feat: add budget warning event, rename app events (#813)

README.md

@@ -486,6 +486,9 @@ Internally Alby Hub uses a basic implementation of the pubsub messaging pattern
     - `nwc_payment_failed` - failed to make a lightning payment
     - `nwc_payment_sent` - successfully made a lightning payment
     - `nwc_payment_received` - received a lightning payment
+    - `nwc_budget_warning` - successfully made a lightning payment, but budget is nearly exceeded
+    - `nwc_app_created` - a new app connection was created
+    - `nwc_app_deleted` - a new app connection was deleted
     - `nwc_lnclient_*` - underlying LNClient events, consumed only by the transactions service.
 
 ### NIP-47 Handlers

apps/apps_service.go

@@ -117,7 +117,7 @@ func (svc *appsService) CreateApp(name string, pubkey string, maxAmountSat uint6
 	}
 
 	svc.eventPublisher.Publish(&events.Event{
-		Event: "app_created",
+		Event: "nwc_app_created",
 		Properties: map[string]interface{}{
 			"name": name,
 			"id":   app.ID,
@@ -134,7 +134,7 @@ func (svc *appsService) DeleteApp(app *db.App) error {
 		return err
 	}
 	svc.eventPublisher.Publish(&events.Event{
-		Event: "app_deleted",
+		Event: "nwc_app_deleted",
 		Properties: map[string]interface{}{
 			"name": app.Name,
 			"id":   app.ID,

service/create_app_consumer.go

@@ -17,7 +17,7 @@ type createAppConsumer struct {
 
 // When a new app is created, subscribe to it on the relay
 func (s *createAppConsumer) ConsumeEvent(ctx context.Context, event *events.Event, globalProperties map[string]interface{}) {
-	if event.Event != "app_created" {
+	if event.Event != "nwc_app_created" {
 		return
 	}
 

service/delete_app_consumer.go

@@ -19,7 +19,7 @@ type deleteAppConsumer struct {
 // When an app is deleted, unsubscribe from events for that app on the relay
 // and publish a deletion event for that app's info event
 func (s *deleteAppConsumer) ConsumeEvent(ctx context.Context, event *events.Event, globalProperties map[string]interface{}) {
-	if event.Event != "app_deleted" {
+	if event.Event != "nwc_app_deleted" {
 		return
 	}
 	properties, ok := event.Properties.(map[string]interface{})

service/start.go

@@ -90,7 +90,7 @@ func (svc *service) startNostr(ctx context.Context) error {
 			}).Info("Connected to the relay")
 			waitToReconnectSeconds = 0
 
-			// register a subscriber for events of "app_created" which handles creation of nostr subscription for new app
+			// register a subscriber for events of "nwc_app_created" which handles creation of nostr subscription for new app
 			if createAppEventListener != nil {
 				svc.eventPublisher.RemoveSubscriber(createAppEventListener)
 			}
@@ -175,7 +175,7 @@ func (svc *service) startAppWalletSubscription(ctx context.Context, relay *nostr
 		return err
 	}
 
-	// register a subscriber for "app_deleted" events, which handles nostr subscription cancel and nip47 info event deletion
+	// register a subscriber for "nwc_app_deleted" events, which handles nostr subscription cancel and nip47 info event deletion
 	deleteEventSubscriber := deleteAppConsumer{nostrSubscription: sub, walletPubkey: appWalletPubKey, svc: svc, relay: relay}
 	svc.eventPublisher.RegisterSubscriber(&deleteEventSubscriber)
 

tests/create_app.go

@@ -1,12 +1,13 @@
 package tests
 
 import (
+	"time"
+
 	db "github.com/getAlby/hub/db"
 	"github.com/getAlby/hub/events"
 	"github.com/nbd-wtf/go-nostr"
 	"github.com/nbd-wtf/go-nostr/nip04"
 	"gorm.io/gorm"
-	"time"
 )
 
 func CreateApp(svc *TestService) (app *db.App, ss []byte, err error) {
@@ -57,7 +58,7 @@ func CreateLegacyApp(svc *TestService, senderPrivkey string) (app *db.App, ss []
 	}
 
 	svc.EventPublisher.Publish(&events.Event{
-		Event: "app_created",
+		Event: "nwc_app_created",
 		Properties: map[string]interface{}{
 			"name": "test",
 			"id":   app.ID,

transactions/transactions_service.go

@@ -978,9 +978,49 @@ func (svc *transactionsService) markTransactionSettled(tx *gorm.DB, dbTransactio
 		Properties: dbTransaction,
 	})
 
+	if dbTransaction.Type == constants.TRANSACTION_TYPE_OUTGOING && dbTransaction.AppId != nil {
+		svc.checkBudgetUsage(dbTransaction)
+	}
+
 	return dbTransaction, nil
 }
 
+func (svc *transactionsService) checkBudgetUsage(dbTransaction *db.Transaction) {
+	var app db.App
+	result := svc.db.Limit(1).Find(&app, &db.App{
+		ID: *dbTransaction.AppId,
+	})
+	if result.RowsAffected == 0 {
+		logger.Logger.WithField("app_id", dbTransaction.AppId).Error("failed to find app by id")
+		return
+	}
+	if app.Isolated {
+		return
+	}
+
+	var appPermission db.AppPermission
+	result = svc.db.Limit(1).Find(&appPermission, &db.AppPermission{
+		AppId: app.ID,
+		Scope: constants.PAY_INVOICE_SCOPE,
+	})
+	if result.RowsAffected == 0 {
+		logger.Logger.WithField("app_id", dbTransaction.AppId).Error("failed to find pay_invoice scope")
+		return
+	}
+
+	budgetUsage := queries.GetBudgetUsageSat(svc.db, &appPermission)
+	warningUsage := uint64(math.Floor(float64(appPermission.MaxAmountSat) * 0.8))
+	if budgetUsage >= warningUsage && budgetUsage-dbTransaction.AmountMsat/1000 < warningUsage {
+		svc.eventPublisher.Publish(&events.Event{
+			Event: "nwc_budget_warning",
+			Properties: map[string]interface{}{
+				"name": app.Name,
+				"id":   app.ID,
+			},
+		})
+	}
+}
+
 func (svc *transactionsService) markPaymentFailed(tx *gorm.DB, dbTransaction *db.Transaction, reason string) error {
 	var existingTransaction db.Transaction
 	result := tx.Limit(1).Find(&existingTransaction, &db.Transaction{