From 0cb2c965f61b539fd6db4a196b55845dafc35488 Mon Sep 17 00:00:00 2001
From: Hironsan <light.tree.1.13@gmail.com>
Date: Tue, 2 Mar 2021 20:17:22 +0900
Subject: [PATCH] Add signal to fix #822

---
 app/api/models.py        | 43 +++++++++++++++++++++++++++-------------
 app/api/views/project.py |  4 +---
 2 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/app/api/models.py b/app/api/models.py
index 648a77f1..fc1831f7 100644
--- a/app/api/models.py
+++ b/app/api/models.py
@@ -5,7 +5,7 @@ from django.conf import settings
 from django.contrib.auth.models import User
 from django.core.exceptions import ValidationError
 from django.db import models
-from django.db.models.signals import post_save, pre_delete
+from django.db.models.signals import post_save, pre_delete, m2m_changed
 from django.dispatch import receiver
 from django.urls import reverse
 from polymorphic.models import PolymorphicModel
@@ -312,19 +312,19 @@ class RoleMapping(models.Model):
         unique_together = ("user", "project")
 
 
-# @receiver(post_save, sender=RoleMapping)
-# def add_linked_project(sender, instance, created, **kwargs):
-#     if not created:
-#         return
-#     userInstance = instance.user
-#     projectInstance = instance.project
-#     if userInstance and projectInstance:
-#         user = User.objects.get(pk=userInstance.pk)
-#         project = Project.objects.get(pk=projectInstance.pk)
-#         user.projects.add(project)
-#         user.save()
-#
-#
+@receiver(post_save, sender=RoleMapping)
+def add_linked_project(sender, instance, created, **kwargs):
+    if not created:
+        return
+    userInstance = instance.user
+    projectInstance = instance.project
+    if userInstance and projectInstance:
+        user = User.objects.get(pk=userInstance.pk)
+        project = Project.objects.get(pk=projectInstance.pk)
+        user.projects.add(project)
+        user.save()
+
+
 # @receiver(post_save)
 # def add_superusers_to_project(sender, instance, created, **kwargs):
 #     if not created:
@@ -351,6 +351,21 @@ class RoleMapping(models.Model):
 #                  for project in projects]
 #             )
 
+@receiver(m2m_changed, sender=Project.users.through)
+def remove_mapping_on_remove_user_from_project(sender, instance, action, reverse, **kwargs):
+    # if reverse is True, pk_set is project_ids and instance is user.
+    # else, pk_set is user_ids and instance is project.
+    user_ids = kwargs['pk_set']
+    if action.startswith('post_remove') and not reverse:
+        RoleMapping.objects.filter(user__in=user_ids, project=instance).delete()
+    elif action.startswith('post_add') and not reverse:
+        admin_role = Role.objects.get(name=settings.ROLE_PROJECT_ADMIN)
+        RoleMapping.objects.bulk_create(
+            [RoleMapping(role=admin_role, project=instance, user_id=user)
+             for user in user_ids
+             if not RoleMapping.objects.filter(project=instance, user_id=user).exists()]
+        )
+
 
 @receiver(pre_delete, sender=RoleMapping)
 def delete_linked_project(sender, instance, using, **kwargs):
diff --git a/app/api/views/project.py b/app/api/views/project.py
index 6b51c879..cbba1672 100644
--- a/app/api/views/project.py
+++ b/app/api/views/project.py
@@ -17,9 +17,7 @@ class ProjectList(generics.ListCreateAPIView):
         return self.request.user.projects
 
     def perform_create(self, serializer):
-        project = serializer.save(users=[self.request.user])
-        admin_role = Role.objects.get(name=settings.ROLE_PROJECT_ADMIN)
-        RoleMapping(role=admin_role, user=self.request.user, project=project).save()
+        serializer.save(users=[self.request.user])
 
     def delete(self, request, *args, **kwargs):
         delete_ids = request.data['ids']