revert "a function to send an event directly to a specific connection."

this reverts commit e9c9d0c3a7 because it is not a good idea and probably useless.

docs/cookbook/auth.md

@@ -60,3 +60,26 @@ relay.RejectFilter = append(relay.RejectFilter, func(ctx context.Context, filter
 	}
 })
 ```
+
+## Reacting to a successful authentication
+
+Each `khatru.WebSocket` object has an `.Authed` channel that is closed whenever that connection performs a successful authentication.
+
+You can use that to emulate a listener for these events in case you want to keep track of who is authenticating in real time and not only check it when they request for something.
+
+```go
+	relay.OnConnect = append(relay.OnConnect,
+		khatru.RequestAuth,
+		func(ctx context.Context) {
+			go func(ctx context.Context) {
+				conn := khatru.GetConnection(ctx)
+				select {
+				case <-ctx.Done():
+					fmt.Println("connection closed")
+				case <-conn.Authed:
+					fmt.Println("authenticated as", conn.AuthedPublicKey)
+				}
+			}(ctx)
+		},
+	)
+```

docs/use-cases.md

@@ -10,6 +10,7 @@
 * [song](https://git.fiatjaf.com/song), a personal git server that comes with an embedded relay dedicated to dealing with [NIP-34](https://nips.nostr.com/34) git-related Nostr events
 * [relay29](https://github.com/fiatjaf/relay29), a relay that powers most of the [NIP-29](https://nips.nostr.com/29) Nostr groups ecosystem
 * [fiatjaf.com](https://fiatjaf.com), a personal website that serves the same content as HTML but also as Nostr events.
+* [gm-relay](https://github.com/ptrio42/gm-relay), a relay that only accepts GM notes once a day.
 
 ## Other possible use cases
 

get-started.go

@@ -53,6 +53,7 @@ func (rl *Relay) Shutdown(ctx context.Context) {
 	defer rl.clientsMutex.Unlock()
 	for ws := range rl.clients {
 		ws.conn.WriteControl(websocket.CloseMessage, nil, time.Now().Add(time.Second))
+		ws.cancel()
 		ws.conn.Close()
 	}
 	clear(rl.clients)

handlers.go

@@ -58,6 +58,7 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 		Request:   r,
 		Challenge: hex.EncodeToString(challenge),
 	}
+	ws.Context, ws.cancel = context.WithCancel(context.Background())
 
 	rl.clientsMutex.Lock()
 	rl.clients[ws] = make([]listenerSpec, 0, 2)
@@ -77,7 +78,8 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 
 		ticker.Stop()
 		cancel()
-		conn.Close()
+		ws.cancel()
+		ws.conn.Close()
 
 		rl.removeClientAndListeners(ws)
 	}
@@ -85,10 +87,10 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 	go func() {
 		defer kill()
 
-		conn.SetReadLimit(rl.MaxMessageSize)
-		conn.SetReadDeadline(time.Now().Add(rl.PongWait))
-		conn.SetPongHandler(func(string) error {
-			conn.SetReadDeadline(time.Now().Add(rl.PongWait))
+		ws.conn.SetReadLimit(rl.MaxMessageSize)
+		ws.conn.SetReadDeadline(time.Now().Add(rl.PongWait))
+		ws.conn.SetPongHandler(func(string) error {
+			ws.conn.SetReadDeadline(time.Now().Add(rl.PongWait))
 			return nil
 		})
 
@@ -97,7 +99,7 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 		}
 
 		for {
-			typ, message, err := conn.ReadMessage()
+			typ, message, err := ws.conn.ReadMessage()
 			if err != nil {
 				if websocket.IsUnexpectedCloseError(
 					err,
@@ -109,6 +111,7 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 				) {
 					rl.Log.Printf("unexpected close error from %s: %v\n", r.Header.Get("X-Forwarded-For"), err)
 				}
+				ws.cancel()
 				return
 			}
 
@@ -127,7 +130,7 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 				switch env := envelope.(type) {
 				case *nostr.EventEnvelope:
 					// check id
-					if env.Event.CheckID() {
+					if !env.Event.CheckID() {
 						ws.WriteJSON(nostr.OKEnvelope{EventID: env.Event.ID, OK: false, Reason: "invalid: id is computed incorrectly"})
 						return
 					}

websocket.go

@@ -1,6 +1,7 @@
 package khatru
 
 import (
+	"context"
 	"net/http"
 	"sync"
 
@@ -14,6 +15,10 @@ type WebSocket struct {
 	// original request
 	Request *http.Request
 
+	// this Context will be canceled whenever the connection is closed from the client side or server-side.
+	Context context.Context
+	cancel  context.CancelFunc
+
 	// nip42
 	Challenge       string
 	AuthedPublicKey string