From 70a669a29c101867c7f988ade43c6cb836e2c706 Mon Sep 17 00:00:00 2001
From: Jesse Wierzbinski <contact@cpluspatch.com>
Date: Thu, 13 Jun 2024 22:19:15 -1000
Subject: [PATCH] docs(api): :memo: Document API parameter to change username

---
 docs/api/mastodon.md                                |  9 ++++++++-
 .../api/api/v1/accounts/update_credentials/index.ts | 13 +++++++++++--
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/docs/api/mastodon.md b/docs/api/mastodon.md
index fb539fc6..d1047edd 100644
--- a/docs/api/mastodon.md
+++ b/docs/api/mastodon.md
@@ -61,4 +61,11 @@ An extra attribute has been adding to all returned account objects:
 
 ### `roles`
 
-An array of roles from [Lysand Roles](./roles.md).
\ No newline at end of file
+An array of roles from [Lysand Roles](./roles.md).
+
+### `/api/v1/accounts/update_credentials`
+
+The `username` parameter can now (optionally) be set to change the user's handle.
+
+> [!WARNING]
+> Clients should indicate to users that changing their handle will break existing links to their profile. This is reversible, but the old handle will be available for anyone to claim.
\ No newline at end of file
diff --git a/server/api/api/v1/accounts/update_credentials/index.ts b/server/api/api/v1/accounts/update_credentials/index.ts
index a5b7ef59..2b664489 100644
--- a/server/api/api/v1/accounts/update_credentials/index.ts
+++ b/server/api/api/v1/accounts/update_credentials/index.ts
@@ -3,7 +3,7 @@ import { errorResponse, jsonResponse } from "@/response";
 import { sanitizedHtmlStrip } from "@/sanitization";
 import { zValidator } from "@hono/zod-validator";
 import { config } from "config-manager";
-import { and, eq } from "drizzle-orm";
+import { and, eq, isNull } from "drizzle-orm";
 import type { Hono } from "hono";
 import ISO6391 from "iso-639-1";
 import { MediaBackend } from "media-manager";
@@ -12,7 +12,7 @@ import { getUrl } from "~/database/entities/attachment";
 import { parseEmojis } from "~/database/entities/emoji";
 import { contentToHtml } from "~/database/entities/status";
 import { db } from "~/drizzle/db";
-import { EmojiToUser, RolePermissions } from "~/drizzle/schema";
+import { EmojiToUser, RolePermissions, Users } from "~/drizzle/schema";
 import type { Emoji } from "~/packages/database-interface/emoji";
 import { User } from "~/packages/database-interface/user";
 
@@ -191,6 +191,15 @@ export default (app: Hono) =>
             }
 
             if (username) {
+                // Check if username is already taken
+                const existingUser = await User.fromSql(
+                    and(isNull(Users.instanceId), eq(Users.username, username)),
+                );
+
+                if (existingUser) {
+                    return errorResponse("Username is already taken", 400);
+                }
+
                 self.username = username;
             }