use discord avatar as fallback

src/app/api/register/route.ts

@@ -1,6 +1,7 @@
 import * as ldap from "@/ldap";
 import prisma from "@/prisma";
 import { getUserFromRequest } from "@/auth";
+import { getDiscordAvatar } from "@/app/oauth/discord/oauth";
 
 type RequestBody = {
   username: string;
@@ -67,6 +68,16 @@ export async function POST(request: Request) {
     }
   }
 
+  const discordAuth = await prisma.discordAuth.findFirst({
+    where: {
+      userId: user.id
+    }
+  });
+
+  if (discordAuth !== null && avatarBuf === undefined) {
+    avatarBuf = await getDiscordAvatar(discordAuth.accessToken);
+  }
+
   const users = await ldap.getUsers();
   for (const user of users) {
     if (user.id.toLowerCase() === username.toLowerCase()) {

src/app/oauth/discord/oauth.ts

@@ -10,6 +10,7 @@ export type DiscordAccessTokenResponse = {
 
 export type DiscordUserResponse = {
   id: string;
+  avatar: string;
 };
 
 export type DiscordGuildResponse = {
@@ -39,3 +40,18 @@ export async function getDiscordGuilds(token: string) {
   const res: DiscordGuildResponse[] = await req.json();
   return res.map((guild) => guild.id);
 }
+
+export async function getDiscordAvatar(token: string) {
+  const req = await fetch("https://discord.com/api/users/@me", {
+    headers: {
+      Authorization: `Bearer ${token}`
+    }
+  });
+
+  const res: DiscordUserResponse = await req.json();
+  const file = `https://cdn.discordapp.com/avatars/${res.id}/${res.avatar}.png`;
+
+  const avatarReq = await fetch(file);
+  const avatarBuffer = await avatarReq.arrayBuffer();
+  return Buffer.from(avatarBuffer);
+}

src/app/register/RegisterForm.tsx

@@ -184,7 +184,10 @@ export default function RegisterForm({ ticket }: { ticket: string }) {
         />
 
         <Input
-          hint="This image will automatically be used as your avatar with supported services. Optional - maximum 1 MB."
+          hint={
+            "This image will automatically be used as your avatar with supported services - maximum 1 MB. " +
+            "Will use the avatar of the service you signed up with if not provided."
+          }
           type="file"
           name="avatar"
           label="Avatar"