only upserting kind0 event if created at is newer

readme.md

@@ -1,6 +1,6 @@
 # GRAIN 🌾
 
-**Go Relay Archetecture for Implementing Nostr**
+## Go Relay Archetecture for Implementing Nostr
 
 GRAIN is an open-source Nostr relay implementation written in Go. This project aims to provide a robust and efficient Nostr relay that currently supports the NIP-01 of the nostr protocol.
 
@@ -29,8 +29,7 @@ cp config.example.yml config.yml
 
 ### TODO
 
-- Handle more kinds
-- Fix Request Query to handle and serve unhandled events by kind
+- Explicitely Handle more kinds
 - create whitelist/blacklist functionality
   for:
   - valid nip05 domain

relay/handlers/event.go

@@ -54,7 +54,7 @@ func HandleKind(ctx context.Context, evt relay.Event, ws *websocket.Conn) {
 	var err error
 	switch evt.Kind {
 	case 0:
-		err = kinds.HandleKind0(ctx, evt, collection)
+		err = kinds.HandleKind0(ctx, evt, collection, ws)
 	case 1:
 		err = kinds.HandleKind1(ctx, evt, collection)
 	default:

relay/kinds/kind0.go

@@ -2,18 +2,35 @@ package kinds
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
-
 	relay "grain/relay/types"
 
 	"go.mongodb.org/mongo-driver/bson"
 	"go.mongodb.org/mongo-driver/mongo"
 	"go.mongodb.org/mongo-driver/mongo/options"
+	"golang.org/x/net/websocket"
 )
 
-func HandleKind0(ctx context.Context, evt relay.Event, collection *mongo.Collection) error {
-	// Replace the existing event if it has the same pubkey
+func HandleKind0(ctx context.Context, evt relay.Event, collection *mongo.Collection, ws *websocket.Conn) error {
+	// Find the existing event with the same pubkey
 	filter := bson.M{"pubkey": evt.PubKey}
+	var existingEvent relay.Event
+	err := collection.FindOne(ctx, filter).Decode(&existingEvent)
+	if err != nil && err != mongo.ErrNoDocuments {
+		return fmt.Errorf("Error finding existing event: %v", err)
+	}
+
+	// If an existing event is found, compare the created_at times
+	if err != mongo.ErrNoDocuments {
+		if existingEvent.CreatedAt >= evt.CreatedAt {
+			// If the existing event is newer or the same, respond with a NOTICE
+			sendNotice(ws, evt.PubKey, "relay already has a newer kind 0 event for this pubkey")
+			return nil
+		}
+	}
+
+	// Replace the existing event if it has the same pubkey
 	update := bson.M{
 		"$set": bson.M{
 			"id":         evt.ID,
@@ -26,7 +43,7 @@ func HandleKind0(ctx context.Context, evt relay.Event, collection *mongo.Collect
 	}
 
 	opts := options.Update().SetUpsert(true) // Insert if not found
-	_, err := collection.UpdateOne(ctx, filter, update, opts)
+	_, err = collection.UpdateOne(ctx, filter, update, opts)
 	if err != nil {
 		return fmt.Errorf("Error updating/inserting event kind 0 into MongoDB: %v", err)
 	}
@@ -34,3 +51,9 @@ func HandleKind0(ctx context.Context, evt relay.Event, collection *mongo.Collect
 	fmt.Println("Upserted event kind 0 into MongoDB:", evt.ID)
 	return nil
 }
+
+func sendNotice(ws *websocket.Conn, pubKey, message string) {
+	notice := []interface{}{"NOTICE", pubKey, message}
+	noticeBytes, _ := json.Marshal(notice)
+	websocket.Message.Send(ws, string(noticeBytes))
+}