package lnwire

import "io"

// PongPayload is a set of opaque bytes sent in response to a ping message.
type PongPayload []byte

// Pong defines a message which is the direct response to a received Ping
// message. A Pong reply indicates that a connection is still active. The Pong
// reply to a Ping message should contain the nonce carried in the original
// Pong message.
type Pong struct {
	// PongBytes is a set of opaque bytes that corresponds to the
	// NumPongBytes defined in the ping message that this this pong is
	// replying to.
	PongBytes PongPayload
}

// NewPong returns a new Pong message.
func NewPong(pongBytes []byte) *Pong {
	return &Pong{
		PongBytes: pongBytes,
	}
}

// A compile time check to ensure Pong implements the lnwire.Message interface.
var _ Message = (*Pong)(nil)

// Decode deserializes a serialized Pong message stored in the passed io.Reader
// observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (p *Pong) Decode(r io.Reader, pver uint32) error {
	return readElements(r,
		&p.PongBytes,
	)
}

// Encode serializes the target Pong into the passed io.Writer observing the
// protocol version specified.
//
// This is part of the lnwire.Message interface.
func (p *Pong) Encode(w io.Writer, pver uint32) error {
	return writeElements(w,
		p.PongBytes,
	)
}

// MsgType returns the integer uniquely identifying this message type on the
// wire.
//
// This is part of the lnwire.Message interface.
func (p *Pong) MsgType() MessageType {
	return MsgPong
}

// MaxPayloadLength returns the maximum allowed payload size for a Pong
// complete message observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (p *Pong) MaxPayloadLength(uint32) uint32 {
	return 65532
}
