在MongoDB中聚合到具有特定记录的数组中

我的数据库看起来像:

{email:"user", contacts: 
 [
  {emailContact:"test", firstName:"test", lastName:"test", messages:
   [
    {email:"user", content:"hi", date:"ISODate(...)"}
    {email:"test", content:"how are you?", date:"ISODate(...)"}
    {email:"user", content:"im fine", date:"ISODate(...)"}
   ]
  },
  {emailContact:test2, firstName:"test2", lastName:"test2", messages:
   [
    {email:"user", content:"hahaha", date:"ISODate(...)"}
    {email:"test2", content:"yea thats right", date:"ISODate(...)"}
    {email:"user", content:"xd", date:"ISODate(...)"}
   ]
  }
 ]
}

我需要从具有给定联系人的特定用户获取最后两条消息。

我已经试过几个类似的:

db.contacts.aggregate([{$match:{email:"user",emailContact:"test"}},{$unwind:{'contacts.messages'}},{$sort:{'contacts.messages.date':1,'contacts.messages.content':1,'contacts.messages.emailContact':1}},{$group:{who:'$email', content:'$content', date:{$last:'$date'}}}])

谢谢你的帮助