feat: 站内信 (#6183)

* 添加站内信

* s

* s

* 添加接口

* fix

* fix

* 重构了一些

* 完成

* 完善

* s

* s

* s

* s

* s

* s

* 测试ok

* 替换业务中发送消息的方式

* 修改

* s

* 去掉 update 兼容 create

* 添加 unread total 接口

* 调整json字段

Co-authored-by: xinwen <coderWen@126.com>

apps/notifications/models/notification.py

@@ -0,0 +1,50 @@
+from django.db import models
+
+from common.db.models import JMSModel
+
+__all__ = ('SystemMsgSubscription', 'UserMsgSubscription')
+
+
+class UserMsgSubscription(JMSModel):
+    message_type = models.CharField(max_length=128)
+    user = models.ForeignKey('users.User', related_name='user_msg_subscriptions', on_delete=models.CASCADE)
+    receive_backends = models.JSONField(default=list)
+
+    def __str__(self):
+        return f'{self.message_type}'
+
+
+class SystemMsgSubscription(JMSModel):
+    message_type = models.CharField(max_length=128, unique=True)
+    users = models.ManyToManyField('users.User', related_name='system_msg_subscriptions')
+    groups = models.ManyToManyField('users.UserGroup', related_name='system_msg_subscriptions')
+    receive_backends = models.JSONField(default=list)
+
+    message_type_label = ''
+
+    def __str__(self):
+        return f'{self.message_type}'
+
+    def __repr__(self):
+        return self.__str__()
+
+    @property
+    def receivers(self):
+        from notifications.backends import BACKEND
+
+        users = [user for user in self.users.all()]
+
+        for group in self.groups.all():
+            for user in group.users.all():
+                users.append(user)
+
+        receive_backends = self.receive_backends
+        receviers = []
+
+        for user in users:
+            recevier = {'name': str(user), 'id': user.id}
+            for backend in receive_backends:
+                recevier[backend] = bool(BACKEND(backend).get_account(user))
+            receviers.append(recevier)
+
+        return receviers