有一个permissions集合，其中包含权限以及为给定资源分配了该权限的用户或组。
permissions

[{
  "_id": 1,
  "resource": "resource:docs/61",
  "permissions": [
    {
      "permission": "role:documentOwner",
      "users": [
        "user:abc",
        "user:def",
        "group:abc",
        "group:bff"
      ]
    },
    {
      "permission": "document.read",
      "users": ["user:xxx"]
    },
    {
      "permission": "document.update",
      "users": ["user:xxx"]
    }
  ]
}]

和将用户分配到组的groups集合。
groups

[
  {
    "_id": 1,
    "id": "abc",
    "name": "Test Group",
    "users": ["cpo", "yyy"]
  },
  {
    "_id": 2,
    "id": "bff",
    "name": "Another Group",
    "users": ["xxx"]
  }
]

我正在尝试查询permissions集合中的resource:docs/61，对于每个权限，将users属性中的任何组解析为匹配组的users。

预期结果

{
  "resource": "resource:docs/61",
  "permissions": [
    {
      "permission": "role:documentOwner",
      "users": [
        "user:abc",
        "user:def",
        "user:cpo",
        "user:yyy",
        "user:xxx"
      ]
    },
    {
      "permission": "document.read",
      "users": ["user:xxx"]
    },
    {
      "permission": "document.update",
      "users": ["user:xxx"]
    }
  ]
}

型
我安装了一个Mongo Playground，我一直在尝试让它工作......但没有成功。下面是我目前的尝试。我不知道如何将组Map到他们尊敬的用户，然后逆转$unwind。或者我甚至不需要$unwind🤷‍ ♂️

db.permissions.aggregate([
  {
    "$match": {
      "resource": "resource:docs/61"
    }
  },
  {
    $unwind: "$permissions"
  },
  {
    "$lookup": {
      "from": "groups",
      "let": {
        "users": {
          "$filter": {
            "input": "$permissions.users",
            "as": "user",
            "cond": {
              "$ne": [
                -1,
                {
                  "$indexOfCP": [
                    "$$user",
                    "group:"
                  ]
                }
              ]
            }
          }
        }
      },
      "pipeline": [
        {
          "$match": {
            "$expr": {
              "$in": [
                {
                  "$concat": [
                    "group:",
                    "$id"
                  ]
                },
                "$$users"
              ]
            }
          }
        },
        {
          "$project": {
            "_id": 0,
            "id": {
              "$concat": [
                "group:",
                "$id"
              ]
            },
            "users": 1
          }
        }
      ],
      "as": "groups"
    }
  },
  {
    "$project": {
      "groups": 1,
      "permissions": {
        "permission": "$permissions.permission",
        "users": "permissions.users"
      }
    }
  }
])