package models

// ChannelAuthProof is the authentication proof (the signature portion) for a
// channel. Using the four signatures contained in the struct, and some
// auxiliary knowledge (the funding script, node identities, and outpoint) nodes
// on the network are able to validate the authenticity and existence of a
// channel. Each of these signatures signs the following digest: chanID ||
// nodeID1 || nodeID2 || bitcoinKey1|| bitcoinKey2 || 2-byte-feature-len ||
// features.
type ChannelAuthProof struct {
	// NodeSig1Bytes are the raw bytes of the first node signature encoded
	// in DER format.
	NodeSig1Bytes []byte

	// NodeSig2Bytes are the raw bytes of the second node signature
	// encoded in DER format.
	NodeSig2Bytes []byte

	// BitcoinSig1Bytes are the raw bytes of the first bitcoin signature
	// encoded in DER format.
	BitcoinSig1Bytes []byte

	// BitcoinSig2Bytes are the raw bytes of the second bitcoin signature
	// encoded in DER format.
	BitcoinSig2Bytes []byte
}

// IsEmpty check is the authentication proof is empty Proof is empty if at
// least one of the signatures are equal to nil.
func (c *ChannelAuthProof) IsEmpty() bool {
	return len(c.NodeSig1Bytes) == 0 ||
		len(c.NodeSig2Bytes) == 0 ||
		len(c.BitcoinSig1Bytes) == 0 ||
		len(c.BitcoinSig2Bytes) == 0
}