How to query on collection values and referenced documents values in MongoDB?

I don’t know how correctly I formulated the question. I need to execute a query on both the values of the collection and the values of the referenced objects.

The original collection looks like this:

{
  "houses": [
    {
      "_id": "5fe72f0b4fd2c131bcc7dae0",
      "name": "John",
      "district": "Texas",
      "events": [
        {
          "_id": "5fe73e91ede45b3d2eca504c",
          "kind": "developer",
          "group": "facebook"
        }
      ]
    },
    {
      "_id": "5fe72f0b4fd2c131bcc7dadf",
      "name": "Michael",
      "district": "Texas",
      "events": [
        {
          "_id": "5fe73e91ede45b3d2eca504b",
          "kind": "advertiser",
          "group": "instagram"
        }
      ]
    },
    {
      "_id": "5fe72f0b4fd2c131bcc7dade",
      "name": "Frank",
      "district": "Washington",
      "events": [
        {
          "_id": "5fe73e91ede45b3d2eca504a",
          "kind": "developer",
          "group": "school"
        }
      ]
    }
  ]
}

When executing a query that meets the condition district == "Texas", I need to get the following result:

{
  "houses": [
    {
      "_id": "5fe72f0b4fd2c131bcc7dae0",
      "name": "John",
      "district": "Texas",
      "events": [
        {
          "_id": "5fe73e91ede45b3d2eca504c",
          "kind": "developer",
          "group": "facebook"
        }
      ]
    },
    {
      "_id": "5fe72f0b4fd2c131bcc7dadf",
      "name": "Michael",
      "district": "Texas",
      "events": [
        {
          "_id": "5fe73e91ede45b3d2eca504b",
          "kind": "advertiser",
          "group": "instagram"
        }
      ]
    }
  ]
}

Under this condition: kind == "developer", get the following result:

{
  "houses": [
    {
      "_id": "5fe72f0b4fd2c131bcc7dae0",
      "name": "John",
      "district": "Texas",
      "events": [
        {
          "_id": "5fe73e91ede45b3d2eca504c",
          "kind": "developer",
          "group": "facebook"
        }
      ]
    },
    {
      "_id": "5fe72f0b4fd2c131bcc7dade",
      "name": "Frank",
      "district": "Washington",
      "events": [
        {
          "_id": "5fe73e91ede45b3d2eca504a",
          "kind": "developer",
          "group": "school"
        }
      ]
    }
  ]
}

And for a query that satisfies the condition: district == "Texas" && kind == "developer", get the result:

{
  "houses": [
    {
      "_id": "5fe72f0b4fd2c131bcc7dae0",
      "name": "John",
      "district": "Texas",
      "events": [
        {
          "_id": "5fe73e91ede45b3d2eca504c",
          "kind": "developer",
          "group": "facebook"
        }
      ]
    }
  ]
}

The query should be executed using mongoose inside the express route, and should be universal, processing a different set of request parameters:

router.get('/report', (req, res) => {
  let params = {}; 
  let { district, kind } = req.headers;

  if (district) params["district"] = district;
  if (kind) params["kind"] = kind;
  // Here should be the query
});

The House model refs to Event:

const mongoose = require('mongoose');

const Schema = mongoose.Schema;

const HouseSchema = new Schema({
  name: String,
  district: String,
  events: [{
    type: mongoose.Schema.Types.ObjectId,
    ref: 'Event'
  }]
});

module.exports = mongoose.model('House', HouseSchema);

I am learning MongoDB and aggregation, but I don’t know so deeply all its functions. Please tell me how to correctly execute such a request in the traditional way? I will be very grateful!

Answer

db.collection.aggregate([
{$unwind:"$houses"},
{$match:{"houses.district":"Texas","houses.events":{$elemMatch:{"kind":"developer"}}}},
{$group:{
    _id:null,
    houses:{$push:"$houses"}
}},
{$project:{_id:0}}])

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Answer