Wire the media archive into the daemon: command, service, and API

media-scrape/src/puppet-backend.ts

@@ -0,0 +1,25 @@
+/*
+ * The puppet scrape backend: history pages over the validated core bridge.
+ */
+
+import type { FetchPage, ScrapeBackend } from "./engine.js";
+import type { CoreMessage } from "./types.js";
+
+/** The core `message.fetch` call the daemon injects. */
+export type CoreFetch = (
+    channelId: string,
+    limit: number,
+    options?: { before?: string; after?: string }
+) => Promise<{ messages?: unknown[] }>;
+
+export class PuppetBackend implements ScrapeBackend {
+    readonly name = "puppet" as const;
+
+    constructor(private readonly fetchMessages: CoreFetch) {}
+
+    async fetchPage(channelId: string, before: string | null, limit: number): Promise<FetchPage> {
+        const result = await this.fetchMessages(channelId, limit, before ? { before } : {});
+        const messages = (result?.messages ?? []) as CoreMessage[];
+        return { messages };
+    }
+}

media-scrape/test/run.ts

@@ -9,6 +9,7 @@ import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { ScrapeEngine, type FetchPage, type ScrapeBackend } from "../src/engine.js";
 import { extractMedia } from "../src/extract.js";
+import { PuppetBackend } from "../src/puppet-backend.js";
 import { dirSizeBytes, listScrapes, ScrapeStore } from "../src/store.js";
 import type { CoreAttachment, CoreMessage } from "../src/types.js";
 
@@ -258,6 +259,19 @@ void (async () => {
         assert.equal(meta?.pages, 1);
     });
 
+    await test("puppet backend passes before and limit to the core", async () => {
+        const calls: Array<Record<string, unknown>> = [];
+        const backend = new PuppetBackend(async (channelId, limit, options) => {
+            calls.push({ channelId, limit, ...options });
+            return { messages: [message("50")] };
+        });
+
+        const page = await backend.fetchPage("123", "60", 5);
+        assert.equal(page.messages.length, 1);
+        assert.equal(page.messages[0].id, "50");
+        assert.deepEqual(calls[0], { channelId: "123", limit: 5, before: "60" });
+    });
+
     rmSync(root, { recursive: true, force: true });
 
     if (failures > 0) {