refactor(page): move next page position query into page repo

apps/server/src/core/page/services/page.service.ts

@@ -175,44 +175,7 @@ export class PageService {
   }
 
   async nextPagePosition(spaceId: string, parentPageId?: string) {
-    let pagePosition: string;
-
-    const lastPageQuery = this.db
-      .selectFrom('pages')
-      .select(['position'])
-      .where('spaceId', '=', spaceId)
-      .where('deletedAt', 'is', null)
-      .orderBy('position', (ob) => ob.collate('C').desc())
-      .limit(1);
-
-    if (parentPageId) {
-      // check for children of this page
-      const lastPage = await lastPageQuery
-        .where('parentPageId', '=', parentPageId)
-        .executeTakeFirst();
-
-      if (!lastPage) {
-        pagePosition = generateJitteredKeyBetween(null, null);
-      } else {
-        // if there is an existing page, we should get a position below it
-        pagePosition = generateJitteredKeyBetween(lastPage.position, null);
-      }
-    } else {
-      // for root page
-      const lastPage = await lastPageQuery
-        .where('parentPageId', 'is', null)
-        .executeTakeFirst();
-
-      // if no existing page, make this the first
-      if (!lastPage) {
-        pagePosition = generateJitteredKeyBetween(null, null); // we expect "a0"
-      } else {
-        // if there is an existing page, we should get a position below it
-        pagePosition = generateJitteredKeyBetween(lastPage.position, null);
-      }
-    }
-
-    return pagePosition;
+    return this.pageRepo.nextPagePosition(spaceId, parentPageId);
   }
 
   async update(

apps/server/src/database/repos/page/page.repo.ts

@@ -16,6 +16,7 @@ import { jsonArrayFrom, jsonObjectFrom } from 'kysely/helpers/postgres';
 import { SpaceMemberRepo } from '@docmost/db/repos/space/space-member.repo';
 import { EventEmitter2 } from '@nestjs/event-emitter';
 import { EventName } from '../../../common/events/event.contants';
+import { generateJitteredKeyBetween } from 'fractional-indexing-jittered';
 
 @Injectable()
 export class PageRepo {
@@ -605,4 +606,27 @@ export class PageRepo {
         .execute()
     );
   }
+
+  async nextPagePosition(
+    spaceId: string,
+    parentPageId?: string,
+  ): Promise<string> {
+    const lastPageQuery = this.db
+      .selectFrom('pages')
+      .select(['position'])
+      .where('spaceId', '=', spaceId)
+      .where('deletedAt', 'is', null)
+      .orderBy('position', (ob) => ob.collate('C').desc())
+      .limit(1);
+
+    const lastPage = parentPageId
+      ? await lastPageQuery
+          .where('parentPageId', '=', parentPageId)
+          .executeTakeFirst()
+      : await lastPageQuery
+          .where('parentPageId', 'is', null)
+          .executeTakeFirst();
+
+    return generateJitteredKeyBetween(lastPage?.position ?? null, null);
+  }
 }