lnd/graph/db/sql_store.go

package graphdb

import (
	"bytes"
	"context"
	"database/sql"
	"encoding/hex"
	"errors"
	"fmt"
	"maps"
	"math"
	"net"
	"slices"
	"strconv"
	"sync"
	"time"

	"github.com/btcsuite/btcd/btcec/v2"
	"github.com/btcsuite/btcd/btcutil"
	"github.com/btcsuite/btcd/chaincfg/chainhash"
	"github.com/btcsuite/btcd/wire"
	"github.com/lightningnetwork/lnd/aliasmgr"
	"github.com/lightningnetwork/lnd/batch"
	"github.com/lightningnetwork/lnd/fn/v2"
	"github.com/lightningnetwork/lnd/graph/db/models"
	"github.com/lightningnetwork/lnd/lnwire"
	"github.com/lightningnetwork/lnd/routing/route"
	"github.com/lightningnetwork/lnd/sqldb"
	"github.com/lightningnetwork/lnd/sqldb/sqlc"
	"github.com/lightningnetwork/lnd/tlv"
	"github.com/lightningnetwork/lnd/tor"
)

// pageSize is the limit for the number of records that can be returned
// in a paginated query. This can be tuned after some benchmarks.
const pageSize = 2000

// ProtocolVersion is an enum that defines the gossip protocol version of a
// message.
type ProtocolVersion uint8

const (
	// ProtocolV1 is the gossip protocol version defined in BOLT #7.
	ProtocolV1 ProtocolVersion = 1
)

// String returns a string representation of the protocol version.
func (v ProtocolVersion) String() string {
	return fmt.Sprintf("V%d", v)
}

// SQLQueries is a subset of the sqlc.Querier interface that can be used to
// execute queries against the SQL graph tables.
//
//nolint:ll,interfacebloat
type SQLQueries interface {
	/*
		Node queries.
	*/
	UpsertNode(ctx context.Context, arg sqlc.UpsertNodeParams) (int64, error)
	GetNodeByPubKey(ctx context.Context, arg sqlc.GetNodeByPubKeyParams) (sqlc.Node, error)
	GetNodeIDByPubKey(ctx context.Context, arg sqlc.GetNodeIDByPubKeyParams) (int64, error)
	GetNodesByLastUpdateRange(ctx context.Context, arg sqlc.GetNodesByLastUpdateRangeParams) ([]sqlc.Node, error)
	ListNodesPaginated(ctx context.Context, arg sqlc.ListNodesPaginatedParams) ([]sqlc.Node, error)
	ListNodeIDsAndPubKeys(ctx context.Context, arg sqlc.ListNodeIDsAndPubKeysParams) ([]sqlc.ListNodeIDsAndPubKeysRow, error)
	IsPublicV1Node(ctx context.Context, pubKey []byte) (bool, error)
	DeleteUnconnectedNodes(ctx context.Context) ([][]byte, error)
	DeleteNodeByPubKey(ctx context.Context, arg sqlc.DeleteNodeByPubKeyParams) (sql.Result, error)
	DeleteNode(ctx context.Context, id int64) error

	GetExtraNodeTypes(ctx context.Context, nodeID int64) ([]sqlc.NodeExtraType, error)
	UpsertNodeExtraType(ctx context.Context, arg sqlc.UpsertNodeExtraTypeParams) error
	DeleteExtraNodeType(ctx context.Context, arg sqlc.DeleteExtraNodeTypeParams) error

	InsertNodeAddress(ctx context.Context, arg sqlc.InsertNodeAddressParams) error
	GetNodeAddressesByPubKey(ctx context.Context, arg sqlc.GetNodeAddressesByPubKeyParams) ([]sqlc.GetNodeAddressesByPubKeyRow, error)
	DeleteNodeAddresses(ctx context.Context, nodeID int64) error

	InsertNodeFeature(ctx context.Context, arg sqlc.InsertNodeFeatureParams) error
	GetNodeFeatures(ctx context.Context, nodeID int64) ([]sqlc.NodeFeature, error)
	GetNodeFeaturesByPubKey(ctx context.Context, arg sqlc.GetNodeFeaturesByPubKeyParams) ([]int32, error)
	DeleteNodeFeature(ctx context.Context, arg sqlc.DeleteNodeFeatureParams) error

	/*
		Source node queries.
	*/
	AddSourceNode(ctx context.Context, nodeID int64) error
	GetSourceNodesByVersion(ctx context.Context, version int16) ([]sqlc.GetSourceNodesByVersionRow, error)

	/*
		Channel queries.
	*/
	CreateChannel(ctx context.Context, arg sqlc.CreateChannelParams) (int64, error)
	AddV1ChannelProof(ctx context.Context, arg sqlc.AddV1ChannelProofParams) (sql.Result, error)
	GetChannelBySCID(ctx context.Context, arg sqlc.GetChannelBySCIDParams) (sqlc.Channel, error)
	GetChannelByOutpoint(ctx context.Context, outpoint string) (sqlc.GetChannelByOutpointRow, error)
	GetChannelsBySCIDRange(ctx context.Context, arg sqlc.GetChannelsBySCIDRangeParams) ([]sqlc.GetChannelsBySCIDRangeRow, error)
	GetChannelBySCIDWithPolicies(ctx context.Context, arg sqlc.GetChannelBySCIDWithPoliciesParams) (sqlc.GetChannelBySCIDWithPoliciesRow, error)
	GetChannelAndNodesBySCID(ctx context.Context, arg sqlc.GetChannelAndNodesBySCIDParams) (sqlc.GetChannelAndNodesBySCIDRow, error)
	GetChannelFeaturesAndExtras(ctx context.Context, channelID int64) ([]sqlc.GetChannelFeaturesAndExtrasRow, error)
	HighestSCID(ctx context.Context, version int16) ([]byte, error)
	ListChannelsByNodeID(ctx context.Context, arg sqlc.ListChannelsByNodeIDParams) ([]sqlc.ListChannelsByNodeIDRow, error)
	ListChannelsWithPoliciesPaginated(ctx context.Context, arg sqlc.ListChannelsWithPoliciesPaginatedParams) ([]sqlc.ListChannelsWithPoliciesPaginatedRow, error)
	ListChannelsPaginated(ctx context.Context, arg sqlc.ListChannelsPaginatedParams) ([]sqlc.ListChannelsPaginatedRow, error)
	GetChannelsByPolicyLastUpdateRange(ctx context.Context, arg sqlc.GetChannelsByPolicyLastUpdateRangeParams) ([]sqlc.GetChannelsByPolicyLastUpdateRangeRow, error)
	GetChannelByOutpointWithPolicies(ctx context.Context, arg sqlc.GetChannelByOutpointWithPoliciesParams) (sqlc.GetChannelByOutpointWithPoliciesRow, error)
	GetPublicV1ChannelsBySCID(ctx context.Context, arg sqlc.GetPublicV1ChannelsBySCIDParams) ([]sqlc.Channel, error)
	GetSCIDByOutpoint(ctx context.Context, arg sqlc.GetSCIDByOutpointParams) ([]byte, error)
	DeleteChannel(ctx context.Context, id int64) error

	CreateChannelExtraType(ctx context.Context, arg sqlc.CreateChannelExtraTypeParams) error
	InsertChannelFeature(ctx context.Context, arg sqlc.InsertChannelFeatureParams) error

	/*
		Channel Policy table queries.
	*/
	UpsertEdgePolicy(ctx context.Context, arg sqlc.UpsertEdgePolicyParams) (int64, error)
	GetChannelPolicyByChannelAndNode(ctx context.Context, arg sqlc.GetChannelPolicyByChannelAndNodeParams) (sqlc.ChannelPolicy, error)
	GetV1DisabledSCIDs(ctx context.Context) ([][]byte, error)

	InsertChanPolicyExtraType(ctx context.Context, arg sqlc.InsertChanPolicyExtraTypeParams) error
	GetChannelPolicyExtraTypes(ctx context.Context, arg sqlc.GetChannelPolicyExtraTypesParams) ([]sqlc.GetChannelPolicyExtraTypesRow, error)
	DeleteChannelPolicyExtraTypes(ctx context.Context, channelPolicyID int64) error

	/*
		Zombie index queries.
	*/
	UpsertZombieChannel(ctx context.Context, arg sqlc.UpsertZombieChannelParams) error
	GetZombieChannel(ctx context.Context, arg sqlc.GetZombieChannelParams) (sqlc.ZombieChannel, error)
	CountZombieChannels(ctx context.Context, version int16) (int64, error)
	DeleteZombieChannel(ctx context.Context, arg sqlc.DeleteZombieChannelParams) (sql.Result, error)
	IsZombieChannel(ctx context.Context, arg sqlc.IsZombieChannelParams) (bool, error)

	/*
		Prune log table queries.
	*/
	GetPruneTip(ctx context.Context) (sqlc.PruneLog, error)
	UpsertPruneLogEntry(ctx context.Context, arg sqlc.UpsertPruneLogEntryParams) error
	DeletePruneLogEntriesInRange(ctx context.Context, arg sqlc.DeletePruneLogEntriesInRangeParams) error

	/*
		Closed SCID table queries.
	*/
	InsertClosedChannel(ctx context.Context, scid []byte) error
	IsClosedChannel(ctx context.Context, scid []byte) (bool, error)
}

// BatchedSQLQueries is a version of SQLQueries that's capable of batched
// database operations.
type BatchedSQLQueries interface {
	SQLQueries
	sqldb.BatchedTx[SQLQueries]
}

// SQLStore is an implementation of the V1Store interface that uses a SQL
// database as the backend.
type SQLStore struct {
	cfg *SQLStoreConfig
	db  BatchedSQLQueries

	// cacheMu guards all caches (rejectCache and chanCache). If
	// this mutex will be acquired at the same time as the DB mutex then
	// the cacheMu MUST be acquired first to prevent deadlock.
	cacheMu     sync.RWMutex
	rejectCache *rejectCache
	chanCache   *channelCache

	chanScheduler batch.Scheduler[SQLQueries]
	nodeScheduler batch.Scheduler[SQLQueries]

	srcNodes  map[ProtocolVersion]*srcNodeInfo
	srcNodeMu sync.Mutex
}

// A compile-time assertion to ensure that SQLStore implements the V1Store
// interface.
var _ V1Store = (*SQLStore)(nil)

// SQLStoreConfig holds the configuration for the SQLStore.
type SQLStoreConfig struct {
	// ChainHash is the genesis hash for the chain that all the gossip
	// messages in this store are aimed at.
	ChainHash chainhash.Hash
}

// NewSQLStore creates a new SQLStore instance given an open BatchedSQLQueries
// storage backend.
func NewSQLStore(cfg *SQLStoreConfig, db BatchedSQLQueries,
	options ...StoreOptionModifier) (*SQLStore, error) {

	opts := DefaultOptions()
	for _, o := range options {
		o(opts)
	}

	if opts.NoMigration {
		return nil, fmt.Errorf("the NoMigration option is not yet " +
			"supported for SQL stores")
	}

	s := &SQLStore{
		cfg:         cfg,
		db:          db,
		rejectCache: newRejectCache(opts.RejectCacheSize),
		chanCache:   newChannelCache(opts.ChannelCacheSize),
		srcNodes:    make(map[ProtocolVersion]*srcNodeInfo),
	}

	s.chanScheduler = batch.NewTimeScheduler(
		db, &s.cacheMu, opts.BatchCommitInterval,
	)
	s.nodeScheduler = batch.NewTimeScheduler(
		db, nil, opts.BatchCommitInterval,
	)

	return s, nil
}

// AddLightningNode adds a vertex/node to the graph database. If the node is not
// in the database from before, this will add a new, unconnected one to the
// graph. If it is present from before, this will update that node's
// information.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) AddLightningNode(ctx context.Context,
	node *models.LightningNode, opts ...batch.SchedulerOption) error {

	r := &batch.Request[SQLQueries]{
		Opts: batch.NewSchedulerOptions(opts...),
		Do: func(queries SQLQueries) error {
			_, err := upsertNode(ctx, queries, node)
			return err
		},
	}

	return s.nodeScheduler.Execute(ctx, r)
}

// FetchLightningNode attempts to look up a target node by its identity public
// key. If the node isn't found in the database, then ErrGraphNodeNotFound is
// returned.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) FetchLightningNode(ctx context.Context,
	pubKey route.Vertex) (*models.LightningNode, error) {

	var node *models.LightningNode
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		var err error
		_, node, err = getNodeByPubKey(ctx, db, pubKey)

		return err
	}, sqldb.NoOpReset)
	if err != nil {
		return nil, fmt.Errorf("unable to fetch node: %w", err)
	}

	return node, nil
}

// HasLightningNode determines if the graph has a vertex identified by the
// target node identity public key. If the node exists in the database, a
// timestamp of when the data for the node was lasted updated is returned along
// with a true boolean. Otherwise, an empty time.Time is returned with a false
// boolean.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) HasLightningNode(ctx context.Context,
	pubKey [33]byte) (time.Time, bool, error) {

	var (
		exists     bool
		lastUpdate time.Time
	)
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		dbNode, err := db.GetNodeByPubKey(
			ctx, sqlc.GetNodeByPubKeyParams{
				Version: int16(ProtocolV1),
				PubKey:  pubKey[:],
			},
		)
		if errors.Is(err, sql.ErrNoRows) {
			return nil
		} else if err != nil {
			return fmt.Errorf("unable to fetch node: %w", err)
		}

		exists = true

		if dbNode.LastUpdate.Valid {
			lastUpdate = time.Unix(dbNode.LastUpdate.Int64, 0)
		}

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return time.Time{}, false,
			fmt.Errorf("unable to fetch node: %w", err)
	}

	return lastUpdate, exists, nil
}

// AddrsForNode returns all known addresses for the target node public key
// that the graph DB is aware of. The returned boolean indicates if the
// given node is unknown to the graph DB or not.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) AddrsForNode(ctx context.Context,
	nodePub *btcec.PublicKey) (bool, []net.Addr, error) {

	var (
		addresses []net.Addr
		known     bool
	)
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		var err error
		known, addresses, err = getNodeAddresses(
			ctx, db, nodePub.SerializeCompressed(),
		)
		if err != nil {
			return fmt.Errorf("unable to fetch node addresses: %w",
				err)
		}

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return false, nil, fmt.Errorf("unable to get addresses for "+
			"node(%x): %w", nodePub.SerializeCompressed(), err)
	}

	return known, addresses, nil
}

// DeleteLightningNode starts a new database transaction to remove a vertex/node
// from the database according to the node's public key.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) DeleteLightningNode(ctx context.Context,
	pubKey route.Vertex) error {

	err := s.db.ExecTx(ctx, sqldb.WriteTxOpt(), func(db SQLQueries) error {
		res, err := db.DeleteNodeByPubKey(
			ctx, sqlc.DeleteNodeByPubKeyParams{
				Version: int16(ProtocolV1),
				PubKey:  pubKey[:],
			},
		)
		if err != nil {
			return err
		}

		rows, err := res.RowsAffected()
		if err != nil {
			return err
		}

		if rows == 0 {
			return ErrGraphNodeNotFound
		} else if rows > 1 {
			return fmt.Errorf("deleted %d rows, expected 1", rows)
		}

		return err
	}, sqldb.NoOpReset)
	if err != nil {
		return fmt.Errorf("unable to delete node: %w", err)
	}

	return nil
}

// FetchNodeFeatures returns the features of the given node. If no features are
// known for the node, an empty feature vector is returned.
//
// NOTE: this is part of the graphdb.NodeTraverser interface.
func (s *SQLStore) FetchNodeFeatures(nodePub route.Vertex) (
	*lnwire.FeatureVector, error) {

	ctx := context.TODO()

	return fetchNodeFeatures(ctx, s.db, nodePub)
}

// DisabledChannelIDs returns the channel ids of disabled channels.
// A channel is disabled when two of the associated ChanelEdgePolicies
// have their disabled bit on.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) DisabledChannelIDs() ([]uint64, error) {
	var (
		ctx     = context.TODO()
		chanIDs []uint64
	)
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		dbChanIDs, err := db.GetV1DisabledSCIDs(ctx)
		if err != nil {
			return fmt.Errorf("unable to fetch disabled "+
				"channels: %w", err)
		}

		chanIDs = fn.Map(dbChanIDs, byteOrder.Uint64)

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return nil, fmt.Errorf("unable to fetch disabled channels: %w",
			err)
	}

	return chanIDs, nil
}

// LookupAlias attempts to return the alias as advertised by the target node.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) LookupAlias(ctx context.Context,
	pub *btcec.PublicKey) (string, error) {

	var alias string
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		dbNode, err := db.GetNodeByPubKey(
			ctx, sqlc.GetNodeByPubKeyParams{
				Version: int16(ProtocolV1),
				PubKey:  pub.SerializeCompressed(),
			},
		)
		if errors.Is(err, sql.ErrNoRows) {
			return ErrNodeAliasNotFound
		} else if err != nil {
			return fmt.Errorf("unable to fetch node: %w", err)
		}

		if !dbNode.Alias.Valid {
			return ErrNodeAliasNotFound
		}

		alias = dbNode.Alias.String

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return "", fmt.Errorf("unable to look up alias: %w", err)
	}

	return alias, nil
}

// SourceNode returns the source node of the graph. The source node is treated
// as the center node within a star-graph. This method may be used to kick off
// a path finding algorithm in order to explore the reachability of another
// node based off the source node.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) SourceNode(ctx context.Context) (*models.LightningNode,
	error) {

	var node *models.LightningNode
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		_, nodePub, err := s.getSourceNode(ctx, db, ProtocolV1)
		if err != nil {
			return fmt.Errorf("unable to fetch V1 source node: %w",
				err)
		}

		_, node, err = getNodeByPubKey(ctx, db, nodePub)

		return err
	}, sqldb.NoOpReset)
	if err != nil {
		return nil, fmt.Errorf("unable to fetch source node: %w", err)
	}

	return node, nil
}

// SetSourceNode sets the source node within the graph database. The source
// node is to be used as the center of a star-graph within path finding
// algorithms.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) SetSourceNode(ctx context.Context,
	node *models.LightningNode) error {

	return s.db.ExecTx(ctx, sqldb.WriteTxOpt(), func(db SQLQueries) error {
		id, err := upsertNode(ctx, db, node)
		if err != nil {
			return fmt.Errorf("unable to upsert source node: %w",
				err)
		}

		// Make sure that if a source node for this version is already
		// set, then the ID is the same as the one we are about to set.
		dbSourceNodeID, _, err := s.getSourceNode(ctx, db, ProtocolV1)
		if err != nil && !errors.Is(err, ErrSourceNodeNotSet) {
			return fmt.Errorf("unable to fetch source node: %w",
				err)
		} else if err == nil {
			if dbSourceNodeID != id {
				return fmt.Errorf("v1 source node already "+
					"set to a different node: %d vs %d",
					dbSourceNodeID, id)
			}

			return nil
		}

		return db.AddSourceNode(ctx, id)
	}, sqldb.NoOpReset)
}

// NodeUpdatesInHorizon returns all the known lightning node which have an
// update timestamp within the passed range. This method can be used by two
// nodes to quickly determine if they have the same set of up to date node
// announcements.
//
// NOTE: This is part of the V1Store interface.
func (s *SQLStore) NodeUpdatesInHorizon(startTime,
	endTime time.Time) ([]models.LightningNode, error) {

	ctx := context.TODO()

	var nodes []models.LightningNode
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		dbNodes, err := db.GetNodesByLastUpdateRange(
			ctx, sqlc.GetNodesByLastUpdateRangeParams{
				StartTime: sqldb.SQLInt64(startTime.Unix()),
				EndTime:   sqldb.SQLInt64(endTime.Unix()),
			},
		)
		if err != nil {
			return fmt.Errorf("unable to fetch nodes: %w", err)
		}

		for _, dbNode := range dbNodes {
			node, err := buildNode(ctx, db, &dbNode)
			if err != nil {
				return fmt.Errorf("unable to build node: %w",
					err)
			}

			nodes = append(nodes, *node)
		}

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return nil, fmt.Errorf("unable to fetch nodes: %w", err)
	}

	return nodes, nil
}

// AddChannelEdge adds a new (undirected, blank) edge to the graph database. An
// undirected edge from the two target nodes are created. The information stored
// denotes the static attributes of the channel, such as the channelID, the keys
// involved in creation of the channel, and the set of features that the channel
// supports. The chanPoint and chanID are used to uniquely identify the edge
// globally within the database.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) AddChannelEdge(ctx context.Context,
	edge *models.ChannelEdgeInfo, opts ...batch.SchedulerOption) error {

	var alreadyExists bool
	r := &batch.Request[SQLQueries]{
		Opts: batch.NewSchedulerOptions(opts...),
		Reset: func() {
			alreadyExists = false
		},
		Do: func(tx SQLQueries) error {
			err := insertChannel(ctx, tx, edge)

			// Silence ErrEdgeAlreadyExist so that the batch can
			// succeed, but propagate the error via local state.
			if errors.Is(err, ErrEdgeAlreadyExist) {
				alreadyExists = true
				return nil
			}

			return err
		},
		OnCommit: func(err error) error {
			switch {
			case err != nil:
				return err
			case alreadyExists:
				return ErrEdgeAlreadyExist
			default:
				s.rejectCache.remove(edge.ChannelID)
				s.chanCache.remove(edge.ChannelID)
				return nil
			}
		},
	}

	return s.chanScheduler.Execute(ctx, r)
}

// HighestChanID returns the "highest" known channel ID in the channel graph.
// This represents the "newest" channel from the PoV of the chain. This method
// can be used by peers to quickly determine if their graphs are in sync.
//
// NOTE: This is part of the V1Store interface.
func (s *SQLStore) HighestChanID(ctx context.Context) (uint64, error) {
	var highestChanID uint64
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		chanID, err := db.HighestSCID(ctx, int16(ProtocolV1))
		if errors.Is(err, sql.ErrNoRows) {
			return nil
		} else if err != nil {
			return fmt.Errorf("unable to fetch highest chan ID: %w",
				err)
		}

		highestChanID = byteOrder.Uint64(chanID)

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return 0, fmt.Errorf("unable to fetch highest chan ID: %w", err)
	}

	return highestChanID, nil
}

// UpdateEdgePolicy updates the edge routing policy for a single directed edge
// within the database for the referenced channel. The `flags` attribute within
// the ChannelEdgePolicy determines which of the directed edges are being
// updated. If the flag is 1, then the first node's information is being
// updated, otherwise it's the second node's information. The node ordering is
// determined by the lexicographical ordering of the identity public keys of the
// nodes on either side of the channel.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) UpdateEdgePolicy(ctx context.Context,
	edge *models.ChannelEdgePolicy,
	opts ...batch.SchedulerOption) (route.Vertex, route.Vertex, error) {

	var (
		isUpdate1    bool
		edgeNotFound bool
		from, to     route.Vertex
	)

	r := &batch.Request[SQLQueries]{
		Opts: batch.NewSchedulerOptions(opts...),
		Reset: func() {
			isUpdate1 = false
			edgeNotFound = false
		},
		Do: func(tx SQLQueries) error {
			var err error
			from, to, isUpdate1, err = updateChanEdgePolicy(
				ctx, tx, edge,
			)
			if err != nil {
				log.Errorf("UpdateEdgePolicy faild: %v", err)
			}

			// Silence ErrEdgeNotFound so that the batch can
			// succeed, but propagate the error via local state.
			if errors.Is(err, ErrEdgeNotFound) {
				edgeNotFound = true
				return nil
			}

			return err
		},
		OnCommit: func(err error) error {
			switch {
			case err != nil:
				return err
			case edgeNotFound:
				return ErrEdgeNotFound
			default:
				s.updateEdgeCache(edge, isUpdate1)
				return nil
			}
		},
	}

	err := s.chanScheduler.Execute(ctx, r)

	return from, to, err
}

// updateEdgeCache updates our reject and channel caches with the new
// edge policy information.
func (s *SQLStore) updateEdgeCache(e *models.ChannelEdgePolicy,
	isUpdate1 bool) {

	// If an entry for this channel is found in reject cache, we'll modify
	// the entry with the updated timestamp for the direction that was just
	// written. If the edge doesn't exist, we'll load the cache entry lazily
	// during the next query for this edge.
	if entry, ok := s.rejectCache.get(e.ChannelID); ok {
		if isUpdate1 {
			entry.upd1Time = e.LastUpdate.Unix()
		} else {
			entry.upd2Time = e.LastUpdate.Unix()
		}
		s.rejectCache.insert(e.ChannelID, entry)
	}

	// If an entry for this channel is found in channel cache, we'll modify
	// the entry with the updated policy for the direction that was just
	// written. If the edge doesn't exist, we'll defer loading the info and
	// policies and lazily read from disk during the next query.
	if channel, ok := s.chanCache.get(e.ChannelID); ok {
		if isUpdate1 {
			channel.Policy1 = e
		} else {
			channel.Policy2 = e
		}
		s.chanCache.insert(e.ChannelID, channel)
	}
}

// ForEachSourceNodeChannel iterates through all channels of the source node,
// executing the passed callback on each. The call-back is provided with the
// channel's outpoint, whether we have a policy for the channel and the channel
// peer's node information.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) ForEachSourceNodeChannel(cb func(chanPoint wire.OutPoint,
	havePolicy bool, otherNode *models.LightningNode) error) error {

	var ctx = context.TODO()

	return s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		nodeID, nodePub, err := s.getSourceNode(ctx, db, ProtocolV1)
		if err != nil {
			return fmt.Errorf("unable to fetch source node: %w",
				err)
		}

		return forEachNodeChannel(
			ctx, db, s.cfg.ChainHash, nodeID,
			func(info *models.ChannelEdgeInfo,
				outPolicy *models.ChannelEdgePolicy,
				_ *models.ChannelEdgePolicy) error {

				// Fetch the other node.
				var (
					otherNodePub [33]byte
					node1        = info.NodeKey1Bytes
					node2        = info.NodeKey2Bytes
				)
				switch {
				case bytes.Equal(node1[:], nodePub[:]):
					otherNodePub = node2
				case bytes.Equal(node2[:], nodePub[:]):
					otherNodePub = node1
				default:
					return fmt.Errorf("node not " +
						"participating in this channel")
				}

				_, otherNode, err := getNodeByPubKey(
					ctx, db, otherNodePub,
				)
				if err != nil {
					return fmt.Errorf("unable to fetch "+
						"other node(%x): %w",
						otherNodePub, err)
				}

				return cb(
					info.ChannelPoint, outPolicy != nil,
					otherNode,
				)
			},
		)
	}, sqldb.NoOpReset)
}

// ForEachNode iterates through all the stored vertices/nodes in the graph,
// executing the passed callback with each node encountered. If the callback
// returns an error, then the transaction is aborted and the iteration stops
// early. Any operations performed on the NodeTx passed to the call-back are
// executed under the same read transaction and so, methods on the NodeTx object
// _MUST_ only be called from within the call-back.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) ForEachNode(cb func(tx NodeRTx) error) error {
	var (
		ctx          = context.TODO()
		lastID int64 = 0
	)

	handleNode := func(db SQLQueries, dbNode sqlc.Node) error {
		node, err := buildNode(ctx, db, &dbNode)
		if err != nil {
			return fmt.Errorf("unable to build node(id=%d): %w",
				dbNode.ID, err)
		}

		err = cb(
			newSQLGraphNodeTx(db, s.cfg.ChainHash, dbNode.ID, node),
		)
		if err != nil {
			return fmt.Errorf("callback failed for node(id=%d): %w",
				dbNode.ID, err)
		}

		return nil
	}

	return s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		for {
			nodes, err := db.ListNodesPaginated(
				ctx, sqlc.ListNodesPaginatedParams{
					Version: int16(ProtocolV1),
					ID:      lastID,
					Limit:   pageSize,
				},
			)
			if err != nil {
				return fmt.Errorf("unable to fetch nodes: %w",
					err)
			}

			if len(nodes) == 0 {
				break
			}

			for _, dbNode := range nodes {
				err = handleNode(db, dbNode)
				if err != nil {
					return err
				}

				lastID = dbNode.ID
			}
		}

		return nil
	}, sqldb.NoOpReset)
}

// sqlGraphNodeTx is an implementation of the NodeRTx interface backed by the
// SQLStore and a SQL transaction.
type sqlGraphNodeTx struct {
	db    SQLQueries
	id    int64
	node  *models.LightningNode
	chain chainhash.Hash
}

// A compile-time constraint to ensure sqlGraphNodeTx implements the NodeRTx
// interface.
var _ NodeRTx = (*sqlGraphNodeTx)(nil)

func newSQLGraphNodeTx(db SQLQueries, chain chainhash.Hash,
	id int64, node *models.LightningNode) *sqlGraphNodeTx {

	return &sqlGraphNodeTx{
		db:    db,
		chain: chain,
		id:    id,
		node:  node,
	}
}

// Node returns the raw information of the node.
//
// NOTE: This is a part of the NodeRTx interface.
func (s *sqlGraphNodeTx) Node() *models.LightningNode {
	return s.node
}

// ForEachChannel can be used to iterate over the node's channels under the same
// transaction used to fetch the node.
//
// NOTE: This is a part of the NodeRTx interface.
func (s *sqlGraphNodeTx) ForEachChannel(cb func(*models.ChannelEdgeInfo,
	*models.ChannelEdgePolicy, *models.ChannelEdgePolicy) error) error {

	ctx := context.TODO()

	return forEachNodeChannel(ctx, s.db, s.chain, s.id, cb)
}

// FetchNode fetches the node with the given pub key under the same transaction
// used to fetch the current node. The returned node is also a NodeRTx and any
// operations on that NodeRTx will also be done under the same transaction.
//
// NOTE: This is a part of the NodeRTx interface.
func (s *sqlGraphNodeTx) FetchNode(nodePub route.Vertex) (NodeRTx, error) {
	ctx := context.TODO()

	id, node, err := getNodeByPubKey(ctx, s.db, nodePub)
	if err != nil {
		return nil, fmt.Errorf("unable to fetch V1 node(%x): %w",
			nodePub, err)
	}

	return newSQLGraphNodeTx(s.db, s.chain, id, node), nil
}

// ForEachNodeDirectedChannel iterates through all channels of a given node,
// executing the passed callback on the directed edge representing the channel
// and its incoming policy. If the callback returns an error, then the iteration
// is halted with the error propagated back up to the caller.
//
// Unknown policies are passed into the callback as nil values.
//
// NOTE: this is part of the graphdb.NodeTraverser interface.
func (s *SQLStore) ForEachNodeDirectedChannel(nodePub route.Vertex,
	cb func(channel *DirectedChannel) error) error {

	var ctx = context.TODO()

	return s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		return forEachNodeDirectedChannel(ctx, db, nodePub, cb)
	}, sqldb.NoOpReset)
}

// ForEachNodeCacheable iterates through all the stored vertices/nodes in the
// graph, executing the passed callback with each node encountered. If the
// callback returns an error, then the transaction is aborted and the iteration
// stops early.
//
// NOTE: This is a part of the V1Store interface.
func (s *SQLStore) ForEachNodeCacheable(cb func(route.Vertex,
	*lnwire.FeatureVector) error) error {

	ctx := context.TODO()

	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		return forEachNodeCacheable(ctx, db, func(nodeID int64,
			nodePub route.Vertex) error {

			features, err := getNodeFeatures(ctx, db, nodeID)
			if err != nil {
				return fmt.Errorf("unable to fetch node "+
					"features: %w", err)
			}

			return cb(nodePub, features)
		})
	}, sqldb.NoOpReset)
	if err != nil {
		return fmt.Errorf("unable to fetch nodes: %w", err)
	}

	return nil
}

// ForEachNodeChannel iterates through all channels of the given node,
// executing the passed callback with an edge info structure and the policies
// of each end of the channel. The first edge policy is the outgoing edge *to*
// the connecting node, while the second is the incoming edge *from* the
// connecting node. If the callback returns an error, then the iteration is
// halted with the error propagated back up to the caller.
//
// Unknown policies are passed into the callback as nil values.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) ForEachNodeChannel(nodePub route.Vertex,
	cb func(*models.ChannelEdgeInfo, *models.ChannelEdgePolicy,
		*models.ChannelEdgePolicy) error) error {

	var ctx = context.TODO()

	return s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		dbNode, err := db.GetNodeByPubKey(
			ctx, sqlc.GetNodeByPubKeyParams{
				Version: int16(ProtocolV1),
				PubKey:  nodePub[:],
			},
		)
		if errors.Is(err, sql.ErrNoRows) {
			return nil
		} else if err != nil {
			return fmt.Errorf("unable to fetch node: %w", err)
		}

		return forEachNodeChannel(
			ctx, db, s.cfg.ChainHash, dbNode.ID, cb,
		)
	}, sqldb.NoOpReset)
}

// ChanUpdatesInHorizon returns all the known channel edges which have at least
// one edge that has an update timestamp within the specified horizon.
//
// NOTE: This is part of the V1Store interface.
func (s *SQLStore) ChanUpdatesInHorizon(startTime,
	endTime time.Time) ([]ChannelEdge, error) {

	s.cacheMu.Lock()
	defer s.cacheMu.Unlock()

	var (
		ctx = context.TODO()
		// To ensure we don't return duplicate ChannelEdges, we'll use
		// an additional map to keep track of the edges already seen to
		// prevent re-adding it.
		edgesSeen    = make(map[uint64]struct{})
		edgesToCache = make(map[uint64]ChannelEdge)
		edges        []ChannelEdge
		hits         int
	)
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		rows, err := db.GetChannelsByPolicyLastUpdateRange(
			ctx, sqlc.GetChannelsByPolicyLastUpdateRangeParams{
				Version:   int16(ProtocolV1),
				StartTime: sqldb.SQLInt64(startTime.Unix()),
				EndTime:   sqldb.SQLInt64(endTime.Unix()),
			},
		)
		if err != nil {
			return err
		}

		for _, row := range rows {
			// If we've already retrieved the info and policies for
			// this edge, then we can skip it as we don't need to do
			// so again.
			chanIDInt := byteOrder.Uint64(row.Channel.Scid)
			if _, ok := edgesSeen[chanIDInt]; ok {
				continue
			}

			if channel, ok := s.chanCache.get(chanIDInt); ok {
				hits++
				edgesSeen[chanIDInt] = struct{}{}
				edges = append(edges, channel)

				continue
			}

			node1, node2, err := buildNodes(
				ctx, db, row.Node, row.Node_2,
			)
			if err != nil {
				return err
			}

			channel, err := getAndBuildEdgeInfo(
				ctx, db, s.cfg.ChainHash, row.Channel.ID,
				row.Channel, node1.PubKeyBytes,
				node2.PubKeyBytes,
			)
			if err != nil {
				return fmt.Errorf("unable to build channel "+
					"info: %w", err)
			}

			dbPol1, dbPol2, err := extractChannelPolicies(row)
			if err != nil {
				return fmt.Errorf("unable to extract channel "+
					"policies: %w", err)
			}

			p1, p2, err := getAndBuildChanPolicies(
				ctx, db, dbPol1, dbPol2, channel.ChannelID,
				node1.PubKeyBytes, node2.PubKeyBytes,
			)
			if err != nil {
				return fmt.Errorf("unable to build channel "+
					"policies: %w", err)
			}

			edgesSeen[chanIDInt] = struct{}{}
			chanEdge := ChannelEdge{
				Info:    channel,
				Policy1: p1,
				Policy2: p2,
				Node1:   node1,
				Node2:   node2,
			}
			edges = append(edges, chanEdge)
			edgesToCache[chanIDInt] = chanEdge
		}

		return nil
	}, func() {
		edgesSeen = make(map[uint64]struct{})
		edgesToCache = make(map[uint64]ChannelEdge)
		edges = nil
	})
	if err != nil {
		return nil, fmt.Errorf("unable to fetch channels: %w", err)
	}

	// Insert any edges loaded from disk into the cache.
	for chanid, channel := range edgesToCache {
		s.chanCache.insert(chanid, channel)
	}

	if len(edges) > 0 {
		log.Debugf("ChanUpdatesInHorizon hit percentage: %.2f (%d/%d)",
			float64(hits)*100/float64(len(edges)), hits, len(edges))
	} else {
		log.Debugf("ChanUpdatesInHorizon returned no edges in "+
			"horizon (%s, %s)", startTime, endTime)
	}

	return edges, nil
}

// ForEachNodeCached is similar to forEachNode, but it returns DirectedChannel
// data to the call-back.
//
// NOTE: The callback contents MUST not be modified.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) ForEachNodeCached(cb func(node route.Vertex,
	chans map[uint64]*DirectedChannel) error) error {

	var ctx = context.TODO()

	return s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		return forEachNodeCacheable(ctx, db, func(nodeID int64,
			nodePub route.Vertex) error {

			features, err := getNodeFeatures(ctx, db, nodeID)
			if err != nil {
				return fmt.Errorf("unable to fetch "+
					"node(id=%d) features: %w", nodeID, err)
			}

			toNodeCallback := func() route.Vertex {
				return nodePub
			}

			rows, err := db.ListChannelsByNodeID(
				ctx, sqlc.ListChannelsByNodeIDParams{
					Version: int16(ProtocolV1),
					NodeID1: nodeID,
				},
			)
			if err != nil {
				return fmt.Errorf("unable to fetch channels "+
					"of node(id=%d): %w", nodeID, err)
			}

			channels := make(map[uint64]*DirectedChannel, len(rows))
			for _, row := range rows {
				node1, node2, err := buildNodeVertices(
					row.Node1Pubkey, row.Node2Pubkey,
				)
				if err != nil {
					return err
				}

				e, err := getAndBuildEdgeInfo(
					ctx, db, s.cfg.ChainHash,
					row.Channel.ID, row.Channel, node1,
					node2,
				)
				if err != nil {
					return fmt.Errorf("unable to build "+
						"channel info: %w", err)
				}

				dbPol1, dbPol2, err := extractChannelPolicies(
					row,
				)
				if err != nil {
					return fmt.Errorf("unable to "+
						"extract channel "+
						"policies: %w", err)
				}

				p1, p2, err := getAndBuildChanPolicies(
					ctx, db, dbPol1, dbPol2, e.ChannelID,
					node1, node2,
				)
				if err != nil {
					return fmt.Errorf("unable to "+
						"build channel policies: %w",
						err)
				}

				// Determine the outgoing and incoming policy
				// for this channel and node combo.
				outPolicy, inPolicy := p1, p2
				if p1 != nil && p1.ToNode == nodePub {
					outPolicy, inPolicy = p2, p1
				} else if p2 != nil && p2.ToNode != nodePub {
					outPolicy, inPolicy = p2, p1
				}

				var cachedInPolicy *models.CachedEdgePolicy
				if inPolicy != nil {
					cachedInPolicy = models.NewCachedPolicy(
						p2,
					)
					cachedInPolicy.ToNodePubKey =
						toNodeCallback
					cachedInPolicy.ToNodeFeatures =
						features
				}

				var inboundFee lnwire.Fee
				outPolicy.InboundFee.WhenSome(
					func(fee lnwire.Fee) {
						inboundFee = fee
					},
				)

				directedChannel := &DirectedChannel{
					ChannelID: e.ChannelID,
					IsNode1: nodePub ==
						e.NodeKey1Bytes,
					OtherNode:    e.NodeKey2Bytes,
					Capacity:     e.Capacity,
					OutPolicySet: p1 != nil,
					InPolicy:     cachedInPolicy,
					InboundFee:   inboundFee,
				}

				if nodePub == e.NodeKey2Bytes {
					directedChannel.OtherNode =
						e.NodeKey1Bytes
				}

				channels[e.ChannelID] = directedChannel
			}

			return cb(nodePub, channels)
		})
	}, sqldb.NoOpReset)
}

// ForEachChannelCacheable iterates through all the channel edges stored
// within the graph and invokes the passed callback for each edge. The
// callback takes two edges as since this is a directed graph, both the
// in/out edges are visited. If the callback returns an error, then the
// transaction is aborted and the iteration stops early.
//
// NOTE: If an edge can't be found, or wasn't advertised, then a nil
// pointer for that particular channel edge routing policy will be
// passed into the callback.
//
// NOTE: this method is like ForEachChannel but fetches only the data
// required for the graph cache.
func (s *SQLStore) ForEachChannelCacheable(cb func(*models.CachedEdgeInfo,
	*models.CachedEdgePolicy,
	*models.CachedEdgePolicy) error) error {

	ctx := context.TODO()

	handleChannel := func(db SQLQueries,
		row sqlc.ListChannelsWithPoliciesPaginatedRow) error {

		node1, node2, err := buildNodeVertices(
			row.Node1Pubkey, row.Node2Pubkey,
		)
		if err != nil {
			return err
		}

		edge := buildCacheableChannelInfo(row.Channel, node1, node2)

		dbPol1, dbPol2, err := extractChannelPolicies(row)
		if err != nil {
			return err
		}

		var pol1, pol2 *models.CachedEdgePolicy
		if dbPol1 != nil {
			policy1, err := buildChanPolicy(
				*dbPol1, edge.ChannelID, nil, node2,
			)
			if err != nil {
				return err
			}

			pol1 = models.NewCachedPolicy(policy1)
		}
		if dbPol2 != nil {
			policy2, err := buildChanPolicy(
				*dbPol2, edge.ChannelID, nil, node1,
			)
			if err != nil {
				return err
			}

			pol2 = models.NewCachedPolicy(policy2)
		}

		if err := cb(edge, pol1, pol2); err != nil {
			return err
		}

		return nil
	}

	return s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		lastID := int64(-1)
		for {
			//nolint:ll
			rows, err := db.ListChannelsWithPoliciesPaginated(
				ctx, sqlc.ListChannelsWithPoliciesPaginatedParams{
					Version: int16(ProtocolV1),
					ID:      lastID,
					Limit:   pageSize,
				},
			)
			if err != nil {
				return err
			}

			if len(rows) == 0 {
				break
			}

			for _, row := range rows {
				err := handleChannel(db, row)
				if err != nil {
					return err
				}

				lastID = row.Channel.ID
			}
		}

		return nil
	}, sqldb.NoOpReset)
}

// ForEachChannel iterates through all the channel edges stored within the
// graph and invokes the passed callback for each edge. The callback takes two
// edges as since this is a directed graph, both the in/out edges are visited.
// If the callback returns an error, then the transaction is aborted and the
// iteration stops early.
//
// NOTE: If an edge can't be found, or wasn't advertised, then a nil pointer
// for that particular channel edge routing policy will be passed into the
// callback.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) ForEachChannel(cb func(*models.ChannelEdgeInfo,
	*models.ChannelEdgePolicy, *models.ChannelEdgePolicy) error) error {

	ctx := context.TODO()

	handleChannel := func(db SQLQueries,
		row sqlc.ListChannelsWithPoliciesPaginatedRow) error {

		node1, node2, err := buildNodeVertices(
			row.Node1Pubkey, row.Node2Pubkey,
		)
		if err != nil {
			return fmt.Errorf("unable to build node vertices: %w",
				err)
		}

		edge, err := getAndBuildEdgeInfo(
			ctx, db, s.cfg.ChainHash, row.Channel.ID, row.Channel,
			node1, node2,
		)
		if err != nil {
			return fmt.Errorf("unable to build channel info: %w",
				err)
		}

		dbPol1, dbPol2, err := extractChannelPolicies(row)
		if err != nil {
			return fmt.Errorf("unable to extract channel "+
				"policies: %w", err)
		}

		p1, p2, err := getAndBuildChanPolicies(
			ctx, db, dbPol1, dbPol2, edge.ChannelID, node1, node2,
		)
		if err != nil {
			return fmt.Errorf("unable to build channel "+
				"policies: %w", err)
		}

		err = cb(edge, p1, p2)
		if err != nil {
			return fmt.Errorf("callback failed for channel "+
				"id=%d: %w", edge.ChannelID, err)
		}

		return nil
	}

	return s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		lastID := int64(-1)
		for {
			//nolint:ll
			rows, err := db.ListChannelsWithPoliciesPaginated(
				ctx, sqlc.ListChannelsWithPoliciesPaginatedParams{
					Version: int16(ProtocolV1),
					ID:      lastID,
					Limit:   pageSize,
				},
			)
			if err != nil {
				return err
			}

			if len(rows) == 0 {
				break
			}

			for _, row := range rows {
				err := handleChannel(db, row)
				if err != nil {
					return err
				}

				lastID = row.Channel.ID
			}
		}

		return nil
	}, sqldb.NoOpReset)
}

// FilterChannelRange returns the channel ID's of all known channels which were
// mined in a block height within the passed range. The channel IDs are grouped
// by their common block height. This method can be used to quickly share with a
// peer the set of channels we know of within a particular range to catch them
// up after a period of time offline. If withTimestamps is true then the
// timestamp info of the latest received channel update messages of the channel
// will be included in the response.
//
// NOTE: This is part of the V1Store interface.
func (s *SQLStore) FilterChannelRange(startHeight, endHeight uint32,
	withTimestamps bool) ([]BlockChannelRange, error) {

	var (
		ctx       = context.TODO()
		startSCID = &lnwire.ShortChannelID{
			BlockHeight: startHeight,
		}
		endSCID = lnwire.ShortChannelID{
			BlockHeight: endHeight,
			TxIndex:     math.MaxUint32 & 0x00ffffff,
			TxPosition:  math.MaxUint16,
		}
		chanIDStart = channelIDToBytes(startSCID.ToUint64())
		chanIDEnd   = channelIDToBytes(endSCID.ToUint64())
	)

	// 1) get all channels where channelID is between start and end chan ID.
	// 2) skip if not public (ie, no channel_proof)
	// 3) collect that channel.
	// 4) if timestamps are wanted, fetch both policies for node 1 and node2
	//    and add those timestamps to the collected channel.
	channelsPerBlock := make(map[uint32][]ChannelUpdateInfo)
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		dbChans, err := db.GetPublicV1ChannelsBySCID(
			ctx, sqlc.GetPublicV1ChannelsBySCIDParams{
				StartScid: chanIDStart,
				EndScid:   chanIDEnd,
			},
		)
		if err != nil {
			return fmt.Errorf("unable to fetch channel range: %w",
				err)
		}

		for _, dbChan := range dbChans {
			cid := lnwire.NewShortChanIDFromInt(
				byteOrder.Uint64(dbChan.Scid),
			)
			chanInfo := NewChannelUpdateInfo(
				cid, time.Time{}, time.Time{},
			)

			if !withTimestamps {
				channelsPerBlock[cid.BlockHeight] = append(
					channelsPerBlock[cid.BlockHeight],
					chanInfo,
				)

				continue
			}

			//nolint:ll
			node1Policy, err := db.GetChannelPolicyByChannelAndNode(
				ctx, sqlc.GetChannelPolicyByChannelAndNodeParams{
					Version:   int16(ProtocolV1),
					ChannelID: dbChan.ID,
					NodeID:    dbChan.NodeID1,
				},
			)
			if err != nil && !errors.Is(err, sql.ErrNoRows) {
				return fmt.Errorf("unable to fetch node1 "+
					"policy: %w", err)
			} else if err == nil {
				chanInfo.Node1UpdateTimestamp = time.Unix(
					node1Policy.LastUpdate.Int64, 0,
				)
			}

			//nolint:ll
			node2Policy, err := db.GetChannelPolicyByChannelAndNode(
				ctx, sqlc.GetChannelPolicyByChannelAndNodeParams{
					Version:   int16(ProtocolV1),
					ChannelID: dbChan.ID,
					NodeID:    dbChan.NodeID2,
				},
			)
			if err != nil && !errors.Is(err, sql.ErrNoRows) {
				return fmt.Errorf("unable to fetch node2 "+
					"policy: %w", err)
			} else if err == nil {
				chanInfo.Node2UpdateTimestamp = time.Unix(
					node2Policy.LastUpdate.Int64, 0,
				)
			}

			channelsPerBlock[cid.BlockHeight] = append(
				channelsPerBlock[cid.BlockHeight], chanInfo,
			)
		}

		return nil
	}, func() {
		channelsPerBlock = make(map[uint32][]ChannelUpdateInfo)
	})
	if err != nil {
		return nil, fmt.Errorf("unable to fetch channel range: %w", err)
	}

	if len(channelsPerBlock) == 0 {
		return nil, nil
	}

	// Return the channel ranges in ascending block height order.
	blocks := slices.Collect(maps.Keys(channelsPerBlock))
	slices.Sort(blocks)

	return fn.Map(blocks, func(block uint32) BlockChannelRange {
		return BlockChannelRange{
			Height:   block,
			Channels: channelsPerBlock[block],
		}
	}), nil
}

// MarkEdgeZombie attempts to mark a channel identified by its channel ID as a
// zombie. This method is used on an ad-hoc basis, when channels need to be
// marked as zombies outside the normal pruning cycle.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) MarkEdgeZombie(chanID uint64,
	pubKey1, pubKey2 [33]byte) error {

	ctx := context.TODO()

	s.cacheMu.Lock()
	defer s.cacheMu.Unlock()

	chanIDB := channelIDToBytes(chanID)

	err := s.db.ExecTx(ctx, sqldb.WriteTxOpt(), func(db SQLQueries) error {
		return db.UpsertZombieChannel(
			ctx, sqlc.UpsertZombieChannelParams{
				Version:  int16(ProtocolV1),
				Scid:     chanIDB,
				NodeKey1: pubKey1[:],
				NodeKey2: pubKey2[:],
			},
		)
	}, sqldb.NoOpReset)
	if err != nil {
		return fmt.Errorf("unable to upsert zombie channel "+
			"(channel_id=%d): %w", chanID, err)
	}

	s.rejectCache.remove(chanID)
	s.chanCache.remove(chanID)

	return nil
}

// MarkEdgeLive clears an edge from our zombie index, deeming it as live.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) MarkEdgeLive(chanID uint64) error {
	s.cacheMu.Lock()
	defer s.cacheMu.Unlock()

	var (
		ctx     = context.TODO()
		chanIDB = channelIDToBytes(chanID)
	)

	err := s.db.ExecTx(ctx, sqldb.WriteTxOpt(), func(db SQLQueries) error {
		res, err := db.DeleteZombieChannel(
			ctx, sqlc.DeleteZombieChannelParams{
				Scid:    chanIDB,
				Version: int16(ProtocolV1),
			},
		)
		if err != nil {
			return fmt.Errorf("unable to delete zombie channel: %w",
				err)
		}

		rows, err := res.RowsAffected()
		if err != nil {
			return err
		}

		if rows == 0 {
			return ErrZombieEdgeNotFound
		} else if rows > 1 {
			return fmt.Errorf("deleted %d zombie rows, "+
				"expected 1", rows)
		}

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return fmt.Errorf("unable to mark edge live "+
			"(channel_id=%d): %w", chanID, err)
	}

	s.rejectCache.remove(chanID)
	s.chanCache.remove(chanID)

	return err
}

// IsZombieEdge returns whether the edge is considered zombie. If it is a
// zombie, then the two node public keys corresponding to this edge are also
// returned.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) IsZombieEdge(chanID uint64) (bool, [33]byte, [33]byte,
	error) {

	var (
		ctx              = context.TODO()
		isZombie         bool
		pubKey1, pubKey2 route.Vertex
		chanIDB          = channelIDToBytes(chanID)
	)

	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		zombie, err := db.GetZombieChannel(
			ctx, sqlc.GetZombieChannelParams{
				Scid:    chanIDB,
				Version: int16(ProtocolV1),
			},
		)
		if errors.Is(err, sql.ErrNoRows) {
			return nil
		}
		if err != nil {
			return fmt.Errorf("unable to fetch zombie channel: %w",
				err)
		}

		copy(pubKey1[:], zombie.NodeKey1)
		copy(pubKey2[:], zombie.NodeKey2)
		isZombie = true

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return false, route.Vertex{}, route.Vertex{},
			fmt.Errorf("%w: %w (chanID=%d)",
				ErrCantCheckIfZombieEdgeStr, err, chanID)
	}

	return isZombie, pubKey1, pubKey2, nil
}

// NumZombies returns the current number of zombie channels in the graph.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) NumZombies() (uint64, error) {
	var (
		ctx        = context.TODO()
		numZombies uint64
	)
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		count, err := db.CountZombieChannels(ctx, int16(ProtocolV1))
		if err != nil {
			return fmt.Errorf("unable to count zombie channels: %w",
				err)
		}

		numZombies = uint64(count)

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return 0, fmt.Errorf("unable to count zombies: %w", err)
	}

	return numZombies, nil
}

// DeleteChannelEdges removes edges with the given channel IDs from the
// database and marks them as zombies. This ensures that we're unable to re-add
// it to our database once again. If an edge does not exist within the
// database, then ErrEdgeNotFound will be returned. If strictZombiePruning is
// true, then when we mark these edges as zombies, we'll set up the keys such
// that we require the node that failed to send the fresh update to be the one
// that resurrects the channel from its zombie state. The markZombie bool
// denotes whether to mark the channel as a zombie.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) DeleteChannelEdges(strictZombiePruning, markZombie bool,
	chanIDs ...uint64) ([]*models.ChannelEdgeInfo, error) {

	s.cacheMu.Lock()
	defer s.cacheMu.Unlock()

	var (
		ctx     = context.TODO()
		deleted []*models.ChannelEdgeInfo
	)
	err := s.db.ExecTx(ctx, sqldb.WriteTxOpt(), func(db SQLQueries) error {
		for _, chanID := range chanIDs {
			chanIDB := channelIDToBytes(chanID)

			row, err := db.GetChannelBySCIDWithPolicies(
				ctx, sqlc.GetChannelBySCIDWithPoliciesParams{
					Scid:    chanIDB,
					Version: int16(ProtocolV1),
				},
			)
			if errors.Is(err, sql.ErrNoRows) {
				return ErrEdgeNotFound
			} else if err != nil {
				return fmt.Errorf("unable to fetch channel: %w",
					err)
			}

			node1, node2, err := buildNodeVertices(
				row.Node.PubKey, row.Node_2.PubKey,
			)
			if err != nil {
				return err
			}

			info, err := getAndBuildEdgeInfo(
				ctx, db, s.cfg.ChainHash, row.Channel.ID,
				row.Channel, node1, node2,
			)
			if err != nil {
				return err
			}

			err = db.DeleteChannel(ctx, row.Channel.ID)
			if err != nil {
				return fmt.Errorf("unable to delete "+
					"channel: %w", err)
			}

			deleted = append(deleted, info)

			if !markZombie {
				continue
			}

			nodeKey1, nodeKey2 := info.NodeKey1Bytes,
				info.NodeKey2Bytes
			if strictZombiePruning {
				var e1UpdateTime, e2UpdateTime *time.Time
				if row.Policy1LastUpdate.Valid {
					e1Time := time.Unix(
						row.Policy1LastUpdate.Int64, 0,
					)
					e1UpdateTime = &e1Time
				}
				if row.Policy2LastUpdate.Valid {
					e2Time := time.Unix(
						row.Policy2LastUpdate.Int64, 0,
					)
					e2UpdateTime = &e2Time
				}

				nodeKey1, nodeKey2 = makeZombiePubkeys(
					info, e1UpdateTime, e2UpdateTime,
				)
			}

			err = db.UpsertZombieChannel(
				ctx, sqlc.UpsertZombieChannelParams{
					Version:  int16(ProtocolV1),
					Scid:     chanIDB,
					NodeKey1: nodeKey1[:],
					NodeKey2: nodeKey2[:],
				},
			)
			if err != nil {
				return fmt.Errorf("unable to mark channel as "+
					"zombie: %w", err)
			}
		}

		return nil
	}, func() {
		deleted = nil
	})
	if err != nil {
		return nil, fmt.Errorf("unable to delete channel edges: %w",
			err)
	}

	for _, chanID := range chanIDs {
		s.rejectCache.remove(chanID)
		s.chanCache.remove(chanID)
	}

	return deleted, nil
}

// FetchChannelEdgesByID attempts to lookup the two directed edges for the
// channel identified by the channel ID. If the channel can't be found, then
// ErrEdgeNotFound is returned. A struct which houses the general information
// for the channel itself is returned as well as two structs that contain the
// routing policies for the channel in either direction.
//
// ErrZombieEdge an be returned if the edge is currently marked as a zombie
// within the database. In this case, the ChannelEdgePolicy's will be nil, and
// the ChannelEdgeInfo will only include the public keys of each node.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) FetchChannelEdgesByID(chanID uint64) (
	*models.ChannelEdgeInfo, *models.ChannelEdgePolicy,
	*models.ChannelEdgePolicy, error) {

	var (
		ctx              = context.TODO()
		edge             *models.ChannelEdgeInfo
		policy1, policy2 *models.ChannelEdgePolicy
		chanIDB          = channelIDToBytes(chanID)
	)
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		row, err := db.GetChannelBySCIDWithPolicies(
			ctx, sqlc.GetChannelBySCIDWithPoliciesParams{
				Scid:    chanIDB,
				Version: int16(ProtocolV1),
			},
		)
		if errors.Is(err, sql.ErrNoRows) {
			// First check if this edge is perhaps in the zombie
			// index.
			zombie, err := db.GetZombieChannel(
				ctx, sqlc.GetZombieChannelParams{
					Scid:    chanIDB,
					Version: int16(ProtocolV1),
				},
			)
			if errors.Is(err, sql.ErrNoRows) {
				return ErrEdgeNotFound
			} else if err != nil {
				return fmt.Errorf("unable to check if "+
					"channel is zombie: %w", err)
			}

			// At this point, we know the channel is a zombie, so
			// we'll return an error indicating this, and we will
			// populate the edge info with the public keys of each
			// party as this is the only information we have about
			// it.
			edge = &models.ChannelEdgeInfo{}
			copy(edge.NodeKey1Bytes[:], zombie.NodeKey1)
			copy(edge.NodeKey2Bytes[:], zombie.NodeKey2)

			return ErrZombieEdge
		} else if err != nil {
			return fmt.Errorf("unable to fetch channel: %w", err)
		}

		node1, node2, err := buildNodeVertices(
			row.Node.PubKey, row.Node_2.PubKey,
		)
		if err != nil {
			return err
		}

		edge, err = getAndBuildEdgeInfo(
			ctx, db, s.cfg.ChainHash, row.Channel.ID, row.Channel,
			node1, node2,
		)
		if err != nil {
			return fmt.Errorf("unable to build channel info: %w",
				err)
		}

		dbPol1, dbPol2, err := extractChannelPolicies(row)
		if err != nil {
			return fmt.Errorf("unable to extract channel "+
				"policies: %w", err)
		}

		policy1, policy2, err = getAndBuildChanPolicies(
			ctx, db, dbPol1, dbPol2, edge.ChannelID, node1, node2,
		)
		if err != nil {
			return fmt.Errorf("unable to build channel "+
				"policies: %w", err)
		}

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		// If we are returning the ErrZombieEdge, then we also need to
		// return the edge info as the method comment indicates that
		// this will be populated when the edge is a zombie.
		return edge, nil, nil, fmt.Errorf("could not fetch channel: %w",
			err)
	}

	return edge, policy1, policy2, nil
}

// FetchChannelEdgesByOutpoint attempts to lookup the two directed edges for
// the channel identified by the funding outpoint. If the channel can't be
// found, then ErrEdgeNotFound is returned. A struct which houses the general
// information for the channel itself is returned as well as two structs that
// contain the routing policies for the channel in either direction.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) FetchChannelEdgesByOutpoint(op *wire.OutPoint) (
	*models.ChannelEdgeInfo, *models.ChannelEdgePolicy,
	*models.ChannelEdgePolicy, error) {

	var (
		ctx              = context.TODO()
		edge             *models.ChannelEdgeInfo
		policy1, policy2 *models.ChannelEdgePolicy
	)
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		row, err := db.GetChannelByOutpointWithPolicies(
			ctx, sqlc.GetChannelByOutpointWithPoliciesParams{
				Outpoint: op.String(),
				Version:  int16(ProtocolV1),
			},
		)
		if errors.Is(err, sql.ErrNoRows) {
			return ErrEdgeNotFound
		} else if err != nil {
			return fmt.Errorf("unable to fetch channel: %w", err)
		}

		node1, node2, err := buildNodeVertices(
			row.Node1Pubkey, row.Node2Pubkey,
		)
		if err != nil {
			return err
		}

		edge, err = getAndBuildEdgeInfo(
			ctx, db, s.cfg.ChainHash, row.Channel.ID, row.Channel,
			node1, node2,
		)
		if err != nil {
			return fmt.Errorf("unable to build channel info: %w",
				err)
		}

		dbPol1, dbPol2, err := extractChannelPolicies(row)
		if err != nil {
			return fmt.Errorf("unable to extract channel "+
				"policies: %w", err)
		}

		policy1, policy2, err = getAndBuildChanPolicies(
			ctx, db, dbPol1, dbPol2, edge.ChannelID, node1, node2,
		)
		if err != nil {
			return fmt.Errorf("unable to build channel "+
				"policies: %w", err)
		}

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return nil, nil, nil, fmt.Errorf("could not fetch channel: %w",
			err)
	}

	return edge, policy1, policy2, nil
}

// HasChannelEdge returns true if the database knows of a channel edge with the
// passed channel ID, and false otherwise. If an edge with that ID is found
// within the graph, then two time stamps representing the last time the edge
// was updated for both directed edges are returned along with the boolean. If
// it is not found, then the zombie index is checked and its result is returned
// as the second boolean.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) HasChannelEdge(chanID uint64) (time.Time, time.Time, bool,
	bool, error) {

	ctx := context.TODO()

	var (
		exists          bool
		isZombie        bool
		node1LastUpdate time.Time
		node2LastUpdate time.Time
	)

	// We'll query the cache with the shared lock held to allow multiple
	// readers to access values in the cache concurrently if they exist.
	s.cacheMu.RLock()
	if entry, ok := s.rejectCache.get(chanID); ok {
		s.cacheMu.RUnlock()
		node1LastUpdate = time.Unix(entry.upd1Time, 0)
		node2LastUpdate = time.Unix(entry.upd2Time, 0)
		exists, isZombie = entry.flags.unpack()

		return node1LastUpdate, node2LastUpdate, exists, isZombie, nil
	}
	s.cacheMu.RUnlock()

	s.cacheMu.Lock()
	defer s.cacheMu.Unlock()

	// The item was not found with the shared lock, so we'll acquire the
	// exclusive lock and check the cache again in case another method added
	// the entry to the cache while no lock was held.
	if entry, ok := s.rejectCache.get(chanID); ok {
		node1LastUpdate = time.Unix(entry.upd1Time, 0)
		node2LastUpdate = time.Unix(entry.upd2Time, 0)
		exists, isZombie = entry.flags.unpack()

		return node1LastUpdate, node2LastUpdate, exists, isZombie, nil
	}

	chanIDB := channelIDToBytes(chanID)
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		channel, err := db.GetChannelBySCID(
			ctx, sqlc.GetChannelBySCIDParams{
				Scid:    chanIDB,
				Version: int16(ProtocolV1),
			},
		)
		if errors.Is(err, sql.ErrNoRows) {
			// Check if it is a zombie channel.
			isZombie, err = db.IsZombieChannel(
				ctx, sqlc.IsZombieChannelParams{
					Scid:    chanIDB,
					Version: int16(ProtocolV1),
				},
			)
			if err != nil {
				return fmt.Errorf("could not check if channel "+
					"is zombie: %w", err)
			}

			return nil
		} else if err != nil {
			return fmt.Errorf("unable to fetch channel: %w", err)
		}

		exists = true

		policy1, err := db.GetChannelPolicyByChannelAndNode(
			ctx, sqlc.GetChannelPolicyByChannelAndNodeParams{
				Version:   int16(ProtocolV1),
				ChannelID: channel.ID,
				NodeID:    channel.NodeID1,
			},
		)
		if err != nil && !errors.Is(err, sql.ErrNoRows) {
			return fmt.Errorf("unable to fetch channel policy: %w",
				err)
		} else if err == nil {
			node1LastUpdate = time.Unix(policy1.LastUpdate.Int64, 0)
		}

		policy2, err := db.GetChannelPolicyByChannelAndNode(
			ctx, sqlc.GetChannelPolicyByChannelAndNodeParams{
				Version:   int16(ProtocolV1),
				ChannelID: channel.ID,
				NodeID:    channel.NodeID2,
			},
		)
		if err != nil && !errors.Is(err, sql.ErrNoRows) {
			return fmt.Errorf("unable to fetch channel policy: %w",
				err)
		} else if err == nil {
			node2LastUpdate = time.Unix(policy2.LastUpdate.Int64, 0)
		}

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return time.Time{}, time.Time{}, false, false,
			fmt.Errorf("unable to fetch channel: %w", err)
	}

	s.rejectCache.insert(chanID, rejectCacheEntry{
		upd1Time: node1LastUpdate.Unix(),
		upd2Time: node2LastUpdate.Unix(),
		flags:    packRejectFlags(exists, isZombie),
	})

	return node1LastUpdate, node2LastUpdate, exists, isZombie, nil
}

// ChannelID attempt to lookup the 8-byte compact channel ID which maps to the
// passed channel point (outpoint). If the passed channel doesn't exist within
// the database, then ErrEdgeNotFound is returned.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) ChannelID(chanPoint *wire.OutPoint) (uint64, error) {
	var (
		ctx       = context.TODO()
		channelID uint64
	)
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		chanID, err := db.GetSCIDByOutpoint(
			ctx, sqlc.GetSCIDByOutpointParams{
				Outpoint: chanPoint.String(),
				Version:  int16(ProtocolV1),
			},
		)
		if errors.Is(err, sql.ErrNoRows) {
			return ErrEdgeNotFound
		} else if err != nil {
			return fmt.Errorf("unable to fetch channel ID: %w",
				err)
		}

		channelID = byteOrder.Uint64(chanID)

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return 0, fmt.Errorf("unable to fetch channel ID: %w", err)
	}

	return channelID, nil
}

// IsPublicNode is a helper method that determines whether the node with the
// given public key is seen as a public node in the graph from the graph's
// source node's point of view.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) IsPublicNode(pubKey [33]byte) (bool, error) {
	ctx := context.TODO()

	var isPublic bool
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		var err error
		isPublic, err = db.IsPublicV1Node(ctx, pubKey[:])

		return err
	}, sqldb.NoOpReset)
	if err != nil {
		return false, fmt.Errorf("unable to check if node is "+
			"public: %w", err)
	}

	return isPublic, nil
}

// FetchChanInfos returns the set of channel edges that correspond to the passed
// channel ID's. If an edge is the query is unknown to the database, it will
// skipped and the result will contain only those edges that exist at the time
// of the query. This can be used to respond to peer queries that are seeking to
// fill in gaps in their view of the channel graph.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) FetchChanInfos(chanIDs []uint64) ([]ChannelEdge, error) {
	var (
		ctx   = context.TODO()
		edges []ChannelEdge
	)
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		for _, chanID := range chanIDs {
			chanIDB := channelIDToBytes(chanID)

			// TODO(elle): potentially optimize this by using
			//  sqlc.slice() once that works for both SQLite and
			//  Postgres.
			row, err := db.GetChannelBySCIDWithPolicies(
				ctx, sqlc.GetChannelBySCIDWithPoliciesParams{
					Scid:    chanIDB,
					Version: int16(ProtocolV1),
				},
			)
			if errors.Is(err, sql.ErrNoRows) {
				continue
			} else if err != nil {
				return fmt.Errorf("unable to fetch channel: %w",
					err)
			}

			node1, node2, err := buildNodes(
				ctx, db, row.Node, row.Node_2,
			)
			if err != nil {
				return fmt.Errorf("unable to fetch nodes: %w",
					err)
			}

			edge, err := getAndBuildEdgeInfo(
				ctx, db, s.cfg.ChainHash, row.Channel.ID,
				row.Channel, node1.PubKeyBytes,
				node2.PubKeyBytes,
			)
			if err != nil {
				return fmt.Errorf("unable to build "+
					"channel info: %w", err)
			}

			dbPol1, dbPol2, err := extractChannelPolicies(row)
			if err != nil {
				return fmt.Errorf("unable to extract channel "+
					"policies: %w", err)
			}

			p1, p2, err := getAndBuildChanPolicies(
				ctx, db, dbPol1, dbPol2, edge.ChannelID,
				node1.PubKeyBytes, node2.PubKeyBytes,
			)
			if err != nil {
				return fmt.Errorf("unable to build channel "+
					"policies: %w", err)
			}

			edges = append(edges, ChannelEdge{
				Info:    edge,
				Policy1: p1,
				Policy2: p2,
				Node1:   node1,
				Node2:   node2,
			})
		}

		return nil
	}, func() {
		edges = nil
	})
	if err != nil {
		return nil, fmt.Errorf("unable to fetch channels: %w", err)
	}

	return edges, nil
}

// FilterKnownChanIDs takes a set of channel IDs and return the subset of chan
// ID's that we don't know and are not known zombies of the passed set. In other
// words, we perform a set difference of our set of chan ID's and the ones
// passed in. This method can be used by callers to determine the set of
// channels another peer knows of that we don't. The ChannelUpdateInfos for the
// known zombies is also returned.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) FilterKnownChanIDs(chansInfo []ChannelUpdateInfo) ([]uint64,
	[]ChannelUpdateInfo, error) {

	var (
		ctx          = context.TODO()
		newChanIDs   []uint64
		knownZombies []ChannelUpdateInfo
	)
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		for _, chanInfo := range chansInfo {
			channelID := chanInfo.ShortChannelID.ToUint64()
			chanIDB := channelIDToBytes(channelID)

			// TODO(elle): potentially optimize this by using
			//  sqlc.slice() once that works for both SQLite and
			//  Postgres.
			_, err := db.GetChannelBySCID(
				ctx, sqlc.GetChannelBySCIDParams{
					Version: int16(ProtocolV1),
					Scid:    chanIDB,
				},
			)
			if err == nil {
				continue
			} else if !errors.Is(err, sql.ErrNoRows) {
				return fmt.Errorf("unable to fetch channel: %w",
					err)
			}

			isZombie, err := db.IsZombieChannel(
				ctx, sqlc.IsZombieChannelParams{
					Scid:    chanIDB,
					Version: int16(ProtocolV1),
				},
			)
			if err != nil {
				return fmt.Errorf("unable to fetch zombie "+
					"channel: %w", err)
			}

			if isZombie {
				knownZombies = append(knownZombies, chanInfo)

				continue
			}

			newChanIDs = append(newChanIDs, channelID)
		}

		return nil
	}, func() {
		newChanIDs = nil
		knownZombies = nil
	})
	if err != nil {
		return nil, nil, fmt.Errorf("unable to fetch channels: %w", err)
	}

	return newChanIDs, knownZombies, nil
}

// PruneGraphNodes is a garbage collection method which attempts to prune out
// any nodes from the channel graph that are currently unconnected. This ensure
// that we only maintain a graph of reachable nodes. In the event that a pruned
// node gains more channels, it will be re-added back to the graph.
//
// NOTE: this prunes nodes across protocol versions. It will never prune the
// source nodes.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) PruneGraphNodes() ([]route.Vertex, error) {
	var ctx = context.TODO()

	var prunedNodes []route.Vertex
	err := s.db.ExecTx(ctx, sqldb.WriteTxOpt(), func(db SQLQueries) error {
		var err error
		prunedNodes, err = s.pruneGraphNodes(ctx, db)

		return err
	}, func() {
		prunedNodes = nil
	})
	if err != nil {
		return nil, fmt.Errorf("unable to prune nodes: %w", err)
	}

	return prunedNodes, nil
}

// PruneGraph prunes newly closed channels from the channel graph in response
// to a new block being solved on the network. Any transactions which spend the
// funding output of any known channels within he graph will be deleted.
// Additionally, the "prune tip", or the last block which has been used to
// prune the graph is stored so callers can ensure the graph is fully in sync
// with the current UTXO state. A slice of channels that have been closed by
// the target block along with any pruned nodes are returned if the function
// succeeds without error.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) PruneGraph(spentOutputs []*wire.OutPoint,
	blockHash *chainhash.Hash, blockHeight uint32) (
	[]*models.ChannelEdgeInfo, []route.Vertex, error) {

	ctx := context.TODO()

	s.cacheMu.Lock()
	defer s.cacheMu.Unlock()

	var (
		closedChans []*models.ChannelEdgeInfo
		prunedNodes []route.Vertex
	)
	err := s.db.ExecTx(ctx, sqldb.WriteTxOpt(), func(db SQLQueries) error {
		for _, outpoint := range spentOutputs {
			// TODO(elle): potentially optimize this by using
			//  sqlc.slice() once that works for both SQLite and
			//  Postgres.
			//
			// NOTE: this fetches channels for all protocol
			// versions.
			row, err := db.GetChannelByOutpoint(
				ctx, outpoint.String(),
			)
			if errors.Is(err, sql.ErrNoRows) {
				continue
			} else if err != nil {
				return fmt.Errorf("unable to fetch channel: %w",
					err)
			}

			node1, node2, err := buildNodeVertices(
				row.Node1Pubkey, row.Node2Pubkey,
			)
			if err != nil {
				return err
			}

			info, err := getAndBuildEdgeInfo(
				ctx, db, s.cfg.ChainHash, row.Channel.ID,
				row.Channel, node1, node2,
			)
			if err != nil {
				return err
			}

			err = db.DeleteChannel(ctx, row.Channel.ID)
			if err != nil {
				return fmt.Errorf("unable to delete "+
					"channel: %w", err)
			}

			closedChans = append(closedChans, info)
		}

		err := db.UpsertPruneLogEntry(
			ctx, sqlc.UpsertPruneLogEntryParams{
				BlockHash:   blockHash[:],
				BlockHeight: int64(blockHeight),
			},
		)
		if err != nil {
			return fmt.Errorf("unable to insert prune log "+
				"entry: %w", err)
		}

		// Now that we've pruned some channels, we'll also prune any
		// nodes that no longer have any channels.
		prunedNodes, err = s.pruneGraphNodes(ctx, db)
		if err != nil {
			return fmt.Errorf("unable to prune graph nodes: %w",
				err)
		}

		return nil
	}, func() {
		prunedNodes = nil
		closedChans = nil
	})
	if err != nil {
		return nil, nil, fmt.Errorf("unable to prune graph: %w", err)
	}

	for _, channel := range closedChans {
		s.rejectCache.remove(channel.ChannelID)
		s.chanCache.remove(channel.ChannelID)
	}

	return closedChans, prunedNodes, nil
}

// ChannelView returns the verifiable edge information for each active channel
// within the known channel graph. The set of UTXOs (along with their scripts)
// returned are the ones that need to be watched on chain to detect channel
// closes on the resident blockchain.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) ChannelView() ([]EdgePoint, error) {
	var (
		ctx        = context.TODO()
		edgePoints []EdgePoint
	)

	handleChannel := func(db SQLQueries,
		channel sqlc.ListChannelsPaginatedRow) error {

		pkScript, err := genMultiSigP2WSH(
			channel.BitcoinKey1, channel.BitcoinKey2,
		)
		if err != nil {
			return err
		}

		op, err := wire.NewOutPointFromString(channel.Outpoint)
		if err != nil {
			return err
		}

		edgePoints = append(edgePoints, EdgePoint{
			FundingPkScript: pkScript,
			OutPoint:        *op,
		})

		return nil
	}

	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		lastID := int64(-1)
		for {
			rows, err := db.ListChannelsPaginated(
				ctx, sqlc.ListChannelsPaginatedParams{
					Version: int16(ProtocolV1),
					ID:      lastID,
					Limit:   pageSize,
				},
			)
			if err != nil {
				return err
			}

			if len(rows) == 0 {
				break
			}

			for _, row := range rows {
				err := handleChannel(db, row)
				if err != nil {
					return err
				}

				lastID = row.ID
			}
		}

		return nil
	}, func() {
		edgePoints = nil
	})
	if err != nil {
		return nil, fmt.Errorf("unable to fetch channel view: %w", err)
	}

	return edgePoints, nil
}

// PruneTip returns the block height and hash of the latest block that has been
// used to prune channels in the graph. Knowing the "prune tip" allows callers
// to tell if the graph is currently in sync with the current best known UTXO
// state.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) PruneTip() (*chainhash.Hash, uint32, error) {
	var (
		ctx       = context.TODO()
		tipHash   chainhash.Hash
		tipHeight uint32
	)
	err := s.db.ExecTx(ctx, sqldb.WriteTxOpt(), func(db SQLQueries) error {
		pruneTip, err := db.GetPruneTip(ctx)
		if errors.Is(err, sql.ErrNoRows) {
			return ErrGraphNeverPruned
		} else if err != nil {
			return fmt.Errorf("unable to fetch prune tip: %w", err)
		}

		tipHash = chainhash.Hash(pruneTip.BlockHash)
		tipHeight = uint32(pruneTip.BlockHeight)

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return nil, 0, err
	}

	return &tipHash, tipHeight, nil
}

// pruneGraphNodes deletes any node in the DB that doesn't have a channel.
//
// NOTE: this prunes nodes across protocol versions. It will never prune the
// source nodes.
func (s *SQLStore) pruneGraphNodes(ctx context.Context,
	db SQLQueries) ([]route.Vertex, error) {

	nodeKeys, err := db.DeleteUnconnectedNodes(ctx)
	if err != nil {
		return nil, fmt.Errorf("unable to delete unconnected "+
			"nodes: %w", err)
	}

	prunedNodes := make([]route.Vertex, len(nodeKeys))
	for i, nodeKey := range nodeKeys {
		pub, err := route.NewVertexFromBytes(nodeKey)
		if err != nil {
			return nil, fmt.Errorf("unable to parse pubkey "+
				"from bytes: %w", err)
		}

		prunedNodes[i] = pub
	}

	return prunedNodes, nil
}

// DisconnectBlockAtHeight is used to indicate that the block specified
// by the passed height has been disconnected from the main chain. This
// will "rewind" the graph back to the height below, deleting channels
// that are no longer confirmed from the graph. The prune log will be
// set to the last prune height valid for the remaining chain.
// Channels that were removed from the graph resulting from the
// disconnected block are returned.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) DisconnectBlockAtHeight(height uint32) (
	[]*models.ChannelEdgeInfo, error) {

	ctx := context.TODO()

	var (
		// Every channel having a ShortChannelID starting at 'height'
		// will no longer be confirmed.
		startShortChanID = lnwire.ShortChannelID{
			BlockHeight: height,
		}

		// Delete everything after this height from the db up until the
		// SCID alias range.
		endShortChanID = aliasmgr.StartingAlias

		removedChans []*models.ChannelEdgeInfo

		chanIDStart = channelIDToBytes(startShortChanID.ToUint64())
		chanIDEnd   = channelIDToBytes(endShortChanID.ToUint64())
	)

	err := s.db.ExecTx(ctx, sqldb.WriteTxOpt(), func(db SQLQueries) error {
		rows, err := db.GetChannelsBySCIDRange(
			ctx, sqlc.GetChannelsBySCIDRangeParams{
				StartScid: chanIDStart,
				EndScid:   chanIDEnd,
			},
		)
		if err != nil {
			return fmt.Errorf("unable to fetch channels: %w", err)
		}

		for _, row := range rows {
			node1, node2, err := buildNodeVertices(
				row.Node1PubKey, row.Node2PubKey,
			)
			if err != nil {
				return err
			}

			channel, err := getAndBuildEdgeInfo(
				ctx, db, s.cfg.ChainHash, row.Channel.ID,
				row.Channel, node1, node2,
			)
			if err != nil {
				return err
			}

			err = db.DeleteChannel(ctx, row.Channel.ID)
			if err != nil {
				return fmt.Errorf("unable to delete "+
					"channel: %w", err)
			}

			removedChans = append(removedChans, channel)
		}

		return db.DeletePruneLogEntriesInRange(
			ctx, sqlc.DeletePruneLogEntriesInRangeParams{
				StartHeight: int64(height),
				EndHeight:   int64(endShortChanID.BlockHeight),
			},
		)
	}, func() {
		removedChans = nil
	})
	if err != nil {
		return nil, fmt.Errorf("unable to disconnect block at "+
			"height: %w", err)
	}

	for _, channel := range removedChans {
		s.rejectCache.remove(channel.ChannelID)
		s.chanCache.remove(channel.ChannelID)
	}

	return removedChans, nil
}

// AddEdgeProof sets the proof of an existing edge in the graph database.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) AddEdgeProof(scid lnwire.ShortChannelID,
	proof *models.ChannelAuthProof) error {

	var (
		ctx       = context.TODO()
		scidBytes = channelIDToBytes(scid.ToUint64())
	)

	err := s.db.ExecTx(ctx, sqldb.WriteTxOpt(), func(db SQLQueries) error {
		res, err := db.AddV1ChannelProof(
			ctx, sqlc.AddV1ChannelProofParams{
				Scid:              scidBytes,
				Node1Signature:    proof.NodeSig1Bytes,
				Node2Signature:    proof.NodeSig2Bytes,
				Bitcoin1Signature: proof.BitcoinSig1Bytes,
				Bitcoin2Signature: proof.BitcoinSig2Bytes,
			},
		)
		if err != nil {
			return fmt.Errorf("unable to add edge proof: %w", err)
		}

		n, err := res.RowsAffected()
		if err != nil {
			return err
		}

		if n == 0 {
			return fmt.Errorf("no rows affected when adding edge "+
				"proof for SCID %v", scid)
		} else if n > 1 {
			return fmt.Errorf("multiple rows affected when adding "+
				"edge proof for SCID %v: %d rows affected",
				scid, n)
		}

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return fmt.Errorf("unable to add edge proof: %w", err)
	}

	return nil
}

// PutClosedScid stores a SCID for a closed channel in the database. This is so
// that we can ignore channel announcements that we know to be closed without
// having to validate them and fetch a block.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) PutClosedScid(scid lnwire.ShortChannelID) error {
	var (
		ctx     = context.TODO()
		chanIDB = channelIDToBytes(scid.ToUint64())
	)

	return s.db.ExecTx(ctx, sqldb.WriteTxOpt(), func(db SQLQueries) error {
		return db.InsertClosedChannel(ctx, chanIDB)
	}, sqldb.NoOpReset)
}

// IsClosedScid checks whether a channel identified by the passed in scid is
// closed. This helps avoid having to perform expensive validation checks.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) IsClosedScid(scid lnwire.ShortChannelID) (bool, error) {
	var (
		ctx      = context.TODO()
		isClosed bool
		chanIDB  = channelIDToBytes(scid.ToUint64())
	)
	err := s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		var err error
		isClosed, err = db.IsClosedChannel(ctx, chanIDB)
		if err != nil {
			return fmt.Errorf("unable to fetch closed channel: %w",
				err)
		}

		return nil
	}, sqldb.NoOpReset)
	if err != nil {
		return false, fmt.Errorf("unable to fetch closed channel: %w",
			err)
	}

	return isClosed, nil
}

// GraphSession will provide the call-back with access to a NodeTraverser
// instance which can be used to perform queries against the channel graph.
//
// NOTE: part of the V1Store interface.
func (s *SQLStore) GraphSession(cb func(graph NodeTraverser) error) error {
	var ctx = context.TODO()

	return s.db.ExecTx(ctx, sqldb.ReadTxOpt(), func(db SQLQueries) error {
		return cb(newSQLNodeTraverser(db, s.cfg.ChainHash))
	}, sqldb.NoOpReset)
}

// sqlNodeTraverser implements the NodeTraverser interface but with a backing
// read only transaction for a consistent view of the graph.
type sqlNodeTraverser struct {
	db    SQLQueries
	chain chainhash.Hash
}

// A compile-time assertion to ensure that sqlNodeTraverser implements the
// NodeTraverser interface.
var _ NodeTraverser = (*sqlNodeTraverser)(nil)

// newSQLNodeTraverser creates a new instance of the sqlNodeTraverser.
func newSQLNodeTraverser(db SQLQueries,
	chain chainhash.Hash) *sqlNodeTraverser {

	return &sqlNodeTraverser{
		db:    db,
		chain: chain,
	}
}

// ForEachNodeDirectedChannel calls the callback for every channel of the given
// node.
//
// NOTE: Part of the NodeTraverser interface.
func (s *sqlNodeTraverser) ForEachNodeDirectedChannel(nodePub route.Vertex,
	cb func(channel *DirectedChannel) error) error {

	ctx := context.TODO()

	return forEachNodeDirectedChannel(ctx, s.db, nodePub, cb)
}

// FetchNodeFeatures returns the features of the given node. If the node is
// unknown, assume no additional features are supported.
//
// NOTE: Part of the NodeTraverser interface.
func (s *sqlNodeTraverser) FetchNodeFeatures(nodePub route.Vertex) (
	*lnwire.FeatureVector, error) {

	ctx := context.TODO()

	return fetchNodeFeatures(ctx, s.db, nodePub)
}

// forEachNodeDirectedChannel iterates through all channels of a given
// node, executing the passed callback on the directed edge representing the
// channel and its incoming policy. If the node is not found, no error is
// returned.
func forEachNodeDirectedChannel(ctx context.Context, db SQLQueries,
	nodePub route.Vertex, cb func(channel *DirectedChannel) error) error {

	toNodeCallback := func() route.Vertex {
		return nodePub
	}

	dbID, err := db.GetNodeIDByPubKey(
		ctx, sqlc.GetNodeIDByPubKeyParams{
			Version: int16(ProtocolV1),
			PubKey:  nodePub[:],
		},
	)
	if errors.Is(err, sql.ErrNoRows) {
		return nil
	} else if err != nil {
		return fmt.Errorf("unable to fetch node: %w", err)
	}

	rows, err := db.ListChannelsByNodeID(
		ctx, sqlc.ListChannelsByNodeIDParams{
			Version: int16(ProtocolV1),
			NodeID1: dbID,
		},
	)
	if err != nil {
		return fmt.Errorf("unable to fetch channels: %w", err)
	}

	// Exit early if there are no channels for this node so we don't
	// do the unnecessary feature fetching.
	if len(rows) == 0 {
		return nil
	}

	features, err := getNodeFeatures(ctx, db, dbID)
	if err != nil {
		return fmt.Errorf("unable to fetch node features: %w", err)
	}

	for _, row := range rows {
		node1, node2, err := buildNodeVertices(
			row.Node1Pubkey, row.Node2Pubkey,
		)
		if err != nil {
			return fmt.Errorf("unable to build node vertices: %w",
				err)
		}

		edge := buildCacheableChannelInfo(row.Channel, node1, node2)

		dbPol1, dbPol2, err := extractChannelPolicies(row)
		if err != nil {
			return err
		}

		var p1, p2 *models.CachedEdgePolicy
		if dbPol1 != nil {
			policy1, err := buildChanPolicy(
				*dbPol1, edge.ChannelID, nil, node2,
			)
			if err != nil {
				return err
			}

			p1 = models.NewCachedPolicy(policy1)
		}
		if dbPol2 != nil {
			policy2, err := buildChanPolicy(
				*dbPol2, edge.ChannelID, nil, node1,
			)
			if err != nil {
				return err
			}

			p2 = models.NewCachedPolicy(policy2)
		}

		// Determine the outgoing and incoming policy for this
		// channel and node combo.
		outPolicy, inPolicy := p1, p2
		if p1 != nil && node2 == nodePub {
			outPolicy, inPolicy = p2, p1
		} else if p2 != nil && node1 != nodePub {
			outPolicy, inPolicy = p2, p1
		}

		var cachedInPolicy *models.CachedEdgePolicy
		if inPolicy != nil {
			cachedInPolicy = inPolicy
			cachedInPolicy.ToNodePubKey = toNodeCallback
			cachedInPolicy.ToNodeFeatures = features
		}

		directedChannel := &DirectedChannel{
			ChannelID:    edge.ChannelID,
			IsNode1:      nodePub == edge.NodeKey1Bytes,
			OtherNode:    edge.NodeKey2Bytes,
			Capacity:     edge.Capacity,
			OutPolicySet: outPolicy != nil,
			InPolicy:     cachedInPolicy,
		}
		if outPolicy != nil {
			outPolicy.InboundFee.WhenSome(func(fee lnwire.Fee) {
				directedChannel.InboundFee = fee
			})
		}

		if nodePub == edge.NodeKey2Bytes {
			directedChannel.OtherNode = edge.NodeKey1Bytes
		}

		if err := cb(directedChannel); err != nil {
			return err
		}
	}

	return nil
}

// forEachNodeCacheable fetches all V1 node IDs and pub keys from the database,
// and executes the provided callback for each node.
func forEachNodeCacheable(ctx context.Context, db SQLQueries,
	cb func(nodeID int64, nodePub route.Vertex) error) error {

	lastID := int64(-1)

	for {
		nodes, err := db.ListNodeIDsAndPubKeys(
			ctx, sqlc.ListNodeIDsAndPubKeysParams{
				Version: int16(ProtocolV1),
				ID:      lastID,
				Limit:   pageSize,
			},
		)
		if err != nil {
			return fmt.Errorf("unable to fetch nodes: %w", err)
		}

		if len(nodes) == 0 {
			break
		}

		for _, node := range nodes {
			var pub route.Vertex
			copy(pub[:], node.PubKey)

			if err := cb(node.ID, pub); err != nil {
				return fmt.Errorf("forEachNodeCacheable "+
					"callback failed for node(id=%d): %w",
					node.ID, err)
			}

			lastID = node.ID
		}
	}

	return nil
}

// forEachNodeChannel iterates through all channels of a node, executing
// the passed callback on each. The call-back is provided with the channel's
// edge information, the outgoing policy and the incoming policy for the
// channel and node combo.
func forEachNodeChannel(ctx context.Context, db SQLQueries,
	chain chainhash.Hash, id int64, cb func(*models.ChannelEdgeInfo,
		*models.ChannelEdgePolicy,
		*models.ChannelEdgePolicy) error) error {

	// Get all the V1 channels for this node.Add commentMore actions
	rows, err := db.ListChannelsByNodeID(
		ctx, sqlc.ListChannelsByNodeIDParams{
			Version: int16(ProtocolV1),
			NodeID1: id,
		},
	)
	if err != nil {
		return fmt.Errorf("unable to fetch channels: %w", err)
	}

	// Call the call-back for each channel and its known policies.
	for _, row := range rows {
		node1, node2, err := buildNodeVertices(
			row.Node1Pubkey, row.Node2Pubkey,
		)
		if err != nil {
			return fmt.Errorf("unable to build node vertices: %w",
				err)
		}

		edge, err := getAndBuildEdgeInfo(
			ctx, db, chain, row.Channel.ID, row.Channel, node1,
			node2,
		)
		if err != nil {
			return fmt.Errorf("unable to build channel info: %w",
				err)
		}

		dbPol1, dbPol2, err := extractChannelPolicies(row)
		if err != nil {
			return fmt.Errorf("unable to extract channel "+
				"policies: %w", err)
		}

		p1, p2, err := getAndBuildChanPolicies(
			ctx, db, dbPol1, dbPol2, edge.ChannelID, node1, node2,
		)
		if err != nil {
			return fmt.Errorf("unable to build channel "+
				"policies: %w", err)
		}

		// Determine the outgoing and incoming policy for this
		// channel and node combo.
		p1ToNode := row.Channel.NodeID2
		p2ToNode := row.Channel.NodeID1
		outPolicy, inPolicy := p1, p2
		if (p1 != nil && p1ToNode == id) ||
			(p2 != nil && p2ToNode != id) {

			outPolicy, inPolicy = p2, p1
		}

		if err := cb(edge, outPolicy, inPolicy); err != nil {
			return err
		}
	}

	return nil
}

// updateChanEdgePolicy upserts the channel policy info we have stored for
// a channel we already know of.
func updateChanEdgePolicy(ctx context.Context, tx SQLQueries,
	edge *models.ChannelEdgePolicy) (route.Vertex, route.Vertex, bool,
	error) {

	var (
		node1Pub, node2Pub route.Vertex
		isNode1            bool
		chanIDB            = channelIDToBytes(edge.ChannelID)
	)

	// Check that this edge policy refers to a channel that we already
	// know of. We do this explicitly so that we can return the appropriate
	// ErrEdgeNotFound error if the channel doesn't exist, rather than
	// abort the transaction which would abort the entire batch.
	dbChan, err := tx.GetChannelAndNodesBySCID(
		ctx, sqlc.GetChannelAndNodesBySCIDParams{
			Scid:    chanIDB,
			Version: int16(ProtocolV1),
		},
	)
	if errors.Is(err, sql.ErrNoRows) {
		return node1Pub, node2Pub, false, ErrEdgeNotFound
	} else if err != nil {
		return node1Pub, node2Pub, false, fmt.Errorf("unable to "+
			"fetch channel(%v): %w", edge.ChannelID, err)
	}

	copy(node1Pub[:], dbChan.Node1PubKey)
	copy(node2Pub[:], dbChan.Node2PubKey)

	// Figure out which node this edge is from.
	isNode1 = edge.ChannelFlags&lnwire.ChanUpdateDirection == 0
	nodeID := dbChan.NodeID1
	if !isNode1 {
		nodeID = dbChan.NodeID2
	}

	var (
		inboundBase sql.NullInt64
		inboundRate sql.NullInt64
	)
	edge.InboundFee.WhenSome(func(fee lnwire.Fee) {
		inboundRate = sqldb.SQLInt64(fee.FeeRate)
		inboundBase = sqldb.SQLInt64(fee.BaseFee)
	})

	id, err := tx.UpsertEdgePolicy(ctx, sqlc.UpsertEdgePolicyParams{
		Version:     int16(ProtocolV1),
		ChannelID:   dbChan.ID,
		NodeID:      nodeID,
		Timelock:    int32(edge.TimeLockDelta),
		FeePpm:      int64(edge.FeeProportionalMillionths),
		BaseFeeMsat: int64(edge.FeeBaseMSat),
		MinHtlcMsat: int64(edge.MinHTLC),
		LastUpdate:  sqldb.SQLInt64(edge.LastUpdate.Unix()),
		Disabled: sql.NullBool{
			Valid: true,
			Bool:  edge.IsDisabled(),
		},
		MaxHtlcMsat: sql.NullInt64{
			Valid: edge.MessageFlags.HasMaxHtlc(),
			Int64: int64(edge.MaxHTLC),
		},
		MessageFlags:            sqldb.SQLInt16(edge.MessageFlags),
		ChannelFlags:            sqldb.SQLInt16(edge.ChannelFlags),
		InboundBaseFeeMsat:      inboundBase,
		InboundFeeRateMilliMsat: inboundRate,
		Signature:               edge.SigBytes,
	})
	if err != nil {
		return node1Pub, node2Pub, isNode1,
			fmt.Errorf("unable to upsert edge policy: %w", err)
	}

	// Convert the flat extra opaque data into a map of TLV types to
	// values.
	extra, err := marshalExtraOpaqueData(edge.ExtraOpaqueData)
	if err != nil {
		return node1Pub, node2Pub, false, fmt.Errorf("unable to "+
			"marshal extra opaque data: %w", err)
	}

	// Update the channel policy's extra signed fields.
	err = upsertChanPolicyExtraSignedFields(ctx, tx, id, extra)
	if err != nil {
		return node1Pub, node2Pub, false, fmt.Errorf("inserting chan "+
			"policy extra TLVs: %w", err)
	}

	return node1Pub, node2Pub, isNode1, nil
}

// getNodeByPubKey attempts to look up a target node by its public key.
func getNodeByPubKey(ctx context.Context, db SQLQueries,
	pubKey route.Vertex) (int64, *models.LightningNode, error) {

	dbNode, err := db.GetNodeByPubKey(
		ctx, sqlc.GetNodeByPubKeyParams{
			Version: int16(ProtocolV1),
			PubKey:  pubKey[:],
		},
	)
	if errors.Is(err, sql.ErrNoRows) {
		return 0, nil, ErrGraphNodeNotFound
	} else if err != nil {
		return 0, nil, fmt.Errorf("unable to fetch node: %w", err)
	}

	node, err := buildNode(ctx, db, &dbNode)
	if err != nil {
		return 0, nil, fmt.Errorf("unable to build node: %w", err)
	}

	return dbNode.ID, node, nil
}

// buildCacheableChannelInfo builds a models.CachedEdgeInfo instance from the
// provided database channel row and the public keys of the two nodes
// involved in the channel.
func buildCacheableChannelInfo(dbChan sqlc.Channel, node1Pub,
	node2Pub route.Vertex) *models.CachedEdgeInfo {

	return &models.CachedEdgeInfo{
		ChannelID:     byteOrder.Uint64(dbChan.Scid),
		NodeKey1Bytes: node1Pub,
		NodeKey2Bytes: node2Pub,
		Capacity:      btcutil.Amount(dbChan.Capacity.Int64),
	}
}

// buildNode constructs a LightningNode instance from the given database node
// record. The node's features, addresses and extra signed fields are also
// fetched from the database and set on the node.
func buildNode(ctx context.Context, db SQLQueries, dbNode *sqlc.Node) (
	*models.LightningNode, error) {

	if dbNode.Version != int16(ProtocolV1) {
		return nil, fmt.Errorf("unsupported node version: %d",
			dbNode.Version)
	}

	var pub [33]byte
	copy(pub[:], dbNode.PubKey)

	node := &models.LightningNode{
		PubKeyBytes: pub,
		Features:    lnwire.EmptyFeatureVector(),
		LastUpdate:  time.Unix(0, 0),
	}

	if len(dbNode.Signature) == 0 {
		return node, nil
	}

	node.HaveNodeAnnouncement = true
	node.AuthSigBytes = dbNode.Signature
	node.Alias = dbNode.Alias.String
	node.LastUpdate = time.Unix(dbNode.LastUpdate.Int64, 0)

	var err error
	if dbNode.Color.Valid {
		node.Color, err = DecodeHexColor(dbNode.Color.String)
		if err != nil {
			return nil, fmt.Errorf("unable to decode color: %w",
				err)
		}
	}

	// Fetch the node's features.
	node.Features, err = getNodeFeatures(ctx, db, dbNode.ID)
	if err != nil {
		return nil, fmt.Errorf("unable to fetch node(%d) "+
			"features: %w", dbNode.ID, err)
	}

	// Fetch the node's addresses.
	_, node.Addresses, err = getNodeAddresses(ctx, db, pub[:])
	if err != nil {
		return nil, fmt.Errorf("unable to fetch node(%d) "+
			"addresses: %w", dbNode.ID, err)
	}

	// Fetch the node's extra signed fields.
	extraTLVMap, err := getNodeExtraSignedFields(ctx, db, dbNode.ID)
	if err != nil {
		return nil, fmt.Errorf("unable to fetch node(%d) "+
			"extra signed fields: %w", dbNode.ID, err)
	}

	recs, err := lnwire.CustomRecords(extraTLVMap).Serialize()
	if err != nil {
		return nil, fmt.Errorf("unable to serialize extra signed "+
			"fields: %w", err)
	}

	if len(recs) != 0 {
		node.ExtraOpaqueData = recs
	}

	return node, nil
}

// getNodeFeatures fetches the feature bits and constructs the feature vector
// for a node with the given DB ID.
func getNodeFeatures(ctx context.Context, db SQLQueries,
	nodeID int64) (*lnwire.FeatureVector, error) {

	rows, err := db.GetNodeFeatures(ctx, nodeID)
	if err != nil {
		return nil, fmt.Errorf("unable to get node(%d) features: %w",
			nodeID, err)
	}

	features := lnwire.EmptyFeatureVector()
	for _, feature := range rows {
		features.Set(lnwire.FeatureBit(feature.FeatureBit))
	}

	return features, nil
}

// getNodeExtraSignedFields fetches the extra signed fields for a node with the
// given DB ID.
func getNodeExtraSignedFields(ctx context.Context, db SQLQueries,
	nodeID int64) (map[uint64][]byte, error) {

	fields, err := db.GetExtraNodeTypes(ctx, nodeID)
	if err != nil {
		return nil, fmt.Errorf("unable to get node(%d) extra "+
			"signed fields: %w", nodeID, err)
	}

	extraFields := make(map[uint64][]byte)
	for _, field := range fields {
		extraFields[uint64(field.Type)] = field.Value
	}

	return extraFields, nil
}

// upsertNode upserts the node record into the database. If the node already
// exists, then the node's information is updated. If the node doesn't exist,
// then a new node is created. The node's features, addresses and extra TLV
// types are also updated. The node's DB ID is returned.
func upsertNode(ctx context.Context, db SQLQueries,
	node *models.LightningNode) (int64, error) {

	params := sqlc.UpsertNodeParams{
		Version: int16(ProtocolV1),
		PubKey:  node.PubKeyBytes[:],
	}

	if node.HaveNodeAnnouncement {
		params.LastUpdate = sqldb.SQLInt64(node.LastUpdate.Unix())
		params.Color = sqldb.SQLStr(EncodeHexColor(node.Color))
		params.Alias = sqldb.SQLStr(node.Alias)
		params.Signature = node.AuthSigBytes
	}

	nodeID, err := db.UpsertNode(ctx, params)
	if err != nil {
		return 0, fmt.Errorf("upserting node(%x): %w", node.PubKeyBytes,
			err)
	}

	// We can exit here if we don't have the announcement yet.
	if !node.HaveNodeAnnouncement {
		return nodeID, nil
	}

	// Update the node's features.
	err = upsertNodeFeatures(ctx, db, nodeID, node.Features)
	if err != nil {
		return 0, fmt.Errorf("inserting node features: %w", err)
	}

	// Update the node's addresses.
	err = upsertNodeAddresses(ctx, db, nodeID, node.Addresses)
	if err != nil {
		return 0, fmt.Errorf("inserting node addresses: %w", err)
	}

	// Convert the flat extra opaque data into a map of TLV types to
	// values.
	extra, err := marshalExtraOpaqueData(node.ExtraOpaqueData)
	if err != nil {
		return 0, fmt.Errorf("unable to marshal extra opaque data: %w",
			err)
	}

	// Update the node's extra signed fields.
	err = upsertNodeExtraSignedFields(ctx, db, nodeID, extra)
	if err != nil {
		return 0, fmt.Errorf("inserting node extra TLVs: %w", err)
	}

	return nodeID, nil
}

// upsertNodeFeatures updates the node's features node_features table. This
// includes deleting any feature bits no longer present and inserting any new
// feature bits. If the feature bit does not yet exist in the features table,
// then an entry is created in that table first.
func upsertNodeFeatures(ctx context.Context, db SQLQueries, nodeID int64,
	features *lnwire.FeatureVector) error {

	// Get any existing features for the node.
	existingFeatures, err := db.GetNodeFeatures(ctx, nodeID)
	if err != nil && !errors.Is(err, sql.ErrNoRows) {
		return err
	}

	// Copy the nodes latest set of feature bits.
	newFeatures := make(map[int32]struct{})
	if features != nil {
		for feature := range features.Features() {
			newFeatures[int32(feature)] = struct{}{}
		}
	}

	// For any current feature that already exists in the DB, remove it from
	// the in-memory map. For any existing feature that does not exist in
	// the in-memory map, delete it from the database.
	for _, feature := range existingFeatures {
		// The feature is still present, so there are no updates to be
		// made.
		if _, ok := newFeatures[feature.FeatureBit]; ok {
			delete(newFeatures, feature.FeatureBit)
			continue
		}

		// The feature is no longer present, so we remove it from the
		// database.
		err := db.DeleteNodeFeature(ctx, sqlc.DeleteNodeFeatureParams{
			NodeID:     nodeID,
			FeatureBit: feature.FeatureBit,
		})
		if err != nil {
			return fmt.Errorf("unable to delete node(%d) "+
				"feature(%v): %w", nodeID, feature.FeatureBit,
				err)
		}
	}

	// Any remaining entries in newFeatures are new features that need to be
	// added to the database for the first time.
	for feature := range newFeatures {
		err = db.InsertNodeFeature(ctx, sqlc.InsertNodeFeatureParams{
			NodeID:     nodeID,
			FeatureBit: feature,
		})
		if err != nil {
			return fmt.Errorf("unable to insert node(%d) "+
				"feature(%v): %w", nodeID, feature, err)
		}
	}

	return nil
}

// fetchNodeFeatures fetches the features for a node with the given public key.
func fetchNodeFeatures(ctx context.Context, queries SQLQueries,
	nodePub route.Vertex) (*lnwire.FeatureVector, error) {

	rows, err := queries.GetNodeFeaturesByPubKey(
		ctx, sqlc.GetNodeFeaturesByPubKeyParams{
			PubKey:  nodePub[:],
			Version: int16(ProtocolV1),
		},
	)
	if err != nil {
		return nil, fmt.Errorf("unable to get node(%s) features: %w",
			nodePub, err)
	}

	features := lnwire.EmptyFeatureVector()
	for _, bit := range rows {
		features.Set(lnwire.FeatureBit(bit))
	}

	return features, nil
}

// dbAddressType is an enum type that represents the different address types
// that we store in the node_addresses table. The address type determines how
// the address is to be serialised/deserialize.
type dbAddressType uint8

const (
	addressTypeIPv4   dbAddressType = 1
	addressTypeIPv6   dbAddressType = 2
	addressTypeTorV2  dbAddressType = 3
	addressTypeTorV3  dbAddressType = 4
	addressTypeOpaque dbAddressType = math.MaxInt8
)

// upsertNodeAddresses updates the node's addresses in the database. This
// includes deleting any existing addresses and inserting the new set of
// addresses. The deletion is necessary since the ordering of the addresses may
// change, and we need to ensure that the database reflects the latest set of
// addresses so that at the time of reconstructing the node announcement, the
// order is preserved and the signature over the message remains valid.
func upsertNodeAddresses(ctx context.Context, db SQLQueries, nodeID int64,
	addresses []net.Addr) error {

	// Delete any existing addresses for the node. This is required since
	// even if the new set of addresses is the same, the ordering may have
	// changed for a given address type.
	err := db.DeleteNodeAddresses(ctx, nodeID)
	if err != nil {
		return fmt.Errorf("unable to delete node(%d) addresses: %w",
			nodeID, err)
	}

	// Copy the nodes latest set of addresses.
	newAddresses := map[dbAddressType][]string{
		addressTypeIPv4:   {},
		addressTypeIPv6:   {},
		addressTypeTorV2:  {},
		addressTypeTorV3:  {},
		addressTypeOpaque: {},
	}
	addAddr := func(t dbAddressType, addr net.Addr) {
		newAddresses[t] = append(newAddresses[t], addr.String())
	}

	for _, address := range addresses {
		switch addr := address.(type) {
		case *net.TCPAddr:
			if ip4 := addr.IP.To4(); ip4 != nil {
				addAddr(addressTypeIPv4, addr)
			} else if ip6 := addr.IP.To16(); ip6 != nil {
				addAddr(addressTypeIPv6, addr)
			} else {
				return fmt.Errorf("unhandled IP address: %v",
					addr)
			}

		case *tor.OnionAddr:
			switch len(addr.OnionService) {
			case tor.V2Len:
				addAddr(addressTypeTorV2, addr)
			case tor.V3Len:
				addAddr(addressTypeTorV3, addr)
			default:
				return fmt.Errorf("invalid length for a tor " +
					"address")
			}

		case *lnwire.OpaqueAddrs:
			addAddr(addressTypeOpaque, addr)

		default:
			return fmt.Errorf("unhandled address type: %T", addr)
		}
	}

	// Any remaining entries in newAddresses are new addresses that need to
	// be added to the database for the first time.
	for addrType, addrList := range newAddresses {
		for position, addr := range addrList {
			err := db.InsertNodeAddress(
				ctx, sqlc.InsertNodeAddressParams{
					NodeID:   nodeID,
					Type:     int16(addrType),
					Address:  addr,
					Position: int32(position),
				},
			)
			if err != nil {
				return fmt.Errorf("unable to insert "+
					"node(%d) address(%v): %w", nodeID,
					addr, err)
			}
		}
	}

	return nil
}

// getNodeAddresses fetches the addresses for a node with the given public key.
func getNodeAddresses(ctx context.Context, db SQLQueries, nodePub []byte) (bool,
	[]net.Addr, error) {

	// GetNodeAddressesByPubKey ensures that the addresses for a given type
	// are returned in the same order as they were inserted.
	rows, err := db.GetNodeAddressesByPubKey(
		ctx, sqlc.GetNodeAddressesByPubKeyParams{
			Version: int16(ProtocolV1),
			PubKey:  nodePub,
		},
	)
	if err != nil {
		return false, nil, err
	}

	// GetNodeAddressesByPubKey uses a left join so there should always be
	// at least one row returned if the node exists even if it has no
	// addresses.
	if len(rows) == 0 {
		return false, nil, nil
	}

	addresses := make([]net.Addr, 0, len(rows))
	for _, addr := range rows {
		if !(addr.Type.Valid && addr.Address.Valid) {
			continue
		}

		address := addr.Address.String

		switch dbAddressType(addr.Type.Int16) {
		case addressTypeIPv4:
			tcp, err := net.ResolveTCPAddr("tcp4", address)
			if err != nil {
				return false, nil, nil
			}
			tcp.IP = tcp.IP.To4()

			addresses = append(addresses, tcp)

		case addressTypeIPv6:
			tcp, err := net.ResolveTCPAddr("tcp6", address)
			if err != nil {
				return false, nil, nil
			}
			addresses = append(addresses, tcp)

		case addressTypeTorV3, addressTypeTorV2:
			service, portStr, err := net.SplitHostPort(address)
			if err != nil {
				return false, nil, fmt.Errorf("unable to "+
					"split tor v3 address: %v",
					addr.Address)
			}

			port, err := strconv.Atoi(portStr)
			if err != nil {
				return false, nil, err
			}

			addresses = append(addresses, &tor.OnionAddr{
				OnionService: service,
				Port:         port,
			})

		case addressTypeOpaque:
			opaque, err := hex.DecodeString(address)
			if err != nil {
				return false, nil, fmt.Errorf("unable to "+
					"decode opaque address: %v", addr)
			}

			addresses = append(addresses, &lnwire.OpaqueAddrs{
				Payload: opaque,
			})

		default:
			return false, nil, fmt.Errorf("unknown address "+
				"type: %v", addr.Type)
		}
	}

	// If we have no addresses, then we'll return nil instead of an
	// empty slice.
	if len(addresses) == 0 {
		addresses = nil
	}

	return true, addresses, nil
}

// upsertNodeExtraSignedFields updates the node's extra signed fields in the
// database. This includes updating any existing types, inserting any new types,
// and deleting any types that are no longer present.
func upsertNodeExtraSignedFields(ctx context.Context, db SQLQueries,
	nodeID int64, extraFields map[uint64][]byte) error {

	// Get any existing extra signed fields for the node.
	existingFields, err := db.GetExtraNodeTypes(ctx, nodeID)
	if err != nil {
		return err
	}

	// Make a lookup map of the existing field types so that we can use it
	// to keep track of any fields we should delete.
	m := make(map[uint64]bool)
	for _, field := range existingFields {
		m[uint64(field.Type)] = true
	}

	// For all the new fields, we'll upsert them and remove them from the
	// map of existing fields.
	for tlvType, value := range extraFields {
		err = db.UpsertNodeExtraType(
			ctx, sqlc.UpsertNodeExtraTypeParams{
				NodeID: nodeID,
				Type:   int64(tlvType),
				Value:  value,
			},
		)
		if err != nil {
			return fmt.Errorf("unable to upsert node(%d) extra "+
				"signed field(%v): %w", nodeID, tlvType, err)
		}

		// Remove the field from the map of existing fields if it was
		// present.
		delete(m, tlvType)
	}

	// For all the fields that are left in the map of existing fields, we'll
	// delete them as they are no longer present in the new set of fields.
	for tlvType := range m {
		err = db.DeleteExtraNodeType(
			ctx, sqlc.DeleteExtraNodeTypeParams{
				NodeID: nodeID,
				Type:   int64(tlvType),
			},
		)
		if err != nil {
			return fmt.Errorf("unable to delete node(%d) extra "+
				"signed field(%v): %w", nodeID, tlvType, err)
		}
	}

	return nil
}

// srcNodeInfo holds the information about the source node of the graph.
type srcNodeInfo struct {
	// id is the DB level ID of the source node entry in the "nodes" table.
	id int64

	// pub is the public key of the source node.
	pub route.Vertex
}

// sourceNode returns the DB node ID and pub key of the source node for the
// specified protocol version.
func (s *SQLStore) getSourceNode(ctx context.Context, db SQLQueries,
	version ProtocolVersion) (int64, route.Vertex, error) {

	s.srcNodeMu.Lock()
	defer s.srcNodeMu.Unlock()

	// If we already have the source node ID and pub key cached, then
	// return them.
	if info, ok := s.srcNodes[version]; ok {
		return info.id, info.pub, nil
	}

	var pubKey route.Vertex

	nodes, err := db.GetSourceNodesByVersion(ctx, int16(version))
	if err != nil {
		return 0, pubKey, fmt.Errorf("unable to fetch source node: %w",
			err)
	}

	if len(nodes) == 0 {
		return 0, pubKey, ErrSourceNodeNotSet
	} else if len(nodes) > 1 {
		return 0, pubKey, fmt.Errorf("multiple source nodes for "+
			"protocol %s found", version)
	}

	copy(pubKey[:], nodes[0].PubKey)

	s.srcNodes[version] = &srcNodeInfo{
		id:  nodes[0].NodeID,
		pub: pubKey,
	}

	return nodes[0].NodeID, pubKey, nil
}

// marshalExtraOpaqueData takes a flat byte slice parses it as a TLV stream.
// This then produces a map from TLV type to value. If the input is not a
// valid TLV stream, then an error is returned.
func marshalExtraOpaqueData(data []byte) (map[uint64][]byte, error) {
	r := bytes.NewReader(data)

	tlvStream, err := tlv.NewStream()
	if err != nil {
		return nil, err
	}

	// Since ExtraOpaqueData is provided by a potentially malicious peer,
	// pass it into the P2P decoding variant.
	parsedTypes, err := tlvStream.DecodeWithParsedTypesP2P(r)
	if err != nil {
		return nil, fmt.Errorf("%w: %w", ErrParsingExtraTLVBytes, err)
	}
	if len(parsedTypes) == 0 {
		return nil, nil
	}

	records := make(map[uint64][]byte)
	for k, v := range parsedTypes {
		records[uint64(k)] = v
	}

	return records, nil
}

// insertChannel inserts a new channel record into the database.
func insertChannel(ctx context.Context, db SQLQueries,
	edge *models.ChannelEdgeInfo) error {

	chanIDB := channelIDToBytes(edge.ChannelID)

	// Make sure that the channel doesn't already exist. We do this
	// explicitly instead of relying on catching a unique constraint error
	// because relying on SQL to throw that error would abort the entire
	// batch of transactions.
	_, err := db.GetChannelBySCID(
		ctx, sqlc.GetChannelBySCIDParams{
			Scid:    chanIDB,
			Version: int16(ProtocolV1),
		},
	)
	if err == nil {
		return ErrEdgeAlreadyExist
	} else if !errors.Is(err, sql.ErrNoRows) {
		return fmt.Errorf("unable to fetch channel: %w", err)
	}

	// Make sure that at least a "shell" entry for each node is present in
	// the nodes table.
	node1DBID, err := maybeCreateShellNode(ctx, db, edge.NodeKey1Bytes)
	if err != nil {
		return fmt.Errorf("unable to create shell node: %w", err)
	}

	node2DBID, err := maybeCreateShellNode(ctx, db, edge.NodeKey2Bytes)
	if err != nil {
		return fmt.Errorf("unable to create shell node: %w", err)
	}

	var capacity sql.NullInt64
	if edge.Capacity != 0 {
		capacity = sqldb.SQLInt64(int64(edge.Capacity))
	}

	createParams := sqlc.CreateChannelParams{
		Version:     int16(ProtocolV1),
		Scid:        chanIDB,
		NodeID1:     node1DBID,
		NodeID2:     node2DBID,
		Outpoint:    edge.ChannelPoint.String(),
		Capacity:    capacity,
		BitcoinKey1: edge.BitcoinKey1Bytes[:],
		BitcoinKey2: edge.BitcoinKey2Bytes[:],
	}

	if edge.AuthProof != nil {
		proof := edge.AuthProof

		createParams.Node1Signature = proof.NodeSig1Bytes
		createParams.Node2Signature = proof.NodeSig2Bytes
		createParams.Bitcoin1Signature = proof.BitcoinSig1Bytes
		createParams.Bitcoin2Signature = proof.BitcoinSig2Bytes
	}

	// Insert the new channel record.
	dbChanID, err := db.CreateChannel(ctx, createParams)
	if err != nil {
		return err
	}

	// Insert any channel features.
	if len(edge.Features) != 0 {
		chanFeatures := lnwire.NewRawFeatureVector()
		err := chanFeatures.Decode(bytes.NewReader(edge.Features))
		if err != nil {
			return err
		}

		fv := lnwire.NewFeatureVector(chanFeatures, lnwire.Features)
		for feature := range fv.Features() {
			err = db.InsertChannelFeature(
				ctx, sqlc.InsertChannelFeatureParams{
					ChannelID:  dbChanID,
					FeatureBit: int32(feature),
				},
			)
			if err != nil {
				return fmt.Errorf("unable to insert "+
					"channel(%d) feature(%v): %w", dbChanID,
					feature, err)
			}
		}
	}

	// Finally, insert any extra TLV fields in the channel announcement.
	extra, err := marshalExtraOpaqueData(edge.ExtraOpaqueData)
	if err != nil {
		return fmt.Errorf("unable to marshal extra opaque data: %w",
			err)
	}

	for tlvType, value := range extra {
		err := db.CreateChannelExtraType(
			ctx, sqlc.CreateChannelExtraTypeParams{
				ChannelID: dbChanID,
				Type:      int64(tlvType),
				Value:     value,
			},
		)
		if err != nil {
			return fmt.Errorf("unable to upsert channel(%d) extra "+
				"signed field(%v): %w", edge.ChannelID,
				tlvType, err)
		}
	}

	return nil
}

// maybeCreateShellNode checks if a shell node entry exists for the
// given public key. If it does not exist, then a new shell node entry is
// created. The ID of the node is returned. A shell node only has a protocol
// version and public key persisted.
func maybeCreateShellNode(ctx context.Context, db SQLQueries,
	pubKey route.Vertex) (int64, error) {

	dbNode, err := db.GetNodeByPubKey(
		ctx, sqlc.GetNodeByPubKeyParams{
			PubKey:  pubKey[:],
			Version: int16(ProtocolV1),
		},
	)
	// The node exists. Return the ID.
	if err == nil {
		return dbNode.ID, nil
	} else if !errors.Is(err, sql.ErrNoRows) {
		return 0, err
	}

	// Otherwise, the node does not exist, so we create a shell entry for
	// it.
	id, err := db.UpsertNode(ctx, sqlc.UpsertNodeParams{
		Version: int16(ProtocolV1),
		PubKey:  pubKey[:],
	})
	if err != nil {
		return 0, fmt.Errorf("unable to create shell node: %w", err)
	}

	return id, nil
}

// upsertChanPolicyExtraSignedFields updates the policy's extra signed fields in
// the database. This includes deleting any existing types and then inserting
// the new types.
func upsertChanPolicyExtraSignedFields(ctx context.Context, db SQLQueries,
	chanPolicyID int64, extraFields map[uint64][]byte) error {

	// Delete all existing extra signed fields for the channel policy.
	err := db.DeleteChannelPolicyExtraTypes(ctx, chanPolicyID)
	if err != nil {
		return fmt.Errorf("unable to delete "+
			"existing policy extra signed fields for policy %d: %w",
			chanPolicyID, err)
	}

	// Insert all new extra signed fields for the channel policy.
	for tlvType, value := range extraFields {
		err = db.InsertChanPolicyExtraType(
			ctx, sqlc.InsertChanPolicyExtraTypeParams{
				ChannelPolicyID: chanPolicyID,
				Type:            int64(tlvType),
				Value:           value,
			},
		)
		if err != nil {
			return fmt.Errorf("unable to insert "+
				"channel_policy(%d) extra signed field(%v): %w",
				chanPolicyID, tlvType, err)
		}
	}

	return nil
}

// getAndBuildEdgeInfo builds a models.ChannelEdgeInfo instance from the
// provided dbChanRow and also fetches any other required information
// to construct the edge info.
func getAndBuildEdgeInfo(ctx context.Context, db SQLQueries,
	chain chainhash.Hash, dbChanID int64, dbChan sqlc.Channel, node1,
	node2 route.Vertex) (*models.ChannelEdgeInfo, error) {

	if dbChan.Version != int16(ProtocolV1) {
		return nil, fmt.Errorf("unsupported channel version: %d",
			dbChan.Version)
	}

	fv, extras, err := getChanFeaturesAndExtras(
		ctx, db, dbChanID,
	)
	if err != nil {
		return nil, err
	}

	op, err := wire.NewOutPointFromString(dbChan.Outpoint)
	if err != nil {
		return nil, err
	}

	var featureBuf bytes.Buffer
	if err := fv.Encode(&featureBuf); err != nil {
		return nil, fmt.Errorf("unable to encode features: %w", err)
	}

	recs, err := lnwire.CustomRecords(extras).Serialize()
	if err != nil {
		return nil, fmt.Errorf("unable to serialize extra signed "+
			"fields: %w", err)
	}
	if recs == nil {
		recs = make([]byte, 0)
	}

	var btcKey1, btcKey2 route.Vertex
	copy(btcKey1[:], dbChan.BitcoinKey1)
	copy(btcKey2[:], dbChan.BitcoinKey2)

	channel := &models.ChannelEdgeInfo{
		ChainHash:        chain,
		ChannelID:        byteOrder.Uint64(dbChan.Scid),
		NodeKey1Bytes:    node1,
		NodeKey2Bytes:    node2,
		BitcoinKey1Bytes: btcKey1,
		BitcoinKey2Bytes: btcKey2,
		ChannelPoint:     *op,
		Capacity:         btcutil.Amount(dbChan.Capacity.Int64),
		Features:         featureBuf.Bytes(),
		ExtraOpaqueData:  recs,
	}

	// We always set all the signatures at the same time, so we can
	// safely check if one signature is present to determine if we have the
	// rest of the signatures for the auth proof.
	if len(dbChan.Bitcoin1Signature) > 0 {
		channel.AuthProof = &models.ChannelAuthProof{
			NodeSig1Bytes:    dbChan.Node1Signature,
			NodeSig2Bytes:    dbChan.Node2Signature,
			BitcoinSig1Bytes: dbChan.Bitcoin1Signature,
			BitcoinSig2Bytes: dbChan.Bitcoin2Signature,
		}
	}

	return channel, nil
}

// buildNodeVertices is a helper that converts raw node public keys
// into route.Vertex instances.
func buildNodeVertices(node1Pub, node2Pub []byte) (route.Vertex,
	route.Vertex, error) {

	node1Vertex, err := route.NewVertexFromBytes(node1Pub)
	if err != nil {
		return route.Vertex{}, route.Vertex{}, fmt.Errorf("unable to "+
			"create vertex from node1 pubkey: %w", err)
	}

	node2Vertex, err := route.NewVertexFromBytes(node2Pub)
	if err != nil {
		return route.Vertex{}, route.Vertex{}, fmt.Errorf("unable to "+
			"create vertex from node2 pubkey: %w", err)
	}

	return node1Vertex, node2Vertex, nil
}

// getChanFeaturesAndExtras fetches the channel features and extra TLV types
// for a channel with the given ID.
func getChanFeaturesAndExtras(ctx context.Context, db SQLQueries,
	id int64) (*lnwire.FeatureVector, map[uint64][]byte, error) {

	rows, err := db.GetChannelFeaturesAndExtras(ctx, id)
	if err != nil {
		return nil, nil, fmt.Errorf("unable to fetch channel "+
			"features and extras: %w", err)
	}

	var (
		fv     = lnwire.EmptyFeatureVector()
		extras = make(map[uint64][]byte)
	)
	for _, row := range rows {
		if row.IsFeature {
			fv.Set(lnwire.FeatureBit(row.FeatureBit))

			continue
		}

		tlvType, ok := row.ExtraKey.(int64)
		if !ok {
			return nil, nil, fmt.Errorf("unexpected type for "+
				"TLV type: %T", row.ExtraKey)
		}

		valueBytes, ok := row.Value.([]byte)
		if !ok {
			return nil, nil, fmt.Errorf("unexpected type for "+
				"Value: %T", row.Value)
		}

		extras[uint64(tlvType)] = valueBytes
	}

	return fv, extras, nil
}

// getAndBuildChanPolicies uses the given sqlc.ChannelPolicy and also retrieves
// all the extra info required to build the complete models.ChannelEdgePolicy
// types. It returns two policies, which may be nil if the provided
// sqlc.ChannelPolicy records are nil.
func getAndBuildChanPolicies(ctx context.Context, db SQLQueries,
	dbPol1, dbPol2 *sqlc.ChannelPolicy, channelID uint64, node1,
	node2 route.Vertex) (*models.ChannelEdgePolicy,
	*models.ChannelEdgePolicy, error) {

	if dbPol1 == nil && dbPol2 == nil {
		return nil, nil, nil
	}

	var (
		policy1ID int64
		policy2ID int64
	)
	if dbPol1 != nil {
		policy1ID = dbPol1.ID
	}
	if dbPol2 != nil {
		policy2ID = dbPol2.ID
	}
	rows, err := db.GetChannelPolicyExtraTypes(
		ctx, sqlc.GetChannelPolicyExtraTypesParams{
			ID:   policy1ID,
			ID_2: policy2ID,
		},
	)
	if err != nil {
		return nil, nil, err
	}

	var (
		dbPol1Extras = make(map[uint64][]byte)
		dbPol2Extras = make(map[uint64][]byte)
	)
	for _, row := range rows {
		switch row.PolicyID {
		case policy1ID:
			dbPol1Extras[uint64(row.Type)] = row.Value
		case policy2ID:
			dbPol2Extras[uint64(row.Type)] = row.Value
		default:
			return nil, nil, fmt.Errorf("unexpected policy ID %d "+
				"in row: %v", row.PolicyID, row)
		}
	}

	var pol1, pol2 *models.ChannelEdgePolicy
	if dbPol1 != nil {
		pol1, err = buildChanPolicy(
			*dbPol1, channelID, dbPol1Extras, node2,
		)
		if err != nil {
			return nil, nil, err
		}
	}
	if dbPol2 != nil {
		pol2, err = buildChanPolicy(
			*dbPol2, channelID, dbPol2Extras, node1,
		)
		if err != nil {
			return nil, nil, err
		}
	}

	return pol1, pol2, nil
}

// buildChanPolicy builds a models.ChannelEdgePolicy instance from the
// provided sqlc.ChannelPolicy and other required information.
func buildChanPolicy(dbPolicy sqlc.ChannelPolicy, channelID uint64,
	extras map[uint64][]byte,
	toNode route.Vertex) (*models.ChannelEdgePolicy, error) {

	recs, err := lnwire.CustomRecords(extras).Serialize()
	if err != nil {
		return nil, fmt.Errorf("unable to serialize extra signed "+
			"fields: %w", err)
	}

	var inboundFee fn.Option[lnwire.Fee]
	if dbPolicy.InboundFeeRateMilliMsat.Valid ||
		dbPolicy.InboundBaseFeeMsat.Valid {

		inboundFee = fn.Some(lnwire.Fee{
			BaseFee: int32(dbPolicy.InboundBaseFeeMsat.Int64),
			FeeRate: int32(dbPolicy.InboundFeeRateMilliMsat.Int64),
		})
	}

	return &models.ChannelEdgePolicy{
		SigBytes:  dbPolicy.Signature,
		ChannelID: channelID,
		LastUpdate: time.Unix(
			dbPolicy.LastUpdate.Int64, 0,
		),
		MessageFlags: sqldb.ExtractSqlInt16[lnwire.ChanUpdateMsgFlags](
			dbPolicy.MessageFlags,
		),
		ChannelFlags: sqldb.ExtractSqlInt16[lnwire.ChanUpdateChanFlags](
			dbPolicy.ChannelFlags,
		),
		TimeLockDelta: uint16(dbPolicy.Timelock),
		MinHTLC: lnwire.MilliSatoshi(
			dbPolicy.MinHtlcMsat,
		),
		MaxHTLC: lnwire.MilliSatoshi(
			dbPolicy.MaxHtlcMsat.Int64,
		),
		FeeBaseMSat: lnwire.MilliSatoshi(
			dbPolicy.BaseFeeMsat,
		),
		FeeProportionalMillionths: lnwire.MilliSatoshi(dbPolicy.FeePpm),
		ToNode:                    toNode,
		InboundFee:                inboundFee,
		ExtraOpaqueData:           recs,
	}, nil
}

// buildNodes builds the models.LightningNode instances for the
// given row which is expected to be a sqlc type that contains node information.
func buildNodes(ctx context.Context, db SQLQueries, dbNode1,
	dbNode2 sqlc.Node) (*models.LightningNode, *models.LightningNode,
	error) {

	node1, err := buildNode(ctx, db, &dbNode1)
	if err != nil {
		return nil, nil, err
	}

	node2, err := buildNode(ctx, db, &dbNode2)
	if err != nil {
		return nil, nil, err
	}

	return node1, node2, nil
}

// extractChannelPolicies extracts the sqlc.ChannelPolicy records from the give
// row which is expected to be a sqlc type that contains channel policy
// information. It returns two policies, which may be nil if the policy
// information is not present in the row.
//
//nolint:ll,dupl,funlen
func extractChannelPolicies(row any) (*sqlc.ChannelPolicy, *sqlc.ChannelPolicy,
	error) {

	var policy1, policy2 *sqlc.ChannelPolicy
	switch r := row.(type) {
	case sqlc.GetChannelByOutpointWithPoliciesRow:
		if r.Policy1ID.Valid {
			policy1 = &sqlc.ChannelPolicy{
				ID:                      r.Policy1ID.Int64,
				Version:                 r.Policy1Version.Int16,
				ChannelID:               r.Channel.ID,
				NodeID:                  r.Policy1NodeID.Int64,
				Timelock:                r.Policy1Timelock.Int32,
				FeePpm:                  r.Policy1FeePpm.Int64,
				BaseFeeMsat:             r.Policy1BaseFeeMsat.Int64,
				MinHtlcMsat:             r.Policy1MinHtlcMsat.Int64,
				MaxHtlcMsat:             r.Policy1MaxHtlcMsat,
				LastUpdate:              r.Policy1LastUpdate,
				InboundBaseFeeMsat:      r.Policy1InboundBaseFeeMsat,
				InboundFeeRateMilliMsat: r.Policy1InboundFeeRateMilliMsat,
				Disabled:                r.Policy1Disabled,
				MessageFlags:            r.Policy1MessageFlags,
				ChannelFlags:            r.Policy1ChannelFlags,
				Signature:               r.Policy1Signature,
			}
		}
		if r.Policy2ID.Valid {
			policy2 = &sqlc.ChannelPolicy{
				ID:                      r.Policy2ID.Int64,
				Version:                 r.Policy2Version.Int16,
				ChannelID:               r.Channel.ID,
				NodeID:                  r.Policy2NodeID.Int64,
				Timelock:                r.Policy2Timelock.Int32,
				FeePpm:                  r.Policy2FeePpm.Int64,
				BaseFeeMsat:             r.Policy2BaseFeeMsat.Int64,
				MinHtlcMsat:             r.Policy2MinHtlcMsat.Int64,
				MaxHtlcMsat:             r.Policy2MaxHtlcMsat,
				LastUpdate:              r.Policy2LastUpdate,
				InboundBaseFeeMsat:      r.Policy2InboundBaseFeeMsat,
				InboundFeeRateMilliMsat: r.Policy2InboundFeeRateMilliMsat,
				Disabled:                r.Policy2Disabled,
				MessageFlags:            r.Policy2MessageFlags,
				ChannelFlags:            r.Policy2ChannelFlags,
				Signature:               r.Policy2Signature,
			}
		}

		return policy1, policy2, nil

	case sqlc.GetChannelBySCIDWithPoliciesRow:
		if r.Policy1ID.Valid {
			policy1 = &sqlc.ChannelPolicy{
				ID:                      r.Policy1ID.Int64,
				Version:                 r.Policy1Version.Int16,
				ChannelID:               r.Channel.ID,
				NodeID:                  r.Policy1NodeID.Int64,
				Timelock:                r.Policy1Timelock.Int32,
				FeePpm:                  r.Policy1FeePpm.Int64,
				BaseFeeMsat:             r.Policy1BaseFeeMsat.Int64,
				MinHtlcMsat:             r.Policy1MinHtlcMsat.Int64,
				MaxHtlcMsat:             r.Policy1MaxHtlcMsat,
				LastUpdate:              r.Policy1LastUpdate,
				InboundBaseFeeMsat:      r.Policy1InboundBaseFeeMsat,
				InboundFeeRateMilliMsat: r.Policy1InboundFeeRateMilliMsat,
				Disabled:                r.Policy1Disabled,
				MessageFlags:            r.Policy1MessageFlags,
				ChannelFlags:            r.Policy1ChannelFlags,
				Signature:               r.Policy1Signature,
			}
		}
		if r.Policy2ID.Valid {
			policy2 = &sqlc.ChannelPolicy{
				ID:                      r.Policy2ID.Int64,
				Version:                 r.Policy2Version.Int16,
				ChannelID:               r.Channel.ID,
				NodeID:                  r.Policy2NodeID.Int64,
				Timelock:                r.Policy2Timelock.Int32,
				FeePpm:                  r.Policy2FeePpm.Int64,
				BaseFeeMsat:             r.Policy2BaseFeeMsat.Int64,
				MinHtlcMsat:             r.Policy2MinHtlcMsat.Int64,
				MaxHtlcMsat:             r.Policy2MaxHtlcMsat,
				LastUpdate:              r.Policy2LastUpdate,
				InboundBaseFeeMsat:      r.Policy2InboundBaseFeeMsat,
				InboundFeeRateMilliMsat: r.Policy2InboundFeeRateMilliMsat,
				Disabled:                r.Policy2Disabled,
				MessageFlags:            r.Policy2MessageFlags,
				ChannelFlags:            r.Policy2ChannelFlags,
				Signature:               r.Policy2Signature,
			}
		}

		return policy1, policy2, nil

	case sqlc.GetChannelsByPolicyLastUpdateRangeRow:
		if r.Policy1ID.Valid {
			policy1 = &sqlc.ChannelPolicy{
				ID:                      r.Policy1ID.Int64,
				Version:                 r.Policy1Version.Int16,
				ChannelID:               r.Channel.ID,
				NodeID:                  r.Policy1NodeID.Int64,
				Timelock:                r.Policy1Timelock.Int32,
				FeePpm:                  r.Policy1FeePpm.Int64,
				BaseFeeMsat:             r.Policy1BaseFeeMsat.Int64,
				MinHtlcMsat:             r.Policy1MinHtlcMsat.Int64,
				MaxHtlcMsat:             r.Policy1MaxHtlcMsat,
				LastUpdate:              r.Policy1LastUpdate,
				InboundBaseFeeMsat:      r.Policy1InboundBaseFeeMsat,
				InboundFeeRateMilliMsat: r.Policy1InboundFeeRateMilliMsat,
				Disabled:                r.Policy1Disabled,
				MessageFlags:            r.Policy1MessageFlags,
				ChannelFlags:            r.Policy1ChannelFlags,
				Signature:               r.Policy1Signature,
			}
		}
		if r.Policy2ID.Valid {
			policy2 = &sqlc.ChannelPolicy{
				ID:                      r.Policy2ID.Int64,
				Version:                 r.Policy2Version.Int16,
				ChannelID:               r.Channel.ID,
				NodeID:                  r.Policy2NodeID.Int64,
				Timelock:                r.Policy2Timelock.Int32,
				FeePpm:                  r.Policy2FeePpm.Int64,
				BaseFeeMsat:             r.Policy2BaseFeeMsat.Int64,
				MinHtlcMsat:             r.Policy2MinHtlcMsat.Int64,
				MaxHtlcMsat:             r.Policy2MaxHtlcMsat,
				LastUpdate:              r.Policy2LastUpdate,
				InboundBaseFeeMsat:      r.Policy2InboundBaseFeeMsat,
				InboundFeeRateMilliMsat: r.Policy2InboundFeeRateMilliMsat,
				Disabled:                r.Policy2Disabled,
				MessageFlags:            r.Policy2MessageFlags,
				ChannelFlags:            r.Policy2ChannelFlags,
				Signature:               r.Policy2Signature,
			}
		}

		return policy1, policy2, nil

	case sqlc.ListChannelsByNodeIDRow:
		if r.Policy1ID.Valid {
			policy1 = &sqlc.ChannelPolicy{
				ID:                      r.Policy1ID.Int64,
				Version:                 r.Policy1Version.Int16,
				ChannelID:               r.Channel.ID,
				NodeID:                  r.Policy1NodeID.Int64,
				Timelock:                r.Policy1Timelock.Int32,
				FeePpm:                  r.Policy1FeePpm.Int64,
				BaseFeeMsat:             r.Policy1BaseFeeMsat.Int64,
				MinHtlcMsat:             r.Policy1MinHtlcMsat.Int64,
				MaxHtlcMsat:             r.Policy1MaxHtlcMsat,
				LastUpdate:              r.Policy1LastUpdate,
				InboundBaseFeeMsat:      r.Policy1InboundBaseFeeMsat,
				InboundFeeRateMilliMsat: r.Policy1InboundFeeRateMilliMsat,
				Disabled:                r.Policy1Disabled,
				MessageFlags:            r.Policy1MessageFlags,
				ChannelFlags:            r.Policy1ChannelFlags,
				Signature:               r.Policy1Signature,
			}
		}
		if r.Policy2ID.Valid {
			policy2 = &sqlc.ChannelPolicy{
				ID:                      r.Policy2ID.Int64,
				Version:                 r.Policy2Version.Int16,
				ChannelID:               r.Channel.ID,
				NodeID:                  r.Policy2NodeID.Int64,
				Timelock:                r.Policy2Timelock.Int32,
				FeePpm:                  r.Policy2FeePpm.Int64,
				BaseFeeMsat:             r.Policy2BaseFeeMsat.Int64,
				MinHtlcMsat:             r.Policy2MinHtlcMsat.Int64,
				MaxHtlcMsat:             r.Policy2MaxHtlcMsat,
				LastUpdate:              r.Policy2LastUpdate,
				InboundBaseFeeMsat:      r.Policy2InboundBaseFeeMsat,
				InboundFeeRateMilliMsat: r.Policy2InboundFeeRateMilliMsat,
				Disabled:                r.Policy2Disabled,
				MessageFlags:            r.Policy2MessageFlags,
				ChannelFlags:            r.Policy2ChannelFlags,
				Signature:               r.Policy2Signature,
			}
		}

		return policy1, policy2, nil

	case sqlc.ListChannelsWithPoliciesPaginatedRow:
		if r.Policy1ID.Valid {
			policy1 = &sqlc.ChannelPolicy{
				ID:                      r.Policy1ID.Int64,
				Version:                 r.Policy1Version.Int16,
				ChannelID:               r.Channel.ID,
				NodeID:                  r.Policy1NodeID.Int64,
				Timelock:                r.Policy1Timelock.Int32,
				FeePpm:                  r.Policy1FeePpm.Int64,
				BaseFeeMsat:             r.Policy1BaseFeeMsat.Int64,
				MinHtlcMsat:             r.Policy1MinHtlcMsat.Int64,
				MaxHtlcMsat:             r.Policy1MaxHtlcMsat,
				LastUpdate:              r.Policy1LastUpdate,
				InboundBaseFeeMsat:      r.Policy1InboundBaseFeeMsat,
				InboundFeeRateMilliMsat: r.Policy1InboundFeeRateMilliMsat,
				Disabled:                r.Policy1Disabled,
				MessageFlags:            r.Policy1MessageFlags,
				ChannelFlags:            r.Policy1ChannelFlags,
				Signature:               r.Policy1Signature,
			}
		}
		if r.Policy2ID.Valid {
			policy2 = &sqlc.ChannelPolicy{
				ID:                      r.Policy2ID.Int64,
				Version:                 r.Policy2Version.Int16,
				ChannelID:               r.Channel.ID,
				NodeID:                  r.Policy2NodeID.Int64,
				Timelock:                r.Policy2Timelock.Int32,
				FeePpm:                  r.Policy2FeePpm.Int64,
				BaseFeeMsat:             r.Policy2BaseFeeMsat.Int64,
				MinHtlcMsat:             r.Policy2MinHtlcMsat.Int64,
				MaxHtlcMsat:             r.Policy2MaxHtlcMsat,
				LastUpdate:              r.Policy2LastUpdate,
				InboundBaseFeeMsat:      r.Policy2InboundBaseFeeMsat,
				InboundFeeRateMilliMsat: r.Policy2InboundFeeRateMilliMsat,
				Disabled:                r.Policy2Disabled,
				MessageFlags:            r.Policy2MessageFlags,
				ChannelFlags:            r.Policy2ChannelFlags,
				Signature:               r.Policy2Signature,
			}
		}

		return policy1, policy2, nil
	default:
		return nil, nil, fmt.Errorf("unexpected row type in "+
			"extractChannelPolicies: %T", r)
	}
}

// channelIDToBytes converts a channel ID (SCID) to a byte array
// representation.
func channelIDToBytes(channelID uint64) []byte {
	var chanIDB [8]byte
	byteOrder.PutUint64(chanIDB[:], channelID)

	return chanIDB[:]
}