Feat: Add users collection pagination

src/principal/service.ts

@@ -46,20 +46,35 @@ export class PrincipalService {
 
   }
 
-  async findAll(type: 'user'): Promise<User[]>;
+  async findAll(type: 'user', page: number): Promise<User[]>;
   async findAll(type: 'group'): Promise<Group[]>;
   async findAll(type: 'app'): Promise<App[]>;
   async findAll(): Promise<Principal[]>;
-  async findAll(type?: PrincipalType): Promise<Principal[]> {
+  async findAll(type?: PrincipalType, page?: number): Promise<Principal[]> {
 
     this.privileges.require('a12n:principals:list');
     const filters: Record<string, any> = {};
     if (type) {
       filters.type = userTypeToInt(type);
     }
 
-    const result = await db('principals')
-      .where(filters);
+    let result: PrincipalsRecord[] = [];
+
+    if(type && page !== undefined){
+
+      page = page < 1 ? 1 : page;
+      const pageSize = 100;
+      const offset = (page - 1) * pageSize;
+
+      result = await db('principals')
+        .where(filters)
+        .limit(pageSize)
+        .offset(offset);
+
+    } else {
+      result = await db('principals')
+        .where(filters);
+    }
 
     const principals: Principal[] = [];
     for (const principal of result) {

src/user/controller/collection.ts

@@ -11,7 +11,11 @@ class UserCollectionController extends Controller {
   async get(ctx: Context) {
 
     const principalService = new services.principal.PrincipalService(ctx.privileges);
-    const users = await principalService.findAll('user');
+
+    const pageInt = parseInt(ctx.request.query.page);
+    const page = isNaN(pageInt) ? 1 : pageInt;
+
+    const users = await principalService.findAll('user', page);
     const embed = ctx.request.prefer('transclude').toString().includes('item') || ctx.query.embed?.includes('item');
 
     const embeddedUsers: HalResource[] = [];
@@ -36,7 +40,8 @@ class UserCollectionController extends Controller {
       }
     }
 
-    ctx.response.body = hal.collection(users, embeddedUsers);
+    const pageSize = 100;
+    ctx.response.body = hal.collection(users, embeddedUsers, page, pageSize);
 
   }
 

src/user/formats/hal.ts

@@ -4,12 +4,22 @@ import { HalResource } from 'hal-types';
 import { LazyPrivilegeBox } from '../../privilege/service.ts';
 import { UserNewResult } from '../../api-types.ts';
 
-export function collection(users: User[], embeddedUsers: HalResource[]): HalResource {
+export function collection(users: User[], embeddedUsers: HalResource[], currentPage: number, pageSize: number): HalResource {
+
+  const totalUsers = users.length;
+  const totalPages = Math.ceil(totalUsers / pageSize);
+  const nextPage = currentPage < totalPages ? currentPage + 1 : null;
+  const prevPage = currentPage > 1 ? currentPage - 1 : null;
+
+  const startIdx = (currentPage - 1) * pageSize;
+  const endIdx = Math.min(startIdx + pageSize, totalUsers);
+
+  const paginatedUsers = users.slice(startIdx, endIdx);
 
   const hal: HalResource = {
     _links: {
-      'self': { href: '/user' },
-      'item': users.map( user => ({
+      'self': { href: `/user?page=${currentPage}` },
+      'item': paginatedUsers.map( user => ({
         href: user.href,
         title: user.nickname,
       })),
@@ -20,9 +30,19 @@ export function collection(users: User[], embeddedUsers: HalResource[]): HalReso
         templated: true,
       },
     },
-    total: users.length,
+    total: totalUsers,
+    currentPage,
+    totalPages,
   };
 
+  if(nextPage){
+    hal._links['next'] = { href: `/user?page=${nextPage}` };
+  }
+
+  if(prevPage){
+    hal._links['previous'] = { href: `/user?page=${prevPage}` };
+  }
+
   if (embeddedUsers.length) {
     hal._embedded = {
       item: embeddedUsers