feat(mastodon): add `username@instance` handler (#498)

api/mastodon.ts

@@ -2,25 +2,52 @@ import got from '../libs/got'
 import { millify } from '../libs/utils'
 import { createBadgenHandler, PathArgs } from '../libs/create-badgen-handler'
 
+const BRAND_COLOR = '3487CE'
+
 export default createBadgenHandler({
   title: 'Mastodon/Pleroma',
   examples: {
-    '/mastodon/follow/1': 'followers (mastodon.social)',
-    '/mastodon/follow/1/mas.to': 'followers (other Mastodon instance)',
-    '/mastodon/follow/3/anime.website': 'followers (Pleroma instance)',
+    '/mastodon/follow/Gargron@mastodon.social': 'followers',
+    '/mastodon/follow/trumpet@mas.to': 'followers',
+    '/mastodon/follow/admin@cawfee.club': 'followers (Pleroma)',
   },
   handlers: {
-    '/mastodon/follow/:userId/:instance?': handler
+    '/mastodon/follow/:account<.+@.+>': accountHandler,
+    '/mastodon/follow/:user-id<\\d>/:instance?': userIdHandler
   }
 })
 
-async function handler ({ userId, instance = 'mastodon.social' }: PathArgs) {
-  const prefixUrl = `https://${instance}/api/v1/`
-  const info = await got(`accounts/${userId}`, { prefixUrl }).json<any>()
-
+async function userIdHandler({ 'user-id': userId, instance = 'mastodon.social' }: PathArgs) {
+  const info = await got(`https://${instance}/api/v1/accounts/${userId}`).json<any>()
+  const account = `${info.username}@${instance}`
   return {
-    subject: `follow @${info.username}@${instance}`,
+    subject: `follow @${account}`,
     status: millify(info.followers_count),
-    color: '3487CE'
+    color: BRAND_COLOR
   }
 }
+
+async function accountHandler({ account }: PathArgs) {
+  const [username, instance] = account.split('@')
+  const { version } = await got(`https://${instance}/api/v1/instance`).json<any>()
+  const isPleroma = /\bPleroma\b/i.test(version)
+  if (isPleroma) return userIdHandler({ 'user-id': username, instance })
+  const resp = await got(`https://${instance}/@${username}.rss`)
+  const params = isFeed(resp) && parseFeed(resp.body, instance)
+  return params || {
+    subject: 'mastodon',
+    status: 'unknown',
+    color: 'grey'
+  }
+}
+
+function isFeed(response: import('got').Response) {
+  const contentType = response.headers['content-type'] || ''
+  return contentType.includes('application/rss+xml')
+}
+
+function parseFeed(feed: string, instance: string) {
+  const reAvatarPath = /\/accounts\/avatars\/(\d{3})\/(\d{3})\/(\d{3})/
+  const userId = feed.match(reAvatarPath)?.slice(1).join('')
+  if (userId) return userIdHandler({ 'user-id': userId, instance })
+}