Make /api/v1/instance and /api/v1/custom_emojis better (#3118)

* Separate commits

From commit dca110ebaa78f64600429f812c238a07d2f1dc1d.

* Re-separate commits

From commit 9719387bee40363f63a837e7ecffacf2a476c334.

2 files changed, 44 insertions, 3 deletions

diff --git a/src/models/mastodon/emoji.ts b/src/models/mastodon/emoji.ts
new file mode 100644
index 0000000000..df19c6e758
--- /dev/null
+++ b/src/models/mastodon/emoji.ts
@@ -0,0 +1,35 @@
+export type IMastodonEmoji = {
+	shortcode: string,
+	url: string,
+	static_url: string,
+	visible_in_picker: boolean
+};
+
+export async function toMastodonEmojis(emoji: any): Promise<IMastodonEmoji[]> {
+	return [{
+		shortcode: emoji.name,
+		url: emoji.url,
+		static_url: emoji.url, // TODO: Implement ensuring static emoji
+		visible_in_picker: true
+	}, ...(emoji.aliases as string[] || []).map(x => ({
+		shortcode: x,
+		url: emoji.url,
+		static_url: emoji.url,
+		visible_in_picker: true
+	}))];
+}
+
+export function toMisskeyEmojiSync(emoji: IMastodonEmoji) {
+	return {
+		name: emoji.shortcode,
+		url: emoji.url
+	};
+}
+
+export function toMisskeyEmojiWithAliasesSync(emoji: IMastodonEmoji, ...aliases: string[]) {
+	return {
+		name: emoji.shortcode,
+		aliases,
+		url: emoji.url
+	};
+}
diff --git a/src/server/api/mastodon.ts b/src/server/api/mastodon.ts
index 33a0b4b5f1..d1e1068da3 100644
--- a/src/server/api/mastodon.ts
+++ b/src/server/api/mastodon.ts
@@ -5,17 +5,18 @@ import config from '../../config';
 import Meta from '../../models/meta';
 import { ObjectID } from 'bson';
 import Emoji from '../../models/emoji';
+import { toMastodonEmojis } from '../../models/mastodon/emoji';
 const pkg = require('../../../package.json');
 
 // Init router
 const router = new Router();
 
 router.get('/v1/custom_emojis', async ctx => ctx.body =
-	await Emoji.find({ host: null }, {
+	(await Emoji.find({ host: null }, {
 		fields: {
 			_id: false
 		}
-	}));
+	})).map(toMastodonEmojis));
 
 router.get('/v1/instance', async ctx => { // TODO: This is a temporary implementation. Consider creating helper methods!
 	const meta = await Meta.findOne() || {};
@@ -40,6 +41,11 @@ router.get('/v1/instance', async ctx => { // TODO: This is a temporary implement
 		notesCount: 0
 	};
 	const acct = maintainer.host ? `${maintainer.username}@${maintainer.host}` : maintainer.username;
+	const emojis = (await Emoji.find({ host: null }, {
+		fields: {
+			_id: false
+		}
+	})).map(toMastodonEmojis);
 
 	ctx.body = {
 		uri: config.hostname,
@@ -79,7 +85,7 @@ router.get('/v1/instance', async ctx => { // TODO: This is a temporary implement
 			followers_count: maintainer.followersCount,
 			following_count: maintainer.followingCount,
 			statuses_count: maintainer.notesCount,
-			emojis: [],
+			emojis: emojis,
 			moved: null,
 			fields: null
 		}