refactor: courses controller

app/Controllers/Http/Api/v1/CoursesController.ts

@@ -1,11 +1,6 @@
 import { Exception, inject, Ioc } from '@adonisjs/core/build/standalone';
 import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext';
 
-/**
- * Datatype
- */
-import Role from 'App/Datatypes/Enums/RoleEnum';
-
 /**
  * Models
  */
@@ -170,54 +165,29 @@ export default class CoursesController extends BaseController {
    * Attach student to course
    * POST /courses/:id/attach-student
    */
-  public async attachStudent({ response, request, params }: HttpContextContract) {
-    try {
-      const payload = await request.validate(AddCourseToUserValidator);
-      const student = await this.User.findOrFail(payload.student_id);
-      const course = await this.Course.findOrFail(params.id);
+  public async attachStudent(ctx: HttpContextContract) {
+    const payload = await ctx.request.validate(AddCourseToUserValidator);
+    const result = await this.courseService.attachUserCourse(ctx.params.id, payload.student_id);
 
-      await course.load('students');
-      await student.load('roles');
-
-      const studentRoles = student.roles.map(r => r.slug);
-
-      if (!studentRoles.includes(Role.STUDENT)) {
-        throw new Exception(`User cannot be attached to the course without "student" role.`, 400, 'E_USER_ROLE');
+    if (!result.success && result.error) {
+      throw new Exception(result.message, result.status, result.error.code);
     }
 
-      await course.related('students').attach([student.id]);
-
-      return response.ok({
-        message: 'Student attached',
-        data: 'SUCCESS',
-      });
-    } catch (error) {
-      if (error?.code === '23505')
-        throw new Exception('Student already attached to that course', 400, 'E_STUDENT_ATTACHED');
-
-      throw error;
-    }
+    return this.sendResponse(ctx, result.data, result.message, result.status);
   }
 
   /**
    * Detach student from course
    */
-  public async detachStudent({ response, request, params }: HttpContextContract) {
-    const payload = await request.validate(DelCourseFromUserValidator);
-    const course = await this.Course.query().preload('students').where('id', params.id).firstOrFail();
-    const candidate = course.students.find(student => student.id === payload.student_id);
+  public async detachStudent(ctx: HttpContextContract) {
+    const payload = await ctx.request.validate(DelCourseFromUserValidator);
+    const result = await this.courseService.detachUserCourse(ctx.params.id, payload.student_id);
 
-    if (!candidate) {
-      throw new Exception('Student not attached to that course', 400, 'E_STUDENT_NOT_ATTACHED');
+    if (!result.success && result.error) {
+      throw new Exception(result.message, result.status, result.error.code);
     }
 
-    const student = await this.User.findOrFail(payload.student_id);
-    await course.related('students').detach([student.id]);
-
-    return response.ok({
-      message: 'Student detached',
-      data: 'SUCCESS',
-    });
+    return this.sendResponse(ctx, result.data, result.message, result.status);
   }
 }
 

app/Repositories/CourseRepository.ts

@@ -40,6 +40,7 @@ export default class CourseRepository {
       .preload('teacher')
       .preload('category')
       .preload('lessons')
+      .preload('students')
       .where('id', id)
       .first();
 

app/Services/CourseService.ts

@@ -322,6 +322,134 @@ export default class CourseService {
       data: course,
     };
   }
+
+  /**
+   * Attach student to course
+   *
+   * @param id Course id
+   * @param studentId Student id
+   * @returns Response
+   */
+  public async attachUserCourse(id: string | number, studentId: string | number): Promise<IResponse> {
+    const course = await this.courseRepository.getById(id);
+
+    if (!course) {
+      return {
+        success: false,
+        status: StatusCodeEnum.NOT_FOUND,
+        message: 'Course not found.',
+        data: {},
+        error: {
+          code: 'E_NOT_FOUND',
+        },
+      };
+    }
+
+    const student = await this.userRepository.getById(studentId);
+
+    if (!student) {
+      return {
+        success: false,
+        status: StatusCodeEnum.NOT_FOUND,
+        message: 'Student not found.',
+        data: {},
+        error: {
+          code: 'E_NOT_FOUND',
+        },
+      };
+    }
+
+    const isStudent = RoleHelper.userHasRoles(student.roles, [RoleEnum.STUDENT]);
+
+    if (!isStudent) {
+      return {
+        success: false,
+        status: StatusCodeEnum.BAD_REQUEST,
+        message: `User cannot be added to the course without "${RoleEnum.STUDENT}" role.`,
+        data: {},
+        error: {
+          code: 'E_BAD_REQUEST',
+        },
+      };
+    }
+
+    try {
+      await course.related('students').attach([student.id]);
+    } catch (error) {
+      if (error.code === '23505') {
+        return {
+          success: false,
+          status: StatusCodeEnum.BAD_REQUEST,
+          message: 'Student already attached to that course.',
+          data: {},
+          error: {
+            code: 'E_BAD_REQUEST',
+          },
+        };
+      }
+      throw new Error(error);
+    }
+
+    return {
+      success: true,
+      status: StatusCodeEnum.OK,
+      message: 'Student attached.',
+      data: {},
+    };
+  }
+
+  public async detachUserCourse(id: string | number, studentId: string | number): Promise<IResponse> {
+    const course = await this.courseRepository.getById(id);
+
+    if (!course) {
+      return {
+        success: false,
+        status: StatusCodeEnum.NOT_FOUND,
+        message: 'Course not found.',
+        data: {},
+        error: {
+          code: 'E_NOT_FOUND',
+        },
+      };
+    }
+
+    const isAttached = course.students.find(student => student.id === studentId);
+
+    if (!isAttached) {
+      return {
+        success: false,
+        status: StatusCodeEnum.BAD_REQUEST,
+        message: 'Student not attached to that course.',
+        data: {},
+        error: {
+          code: 'E_BAD_REQUEST',
+        },
+      };
+    }
+
+    const student = await this.userRepository.getById(studentId);
+
+    if (!student) {
+      return {
+        success: false,
+        status: StatusCodeEnum.NOT_FOUND,
+        message: 'Student not found.',
+        data: {},
+        error: {
+          code: 'E_NOT_FOUND',
+        },
+      };
+    }
+
+    await course.related('students').detach([student.id]);
+
+    return {
+      success: true,
+      status: StatusCodeEnum.OK,
+      message: 'Student detached.',
+      data: {},
+    };
+  }
 }
 
 new Ioc().make(CourseService);