setup basic pubkey relay assignment service

src/classes/subject.ts

@@ -87,6 +87,11 @@ export class Subject<Value> implements Connectable<Value> {
     }
     return this;
   }
+  disconnectAll() {
+    for (const [connectable, listener] of this.upstream) {
+      this.disconnect(connectable);
+    }
+  }
 }
 
 export class PersistentSubject<Value> extends Subject<Value> implements ConnectableApi<Value> {

src/hooks/use-fallback-user-relays.tsx

@@ -1,22 +1,17 @@
 import { useMemo } from "react";
-import { RelayConfig } from "../classes/relay";
 import { normalizeRelayConfigs } from "../helpers/relay";
-import { useUserContacts } from "./use-user-contacts";
-import { useUserRelays } from "./use-user-relays";
+import userRelaysFallbackService from "../services/user-relays-fallback";
+import { useReadRelayUrls } from "./use-client-relays";
+import useSubject from "./use-subject";
 
-export default function useFallbackUserRelays(pubkey: string, alwaysFetch = false) {
-  const contacts = useUserContacts(pubkey, [], alwaysFetch);
-  const userRelays = useUserRelays(pubkey, [], alwaysFetch);
+export default function useFallbackUserRelays(pubkey: string, additionalRelays: string[] = [], alwaysFetch = false) {
+  const readRelays = useReadRelayUrls(additionalRelays);
 
-  return useMemo(() => {
-    let relays: RelayConfig[] = userRelays?.relays ?? [];
+  const observable = useMemo(
+    () => userRelaysFallbackService.requestRelays(pubkey, readRelays, alwaysFetch),
+    [pubkey, readRelays.join("|"), alwaysFetch]
+  );
+  const userRelays = useSubject(observable);
 
-    // use the relays stored in contacts if there are no relay config
-    if (relays.length === 0 && contacts) {
-      relays = contacts.relays;
-    }
-
-    // normalize relay urls and remove bad ones
-    return normalizeRelayConfigs(relays);
-  }, [userRelays, contacts]);
+  return userRelays ? normalizeRelayConfigs(userRelays.relays) : [];
 }

src/services/pubkey-relay-assignment.ts

@@ -0,0 +1,115 @@
+import { RelayMode } from "../classes/relay";
+import Subject, { PersistentSubject } from "../classes/subject";
+import { SuperMap } from "../classes/super-map";
+import { unique } from "../helpers/array";
+import accountService from "./account";
+import clientRelaysService from "./client-relays";
+import relayScoreboardService from "./relay-scoreboard";
+import userContactsService, { UserContacts } from "./user-contacts";
+import { UserRelays } from "./user-relays";
+import userRelaysFallbackService from "./user-relays-fallback";
+
+type pubkey = string;
+type relay = string;
+
+class PubkeyRelayAssignmentService {
+  pubkeys = new Map<pubkey, relay[]>();
+  pubkeyRelays = new SuperMap<string, Subject<UserRelays>>(() => new Subject());
+  assignments = new PersistentSubject<Record<pubkey, relay[]>>({});
+
+  constructor() {
+    let sub: Subject<UserContacts>;
+
+    accountService.current.subscribe((account) => {
+      if (sub) {
+        sub.unsubscribe(this.handleUserContacts, this);
+      }
+      if (account) {
+        this.pubkeys.clear();
+        this.pubkeyRelays.clear();
+        const contactsSub = userContactsService.requestContacts(account.pubkey, account.relays ?? []);
+        contactsSub.subscribe(this.handleUserContacts, this);
+        sub = contactsSub;
+      }
+    });
+  }
+
+  private handleUserContacts(contacts: UserContacts) {
+    for (const pubkey of contacts.contacts) {
+      const relay = contacts.contactRelay[pubkey];
+      pubkeyRelayAssignmentService.addPubkey(pubkey, relay ? [relay] : []);
+    }
+  }
+
+  addPubkey(pubkey: string, relays: string[] = []) {
+    if (this.pubkeys.has(pubkey)) return;
+    this.pubkeys.set(pubkey, relays);
+
+    const readRelays = clientRelaysService.getReadUrls();
+    const subject = userRelaysFallbackService.requestRelays(pubkey, unique([...readRelays, ...relays]));
+    this.pubkeyRelays.set(pubkey, subject);
+    // subject.subscribe(this.updateAssignments, this);
+  }
+  removePubkey(pubkey: string) {
+    if (!this.pubkeys.has(pubkey)) return;
+
+    this.pubkeys.delete(pubkey);
+    this.pubkeyRelays.delete(pubkey);
+  }
+
+  updateAssignments() {
+    const allRelays = new Set<relay>();
+
+    for (const [pubkey, userRelays] of this.pubkeyRelays) {
+      if (!userRelays.value) continue;
+      for (const relayConfig of userRelays.value.relays) {
+        // only use relays the users are writing to
+        if (relayConfig.mode & RelayMode.WRITE) {
+          allRelays.add(relayConfig.url);
+        }
+      }
+    }
+
+    const relayScores = new Map<relay, number>();
+    for (const relay of allRelays) {
+      relayScores.set(relay, relayScoreboardService.getRelayScore(relay));
+    }
+
+    const readRelays = clientRelaysService.getReadUrls();
+    const assignments: Record<pubkey, relay[]> = {};
+    for (const [pubkey] of this.pubkeys) {
+      let userRelays =
+        this.pubkeyRelays
+          .get(pubkey)
+          .value?.relays.filter((r) => r.mode & RelayMode.WRITE)
+          .map((r) => r.url) ?? [];
+
+      if (userRelays.length === 0) userRelays = Array.from(readRelays);
+
+      const rankedOptions = Array.from(userRelays).sort(
+        (a, b) => (relayScores.get(b) ?? 0) - (relayScores.get(a) ?? 0)
+      );
+
+      assignments[pubkey] = rankedOptions.slice(0, 3);
+
+      for (const relay of assignments[pubkey]) {
+        relayScores.set(relay, (relayScores.get(relay) ?? 0) + 1);
+      }
+    }
+
+    this.assignments.next(assignments);
+  }
+}
+
+const pubkeyRelayAssignmentService = new PubkeyRelayAssignmentService();
+
+setInterval(() => {
+  pubkeyRelayAssignmentService.updateAssignments();
+}, 1000 * 5);
+
+if (import.meta.env.DEV) {
+  //@ts-ignore
+  window.pubkeyRelayAssignmentService = pubkeyRelayAssignmentService;
+}
+
+export default pubkeyRelayAssignmentService;

src/services/user-contacts.ts

@@ -5,6 +5,7 @@ import { CachedPubkeyEventRequester } from "../classes/cached-pubkey-event-reque
 import { SuperMap } from "../classes/super-map";
 import Subject from "../classes/subject";
 import { RelayConfig, RelayMode } from "../classes/relay";
+import { normalizeRelayConfigs } from "../helpers/relay";
 
 export type UserContacts = {
   pubkey: string;
@@ -15,7 +16,7 @@ export type UserContacts = {
 };
 
 type RelayJson = Record<string, { read: boolean; write: boolean }>;
-function relayJsonToRelayConfig(relayJson: RelayJson) {
+function relayJsonToRelayConfig(relayJson: RelayJson): RelayConfig[] {
   try {
     return Array.from(Object.entries(relayJson)).map(([url, opts]) => ({
       url,
@@ -27,7 +28,7 @@ function relayJsonToRelayConfig(relayJson: RelayJson) {
 
 function parseContacts(event: NostrEvent): UserContacts {
   const relayJson = safeJson(event.content, {}) as RelayJson;
-  const relays = relayJsonToRelayConfig(relayJson);
+  const relays = normalizeRelayConfigs(relayJsonToRelayConfig(relayJson));
 
   const pubkeys = event.tags.filter(isPTag).map((tag) => tag[1]);
   const contactRelay = event.tags.filter(isPTag).reduce((dir, tag) => {

src/services/user-metadata.ts

@@ -21,6 +21,9 @@ class UserMetadataService {
   }
 
   private parsedSubjects = new SuperMap<string, Subject<Kind0ParsedContent>>(() => new Subject<Kind0ParsedContent>());
+  getSubject(pubkey: string) {
+    return this.parsedSubjects.get(pubkey);
+  }
   requestMetadata(pubkey: string, relays: string[], alwaysRequest = false) {
     const sub = this.parsedSubjects.get(pubkey);
     const requestSub = this.requester.requestEvent(pubkey, relays, alwaysRequest);

src/services/user-relays-fallback.ts

@@ -0,0 +1,41 @@
+import Subject from "../classes/subject";
+import { normalizeRelayConfigs } from "../helpers/relay";
+import userContactsService from "./user-contacts";
+import userRelaysService, { UserRelays } from "./user-relays";
+
+class UserRelaysFallbackService {
+  subjects = new Map<string, Subject<UserRelays>>();
+
+  requestRelays(pubkey: string, relays: string[], alwaysFetch = false) {
+    let subject = this.subjects.get(pubkey);
+    if (!subject) {
+      subject = new Subject();
+      this.subjects.set(pubkey, subject);
+
+      subject.connectWithHandler(userRelaysService.getSubject(pubkey), (userRelays, next, value) => {
+        if (!value || userRelays.created_at > value.created_at) {
+          next(userRelays);
+        }
+      });
+      subject.connectWithHandler(userContactsService.getSubject(pubkey), (contacts, next, value) => {
+        if (!value || contacts.created_at > value.created_at) {
+          next({ pubkey: contacts.pubkey, relays: contacts.relays, created_at: contacts.created_at });
+        }
+      });
+    }
+
+    userRelaysService.requestRelays(pubkey, relays, alwaysFetch);
+    userContactsService.requestContacts(pubkey, relays, alwaysFetch);
+
+    return subject;
+  }
+}
+
+const userRelaysFallbackService = new UserRelaysFallbackService();
+
+if (import.meta.env.DEV) {
+  // @ts-ignore
+  window.userRelaysFallbackService = userRelaysFallbackService;
+}
+
+export default userRelaysFallbackService;

src/services/user-relays.ts

@@ -5,6 +5,7 @@ import { parseRTag } from "../helpers/nostr-event";
 import { CachedPubkeyEventRequester } from "../classes/cached-pubkey-event-requester";
 import { SuperMap } from "../classes/super-map";
 import Subject from "../classes/subject";
+import { normalizeRelayConfigs } from "../helpers/relay";
 
 export type UserRelays = {
   pubkey: string;
@@ -15,7 +16,7 @@ export type UserRelays = {
 function parseRelaysEvent(event: NostrEvent): UserRelays {
   return {
     pubkey: event.pubkey,
-    relays: event.tags.filter(isRTag).map(parseRTag),
+    relays: normalizeRelayConfigs(event.tags.filter(isRTag).map(parseRTag)),
     created_at: event.created_at,
   };
 }
@@ -36,6 +37,9 @@ class UserRelaysService {
   }
 
   private subjects = new SuperMap<string, Subject<UserRelays>>(() => new Subject<UserRelays>());
+  getSubject(pubkey: string) {
+    return this.subjects.get(pubkey);
+  }
   requestRelays(pubkey: string, relays: string[], alwaysRequest = false) {
     const sub = this.subjects.get(pubkey);
     const requestSub = this.requester.requestEvent(pubkey, relays, alwaysRequest);