rename client, update docs/skills

packages/app/src/plugins/sync.ts

@@ -0,0 +1,53 @@
+import {isSignedEvent} from "@welshman/util"
+import type {Filter, SignedEvent} from "@welshman/util"
+import type {IApp} from "../app.js"
+import {Network} from "./network.js"
+import {Relays} from "./relays.js"
+
+export type AppSyncOpts = {
+  relays: string[]
+  filters: Filter[]
+}
+
+/**
+ * Negentropy-aware sync. Pulls/pushes events between the local repository and a
+ * set of relays, using NIP-77 reconciliation where the relay supports it and
+ * falling back to plain request/publish otherwise. Reads NIP-11 relay profiles
+ * from the `Relays` collection to detect negentropy support.
+ */
+export class Sync {
+  constructor(readonly app: IApp) {}
+
+  query = (filters: Filter[]) =>
+    this.app.repository.query(filters, {shouldSort: filters.every(f => f.limit === undefined)})
+
+  pull = async ({relays, filters}: AppSyncOpts) => {
+    const net = this.app.use(Network)
+    const events = this.query(filters).filter(isSignedEvent)
+
+    await Promise.all(
+      relays.map(async relay => {
+        if (await this.app.use(Relays).hasNegentropy(relay)) {
+          await net.pull({filters, events, relays: [relay]})
+        } else {
+          await net.request({filters, relays: [relay], autoClose: true})
+        }
+      }),
+    )
+  }
+
+  push = async ({relays, filters}: AppSyncOpts) => {
+    const net = this.app.use(Network)
+    const events = this.query(filters).filter(isSignedEvent)
+
+    await Promise.all(
+      relays.map(async relay => {
+        if (await this.app.use(Relays).hasNegentropy(relay)) {
+          await net.push({filters, events, relays: [relay]})
+        } else {
+          await Promise.all(events.map((event: SignedEvent) => net.publish({event, relays: [relay]})))
+        }
+      }),
+    )
+  }
+}