feat(api): add rate-limiting and /clear-guild-cache (#198)

packages/api/utils/guild.ts

@@ -10,6 +10,7 @@ import {
 import { AuthType, cacheLayer, discordFetch } from './api-tools';
 import { botClientID, botToken } from './config';
 import { GuildData, Guilds } from './kv';
+import { useRateLimiter } from './rate-limiting';
 
 type APIGuild = {
   // Only relevant stuff
@@ -161,3 +162,14 @@ const calculateRoleSafety = (role: Role | APIRole, highestBotRolePosition: numbe
 
   return safety;
 };
+
+export enum GuildRateLimiterKey {
+  legacyImport = 'legacyImport',
+  cacheClear = 'cacheClear',
+}
+
+export const useGuildRateLimiter = (
+  guildID: string,
+  key: GuildRateLimiterKey,
+  timeoutSeconds: number
+) => useRateLimiter(Guilds, `guilds/${guildID}/rate-limit/${key}`, timeoutSeconds);

packages/api/utils/rate-limiting.ts

@@ -0,0 +1,15 @@
+import { WrappedKVNamespace } from './kv';
+
+export const useRateLimiter = (
+  kv: WrappedKVNamespace,
+  key: string,
+  timeoutSeconds: number
+) => async (): Promise<boolean> => {
+  const value = await kv.get<boolean>(key);
+  if (value) {
+    return true;
+  }
+
+  await kv.put(key, true, timeoutSeconds);
+  return false;
+};

packages/api/utils/responses.ts

@@ -0,0 +1,16 @@
+import { respond } from './api-tools';
+
+export const ok = () => respond({ ok: true });
+
+export const missingParameters = () =>
+  respond({ error: 'missing parameters' }, { status: 400 });
+
+export const lowPermissions = () =>
+  respond({ error: 'no permissions for this action' }, { status: 403 });
+
+export const notFound = () => respond({ error: 'not found' }, { status: 404 });
+
+export const conflict = () => respond({ error: 'conflict' }, { status: 409 });
+
+export const rateLimited = () =>
+  respond({ error: 'rate limit hit, enhance your calm' }, { status: 419 });