Move email notification method into plugin

Fixes #2385

InvenTree/plugin/builtin/integration/core_notifications.py

@@ -0,0 +1,55 @@
+# -*- coding: utf-8 -*-
+"""Core set of Notifications as a Plugin"""
+from django.template.loader import render_to_string
+from django.utils.translation import ugettext_lazy as _
+
+from allauth.account.models import EmailAddress
+
+from plugin import IntegrationPluginBase
+from plugin.mixins import BulkNotificationMethod
+from common.models import InvenTreeUserSetting
+import InvenTree.tasks
+
+
+class CoreNotificationsPlugin(IntegrationPluginBase):
+    """
+    Core notification methods for InvenTree
+    """
+
+    PLUGIN_NAME = "CoreNotificationsPlugin"
+    AUTHOR = _('InvenTree contributors')
+    DESCRIPTION = _('Integrated outgoing notificaton methods')
+
+    class EmailNotification(BulkNotificationMethod):
+        METHOD_NAME = 'mail'
+        CONTEXT_EXTRA = [
+            ('template', ),
+            ('template', 'html', ),
+            ('template', 'subject', ),
+        ]
+
+        def get_targets(self):
+            """
+            Return a list of target email addresses,
+            only for users which allow email notifications
+            """
+
+            allowed_users = []
+
+            for user in self.targets:
+                allows_emails = InvenTreeUserSetting.get_setting('NOTIFICATION_SEND_EMAILS', user=user)
+
+                if allows_emails:
+                    allowed_users.append(user)
+
+            return EmailAddress.objects.filter(
+                user__in=allowed_users,
+            )
+
+        def send_bulk(self):
+            html_message = render_to_string(self.context['template']['html'], self.context)
+            targets = self.targets.values_list('email', flat=True)
+
+            InvenTree.tasks.send_email(self.context['template']['subject'], '', targets, html_message=html_message)
+
+            return True