feat: introduce Joi validation schemas and integrate them across various controllers for categories, lessons, courses, chapters, announcements, and admin course approvals.

Backend/src/controllers/CategoriesController.ts

@@ -2,6 +2,7 @@ import { Get, Body, Post, Route, Tags, SuccessResponse, Response, Delete, Contro
 import { ValidationError } from '../middleware/errorHandler';
 import { CategoryService } from '../services/categories.service';
 import { createCategory, createCategoryResponse, deleteCategoryResponse, updateCategory, updateCategoryResponse, ListCategoriesResponse } from '../types/categories.type';
+import { CreateCategoryValidator, UpdateCategoryValidator } from '../validators/categories.validator';
 
 @Route('api/categories')
 @Tags('Categories')
@@ -27,6 +28,11 @@ export class CategoriesAdminController {
     @Response('401', 'Invalid or expired token')
     public async createCategory(@Request() request: any, @Body() body: createCategory): Promise<createCategoryResponse> {
         const token = request.headers.authorization?.replace('Bearer ', '') || '';
+
+        // Validate body
+        const { error } = CreateCategoryValidator.validate(body);
+        if (error) throw new ValidationError(error.details[0].message);
+
         return await this.categoryService.createCategory(token, body);
     }
 
@@ -36,6 +42,11 @@ export class CategoriesAdminController {
     @Response('401', 'Invalid or expired token')
     public async updateCategory(@Request() request: any, @Body() body: updateCategory): Promise<updateCategoryResponse> {
         const token = request.headers.authorization?.replace('Bearer ', '') || '';
+
+        // Validate body
+        const { error } = UpdateCategoryValidator.validate(body);
+        if (error) throw new ValidationError(error.details[0].message);
+
         return await this.categoryService.updateCategory(token, body.id, body);
     }
 
@@ -45,6 +56,6 @@ export class CategoriesAdminController {
     @Response('401', 'Invalid or expired token')
     public async deleteCategory(@Request() request: any, @Path() id: number): Promise<deleteCategoryResponse> {
         const token = request.headers.authorization?.replace('Bearer ', '') || '';
-        return await this.categoryService.deleteCategory(token,id);
+        return await this.categoryService.deleteCategory(token, id);
     }
 }