client: persist generated invoices for tip receiving

client/client.go

@@ -1123,5 +1123,8 @@ func (c *Client) Run(ctx context.Context) error {
 	// Reload cached RGCMs.
 	g.Go(func() error { return c.loadCachedRGCMs(gctx) })
 
+	// Restart tracking tip receiving.
+	g.Go(func() error { return c.restartTrackGeneratedTipInvoices(gctx) })
+
 	return g.Wait()
 }

client/client_payments.go

@@ -97,6 +97,51 @@ func (c *Client) TipUser(uid UserID, dcrAmount float64, maxAttempts int32) error
 	return nil
 }
 
+// trackGeneratedTipInvoice tracks an invoice generated by the local client for
+// a remote tip payment. This blocks until the invoice is paid or expires.
+func (c *Client) trackGeneratedTipInvoice(ctx context.Context, uid clientintf.UserID, invoice string,
+	wantMAtoms int64) {
+
+	var err error
+	defer func() {
+		if err != nil && !errors.Is(err, context.Canceled) {
+			c.log.Errorf("Unable to handle callback for paid invoice: %v", err)
+		}
+	}()
+
+	// Wait until invoice is settled or expires.
+	receivedMAtoms, err := c.pc.TrackInvoice(ctx, invoice, wantMAtoms)
+	if errors.Is(err, clientintf.ErrInvoiceExpired) {
+		err = c.db.Update(ctx, func(tx clientdb.ReadWriteTx) error {
+			return c.db.MarkGeneratedTipInvoiceExpired(tx, uid, invoice)
+		})
+		return
+	}
+	if err != nil {
+		return
+	}
+
+	// Invoice settled. Update DB and notify UI.
+	ru, err := c.rul.byID(uid)
+	if err != nil {
+		return
+	}
+
+	dcrAmt := float64(receivedMAtoms) / 1e11
+	ru.log.Infof("Received %f DCR as tip", dcrAmt)
+	err = c.dbUpdate(func(tx clientdb.ReadWriteTx) error {
+		if err := c.db.RecordUserPayEvent(tx, uid, "tip", receivedMAtoms, 0); err != nil {
+			return err
+		}
+		return c.db.MarkGeneratedTipInvoiceReceived(tx, uid, invoice, receivedMAtoms)
+	})
+	if err != nil {
+		return
+	}
+
+	c.ntfns.notifyTipReceived(ru, receivedMAtoms)
+}
+
 func (c *Client) handleGetInvoice(ru *RemoteUser, getInvoice rpc.RMGetInvoice) error {
 
 	// Helper to reply with an error.
@@ -120,21 +165,9 @@ func (c *Client) handleGetInvoice(ru *RemoteUser, getInvoice rpc.RMGetInvoice) e
 		return err
 	}
 
-	cb := func(receivedMAtoms int64) {
-		dcrAmt := float64(receivedMAtoms) / 1e11
-		ru.log.Infof("Received %f DCR as tip", dcrAmt)
-		err := c.dbUpdate(func(tx clientdb.ReadWriteTx) error {
-			return c.db.RecordUserPayEvent(tx, ru.ID(), "tip", receivedMAtoms, 0)
-		})
-		if err != nil {
-			c.log.Warnf("Error while updating DB to store tip payment status: %v", err)
-		}
-		c.ntfns.notifyTipReceived(ru, receivedMAtoms)
-	}
-
 	amountMAtoms := int64(getInvoice.MilliAtoms)
 	dcrAmount := float64(amountMAtoms) / 1e11
-	inv, err := c.pc.GetInvoice(c.ctx, amountMAtoms, cb)
+	inv, err := c.pc.GetInvoice(c.ctx, amountMAtoms, nil)
 	if err != nil {
 		c.ntfns.notifyInvoiceGenFailed(ru, dcrAmount, err)
 		replyWithErr(rpc.ErrUnableToGenerateInvoice)
@@ -155,14 +188,23 @@ func (c *Client) handleGetInvoice(ru *RemoteUser, getInvoice rpc.RMGetInvoice) e
 			dcrAmount)
 	}
 
+	// Persist the generated invoice.
+	err = c.dbUpdate(func(tx clientdb.ReadWriteTx) error {
+		return c.db.StoreGeneratedTipInvoice(tx, ru.ID(), inv, amountMAtoms)
+	})
+	if err != nil {
+		return err
+	}
+
+	go c.trackGeneratedTipInvoice(c.ctx, ru.ID(), inv, amountMAtoms)
 	c.ntfns.notifyTipUserInvoiceGenerated(ru, getInvoice.Tag, inv)
 
 	// Send reply.
 	reply := rpc.RMInvoice{
 		Invoice: inv,
 		Tag:     getInvoice.Tag,
 	}
-	return ru.sendRM(reply, "getinvoicereply")
+	return c.sendWithSendQ("getinvoicereply", reply, ru.ID())
 }
 
 // handleTipUserPaymentResult takes the appropriate action after a payment
@@ -732,3 +774,33 @@ func (c *Client) ClearPayStats(uid *UserID) error {
 		return c.db.ClearPayStats(tx, uid)
 	})
 }
+
+// restartTrackGeneratedTipInvoices restarts tracking of invoices generated
+// for tipping.
+func (c *Client) restartTrackGeneratedTipInvoices(ctx context.Context) error {
+	<-c.abLoaded
+
+	// List outstanding invoices.
+	var invoices []clientdb.GeneratedInvoiceForTip
+	err := c.db.View(ctx, func(tx clientdb.ReadTx) error {
+		var err error
+		invoices, err = c.db.ListGeneratedTipInvoices(tx)
+		return err
+	})
+	if err != nil {
+		return err
+	}
+
+	if len(invoices) == 0 {
+		c.log.Debugf("No generated invoices to track for receiving tips")
+	} else {
+		c.log.Infof("Tracking %d invoices for receiving tips", len(invoices))
+	}
+
+	// Check ones that are expired.
+	for _, inv := range invoices {
+		go c.trackGeneratedTipInvoice(ctx, inv.UID, inv.Invoice, int64(inv.MilliAtoms))
+	}
+
+	return nil
+}

client/clientdb/fscdb.go

@@ -58,6 +58,9 @@ const (
 
 	pageSessionsDir         = "pagesessions"
 	pageSessionOverviewFile = "overview.json"
+	genTipInvoicesFile      = "generated-tip-invoices.json"
+	recvTipInvoicesFile     = "received-tip-invoices.json"
+	expiredTipInvoicesFile  = "expired-tip-invoices.json"
 )
 
 var (

client/clientdb/interface.go

@@ -388,6 +388,13 @@ type UnkxdUserInfo struct {
 	AddedToGCTime *time.Time `json:"added_to_gc_time"`
 }
 
+type GeneratedInvoiceForTip struct {
+	UID        UserID    `json:"uid"`
+	Created    time.Time `json:"created"`
+	Invoice    string    `json:"invoice"`
+	MilliAtoms uint64    `json:"milli_atoms"`
+}
+
 var (
 	ErrLocalIDEmpty         = errors.New("local ID is not initialized")
 	ErrServerIDEmpty        = errors.New("server ID is not known")

client/clientdb/payments.go

@@ -1,6 +1,7 @@
 package clientdb
 
 import (
+	"encoding/json"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -184,3 +185,140 @@ func (db *DB) ListOldestValidTipUserAttempts(tx ReadTx, maxLifetime time.Duratio
 
 	return res, nil
 }
+
+// StoreGeneratedTipInvoice stores the specified invoice as one generated for
+// the remote client to pay the local client for a tip.
+func (db *DB) StoreGeneratedTipInvoice(tx ReadWriteTx, uid UserID, invoice string, amountMAtoms int64) error {
+	fname := filepath.Join(db.root, inboundDir, uid.String(), genTipInvoicesFile)
+	data := GeneratedInvoiceForTip{
+		UID:        uid,
+		Created:    time.Now(),
+		Invoice:    invoice,
+		MilliAtoms: uint64(amountMAtoms),
+	}
+	return db.appendToJsonFile(fname, data)
+}
+
+// ListGeneratedTipInvoices lists all invoices generated for tipping from all
+// users.
+func (db *DB) ListGeneratedTipInvoices(tx ReadTx) ([]GeneratedInvoiceForTip, error) {
+	pattern := filepath.Join(db.root, inboundDir, "*", genTipInvoicesFile)
+	files, err := filepath.Glob(pattern)
+	if err != nil {
+		return nil, err
+	}
+
+	var res []GeneratedInvoiceForTip
+	for _, fname := range files {
+		f, err := os.Open(fname)
+		if err != nil {
+			db.log.Warnf("Unable to open file %s for reading "+
+				"generated tip invoices: %v", fname, err)
+			continue
+		}
+
+		dec := json.NewDecoder(f)
+		for {
+			var inv GeneratedInvoiceForTip
+			err := dec.Decode(&inv)
+			if err != nil {
+				break
+			}
+			res = append(res, inv)
+		}
+		_ = f.Close()
+	}
+
+	return res, nil
+}
+
+// removeFromGeneratedTipInvoice removes the invoice from the list of invoices
+// generated for the remote user to tip the local client.
+//
+// Returns the data corresponding to the invoice.
+func (db *DB) removeFromGeneratedTipInvoice(uid UserID, invoice string) (GeneratedInvoiceForTip, error) {
+	var data GeneratedInvoiceForTip
+
+	// Open file.
+	genFname := filepath.Join(db.root, inboundDir, uid.String(), genTipInvoicesFile)
+	f, err := os.Open(genFname)
+	if os.IsNotExist(err) {
+		return data, ErrNotFound
+	}
+	if err != nil {
+		return data, err
+	}
+
+	// Read list of existing generated invoices, adding to res[] all but
+	// the target one.
+	var res []GeneratedInvoiceForTip
+	found := false
+	dec := json.NewDecoder(f)
+	for {
+		var inv GeneratedInvoiceForTip
+		err := dec.Decode(&inv)
+		if err != nil {
+			break
+		}
+		if inv.Invoice == invoice {
+			found = true
+			data = inv
+		} else {
+			res = append(res, inv)
+		}
+	}
+	if err := f.Close(); err != nil {
+		return data, err
+	}
+
+	if !found {
+		return data, ErrNotFound
+	}
+
+	// Either remove the file (if no other invoices remain) or rewrite the
+	// file with the remaining invoices.
+	if len(res) == 0 {
+		err := removeIfExists(genFname)
+		if err != nil {
+			return data, err
+		}
+	} else {
+		f, err := os.Create(genFname)
+		if err != nil {
+			return data, err
+		}
+		enc := json.NewEncoder(f)
+		for _, inv := range res {
+			if err := enc.Encode(inv); err != nil {
+				return data, err
+			}
+		}
+		if err := f.Close(); err != nil {
+			return data, err
+		}
+	}
+
+	return data, nil
+}
+
+// MarkGeneratedTipInvoiceExpired marks an invoice generated for tipping as
+// having expired.
+func (db *DB) MarkGeneratedTipInvoiceExpired(tx ReadWriteTx, uid UserID, invoice string) error {
+	data, err := db.removeFromGeneratedTipInvoice(uid, invoice)
+	if err != nil {
+		return err
+	}
+	expiredFname := filepath.Join(db.root, inboundDir, uid.String(), expiredTipInvoicesFile)
+	return db.appendToJsonFile(expiredFname, data)
+}
+
+// MarkGeneratedTipInvoiceReceived marks an invoice generated for tipping as
+// having been received (i.e. invoice was paid).
+func (db *DB) MarkGeneratedTipInvoiceReceived(tx ReadWriteTx, uid UserID, invoice string, receivedMAtoms int64) error {
+	data, err := db.removeFromGeneratedTipInvoice(uid, invoice)
+	if err != nil {
+		return err
+	}
+	recvFname := filepath.Join(db.root, inboundDir, uid.String(), recvTipInvoicesFile)
+	return db.appendToJsonFile(recvFname, data)
+}

client/clientintf/interface.go

@@ -102,6 +102,7 @@ type PaymentClient interface {
 	GetInvoice(context.Context, int64, func(int64)) (string, error)
 	DecodeInvoice(context.Context, string) (DecodedInvoice, error)
 	IsInvoicePaid(context.Context, int64, string) error
+	TrackInvoice(context.Context, string, int64) (int64, error)
 	IsPaymentCompleted(context.Context, string) (int64, error)
 }
 
@@ -124,6 +125,9 @@ func (pc FreePaymentClient) IsInvoicePaid(context.Context, int64, string) error
 func (pc FreePaymentClient) IsPaymentCompleted(context.Context, string) (int64, error) {
 	return 0, nil
 }
+func (pc FreePaymentClient) TrackInvoice(ctx context.Context, inv string, minMAtoms int64) (int64, error) {
+	return 0, nil
+}
 
 // farFutureExpiryTime is a time far in the future for the expiration of free
 // invoices.
@@ -179,6 +183,7 @@ type ReceivedGCMsg struct {
 var (
 	ErrSubsysExiting             = errors.New("subsys exiting")
 	ErrInvoiceInsufficientlyPaid = errors.New("invoice insufficiently paid")
+	ErrInvoiceExpired            = errors.New("invoice expired")
 	ErrOnboardNoFunds            = errors.New("onboarding invite does not have any funds")
 	ErrRetriablePayment          = errors.New("retriable payment error")
 )

client/internal/lowlevel/rmq.go

@@ -289,7 +289,7 @@ func (q *RMQ) isRVInvoicePaid(ctx context.Context, rv RVID, amt int64, pc client
 	// Check invoice payment actually completed.
 	fees, err := pc.IsPaymentCompleted(ctx, payInvoice)
 	if err != nil {
-		q.log.Warnf("Push payment attempt stored failed IsInvoicePaid "+
+		q.log.Warnf("Push payment attempt stored failed IsPaymentCompleted"+
 			"check: %v", err)
 		return 0, nil
 	}