peer

type Agent interface {
	// Get or create a Peer for the Subscriber
	RetainPeer(Identifier, Subscriber) (Peer, error)

	// Unallocate a peer from the Subscriber
	ReleasePeer(Identifier, Subscriber) error
}

type ChangeListener interface {
	// Add a peer to the List (Called directly from a PeerProvider)
	Add(Identifier) error

	// Remove a peer from the List (Called directly from a PeerProvider)
	Remove(Identifier) error
}

type ConnectionStatus int

type ErrAgentHasNoReferenceToPeer struct {
	AgentName      string
	PeerIdentifier string
}

type ErrChooseContextHasNoDeadline string

type ErrInvalidAgentConversion struct {
	Agent        Agent
	ExpectedType string
}

type ErrInvalidPeerConversion struct {
	Peer         Peer
	ExpectedType string
}

type ErrInvalidPeerType struct {
	ExpectedType   string
	PeerIdentifier Identifier
}

type ErrPeerAddAlreadyInList string

type ErrPeerHasNoReferenceToSubscriber struct {
	PeerIdentifier Identifier
	PeerSubscriber Subscriber
}

type ErrPeerListAlreadyStarted string

type ErrPeerListNotStarted string

type ErrPeerRemoveNotInList string

type Identifier interface {
	Identifier() string
}

type List interface {
	// Notify the PeerList that it will start receiving requests
	Start() error

	// Notify the PeerList that it will stop receiving requests
	Stop() error

	// Choose a Peer for the next call, block until a peer is available (or timeout)
	ChoosePeer(context.Context, *transport.Request) (Peer, error)
}

type Peer interface {
	Identifier

	// Get the status of the Peer
	Status() Status

	// Tell the peer that a request is starting/ending
	// The callsite should look like:
	//   done := peer.StartRequest()
	//   defer done()
	//   // Do request
	StartRequest() (finish func())
}

type Status struct {
	// Current number of pending requests on this peer
	PendingRequestCount int

	// Current status of the Peer's connection
	ConnectionStatus ConnectionStatus
}

type Subscriber interface {
	// The Peer Notifies the Subscriber when its status changes (e.g. connections status, pending requests)
	NotifyStatusChanged(Identifier)
}