feat: controller en service laag toegevoegd voor student/:id/classes

backend/src/services/students.ts

@@ -1,7 +1,14 @@
-import { getStudentRepository } from "../data/repositories";
+import { getClassRepository, getStudentRepository } from "../data/repositories";
+import { Class } from "../entities/classes/class.entity";
+import { ClassDTO } from "../interfaces/classes";
 import { StudentDTO } from "../interfaces/students";
 
-export async function getStudentById(username: string): Promise<StudentDTO | null> {
+export async function getAllStudents(): Promise<StudentDTO[]> {
+    // TODO
+    return [];
+}
+
+export async function getStudent(username: string): Promise<StudentDTO | null> {
     const studentRepository = getStudentRepository();
     const student = await studentRepository.findByUsername(username);
 
@@ -16,3 +23,43 @@ export async function getStudentById(username: string): Promise<StudentDTO | nul
     }
 }
 
+async function fetchStudentClasses(username: string): Promise<Class[]> {
+    const studentRepository = getStudentRepository();
+    const student = await studentRepository.findByUsername(username);
+
+    if (!student) return [];
+
+    const classRepository = getClassRepository();
+    // a weird error when running npm run dev occurs when using .findByStudent
+    // the error says that the function could not be found which is weird
+    // because typescript does not throw any errors
+    const classes = await classRepository.find(
+        { students: student },
+        { populate: ["students", "teachers"] } // voegt student en teacher objecten toe
+    )
+    // const classes = await classRepository.findByStudent(student);
+
+    if (!classes) return [];
+
+    return classes;
+}
+
+export async function getStudentClasses(username: string): Promise<ClassDTO[]> {
+    const classes = await fetchStudentClasses(username);
+
+    return classes.map((cls: Class): ClassDTO => {
+        return {
+            id: cls.classId,
+            displayName: cls.displayName,
+            teachers: cls.teachers.map(teacher => teacher.username),
+            students: cls.students.map(student => student.username),
+            joinRequests: [], // TODO
+        }
+    });
+}
+
+export async function getStudentClassIds(username: string): Promise<string[]> {
+    const classes = await fetchStudentClasses(username);
+    return classes.map(cls => cls.classId); // class is a native keyword
+}
+