From 2dd175c9ffc313b36cb2971751423b1b58cb1472 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?100=E3=81=AE=E4=BA=BA=20=28=E3=82=A8=E3=82=B9=E3=83=91?=
 =?UTF-8?q?=E3=83=BC=E3=83=BB=E3=82=A4=E3=83=BC=E3=82=B7=E3=82=A2=29?=
 <100@pokemori.jp>
Date: Sun, 31 Aug 2025 23:57:10 +0900
Subject: [PATCH] feat(route): add Niconico Mylist (#19938)

---
 lib/routes/nicovideo/mylist.ts | 39 ++++++++++++++++++++++++++++++++++
 lib/routes/nicovideo/types.ts  | 27 +++++++++++++++++++++++
 lib/routes/nicovideo/utils.ts  | 28 +++++++++++++++++++++++-
 3 files changed, 93 insertions(+), 1 deletion(-)
 create mode 100644 lib/routes/nicovideo/mylist.ts

diff --git a/lib/routes/nicovideo/mylist.ts b/lib/routes/nicovideo/mylist.ts
new file mode 100644
index 0000000000..2b47b8d372
--- /dev/null
+++ b/lib/routes/nicovideo/mylist.ts
@@ -0,0 +1,39 @@
+import { DataItem, Route } from '@/types';
+
+import { getMylist, renderVideo } from './utils';
+import { parseDate } from '@/utils/parse-date';
+
+export const route: Route = {
+    name: 'Mylist',
+    path: '/mylist/:id',
+    parameters: { id: 'Mylist ID' },
+    example: '/nicovideo/mylist/2973737',
+    maintainers: ['esperecyan'],
+    radar: [
+        {
+            source: ['www.nicovideo.jp/user/:user/mylist/:id'],
+            target: '/mylist/:id',
+        },
+    ],
+    handler: async (ctx) => {
+        const { id } = ctx.req.param();
+
+        const mylist = await getMylist(id);
+
+        return {
+            title: `マイリスト ${mylist.name}‐ニコニコ動画`,
+            link: `https://www.nicovideo.jp/user/${mylist.owner.id}/mylist/${mylist.id}`,
+            language: 'ja',
+            item: mylist.items.map(
+                (item): DataItem => ({
+                    title: item.video.title,
+                    link: `https://www.nicovideo.jp/watch/${item.video.id}`,
+                    pubDate: parseDate(item.addedAt),
+                    author: [{ name: item.video.owner.name, avatar: item.video.owner.iconUrl, url: `https://www.nicovideo.jp/user/${item.video.owner.id}` }],
+                    description: renderVideo(item.video, false),
+                    image: item.video.thumbnail.nHdUrl ?? item.video.thumbnail.largeUrl ?? item.video.thumbnail.middleUrl ?? undefined,
+                })
+            ),
+        };
+    },
+};
diff --git a/lib/routes/nicovideo/types.ts b/lib/routes/nicovideo/types.ts
index f8690c625e..1c42651e5b 100644
--- a/lib/routes/nicovideo/types.ts
+++ b/lib/routes/nicovideo/types.ts
@@ -52,3 +52,30 @@ export interface VideoItem {
     series: null;
     essential: Essential;
 }
+
+export type Mylist = {
+    id: number;
+    name: string;
+    description: string;
+    decoratedDescriptionHtml: string;
+    defaultSortKey: string;
+    defaultSortOrder: string;
+    items: MylistItem[];
+    totalItemCount: number;
+    hasNext: boolean;
+    isPublic: boolean;
+    owner: Owner;
+    hasInvisibleItems: boolean;
+    followerCount: number;
+    isFollowing: boolean;
+};
+
+type MylistItem = {
+    itemId: number;
+    watchId: string;
+    description: string;
+    decoratedDescriptionHtml: string;
+    addedAt: string;
+    status: string;
+    video: Essential;
+};
diff --git a/lib/routes/nicovideo/utils.ts b/lib/routes/nicovideo/utils.ts
index 3e6c3f293d..2761ebc9e6 100644
--- a/lib/routes/nicovideo/utils.ts
+++ b/lib/routes/nicovideo/utils.ts
@@ -1,4 +1,4 @@
-import { Essential, UserInfo, VideoItem } from './types';
+import { Essential, Mylist, UserInfo, VideoItem } from './types';
 
 import ofetch from '@/utils/ofetch';
 import cache from '@/utils/cache';
@@ -31,4 +31,30 @@ export const getUserVideosById = (id: string) =>
         false
     ) as Promise<VideoItem[]>;
 
+export const getMylist = (id: string): Promise<Mylist> =>
+    cache.tryGet<Mylist>(
+        `nicovideo:mylist:${id}`,
+        async () => {
+            const { data } = await ofetch(`https://nvapi.nicovideo.jp/v2/mylists/${id}`, {
+                headers: {
+                    'X-Frontend-Id': '6',
+                },
+                query: {
+                    sortKey: 'addedAt',
+                    sortOrder: 'desc',
+                    /**
+                     * @remarks
+                     * Up to 500 items can be registered in a single mylist.
+                     * @see https://qa.nicovideo.jp/faq/show/648?site_domain=default
+                     */
+                    pageSize: 500,
+                    page: 1,
+                },
+            });
+            return data.mylist;
+        },
+        config.cache.routeExpire,
+        false
+    );
+
 export const renderVideo = (video: Essential, embed: boolean) => art(path.join(__dirname, 'templates/video.art'), { video, embed });