feat: create route to handle updating watch status in AniList

src/controllers/watch-status/anilist.ts

@@ -0,0 +1,30 @@
+import { graphql } from "gql.tada";
+import { GraphQLClient } from "graphql-request";
+
+import type { WatchStatus } from "~/types/title";
+
+const UpdateWatchStatusQuery = graphql(`
+  mutation UpdateWatchStatus($titleId: Int!, $watchStatus: MediaListStatus!) {
+    SaveMediaListEntry(mediaId: $titleId, status: $watchStatus) {
+      id
+    }
+  }
+`);
+
+/** Updates the watch status for a title on Anilist. If the token is null, the watch status will not be updated. */
+export async function maybeUpdateWatchStatusOnAnilist(
+  titleId: number,
+  watchStatus: WatchStatus,
+  aniListToken: string | undefined,
+) {
+  if (!aniListToken) {
+    return;
+  }
+
+  const client = new GraphQLClient("https://graphql.anilist.co/");
+  const headers = new Headers({ Authorization: `Bearer ${aniListToken}` });
+
+  return client
+    .request(UpdateWatchStatusQuery, { titleId, watchStatus }, headers)
+    .then((data) => !!data?.SaveMediaListEntry?.id);
+}