use EventEmitter

packages/nostr/src/client/index.ts

@@ -3,11 +3,15 @@ import { EventId, Event, EventKind, SignedEvent, RawEvent } from "../event"
 import { PrivateKey, PublicKey } from "../keypair"
 import { Conn, IncomingKind, OutgoingKind } from "./conn"
 import * as secp from "@noble/secp256k1"
+import { EventEmitter } from "./emitter"
 
 /**
  * A nostr client.
+ *
+ * TODO Document the events here
+ * TODO Move all this to that file and add the newListener and removeListener events there as well
  */
-export class Nostr {
+export class Nostr extends EventEmitter {
   // TODO NIP-44 AUTH, leave this for later
   /**
    * Open connections to relays.
@@ -19,39 +23,6 @@ export class Nostr {
    */
   readonly #subscriptions: Map<string, Filters[]> = new Map()
 
-  #eventCallback?: EventCallback
-  #noticeCallback?: NoticeCallback
-  #errorCallback?: ErrorCallback
-
-  /**
-   * Add a new callback for received events.
-   */
-  on(on: "event", cb: EventCallback | undefined | null): void
-  /**
-   * Add a new callback for received notices.
-   */
-  on(on: "notice", cb: NoticeCallback | undefined | null): void
-  /**
-   * Add a new callback for errors.
-   */
-  on(on: "error", cb: ErrorCallback | undefined | null): void
-  // TODO Also add on: ("subscribed", subscriptionId) which checks "OK"/"NOTICE" and makes a callback?
-  // TODO Also add on: ("sent", eventId) which checks "OK"/"NOTICE" and makes a callback?
-  on(
-    on: "event" | "notice" | "error",
-    cb: EventCallback | NoticeCallback | ErrorCallback | undefined | null
-  ) {
-    if (on === "event") {
-      this.#eventCallback = (cb as EventCallback) ?? undefined
-    } else if (on === "notice") {
-      this.#noticeCallback = (cb as NoticeCallback) ?? undefined
-    } else if (on === "error") {
-      this.#errorCallback = (cb as ErrorCallback) ?? undefined
-    } else {
-      throw new Error(`unexpected input: ${on}`)
-    }
-  }
-
   /**
    * Open a connection and start communicating with a relay. This method recreates all existing
    * subscriptions on the new relay as well. If there is already an existing connection,
@@ -83,7 +54,8 @@ export class Nostr {
     conn.on("message", async (msg) => {
       try {
         if (msg.kind === IncomingKind.Event) {
-          this.#eventCallback?.(
+          this.emit(
+            "event",
             {
               signed: msg.signed,
               subscriptionId: msg.subscriptionId,
@@ -92,23 +64,23 @@ export class Nostr {
             this
           )
         } else if (msg.kind === IncomingKind.Notice) {
-          this.#noticeCallback?.(msg.notice, this)
+          this.emit("notice", msg.notice, this)
         } else {
           const err = new ProtocolError(`invalid message ${msg}`)
           try {
-            this.#errorCallback?.(err, this)
+            this.emit("error", err, this)
           } catch (err) {
             // Don't propagate errors from the error callback.
           }
         }
       } catch (err) {
-        this.#errorCallback?.(err, this)
+        this.emit("error", err, this)
       }
     })
 
     // Forward connection errors to the error callbacks.
     conn.on("error", (err) => {
-      this.#errorCallback?.(err, this)
+      this.emit("error", err, this)
     })
 
     // Resend existing subscriptions to this connection.
@@ -286,6 +258,7 @@ export class SubscriptionId {
   }
 }
 
+// TODO Rethink this type. Maybe it's not very idiomatic.
 /**
  * A prefix filter. These filters match events which have the appropriate prefix.
  * This also means that exact matches pass the filters. No special syntax is required.
@@ -322,13 +295,3 @@ export interface Filters {
   until?: Date
   limit?: number
 }
-
-export type EventCallback = (params: EventParams, nostr: Nostr) => unknown
-export type NoticeCallback = (notice: string, nostr: Nostr) => unknown
-export type ErrorCallback = (error: unknown, nostr: Nostr) => unknown
-
-export interface EventParams {
-  signed: SignedEvent
-  subscriptionId: SubscriptionId
-  raw: RawEvent
-}