From e0ab462a7452235189cdacf5f412240363198dee Mon Sep 17 00:00:00 2001
From: George Tsagkarelis <george.tsagkarelis@gmail.com>
Date: Fri, 22 Nov 2024 18:48:43 +0100
Subject: [PATCH] itest: extend liquidity edge cases for rfq htlc tracking

---
 itest/litd_custom_channels_test.go | 97 ++++++++++++++++++++++++++++--
 1 file changed, 93 insertions(+), 4 deletions(-)

diff --git a/itest/litd_custom_channels_test.go b/itest/litd_custom_channels_test.go
index 86790ad82..535affa6a 100644
--- a/itest/litd_custom_channels_test.go
+++ b/itest/litd_custom_channels_test.go
@@ -1,6 +1,7 @@
 package itest
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"math"
@@ -18,12 +19,14 @@ import (
 	"github.com/lightninglabs/taproot-assets/tapchannel"
 	"github.com/lightninglabs/taproot-assets/taprpc"
 	"github.com/lightninglabs/taproot-assets/taprpc/mintrpc"
+	"github.com/lightninglabs/taproot-assets/taprpc/rfqrpc"
 	tchrpc "github.com/lightninglabs/taproot-assets/taprpc/tapchannelrpc"
 	"github.com/lightninglabs/taproot-assets/taprpc/universerpc"
 	"github.com/lightninglabs/taproot-assets/tapscript"
 	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/invoicesrpc"
+	"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
 	"github.com/lightningnetwork/lnd/lnrpc/walletrpc"
 	"github.com/lightningnetwork/lnd/lntest"
 	"github.com/lightningnetwork/lnd/lntest/port"
@@ -1805,7 +1808,7 @@ func testCustomChannelsLiquidityEdgeCases(_ context.Context,
 			SatPerVByte: 5,
 		},
 	)
-	defer closeChannelAndAssert(t, net, dave, channelOp, false)
+	defer closeChannelAndAssert(t, net, dave, channelOp, true)
 
 	// This is the only public channel, we need everyone to be aware of it.
 	assertChannelKnown(t.t, charlie, channelOp)
@@ -2020,10 +2023,11 @@ func testCustomChannelsLiquidityEdgeCases(_ context.Context,
 	logBalance(t.t, nodes, assetID, "after small payment (asset "+
 		"invoice, <354sats)")
 
-	// Edge case: Now Charlie creates an asset invoice to be paid for by
+	// Edge case: Now Dave creates an asset invoice to be paid for by
 	// Yara with satoshi. For the last hop we try to settle the invoice in
-	// satoshi, where we will check whether Charlie's strict forwarding
-	// works as expected.
+	// satoshi, where we will check whether Dave's strict forwarding works
+	// as expected. Charlie is only used as a dummy RFQ peer in this case,
+	// Yara totally ignored the RFQ hint and pays agnostically with sats.
 	invoiceResp = createAssetInvoice(
 		t.t, charlie, dave, 1, assetID,
 	)
@@ -2046,6 +2050,91 @@ func testCustomChannelsLiquidityEdgeCases(_ context.Context,
 
 	logBalance(t.t, nodes, assetID, "after failed payment (asset "+
 		"invoice, strict forwarding)")
+
+	// Edge case: Charlie negotiates a quote with Dave which has a low max
+	// amount (~170k sats). Then Charlie creates an invoice with a total
+	// amount slightly larger than the max allowed in the quote (200k sats).
+	// Erin will try to pay that invoice with sats, in shards of max size
+	// 80k sats. Dave will eventually stop forwarding HTLCs as the RFQ HTLC
+	// tracking mechanism should stop them from being forwarded, as they
+	// violate the maximum allowed amount of the quote.
+
+	// Charlie starts by negotiating the quote.
+	res, err := charlieTap.RfqClient.AddAssetBuyOrder(
+		ctxb, &rfqrpc.AddAssetBuyOrderRequest{
+			AssetSpecifier: &rfqrpc.AssetSpecifier{
+				Id: &rfqrpc.AssetSpecifier_AssetId{
+					AssetId: assetID,
+				},
+			},
+			AssetMaxAmt:    10_000,
+			Expiry:         uint64(time.Now().Add(time.Hour).Unix()),
+			PeerPubKey:     dave.PubKey[:],
+			TimeoutSeconds: 10,
+		},
+	)
+	require.NoError(t.t, err)
+
+	quote, ok := res.Response.(*rfqrpc.AddAssetBuyOrderResponse_AcceptedQuote)
+	require.True(t.t, ok)
+
+	// We now manually add the invoice in order to inject the above,
+	// manually generated, quote.
+	iResp, err := charlie.AddInvoice(ctxb, &lnrpc.Invoice{
+		Memo:       "",
+		Value:      200_000,
+		RPreimage:  bytes.Repeat([]byte{11}, 32),
+		CltvExpiry: 60,
+		RouteHints: []*lnrpc.RouteHint{
+			&lnrpc.RouteHint{
+				HopHints: []*lnrpc.HopHint{
+					&lnrpc.HopHint{
+						NodeId: dave.PubKeyStr,
+						ChanId: quote.AcceptedQuote.Scid,
+					},
+				},
+			},
+		},
+	})
+	require.NoError(t.t, err)
+
+	// Now Erin tries to pay the invoice. Since the multipart payment will
+	// have some of its shards failing the pathfinding logic will keep going
+	// and we won't see a payment failure but a timeout. If a final outcome
+	// is not produced within a reasonable amount of time, we assume the
+	// payment is still trying to find a route, therefore the HTLC rejection
+	// works.
+	timeoutChan = time.After(PaymentTimeout / 2)
+	done = make(chan bool, 1)
+
+	ctxc, cancel := context.WithCancel(context.Background())
+
+	//nolint:lll
+	go func() {
+		// payInvoiceWithSatoshi(t.t, erin, iResp, lnrpc.Payment_FAILED)
+		sendReq := &routerrpc.SendPaymentRequest{
+			PaymentRequest:   iResp.PaymentRequest,
+			TimeoutSeconds:   int32(PaymentTimeout.Seconds()),
+			MaxShardSizeMsat: 80_000_000,
+			FeeLimitMsat:     1_000_000,
+		}
+		stream, err := erin.RouterClient.SendPaymentV2(ctxc, sendReq)
+		if err == nil {
+			_, _ = getPaymentResult(stream)
+		}
+
+		done <- true
+	}()
+
+	select {
+	case <-done:
+		t.Fatalf("Payment should not produce a final outcome")
+
+	case <-timeoutChan:
+		cancel()
+	}
+
+	logBalance(t.t, nodes, assetID, "after htlc track")
 }
 
 // testCustomChannelsBalanceConsistency is a test that test the balance of nodes