Add Void difficulty and publish changelogs

lib/changelog-feed.ts

@@ -0,0 +1,76 @@
+import {
+  parseReleasePost,
+  RELEASE_NEWS_CHANNEL,
+  RELEASE_WEBHOOK_ID,
+  type ReleasePost,
+} from "../shared/changelog";
+
+export async function readChangelogFeed({
+  token,
+  channel = RELEASE_NEWS_CHANNEL,
+  webhookId = RELEASE_WEBHOOK_ID,
+  before,
+  request = fetch,
+}: {
+  token: string;
+  channel?: string;
+  webhookId?: string;
+  before?: string;
+  request?: typeof fetch;
+}) {
+  if (!/^\d{17,20}$/.test(channel) || (before && !/^\d{17,20}$/.test(before)))
+    throw new Error("Invalid news channel or cursor");
+  const url = new URL(
+    `https://discord.com/api/v10/channels/${channel}/messages`,
+  );
+  url.searchParams.set("limit", "100");
+  if (before) url.searchParams.set("before", before);
+  // Reading history only. No Discord write endpoint is used by this feature.
+  const response = await request(url.toString(), {
+    method: "GET",
+    headers: { Authorization: `Bot ${token}` },
+    next: { revalidate: 60 },
+    signal: AbortSignal.timeout(10_000),
+    redirect: "error",
+  });
+  if (!response.ok)
+    throw new Error(`News feed unavailable (${response.status})`);
+  const posts: ReleasePost[] = await response.json();
+  if (
+    !Array.isArray(posts) ||
+    posts.some(
+      (post) =>
+        typeof post.content !== "string" ||
+        post.channel_id !== channel ||
+        !/^\d{17,20}$/.test(post.id),
+    )
+  )
+    throw new Error("Invalid news response");
+  if (
+    posts.some((post) => post.webhook_id === webhookId) &&
+    posts
+      .filter((post) => post.webhook_id === webhookId)
+      .every((post) => !post.content.trim())
+  )
+    throw new Error(
+      "Release text is unavailable; check Discord Message Content access",
+    );
+  const entries = posts
+    .flatMap((post) => {
+      const entry = parseReleasePost(post, webhookId);
+      return entry ? [entry] : [];
+    })
+    .sort(
+      (a, b) =>
+        b.publishedAt.localeCompare(a.publishedAt) ||
+        (BigInt(a.id) > BigInt(b.id) ? -1 : 1),
+    );
+  const oldest = posts.reduce<string | undefined>(
+    (id, post) => (!id || BigInt(post.id) < BigInt(id) ? post.id : id),
+    undefined,
+  );
+  return {
+    entries,
+    before: posts.length === 100 && oldest !== before ? oldest : undefined,
+  };
+}