is set to false otherwise.
	Preferred bool
}