Merge pull request #68 from SELab-2/course-logic

chore: serializers for validation

backend/api/models/course.py

@@ -1,3 +1,4 @@
+from datetime import datetime
 from typing import Self
 from django.db import models
 
@@ -31,6 +32,10 @@ def __str__(self) -> str:
         """The string representation of the course."""
         return str(self.name)
 
+    def is_past(self) -> bool:
+        """Returns whether the course is from a past academic year"""
+        return datetime(self.academic_startyear + 1, 10, 1) < datetime.now()
+
     def clone(self, clone_assistants=True) -> Self:
         """Clone the course to the next academic start year"""
         course = Course(

backend/api/serializers/assistant_serializer.py

@@ -24,3 +24,9 @@ class Meta:
             "create_time",
             "courses",
         ]
+
+
+class AssistantIDSerializer(serializers.Serializer):
+    assistant_id = serializers.PrimaryKeyRelatedField(
+        queryset=Assistant.objects.all()
+    )

backend/api/serializers/course_serializer.py

@@ -1,5 +1,8 @@
+from django.utils.translation import gettext
 from rest_framework import serializers
-from ..models.course import Course
+from rest_framework.exceptions import ValidationError
+from api.serializers.student_serializer import StudentIDSerializer
+from api.models.course import Course
 
 
 class CourseSerializer(serializers.ModelSerializer):
@@ -40,3 +43,47 @@ class Meta:
             "students",
             "projects",
         ]
+
+
+class CourseIDSerializer(serializers.Serializer):
+    student_id = serializers.PrimaryKeyRelatedField(
+        queryset=Course.objects.all()
+    )
+
+
+class StudentJoinSerializer(StudentIDSerializer):
+    def validate(self, data):
+        # The validator needs the course context.
+        if "course" not in self.context:
+            raise ValidationError(gettext("courses.error.context"))
+
+        course: Course = self.context["course"]
+
+        # Check if the student isn't already enrolled.
+        if course.students.contains(data["student_id"]):
+            raise ValidationError(gettext("courses.error.students.already_present"))
+
+        # Check if the course is not from a past academic year.
+        if course.is_past():
+            raise ValidationError(gettext("courses.error.students.past_course"))
+
+        return data
+
+
+class StudentLeaveSerializer(StudentIDSerializer):
+    def validate(self, data):
+        # The validator needs the course context.
+        if "course" not in self.context:
+            raise ValidationError(gettext("courses.error.context"))
+
+        course: Course = self.context["course"]
+
+        # Check if the student isn't already enrolled.
+        if not course.students.contains(data["student_id"]):
+            raise ValidationError(gettext("courses.error.students.not_present"))
+
+        # Check if the course is not from a past academic year.
+        if course.is_past():
+            raise ValidationError(gettext("courses.error.students.past_course"))
+
+        return data

backend/api/serializers/student_serializer.py

@@ -20,3 +20,9 @@ class StudentSerializer(serializers.ModelSerializer):
     class Meta:
         model = Student
         fields = '__all__'
+
+
+class StudentIDSerializer(serializers.Serializer):
+    student_id = serializers.PrimaryKeyRelatedField(
+        queryset=Student.objects.all()
+    )

backend/api/views/course_view.py

@@ -1,18 +1,19 @@
 from django.utils.translation import gettext
 from rest_framework import viewsets
-from rest_framework.exceptions import NotFound
 from rest_framework.permissions import IsAdminUser
 from rest_framework.decorators import action
 from rest_framework.response import Response
 from rest_framework.request import Request
 from api.models.course import Course
-from api.models.assistant import Assistant
-from api.models.student import Student
-from api.permissions.course_permissions import CoursePermission, CourseAssistantPermission, CourseStudentPermission
+from api.permissions.course_permissions import (
+    CoursePermission,
+    CourseAssistantPermission,
+    CourseStudentPermission
+)
 from api.permissions.role_permissions import IsTeacher
-from api.serializers.course_serializer import CourseSerializer
+from api.serializers.course_serializer import CourseSerializer, StudentJoinSerializer, StudentLeaveSerializer
 from api.serializers.teacher_serializer import TeacherSerializer
-from api.serializers.assistant_serializer import AssistantSerializer
+from api.serializers.assistant_serializer import AssistantSerializer, AssistantIDSerializer
 from api.serializers.student_serializer import StudentSerializer
 from api.serializers.project_serializer import ProjectSerializer
 
@@ -42,40 +43,38 @@ def _add_assistant(self, request: Request, **_):
         """Add an assistant to the course"""
         course = self.get_object()
 
-        try:
-            # Add assistant to course
-            assistant = Assistant.objects.get(
-                id=request.data.get("id")
-            )
+        # Add assistant to course
+        serializer = AssistantIDSerializer(
+            data=request.data
+        )
 
-            course.assistants.add(assistant)
+        if serializer.is_valid(raise_exception=True):
+            course.assistants.add(
+                serializer.validated_data["assistant_id"]
+            )
 
-            return Response({
-                "message": gettext("courses.success.assistants.add")
-            })
-        except Assistant.DoesNotExist:
-            # Not found
-            raise NotFound(gettext("assistants.error.404"))
+        return Response({
+            "message": gettext("courses.success.assistants.add")
+        })
 
     @assistants.mapping.delete
     def _remove_assistant(self, request: Request, **_):
         """Remove an assistant from the course"""
         course = self.get_object()
 
-        try:
-            # Add assistant to course
-            assistant = Assistant.objects.get(
-                id=request.data.get("id")
-            )
+        # Remove assistant from course
+        serializer = AssistantIDSerializer(
+            data=request.data
+        )
 
-            course.assistants.remove(assistant)
+        if serializer.is_valid(raise_exception=True):
+            course.assistants.remove(
+                serializer.validated_data["assistant_id"]
+            )
 
-            return Response({
-                "message": gettext("courses.success.assistants.delete")
-            })
-        except Assistant.DoesNotExist:
-            # Not found
-            raise NotFound(gettext("assistants.error.404"))
+        return Response({
+            "message": gettext("courses.success.assistants.add")
+        })
 
     @action(detail=True, methods=["get"], permission_classes=[IsAdminUser | CourseStudentPermission])
     def students(self, request, **_):
@@ -94,40 +93,42 @@ def students(self, request, **_):
     @students.mapping.put
     def _add_student(self, request: Request, **_):
         """Add a student to the course"""
+        # Get the course
         course = self.get_object()
 
-        try:
-            # Add student to course
-            student = Student.objects.get(
-                id=request.data.get("id")
-            )
+        # Add student to course
+        serializer = StudentJoinSerializer(data=request.data, context={
+            "course": course
+        })
 
-            course.students.add(student)
+        if serializer.is_valid(raise_exception=True):
+            course.students.add(
+                serializer.validated_data["student_id"]
+            )
 
-            return Response({
-                "message": gettext("courses.success.students.add")
-            })
-        except Student.DoesNotExist:
-            raise NotFound(gettext("students.error.404"))
+        return Response({
+            "message": gettext("courses.success.students.add")
+        })
 
     @students.mapping.delete
     def _remove_student(self, request: Request, **_):
         """Remove a student from the course"""
+        # Get the course
         course = self.get_object()
 
-        try:
-            # Add student to course
-            student = Student.objects.get(
-                id=request.data.get("id")
-            )
+        # Add student to course
+        serializer = StudentLeaveSerializer(data=request.data, context={
+            "course": course
+        })
 
-            course.students.remove(student)
+        if serializer.is_valid(raise_exception=True):
+            course.students.remove(
+                serializer.validated_data["student_id"]
+            )
 
-            return Response({
-                "message": gettext("courses.success.students.remove")
-            })
-        except Student.DoesNotExist:
-            raise NotFound(gettext("students.error.404"))
+        return Response({
+            "message": gettext("courses.success.students.add")
+        })
 
     @action(detail=True, methods=["get"])
     def teachers(self, request, **_):
@@ -161,8 +162,10 @@ def clone(self, request: Request, **__):
         course: Course = self.get_object()
 
         try:
+            # We should return the already cloned course, if present
             course = course.child_course
         except Course.DoesNotExist:
+            # Else, we clone the course
             course = course.clone(
                 clone_assistants=request.data.get("clone_assistants")
             )