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/site_msg.py

@@ -0,0 +1,29 @@
+from django.db import models
+
+from common.db.models import JMSModel
+
+__all__ = ('SiteMessageUsers', 'SiteMessage')
+
+
+class SiteMessageUsers(JMSModel):
+    sitemessage = models.ForeignKey('notifications.SiteMessage', on_delete=models.CASCADE, db_constraint=False, related_name='m2m_sitemessageusers')
+    user = models.ForeignKey('users.User', on_delete=models.CASCADE, db_constraint=False, related_name='m2m_sitemessageusers')
+    has_read = models.BooleanField(default=False)
+    read_at = models.DateTimeField(default=None, null=True)
+
+
+class SiteMessage(JMSModel):
+    subject = models.CharField(max_length=1024)
+    message = models.TextField()
+    users = models.ManyToManyField(
+        'users.User', through=SiteMessageUsers, related_name='recv_site_messages'
+    )
+    groups = models.ManyToManyField('users.UserGroup')
+    is_broadcast = models.BooleanField(default=False)
+    sender = models.ForeignKey(
+        'users.User', db_constraint=False, on_delete=models.DO_NOTHING, null=True, default=None,
+        related_name='send_site_message'
+    )
+
+    has_read = False
+    read_at = None