package models

import (
	"github.com/btcsuite/btcd/btcutil"
	"github.com/btcsuite/btcd/chaincfg/chainhash"
	"github.com/btcsuite/btcd/wire"
	"github.com/lightningnetwork/lnd/fn/v2"
	"github.com/lightningnetwork/lnd/lnwire"
)

// ChannelEdgeInfo represents a fully authenticated channel along with all its
// unique attributes. Once an authenticated channel announcement has been
// processed on the network, then an instance of ChannelEdgeInfo encapsulating
// the channels attributes is stored. The other portions relevant to routing
// policy of a channel are stored within a ChannelEdgePolicy for each direction
// of the channel.
type ChannelEdgeInfo struct {
	// ChannelID is the unique channel ID for the channel. The first 3
	// bytes are the block height, the next 3 the index within the block,
	// and the last 2 bytes are the output index for the channel.
	ChannelID uint64

	// ChainHash is the hash that uniquely identifies the chain that this
	// channel was opened within.
	ChainHash chainhash.Hash

	// NodeKey1Bytes is the raw public key of the first node.
	NodeKey1Bytes [33]byte

	// NodeKey2Bytes is the raw public key of the first node.
	NodeKey2Bytes [33]byte

	// BitcoinKey1Bytes is the raw public key of the first node.
	BitcoinKey1Bytes [33]byte

	// BitcoinKey2Bytes is the raw public key of the first node.
	BitcoinKey2Bytes [33]byte

	// Features is the list of protocol features supported by this channel
	// edge.
	Features *lnwire.FeatureVector

	// AuthProof is the authentication proof for this channel. This proof
	// contains a set of signatures binding four identities, which attests
	// to the legitimacy of the advertised channel.
	AuthProof *ChannelAuthProof

	// ChannelPoint is the funding outpoint of the channel. This can be
	// used to uniquely identify the channel within the channel graph.
	ChannelPoint wire.OutPoint

	// Capacity is the total capacity of the channel, this is determined by
	// the value output in the outpoint that created this channel.
	Capacity btcutil.Amount

	// FundingScript holds the script of the channel's funding transaction.
	//
	// NOTE: this is not currently persisted and so will not be present if
	// the edge object is loaded from the database.
	FundingScript fn.Option[[]byte]

	// ExtraOpaqueData is the set of data that was appended to this
	// message, some of which we may not actually know how to iterate or
	// parse. By holding onto this data, we ensure that we're able to
	// properly validate the set of signatures that cover these new fields,
	// and ensure we're able to make upgrades to the network in a forwards
	// compatible manner.
	ExtraOpaqueData []byte
}