peer

type Config struct {
	// Size, in bytes, of the buffer this peer reads messages into
	ReadBufferSize int
	// Size, in bytes, of the buffer this peer writes messages into
	WriteBufferSize         int
	Clock                   mockable.Clock
	Metrics                 *Metrics
	MessageCreator          message.Creator
	MessageCreatorWithProto message.Creator

	// TODO: remove this once we complete blueberry migration
	BlueberryTime time.Time

	Log                  logging.Logger
	InboundMsgThrottler  throttling.InboundMsgThrottler
	Network              Network
	Router               router.InboundHandler
	VersionCompatibility version.Compatibility
	MySubnets            ids.Set
	Beacons              validators.Set
	NetworkID            uint32
	PingFrequency        time.Duration
	PongTimeout          time.Duration
	MaxClockDifference   time.Duration

	// Unix time of the last message sent and received respectively
	// Must only be accessed atomically
	LastSent, LastReceived int64

	// Tracks CPU/disk usage caused by each peer.
	ResourceTracker tracker.ResourceTracker
}

type Info struct {
	IP             string     `json:"ip"`
	PublicIP       string     `json:"publicIP,omitempty"`
	ID             ids.NodeID `json:"nodeID"`
	Version        string     `json:"version"`
	LastSent       time.Time  `json:"lastSent"`
	LastReceived   time.Time  `json:"lastReceived"`
	ObservedUptime json.Uint8 `json:"observedUptime"`
	TrackedSubnets []ids.ID   `json:"trackedSubnets"`
}

type MessageMetrics struct {
	ReceivedBytes, SentBytes, NumSent, NumFailed, NumReceived prometheus.Counter
	SavedReceivedBytes, SavedSentBytes                        metric.Averager
}

type MessageQueue interface {
	// Push attempts to add the message to the queue. If the context is
	// canceled, then pushing the message will return `false` and the message
	// will not be added to the queue.
	Push(ctx context.Context, msg message.OutboundMessage) bool

	// Pop blocks until a message is available and then returns the message. If
	// the queue is closed, then `false` is returned.
	Pop() (message.OutboundMessage, bool)

	// PopNow attempts to return a message without blocking. If a message is not
	// available or the queue is closed, then `false` is returned.
	PopNow() (message.OutboundMessage, bool)

	// Close empties the queue and prevents further messages from being pushed
	// onto it. After calling close once, future calls to close will do nothing.
	Close()
}

type Metrics struct {
	Log                     logging.Logger
	FailedToParse           prometheus.Counter
	NumUselessPeerListBytes prometheus.Counter
	MessageMetrics          map[message.Op]*MessageMetrics
}

type Network interface {
	// Connected is called by the peer once the handshake is finished.
	Connected(ids.NodeID)

	// AllowConnection enables the network is signal to the peer that its
	// connection is no longer desired and should be terminated.
	AllowConnection(ids.NodeID) bool

	// Track allows the peer to notify the network of a potential new peer to
	// connect to.
	//
	// Returns false if this call was not "useful". That is, we were already
	// connected to this node, we already had this tracking information, the
	// signature is invalid or we don't want to connect.
	Track(ips.ClaimedIPPort) bool

	// Disconnected is called when the peer finishes shutting down. It is not
	// guaranteed that [Connected] was called for the provided peer. However, it
	// is guaranteed that [Connected] will not be called after [Disconnected]
	// for a given [Peer] object.
	Disconnected(ids.NodeID)

	// Version provides the peer with the Version message to send to the peer
	// during the handshake.
	Version() (message.OutboundMessage, error)

	// Peers provides the peer with the PeerList message to send to the peer
	// during the handshake.
	Peers() (message.OutboundMessage, error)

	// Pong provides the peer with a Pong message to send to the peer in
	// response to a Ping message.
	Pong(ids.NodeID) (message.OutboundMessage, error)
}

type Peer interface {
	// ID returns the nodeID of the remote peer.
	ID() ids.NodeID

	// Cert returns the certificate that the remote peer is using to
	// authenticate their messages.
	Cert() *x509.Certificate

	// LastSent returns the last time a message was sent to the peer.
	LastSent() time.Time

	// LastReceived returns the last time a message was received from the peer.
	LastReceived() time.Time

	// Ready returns true if the peer has finished the p2p handshake and is
	// ready to send and receive messages.
	Ready() bool

	// AwaitReady will block until the peer has finished the p2p handshake. If
	// the context is cancelled or the peer starts closing, then an error will
	// be returned.
	AwaitReady(ctx context.Context) error

	// Info returns a description of the state of this peer. It should only be
	// called after [Ready] returns true.
	Info() Info

	// IP returns the claimed IP and signature provided by this peer during the
	// handshake. It should only be called after [Ready] returns true.
	IP() *SignedIP

	// Version returns the claimed node version this peer is running. It should
	// only be called after [Ready] returns true.
	Version() *version.Application

	// TrackedSubnets returns the subnets this peer is running. It should only
	// be called after [Ready] returns true.
	TrackedSubnets() ids.Set

	// ObservedUptime returns the local node's uptime according to the peer. The
	// value ranges from [0, 100]. It should only be called after [Ready]
	// returns true.
	ObservedUptime() uint8

	// Send attempts to send [msg] to the peer. The peer takes ownership of
	// [msg] for reference counting. This returns false if the message is
	// guaranteed not to be delivered to the peer.
	Send(ctx context.Context, msg message.OutboundMessage) bool

	// StartClose will begin shutting down the peer. It will not block.
	StartClose()

	// Closed returns true once the peer has been fully shutdown. It is
	// guaranteed that no more messages will be received by this peer once this
	// returns true.
	Closed() bool

	// AwaitClosed will block until the peer has been fully shutdown. If the
	// context is cancelled, then an error will be returned.
	AwaitClosed(ctx context.Context) error
}

type SendFailedCallback interface {
	SendFailed(message.OutboundMessage)
}

type SendFailedFunc func(message.OutboundMessage)

type Set interface {
	// Add this peer to the set.
	//
	// If a peer with the same [peer.ID] is already in the set, then the new
	// peer instance will replace the old peer instance.
	//
	// Add does not change the [peer.ID] returned from calls to [GetByIndex].
	Add(peer Peer)

	// GetByID attempts to fetch a [peer] whose [peer.ID] is equal to [nodeID].
	// If no such peer exists in the set, then [false] will be returned.
	GetByID(nodeID ids.NodeID) (Peer, bool)

	// GetByIndex attempts to fetch a peer who has been allocated [index]. If
	// [index] < 0 or [index] >= [Len], then false will be returned.
	GetByIndex(index int) (Peer, bool)

	// Remove any [peer] whose [peer.ID] is equal to [nodeID] from the set.
	Remove(nodeID ids.NodeID)

	// Len returns the number of peers currently in this set.
	Len() int

	// Sample attempts to return a random slice of peers with length [n]. The
	// slice will not include any duplicates. Only peers that cause the
	// [precondition] to return true will be returned in the slice.
	Sample(n int, precondition func(Peer) bool) []Peer

	// Returns information about all the peers.
	AllInfo() []Info

	// Info returns information about the requested peers if they are in the
	// set.
	Info(nodeIDs []ids.NodeID) []Info
}

type SignedIP struct {
	IP        UnsignedIP
	Signature []byte
}

type UnsignedIP struct {
	IP        ips.IPPort
	Timestamp uint64
}

type Upgrader interface {
	// Must be thread safe
	Upgrade(net.Conn) (ids.NodeID, net.Conn, *x509.Certificate, error)
}