From 73362b69c6dd276a2c672976dd50fd6a3b0484b2 Mon Sep 17 00:00:00 2001
From: Tanner Collin <git@tannercollin.com>
Date: Mon, 24 Feb 2020 23:49:14 +0000
Subject: [PATCH] Create an index of all history changes

---
 apiserver/apiserver/api/__init__.py    |  1 +
 apiserver/apiserver/api/apps.py        |  5 ++-
 apiserver/apiserver/api/models.py      | 24 ++++++++++
 apiserver/apiserver/api/permissions.py |  3 ++
 apiserver/apiserver/api/signals.py     | 61 ++++++++++++++++++++++++++
 5 files changed, 93 insertions(+), 1 deletion(-)
 create mode 100644 apiserver/apiserver/api/signals.py

diff --git a/apiserver/apiserver/api/__init__.py b/apiserver/apiserver/api/__init__.py
index e69de29..1e78b81 100644
--- a/apiserver/apiserver/api/__init__.py
+++ b/apiserver/apiserver/api/__init__.py
@@ -0,0 +1 @@
+default_app_config = 'apiserver.api.apps.ApiConfig'
diff --git a/apiserver/apiserver/api/apps.py b/apiserver/apiserver/api/apps.py
index d87006d..1f1ea97 100644
--- a/apiserver/apiserver/api/apps.py
+++ b/apiserver/apiserver/api/apps.py
@@ -2,4 +2,7 @@ from django.apps import AppConfig
 
 
 class ApiConfig(AppConfig):
-    name = 'api'
+    name = 'apiserver.api'
+
+    def ready(self):
+        from . import signals
diff --git a/apiserver/apiserver/api/models.py b/apiserver/apiserver/api/models.py
index be46722..5508a91 100644
--- a/apiserver/apiserver/api/models.py
+++ b/apiserver/apiserver/api/models.py
@@ -1,6 +1,8 @@
 from datetime import date, datetime
 from django.db import models
 from django.contrib.auth.models import User
+from django.contrib.contenttypes.fields import GenericForeignKey
+from django.contrib.contenttypes.models import ContentType
 from django.utils.timezone import now, pytz
 from simple_history.models import HistoricalRecords
 from simple_history import register
@@ -125,3 +127,25 @@ class Training(models.Model):
 
 class MetaInfo(models.Model):
     backup_id = models.TextField()
+
+class HistoryIndex(models.Model):
+    content_type = models.ForeignKey(ContentType, null=True, on_delete=models.SET_NULL)
+    object_id = models.PositiveIntegerField()
+    content_object = GenericForeignKey('content_type', 'object_id')
+
+    owner_id = models.PositiveIntegerField()
+    owner_name = models.TextField()
+    history_user = models.ForeignKey(User, null=True, on_delete=models.SET_NULL)
+    history_date = models.DateTimeField()
+    history_type = models.TextField()
+    revert_url = models.TextField()
+
+    is_system = models.BooleanField()
+    is_admin = models.BooleanField()
+
+class HistoryChange(models.Model):
+    index = models.ForeignKey(HistoryIndex, related_name='changes', null=True, on_delete=models.SET_NULL)
+
+    field = models.TextField()
+    old = models.TextField()
+    new = models.TextField()
diff --git a/apiserver/apiserver/api/permissions.py b/apiserver/apiserver/api/permissions.py
index bde5278..452c865 100644
--- a/apiserver/apiserver/api/permissions.py
+++ b/apiserver/apiserver/api/permissions.py
@@ -5,6 +5,9 @@ class AllowMetadata(BasePermission):
         return request.method in ['OPTIONS', 'HEAD']
 
 def is_admin_director(user):
+    if not user:
+        return False
+
     if user.is_staff:
         return True
 
diff --git a/apiserver/apiserver/api/signals.py b/apiserver/apiserver/api/signals.py
new file mode 100644
index 0000000..11f9ad1
--- /dev/null
+++ b/apiserver/apiserver/api/signals.py
@@ -0,0 +1,61 @@
+from django.dispatch import receiver
+from simple_history.signals import (
+    pre_create_historical_record,
+    post_create_historical_record
+)
+
+from . import models
+from .permissions import is_admin_director
+
+def get_object_owner(obj):
+    full_name = lambda member: member.first_name + ' ' + member.last_name
+
+    if getattr(obj, 'user', False):
+        return full_name(obj.user.member), obj.user.member.id
+
+    if getattr(obj, 'instructor', False):
+        return full_name(obj.instructor.member), obj.instructor.member.id
+
+    if getattr(obj, 'member_id', False):
+        try:
+            member = models.Member.objects.get(id=obj.member_id)
+            return full_name(member), member.id
+        except models.Member.DoesNotExist:
+            pass
+
+    return 'Protospace', 0
+
+@receiver(post_create_historical_record, dispatch_uid='create_hist')
+def post_create_historical_record_callback(
+        sender,
+        instance,
+        history_instance,
+        history_change_reason,
+        history_user,
+        using,
+        **kwargs):
+
+    changes = history_instance.diff_against(history_instance.prev_record).changes
+
+    if changes:
+        owner = get_object_owner(instance)
+
+        index = models.HistoryIndex.objects.create(
+            content_object=history_instance,
+            owner_name=owner[0],
+            owner_id=owner[1],
+            history_user=history_user,
+            history_date=history_instance.history_date,
+            history_type=history_instance.get_history_type_display(),
+            revert_url=history_instance.revert_url(),
+            is_system=bool(history_user == None),
+            is_admin=is_admin_director(history_user),
+        )
+
+        for change in changes:
+            models.HistoryChange.objects.create(
+                index=index,
+                field=change.field,
+                old=change.old,
+                new=change.new,
+            )