Fix Mastodon legacy pagination

src/middleware/paginationMiddleware.ts

@@ -0,0 +1,40 @@
+import { AppMiddleware } from '@/app.ts';
+import { paginationSchema } from '@/schemas/pagination.ts';
+import { Storages } from '@/storages.ts';
+
+/** Fixes compatibility with Mastodon apps by that don't use `Link` headers. */
+export const paginationMiddleware: AppMiddleware = async (c, next) => {
+  const pagination = paginationSchema.parse(c.req.query());
+
+  const {
+    max_id: maxId,
+    min_id: minId,
+    since,
+    until,
+  } = pagination;
+
+  if ((maxId && !until) || (minId && !since)) {
+    const ids: string[] = [];
+
+    if (maxId) ids.push(maxId);
+    if (minId) ids.push(minId);
+
+    if (ids.length) {
+      const store = await Storages.db();
+
+      const events = await store.query(
+        [{ ids, limit: ids.length }],
+        { signal: c.req.raw.signal },
+      );
+
+      for (const event of events) {
+        if (!until && maxId === event.id) pagination.until = event.created_at;
+        if (!since && minId === event.id) pagination.since = event.created_at;
+      }
+    }
+  }
+
+  c.set('pagination', pagination);
+
+  await next();
+};