diff --git a/src/activitypub/util/OrderedCollection.ts b/src/activitypub/util/OrderedCollection.ts
new file mode 100644
index 00000000..83cf9bd9
--- /dev/null
+++ b/src/activitypub/util/OrderedCollection.ts
@@ -0,0 +1,50 @@
+import {
+ APObject,
+ APOrderedCollection,
+ OrderedCollectionItemsField,
+} from "activitypub-types";
+import { Request } from "express";
+
+interface ActivityPubable {
+ toAP(): APObject;
+}
+
+interface CorrectOrderedCollection extends APOrderedCollection {
+ orderedItems?: OrderedCollectionItemsField[];
+}
+
+export const makeOrderedCollection = async <T extends ActivityPubable>(
+ req: Request,
+ id: string,
+ getTotalElements: () => Promise<number>,
+ getElements: (before?: string, after?: string) => Promise<T[]>,
+): Promise<CorrectOrderedCollection> => {
+ const { page, min_id, max_id } = req.query;
+
+ if (!page)
+ return {
+ "@context": "https://www.w3.org/ns/activitystreams",
+ id: id,
+ type: "OrderedCollection",
+ totalItems: await getTotalElements(),
+ first: `${id}?page=true`,
+ last: `${id}?page=true&min_id=0`,
+ };
+
+ const after = min_id ? `${min_id}` : undefined;
+ const before = max_id ? `${max_id}` : undefined;
+
+ const elems = await getElements(before, after);
+
+ const items = elems.map((elem) => elem.toAP());
+
+ return {
+ "@context": "https://www.w3.org/ns/activitystreams",
+ id: `${id}?page=true`,
+ type: "OrderedCollection",
+ first: `${id}?page=true`,
+ last: `${id}?page=true&min_id=0`,
+ totalItems: await getTotalElements(),
+ orderedItems: items,
+ };
+};
|
