Move hono-related functions until utils/web

src/utils/web.ts

@@ -1,4 +1,5 @@
-import { EventTemplate, HTTPException } from '@/deps.ts';
+import { Conf } from '@/config.ts';
+import { type Context, type Event, EventTemplate, HTTPException, parseFormData, z } from '@/deps.ts';
 import * as pipeline from '@/pipeline.ts';
 import { signEvent } from '@/sign.ts';
 import { nostrNow } from '@/utils.ts';
@@ -31,4 +32,59 @@ async function createEvent<K extends number>(t: Omit<EventTemplate<K>, 'created_
   return event;
 }
 
-export { createEvent };
+/** Parse request body to JSON, depending on the content-type of the request. */
+async function parseBody(req: Request): Promise<unknown> {
+  switch (req.headers.get('content-type')?.split(';')[0]) {
+    case 'multipart/form-data':
+    case 'application/x-www-form-urlencoded':
+      return parseFormData(await req.formData());
+    case 'application/json':
+      return req.json();
+  }
+}
+
+/** Schema to parse pagination query params. */
+const paginationSchema = z.object({
+  since: z.coerce.number().optional().catch(undefined),
+  until: z.lazy(() => z.coerce.number().catch(nostrNow())),
+  limit: z.coerce.number().catch(20).transform((value) => Math.min(Math.max(value, 0), 40)),
+});
+
+/** Mastodon API pagination query params. */
+type PaginationParams = z.infer<typeof paginationSchema>;
+
+/** Build HTTP Link header for Mastodon API pagination. */
+function buildLinkHeader(url: string, events: Event[]): string | undefined {
+  if (!events.length) return;
+  const firstEvent = events[0];
+  const lastEvent = events[events.length - 1];
+
+  const { pathname, search } = new URL(url);
+  const next = new URL(pathname + search, Conf.localDomain);
+  const prev = new URL(pathname + search, Conf.localDomain);
+
+  next.searchParams.set('until', String(lastEvent.created_at));
+  prev.searchParams.set('since', String(firstEvent.created_at));
+
+  return `<${next}>; rel="next", <${prev}>; rel="prev"`;
+}
+
+/** JSON-LD context. */
+type LDContext = (string | Record<string, string | Record<string, string>>)[];
+
+/** Add a basic JSON-LD context to ActivityStreams object, if it doesn't already exist. */
+function maybeAddContext<T>(object: T): T & { '@context': LDContext } {
+  return {
+    '@context': ['https://www.w3.org/ns/activitystreams'],
+    ...object,
+  };
+}
+
+/** Like hono's `c.json()` except returns JSON-LD. */
+function activityJson<T, P extends string>(c: Context<any, P>, object: T) {
+  const response = c.json(maybeAddContext(object));
+  response.headers.set('content-type', 'application/activity+json; charset=UTF-8');
+  return response;
+}
+
+export { activityJson, buildLinkHeader, createEvent, type PaginationParams, paginationSchema, parseBody };