backend/app/models.py

@@ -46,6 +46,13 @@ class User(UserMixin, db.Model):
             return True
         return False
 
+    def unenroll(self, c) -> bool:
+        if self.is_enrolled(c):
+            self.enrolled_courses.remove(c)
+            db.session.commit()
+            return True
+        return False
+
     def to_dict(self) -> dict:
         return {
             "id": self.id,

backend/app/routes.py

@@ -124,3 +124,20 @@ def enroll_student(uid, cid):
 
     resp = {"user": u.to_dict(), "course": c.to_dict()}
     return jsonify(resp)
+
+
+@bp.route("/user/<int:uid>/enroll/<int:cid>", methods=["DELETE"])
+@login_required
+def unenroll_student(uid, cid):
+    u = User.query.get(uid)
+    if not u:
+        return error_response(400, f"User with id {uid} does not exist")
+
+    c = Course.query.get(cid)
+    if not c:
+        return error_response(400, f"Course with id {cid} does not exist")
+
+    if not u.unenroll(c):
+        return error_response(400, f"User {uid} is not enrolled in course {cid}")
+    resp = {"user": u.to_dict(), "course": c.to_dict()}
+    return jsonify(resp)